Department of
Neuropathology
Outline and Research Objectives
The long-term goal of the research in our department is to determine the molecular
events that lead to the development of Alzheimer’s disease (AD). For this purpose, we are
analyzing two proteins that have been implicated in the AD pathogenesis: amyloid ß-protein (Aß) and tau.

Faculties and Students
Professor and Chair
Lecturer
Associate

Yasuo Ihara, M.D. (1991~)
Maho Morishima, Ph.D.
Satoru Funamoto, Ph.D.
Kozo Motonaga, Ph.D.
Graduate Student....................7
Secretary .................................1

Past Research and Major Accomplishments
Identification of posttranslational modificationsof tau in paired helical filaments
Tau in paired helical filaments (PHF) is characterized by hyperphosphorylation and ubiquitination. The
former causes the tau to migrate slower that dephosphorylated counterparts, and such particular tau
makes three distinct bands on the Western blot, andcalled PHF-tau. We found that this phosphorylation
somehow resemble that seen in fetal tau, because
many phosphorylation-dependent monoclonal antibodies that react with PHF-tau recognize fetal tau.
This indicates that fetal tau is phosphorylated to agreater extent than adult tau. We underwent thework to determine the exact sites for phosphorylation, using selective modification of phosphorylated
Ser residues and their identification of amino acidsequencing and mass spec. As a result more than 20
phosphorylation sites in PHF-tau were detemined:
about half number of the sites were proline-directed,
while the remaining were nonproline-derected. By ourwork the phosphorylation of PHF-tau was fully characterized.
PHF was found to be ubiquitinated in 1987, andsince then we attempted to determine the ubiquitibation sites in tau, but failed because of purification ofubiquitinated tau was very difficult and provided only
very poor yield. From smeared tau (see below) we
obtained a small amounts of purified ubiquitinatedtau, which was digested by lysysl endopeptidase andgenerated fragments were subjected to mass spec.
Thus ubiquitinated sites were accurately determined,

and found in the microtubule-binding domain of tau.
One of the most remarkable characteristics of thetau in PHF is smearing on the blot from high molecular mass region down to 1-2 kD. The extent of smearing is well-correlated with the density of neurofibrillary tangles. We purified smeared tau using HPLC andanalyzed protein chemically. Deamidation and isoaspartate formation were found, suggesting thatsmeared tau represents aging of NFT in vivo.
(2) Determination of Aß42 as the predominant
species deposited in the brain
At that time, two Aß species were known, but
their significance was unknown, although in the culture media Aß40 that terminates in Val-40 is the
major species. Using end-specific monoclonals thatwere developed by N. Suzuki, we found immnocytochemically that Aß42 that terminates in Ala-42, aminor species among the secreted Aß, is predominant
in the parenchyma of AD cortex. To learn about thetemporal profile for Aß deposition in the humanbrain, we examined the brains from Down syndrome
patients who invariably develop Alzheimer pathologies after the middle ages. In this way we found thatthe first species deposited in the brain is Aß42.
(3) Quantification of Aß accumulation in thehuman brain
With collaboration with N. Suzuki, we constructed
two-site ELISA highly specific for Aß40 or Aß40. We
first applied the ELISA for the quantification of Aß40
and Aß42 in the human brain. The biochemical alterations specific to AD may start much earlier than we
previously thought. The work on CAA suggests fourstages in the evolution: biochemically detectablestage, immunocytochemically detectable stage, histologically (Congo red) detectable stage, and clinically(multiple and recurrent hemorrhage in the aged)
detectable stage. In other words, clinically overt
patients are just a tip of the iceberg. The similar timecourse can be applicable to parenchymal Aß deposition; biochemical accumulation of Aß should start in
the 40s (or even before). And AD patients are most111

likely to represent a tip of the iceberg. A straightforward interpretation would be that AD is the consequence of the longstanding biochemical abnormalities.
Here, we focus on the nature of the initial biochemical abnormality, eventually leading to ß-amyloidogenesis, rather than on why Aß accumulate in
the brain in an exponential way. In particular, we are
currently concerned about possible roles of low-density membrane domain (detergent-insoluble, glicolipid
and cholesterol enriched domain; DIGs) in the Aß 40
and Aß42 metabolism, and in the earliest stage of ßamyloidogenesis.
As Aß accumulates, seemingly, Aß42 shifts tohigher density fractions, but Aß40 tends to stay low.
Possible explanations include: When a large amountof Aß accumulated, the low-density membrane
domain may shift to higher density or Aß42-boundlow-density membrane domain may lose specific lipid
composition (cholesterol and/or sphingolipid), resulting in shift to higher density. In either way, there may
be a certain critical level of Aß42 in the domainbeyond which the membrane-bound Aß42 cannot
float.
(4) Accelerated Aß accumulation in ε4-bearing
subjects
We attempted to determine when Aß deposition
starts in most human brains and how it is influenced
by apolipoprotein E (apoE) allele ε4, a strong risk factor for late-onset AD. We successfully quantitated,using an improved extraction protocol and sensitive
ELISA, the Aß40 and Aß42 levels in the insoluble
fraction of the brains from many nondemented subjects aged 22 to 81 years. Both Aß40 and Aß42 weredetectable in the insoluble fraction of the brains evenfrom young subjects aged 20 to 30 years. The incidence of the subjects significantly accumulating Aßincreased in an age-dependent manner; Aß42 levels
arose steeply in some subjects in their late 40s andthis was accompanied by a much smaller rise in Aß40
levels. ApoE ε4 was found to significantly enhance
Aß42 and, to a less extent, Aß40 accumulation. These
results strongly suggest that the presence of ε4 allele
sets earlier in life the start of Aß accumulation in thebrain.
(5) Discovery of ε-cleavage using a cell-free system
Aß is generated from ß-amyloid precursor protein(APP) when ß-secretase cleavage at the extracellulardomain produces a 99-residue C-terminal fragment
called CTF99 or CTFß. Subsequent cleavage of CTFßin the middle of the transmembrane domain by γ-secretase primarily produces either a 40-residue protein(Aß40) or a 42-residue protein (Aß42). Intramembrane

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γ-secretase cleavage of CTFß should yield a 59- or 57residue cytoplasmic C-terminal fragment (CTFγ41-99
or 43-99; APP712-770 or 714-770 according to thenumbering of APP770 isoform) called CTFγ. To learn
more about the properties of γ-cleavage, we undertook
to establish cell-free system for generation of Aß and
CTFγ, and characterize CTFγ, the other product of thisunusual cleavage. The generated CTFγ consists largelyof CTFγ50-99, and of CTFγ49-99, although the latter isseveral to ten-fold less than the former. Comparisonof the cleavage sites of APP, APLP1, and APLP2 identifies new cleavage site: two to five residues inside thecytoplasmic membrane boundary. Therefore, thisintramembrane cleavage is distinct from the Aß-generating γ-cleavage that occurs in the middle of thetransmembrane domain (more than nine residues
inside the membrane boundary).
It has been unclear why APP is cleaved near the
middle of the transmembrane domain, whereas Notch
1 is cleaved immediately inside the cytoplasmic membrane boundary. Overall, our findings strongly suggestthat the cleavage of Notch corresponds to this distinct
type of cleavage rather than to γ–cleavage.

Current Research and Future Prospects(1) Characterization of the substrate specificity ofγ-secretase
1. Is ε-cleavage a reality? Can we exclude the possibility that γ-cleavage is followed by swift, stepwise cleavages by a particular amino peptidase?
Definite evidence requires demonstration of
longer Aß (Aß1-49 or 1-50) and/or the middle segment (Aß41-49). Can one detect a longer Aßspecies in the membrane?
2. If it is reality, what is the meaning of γ-cleavage?
Does the presence ragged C termini of Aß suggest
participation of a particular carboxyl peptidase in
the generation of Aß?
3. If so, what is the relationship between γ- and εcleavage? The two cleavages may not be in one to
one stoichiometric relationship.
4. The general principle of type 1 membrane protein
degradation. shedding, release of ectodomain, followed by intramembrane (ε-) cleavage. How is theintramembrane segment left after ε-cleavage
degraded?
5. Is Aß40 and Aß42 production separable? How is
Aß40 or Aß42 generation correlated to CTFγ49-99
or CTFγ50-99?
(2) Mechanism of Aß accumulation in the brain
1. At present the mechanism of FAD (Familial AD)
can be understood by altered enzyme-substraterelationship: Mutations in enzyme (presenilin) or
substrate (APP) causes an (small) increase in the
Aß42 production, which eventually leads to AD.
Patients with presenilin or APP mutants usuallyshow higher levels of Aß42 in the plasma.
Presumably, whether this relationship is altered
can be detected by increased levels of Aß42 in theplasma. Another pathway to development of AD
is being proposed: increased tendency to protofibril formation.
2. The role of ApoE4 is not to modify the enzymesubstrate relationship, but to mediate throughother pathways, thereby leading to earlier buildup of senile plaques. Potential target would be in
the exchange of Aß between cell membrane and
HDL particles, in the transport of Aß through BBB
or in the Aß fibrillization.
3. The thought into exponential accumulation curve
may provide us with some insights into the mechanism. The accumulation curve may be simulatedby the equation: A(t)=C(t-40)n/1+(t-40)n, where C:
constant, t, age>40; steepness in the accumulation
depends on n. This equation represents cooperativity phenomena (phase transition), and may suggest that age-dependent Aß accumulation may be
one of such examples in the biology. If so, theunderlying mechanism can be explained byenhanced Aß aggregation force. A point is why
the aggregation potential is enhanced. One possibility is a decrease in the degradation potential(decreased protease activity) during aging.
However, it is a bit difficult to envision, because it
has not so far been known that certain proteases
are acutely inactivated during aging. The otherpossibility is altered environments induced byaging. Altered lipid composition and/or generationof a certain factor to promote Aß aggregation.
Altogether, accumulation is a consequence of
aggregation, and aggregation may be a consequence of an alteration in the environment, but
may not be decreased protease activity. In thisregard, it may be important to investigate the significance of Aß accumulation in the raft. First, toexamine whether raft-accumulated Aß is younger
than extracelluarly deposited Aß by using
pyroGlu-specific antibodies. Other markers for invivo aging include isomerization and racemizationof Asp residues and truncation of the Aß molecule.
(3) Tau and neuronal cell death
What do we know about the significance of intracellular tau deposition, and what should we do in the
future?
1. NFT itself is not so harmful to cell. NFT-bearing
neurons are viable, and still attempt to maintain

2.

3.

4.

5.

6.

7.

dendritic arborization. NFT-bearing oligodendrocytes rather specific for FTDP-intron mutations
still supply enough amounts of myelin. No
demyelination is detected by a classical method.
But often, dendrites of NFT-bearing neurons arecompromised, which reminds us of dying-backneuropathy. Presumably, curly fibers represent
dying-back segments of basal dendrites isolated
from neuronal cell bodies.
FTDP-17 is characterized by tauopathy and neuronal loss. P301L mutation is featured by extensive neuronal loss rather than NFT formation (seetransgenic fly; Wittmann CW et al. Science
2001;293:711-4), while R406W mutation is featured by NFT formation rather than neuronal loss.
Clinical course may depend on neuronal loss
rather than NFT formation. This is consistent
with the old view that the degree of dementia in
AD is best correlated with the extent of neuronal
loss.
Thus, the most important question about tau is
why and how tau kills the neuron, rather than
why and how it aggregates into NFT.
Significance of hyperphosphorylation of tau in
PHF or PHF-like fibrils. Hyperphosphorylation of
tau may be a consequence of degeneration of neuron, but not a cause of degeneration. Study on
R406W brain showed that i) cytosolic R406W tau
is less phosphorylated, which is consistent withan observation with CHO stable transfectant; ii)
but the mutant tau composing PHF-like fibrils is
hyperphosphorylated. A most likely interpretation
is as follows. The mutant tau has a bulky residue
close to its microtubule-binding domain, andwhen the mutant tau interact with tubulin or
microtubules, a particular kinase cannot access toSer-396 and 404, resulting in hypophosphorylation on these residues. Once the interaction withtubulin or microtubules is lost (by degeneration),
the mutant tau takes a random structure as does
wild-type tau, and these residues are freely
accessed by kinase and become hyperphosphorylated.
To do: establishment of FTDP tau knock-in mice;
attempt to increase the tau expression level by
removing the neo gene by breeding with CAG Cre
mice. Breeding with APP transgenic mice (forexample, APPsw mice) may make the pathologicalphenotype to appear within lifespan, and P301L
mice may develop NFT and neuronal loss muchearlier than wild-type knock-in mice.
More data about tau in the cell biology may provide some keys to understanding of the pathogenesis of FTDP-17. For example, differential role ofthree-repeat and four-repeat tau should be more
highlighted.

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8. The data from transgenic fly suggest that expression of even wild-type tau may be somehow
harmful to viability of fly (Wittmann CW et al.
Science. 2001;293:711-4). This can be applied tosynuclein also (Feany MB, Bender WW. Nature
2000;404:394-8). Presumably, the essential featureof FTDP-17 is neuronal death without overt NFT
formation. But in many FTDP-17 cases, both neuronal loss and NFT formation coexist. This meansthat the initial step to neuronal death may beshared by the pathway to NFT formation. In thisrespect, recent observations may be significant(Zhukareva V et al. Loss of brain tau defines novel
sporadic and familial tauopathies with frontotemporal dementia. Ann Neurol. 2001;49:165-75).
9. Currently there is no unifying hypothesis that can
explain remarkable heterogeneity of FTDP-17. If it
does exist, it must explain i) Why exonic mutation cause neuronal degeneration as well as ii)
Why increased levels of four-repeat tau cause neuronal degeneration.

Research Grants
1. Core Research for Evolutional Science andTechnology from the Japan Science and Technology
Corporation
Year : 1996 ~ 2001
¥483,000,000.2. Grant-in-Aid for Scientific Research on Priority
Areas, Advanced Brain
Science Project, from the Ministry of Education,
Culture, Sports, Science and Technology, Japan
Year : 2000 ~ 2002
¥108,000,000.3. Research Grants for Longevity Sciences from the
Ministry of Health and Welfare, Japan
Year: 1999 ~ 2001
¥ 6,000,000.4. Grant-in-Aid for Scientific Research (C) from the
Ministry of Education, Culture, Sports, Science andTechnology, Japan
Year: 1999 ~ 2000
¥ 3,700,000.5. Research Grants for Longevity Sciences from the
Sasakawa Health Science Foundation, Japan
Year: 1999
¥ 2,900,000.-

Select Publications
1. Oyama F, Shimada H, Oyama R, Titani K, Ihara Y:
Differential expression of ß amyloid protein precursor (APP) and tau mRNA in the aged human brain:
Individual variability and correlation between APP751 and four-repeat tau. J Neuropathol Exp Neurol
50: 560-578, 1991

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2. Uchida Y, Takio K, Titani K, Ihara Y, Tomonaga M:
The growth-inhibitory factor that is deficient in the
Alzheimer’s disease brain is a 68-amino acid metallothionein-like protein. Neuron 7: 337-347, 1991
3. Watanabe N, Takio K, Hasegawa M, Arai T, Titani K,
Ihara Y: Tau 2: A probe for a Ser-conformation in theamino terminus of t. J Neurochem 58: 960-966, 1992
4. Kanemaru K, Takio K, Miura R, Titani K, Ihara Y:
Fetal-type phosphorylation of the tau in paired helical filaments. J Neurochem 58: 1667-1675, 1992
5. Iwatsubo T, Hasegawa M, Esaki Y, Ihara Y: Lack ofubiquitin immunoreactivities at both ends of neuropil threads —— possible bidirectional growth ofneuropil threads ——. Am J Pathol 140: 277- 282,
1992
6. Hasegawa M, Morishima-Kawashima M, Takio K,
Suzuki M, Titani K, Ihara Y: Protein sequence andmass spectrometric analyses of tau in the
Alzheimer’s disease brain. J Biol Chem 267: 1704717054, 1992
7. Oyama F, Shimoda H, Oyama R, Titani K, Ihara Y: A
novel correlation between the levels of ß-amyloid
protein precursor and tau transcripts in the aged
human brain. J Neurochem 59: 1117-1125, 1992
8. Tsuji S, Kobayashi H, Uchida Y, Ihara Y, Miyatake T:
Molecular cloning of human growth inhibitory factor
cDNA and its down-regulation in Alzheimer’s disease. EMBO J 11:4843-4850, 1992
9. Oyama F, Shimada H, Oyama R, Titani K, Ihara Y: ßAmyloid protein precursor and tau mRNA levels versus ß-amyloid plaque and neurofibrillary tangles in
the aged human brain. J Neurochem 60:1658-1664,
1993
10. Hasegawa M, Watanabe A, Takio K, Suzuki M, Arai
T, Titani K, Ihara Y: Characterization of two distinct
monoclonal antibodies to paired helical filaments(PHF) — Further evidence for fetal-type phosphorylation of the tau in PHF —. J Neurochem 60:20682077, 1993
11. Morishima-Kawashima M, Hasegawa M, Takio K,
Suzuki M, Titani K, Ihara Y: Ubiquitin is conjugatedwith amino-terminally processed tau in paired helicalfilaments. Neuron 10:1151-1160, 1993
12. Yoshida H, Ihara Y: t in paired helical filaments isfunctionally distinct from fetal t. — assembly incompetence of paired helical filament-t —. J Neurochem
61:1183-1186, 1993
13. Watanabe A, Hasegawa M, Suzuki M, Takio K,
Morishima-Kawashima M, Titani K, Arai T, Kosik
KS, Ihara Y: In vivo phosphorylation sites in fetal
and adult rat tau. J Biol Chem 268:25712-25717,
1993
14. Uéda K, Fukushima H, Masliah E, Xia Y, Iwai A,
Yoshimoto M, Otero DAC, Kondo J, Ihara Y, Saitoh
T: Molecular cloning of a novel component of amyloid in Alzheimer’s disease. Proc Natl Acad Sci USA
90:11282-11286, 1993
15. Oyama F, Cairns NJ, Shimada H, Oyama R, Titani K,
Ihara Y: Down’s syndrome: Upregulation of ß-amyloid protein precursor and tau mRNAs and theirdefective coordination. J Neurochem 62:1062-1066,
1994
16. Iwatsubo T, Hasegawa M, Ihara Y: Neuronal andglial tau-positive inclusions in diverse neurologic diseases share common phosphorylation characteristics.
Acta Neuropathol 88:129-136, 1994
17. Iwatsubo T, Odaka A, Suzuki N, Mizusawa H,
Nukina N, Ihara Y: Visualization of Aß42(43) and
Aß40 in senile plaques with end-specific Aß-monoclonals: Evidence that an initially deposited species is
Aß42(43). Neuron 13:45-53, 1994
18. Suzuki N, Iwatsubo T, Odaka A, Ishibashi Y, Kitada
C, Ihara Y: High tissue content of soluble ß1-40 islinked to cerebral amyloid angiopathy. Am J Pathol
145:452-460, 1994
19. Oyama F, Oyama R, Ihara Y: Apolipoprotein E
Genotype versus Alzheimer’s pathologies and related-gene expression in the aged population. Mol Brain
Res 29:92-98, 1995
20. Morishima-Kawashima M, Hasegawa M, Takio K,
Suzuki M, Titani K, Ihara Y: Proline-directed andnon-proline-directed phosphorylation of PHF-tau. J
Biol Chem 270:823-829, 1995
21. Iwatsubo T, Mann DMA, Odaka A, Suzuki N, Ihara
Y: Amyloid ß-protein (Aß) deposition: Aß42(43) precedes Aß40 in Down’s syndrome. Ann Neurol
37:294-299, 1995
22. Saido TC, Iwatsubo T, Mann DMA, Shimada H,
Ihara Y, Kawashima S: Dominant and differential
deposition of distinct ß-amyloid peptide species,
AßN3(pE), in senile plaques. Neuron 14:457-466,
1995
23. Uchida Y, Ihara Y: The N-terminal portion of growth
inhibitory factor is sufficient for biological activity. J
Biol Chem 270: 3365-3369, 1995
24. Shinkai Y, Yoshimura M, Ito Y, Odaka A, Suzuki N,
Yanagisawa K, Ihara Y: Amyloid ß-proteins (Aß)1-40
and 1-42(43) in the soluble fraction of extra- andintracranial blood vessels. Ann Neurol 38:421-428,
1995
25. Yanagisawa K, Odaka A, Suzuki N, Ihara Y: GM1
ganglioside-bound amyloid ß-protein (Aß): A possible
form of preamyloid in Alzheimer’s disease. Nature
Med 1: 1062-1066, 1995
26. Iwatsubo T, Yamaguchi H, Fujimuro M, Yokosawa
H, Ihara Y, Trojanowski JQ, Lee VM-Y: Purificationand characterization of Lewy bodies from the brainsof patients with diffuse Lewy body disease. Am J
Pathol 148:1517-1529, 1996
27. Gu Y, Oyama F, Ihara Y: t is widely expressed in rat
tissues. J Neurochem 67:1235-1244, 1996
28. Namekata K, Oyama F, Imagawa M, Ihara Y: Humantransferrin (Tf) : A single mutation at codon 570
determines the TfC1 or TfC2 variant. Human Genet
100: 457-458, 1997
29. Yamazaki T, Haass C, Saido TC, Omura S, Ihara Y:
Specific increase in amyloid ß-protein 42 secretion
ratio by calpain inhibition. Biochemistry 36: 83778383, 1997

30. Hamano T, Yoshimura M, Yamazaki T, Shinkai Y,
Yanagisawa K, Kuriyama M, Ihara Y: Amyloid ß-protein (Aß) accumulation in the leptomeninges during
aging and in Alzheimer disease. J Neuropathol Exp
Neurol 56: 922-932, 1997
31. Wild-Bode C, Yamazaki T, Capell A, Leimer U,
Steiner H, Ihara Y, Haass C: Intracellular generation
and accumulation of amyloid ß-peptide terminating
at amino acid 42. J Biol Chem 272: 16085-16088,
1997
32. Shinkai Y, Yoshimura M, Morishima-Kawashima M,
Ito Y, Shimada H, Yanagisawa K, Ihara Y: Amyloid ßprotein deposition in the leptomeninges and cerebral
cortex. Ann Neurol 42: 899-908, 1997
33. Funato H, Yoshimura M, Yamazaki T, Saido TC, Ito
Y, Yokofujita J, Okeda R, Ihara Y: Astrocytes containing amyloid ß-protein (Aß)-positive granules are associated with Aß40-positive diffuse plaques in the aged
human brain. Am J Pathol 152: 983-992, 1998
34. Yoshida H, Watanabe A, Ihara Y: Collapsin response
mediator protein (CRMP)-2 is associated with neurofibrillary tangles in Alzheimer’s disease. J Biol
Chem 273: 9761-9768, 1998
35. Nakabayashi J, Yoshimura M, MorishimaKawashima M, Ito Y, Funato H, Miyakawa T,
Yamazaki T, Ihara Y: Amyloid ß-protein (Aß) accumulation in the putamen and mammillary body during aging and in Alzheimer’s disease. J Neuropathol
Exp Neurol 57: 343-352, 1998
36. Oyama F, Sawamura N, Kobayashi K, MorishimaKawashima M, Kuramochi T, Ito M, Tomita T,
Maruyama K, Saido TC, Iwatsubo T, Capell A, Walter
J, Grünberg J, Ueyama Y, Haass C, Ihara Y: Mutant
presenilin 2 transgenic mouse: Increased Aß levels
and a marked age-dependent increase in the Aß42
ratio in the brain. J Neurochem 71: 313-322, 1998
37. Funato H, Yoshimura M, Yamazaki T, Saido TC, Ito
Y, Yokofujita J, Okeda R, Ihara Y: Quantitation ofamyloid beta-protein (A beta) in the cortex during
aging and in Alzheimer’s disease. Am J Pathol 152:
1633-1640, 1998
38. Murakami N, Oyama Y, Gu Y, McLennan IS, Nonaka
I, Ihara Y: Accumulation of tau in autophagic vacuoles in chloroquine myopathy. J Neuropathol Exp
Neurol 57: 664–673, 1998
39. Morishima-Kawashima M, Ihara Y: The presence ofamyloid ß-protein in the detergent-insoluble membrane compartment of human neuroblastoma cells.
Biochemistry 37: 15247-15253, 1998
40. Enya M, Morishima-Kawashima M, Yoshimura M,
Shinkai Y, Kusui K, Khan K, Games D, Schenk D,
Sugihara S, Yamaguchi H, Ihara Y: Appearance of
sodium dodecyl sulfate-stable amyloid ß-protein (Aß)
dimer in the cortex during aging. Am J Pathol 154:
271-279, 1999
41. Watanabe A, Takio K, Ihara Y: Deamidation andisoaspartate formation in smeared tau in paired helical filaments— unusual properties of the microtubule-binding domain of tau —. J Biol Chem 274:7368-7378, 1999115

42. Matsumura N, Yamazaki T, Ihara Y: Stable expression in Chinese hamster ovary cells of mutated tau
genes causing frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). Am J
Pathol 154: 1649-1656, 1999
43. Funato H, Enya M, Yoshimura M, MorishimaKawashima M, Ihara Y: The presence of sodium
dodecyl sulfate-stable amyloid ß-protein dimers in
the hippocampus CA1 not exhibiting neurofibrillarytangle formation. Am J Pathol 155: 23-28, 1999
44. Misonou H, Morishima-Kawashima M, Ihara Y:
Oxidative stress induces intracellular accumulationof amyloid ß-protein (Aß) in human neuroblastoma
cells. Biochemistry 39:6951-6959, 2000
45. Sawamura N, Morishima-Kawashima M, Waki H,
Kobayashi K, Kuramochi T, Ito M, Oyama F, Ando S,
Ihara Y: Mutant-presenilin 2-transgenic mice: A large
increase in the levels of Aß42 is presumably associated with the low-density membrane domain that contains decreased levels of glycerophospholipids andsphingomyelin. J Biol Chem 275:27901-27908, 2000
46. Morishima-Kawashima M, Oshima N, Ogata H,
Yamaguchi H, Yoshimura M, Sugihara S, lhara Y:
Effect of apolipoprotein E allele ε4 on the initial
phase of amyloid ß -protein accumulation in thehuman brain. Am J Pathol 157: 2093-2099, 2000
47. Oshima N, Morishima-Kawashima M, Yamaguchi H,
Yoshimura M, Sugihara S, Khan K, Games D, Schenk
D, Ihara Y: Accumulation of amyloid beta-protein in
the low-density membrane domain accuratelyreflects the extent of beta-amyloid deposition in thebrain. Am J Pathol 158: 2209-2218, 2001
48. Miyasaka T, Morishima-Kawashima M, Ravid R,
Heutink P, van Swieten JC, Nagashima K, Ihara Y:
Molecular analysis of mutant and wild-type tau
deposited in the brain affected by FTDP-17 R406W
mutation. Am J Pathol 158: 373-379, 2001
49. Yamazaki T, Chang TY, Haass C, Ihara Y:
Accumulation and aggregation of amyloid ß-protein
in late endosomes of Niemann-Pick Type C cells. J
Biol Chem 276: 4454-4460, 2001
50. Gu Y, Misonou H, Sato T, Dohmae N, Takio K, Ihara
Y: Distinct intramembrane cleavage of the ß-amyloid
precursor protein family resembling γ-secretase-likecleavage of Notch. J Biol Chem 276:35235-35238,
2001

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Department of
Cognitive Neuroscience
Outline and Research Objectives
The Department of Cognitive Neuroscience is one of the three departments composing
the Speech and Cognitive Science Section. Since the establishment of this department in
1991, we have been working in the field of brain and cognition, especially from the point ofview of language.
Main research topics:
1. Research on the brain damaged patient: callosal syndrome, right temporal lobe syndrome, macular sparing, aphasia therapy
2. Functional magnetic resonance imaging (fMRI) during cognitive process: mental writing,writing, face recognition, reading comprehension, naming, reading aloud
3. Magnetoencephalographic (MEG) study of cognitive function: early component of thevisual evoked magnetic field, motor imagery
4. Brain mechanism of Japanese kanji processing
Teaching activities:
1. Graduate course: Speech science and language communication, Pathophysiology ofspeech and language Communication, Introduction to neuroscience
2. Master course: Cognitive neuroscience
3. Graduate course, Faculty of Literature: Experimental phonetics
4. Undergraduate course: Speech and language communication, Medical data processing
5. Undergraduate course, Faculty of Education: Fundamentals of speech science
Clinical activities:
The assessments and therapies for aphasia, apraxia, agnosia, amnesia and dementia are
conducted in collaboration with the Deptment of Neurology, Department of Neurosurgery
and Department of Otorhinolaryngology

Faculties and Students
Professor

Morihiro Sugishita Dr. Health Sci.,
Dr. Medical Sci. 1993~
Associate .................................2
Graduate Students .................2.
Research Students...................1
Guest Researchers...................2

Past Research and Major Accomplishments
1. Research on the Brain Damaged Patient1-1) Sugishita M, et al. Dichotic listening inpatients with partial section of the corpus callosum.
Brain 118, 417-427, 1995 : Despite the common
assumption that damage to the posterior part of thetrunk of the corpus callosum causes strong left-ear
suppression, the results indicated that damage to thesplenium causes strong left-ear suppression.

1-2) Koike A, et al. Preserved musical abilities following right temporal lobectomy. Journal of
Neurosurgery 85, 1000-1004, 1996: No disturbancesin the Seashore Measures were detected after temporal lobectomy on either side.
1-3) Sugishita M, et al. Hemispheric representationof the central retina of comissurotomized subjects.
Neuropsychologia 32, 399-415, 1994: The region of
the right (temporal) hemiretina represented by bothhemispheres in letter processing, if it exists, was estimated as less than 0.6º from the foveal center.
2. Functional Magnetic Resonance Imaging (fMRI)
During Cognitive Process2-1) Sugishita M, et al. Functional maguetic resonance imaging (fMRI) during mental writing withphonograms. NeuroReport 7, 1917-1921, 1996: Four
regions were activated during mental writing in all six
subjects; the left intraparietal sulcus, the middle partof the left precentral sulcus and the posterior part of117

the left superior frontal sulcus, the right intraparietal
sulcus, and either or both of the left and right cingulate sulci. The left intraparietal region was usually themost extensively activated.
2-2) Katanoda K, et al. A functional MRI study on
the neural substrates for writing. Human Brain
Mapping 13, 34-42, 2001: During writing, activations
were observed in the anterior part of the left superiorparietal lobule, the posterior part of the left middle
and superior frontal gyri, and the right cerebellum.
2-3) Katanoda K, et al. Neural substrates for therecognition of newly learned faces: a functional MRI
study. Neuropsychologia 38, 1616-1625, 2000: The
bilateral fusiform gyrus is involved, not only in faceperception, but in a certain aspect of face recognition
memory, and this aspect is related to the actual recognition of previously viewed faces rather than the processing of novel ones. The right parietal and frontal
regions, in contrast, are differentially more associatedwith the detection of novel faces or retrieval effort.
3. Magnetoencephalographic (MEG) Study of
Cognitive Function3-1) Yoneda K, et al. The early component of thevisual evoked magnetic field. NeuroReport 6, 797-800,
1995: The early component was observed in three ofthe nine subjects. The latency ranged from 40 to 45
ms in MEG and from 39 to 47 ms in EEG. The resultof dipole localization analysis showed that its origin
was cortical, and specifically, the striate cortex.
3-2) Ogiso T, et al. The precuneus in motor
imagery: a magnetoencephalographic study.
NeuroReport 11, 1345-1349, 2000: MEG was applied
to subjects who imagined themselves hurdling in selfcentered space. In three of six subjects all 300 trials in
the motor imagery condition revealed the precuneus
dipole. When we divided the 300 trials into four overlapping blocks, all six subjects showed precuneus
activity.
4. Brain Mechanism of Japanese Kanji Processing4-1) Sugishita M, Omura K. Learning Chinese characters may improve visual recall. Perceptual andMotor Skills 93, 579-594, 2001 : From elementarythrough high school, Japanese children are required tomemorize a large number of distinct visual forms, i.e.,roughly 2,000 Chinese characters, and tremendous
effort is expended in learning to read and write them.
We hypothesized that early training in memorizing
Chinese characters and the use of these characters indaily life shapes brain development and facilitatesrecall of visual forms in general. We administered theWechsler Memory Scale-Revised (WMS-R) to a repre-

118

sentative sample of the normal Japanese population(316 persons, 100% Japanese) and compared theirscores with data previously obtained from a representative sample of the normal U.S. population (316 persons, 82.5% Caucasian). Compared to the Americans,
the Japanese group obtained significantly higherscores on these two visual recall subtests in all six age
groups (16 to 74 years old).

Current Research
Research on the brain damaged patients: callosal
syndrome, right temporal lobe syndrome, macularsparing, aphasia therapy
1. fMRI during cognitive process: mental writing,writing, face recognition, reading comprehension,naming, reading aloud2. fMRI study on speech dominance in split-brain
patients
3. MEG study of cognitive function: visual evokedmagnetic fields, motor imagery
4. Brain mechanism of Japanese kanji processing

Future Prospect
1. Cerebral localization of neuropsychological deficits(aphasia, apraxia, agnosia and amnesia): The sitesof lesions responsible for neuropsychologicaldeficits will be more precisely localized with the
MRI findings of the patient.
2. Brain functional imaging: Functional MRI study
will be advanced with development of imaging
techniques such as arterial spin labeling other than
BOLD techniques and with refinement of experimental paradigm.

Research Grants
1. JSPS Research for the Future Program (Higher Brain
Functions) [FY1997~FY 2001] ($1,095,000/¥131,000,000) "Neuroimaging contributions to theunderstanding of brain language mechanism"
2. JSPS Scientific Research (B) [FY1997~FY 1998]($79,170/ ¥9,500,000) "Neuroimaging contributions
to the understanding music"
3. JSPS Exploratory Research [FY1997] ($11,700/¥1,400,000) "Study on brain mechanism of spoken
word discrimination by MEG"
4. MEXT COE Research (Neuroscience of Music)[FY1997-2001] ($0/ ¥0) "Paradigm creation in behavioral neurology"
5. MEXT Scientific Research in Priority Areas (MindDevelopment) [FY1994-1998] ($100,000/ ¥12,000,000)"Research on disorders of cognitive development byfunctional MRI"

Select Publications
1. Takayama Y, Sugishita M, Akiguchi I, Kimura J.
Isolated acalculia due to left parietal lesion. Archivesof Neurology, 51, 286-291, 1994
2. Ishiai S, Sugishita M, Watabiki S, Nakayama T,
Kotera M, Gono S. Improvement of left unilateral
spatial neglect in a line extension task. Neurology
44, 294- 298, 1994
3. Sugishita M, Hamilton CR, Sakuma I, Henmi I.
Hemispheric representation of the central retina ofcomissurotomized subjects. Neuropsychologia 32,
399-415, 1994
4. Takayama Y, Sugishita M, Kido T, Ogawa M,
Fukuyama H, Akiguchi I. Impaired stereoacuity due
to a lesion in the left pulvinar. Journal of Neurology
Neurosurgery and Psychiatry 57, 652-654, 1994
5. Takayama Y, Kido T, Sugishita M, Ogawa M,
Akiguchi I, A case of foreign accent syndrome without aphasia caused by a lesion of the left precentral
gyrus. Neurology 44, 990, 1994
6. Takayama Y, Sugishita M. Astereopsis induced byrepetitive magnetic stimulation of occipital cortex.
Journal of Neurology 241, 522-525, 1994
7. Takayama Y, Sugishita M, Hirose S, Akiguchi I,
Anosodiaphoria for dressing apraxia: contoributory
factor to dressing apraxia. Clinical Neurology and
Neurosurgery 96, 254-256, 1994
8. Yoneda K, Sekimoto S, Yumoto M, Sugishita M. The
early component of the visual evoked magnetic field.
Neuroreport 6, 797-800, 1995
9. Sugishita M, Otomo K, Yamazaki K, Shimizu H,
Yoshioka M, Shinohara A. Dichotic listening inpatients with partial section of the corpus callosum.
Brain 118, 417-427, 1995
10. Seki K, Yajima M, Sugishita M. The efficacy of kinesthetic reading treatment for pure alexia.
Neuropsychologia, 33, 595-609, 1995
11. Sodeyama N, Tamaki M, Sugishita M. Persistentpure verbal amnesia and transient aphasia after leftthalamic infarction. Journal of Neurology 242, 289294, 1995
12. Takeda K, Sugishita M. Word length error types inJapanese left-sided neglect dyslexia.Clinical
Neurology and Neurosurgery 97, 125-130, 1995
13. Nishiyama K, Momose T, Sugishita M, Sakuta M,
Positron emission tomography of reversible intellectual impairment induced by long-term anticholinergic therapy. Journal of the Neurological Sciences,132, 89-92, 1995
14. Takayama Y, Sugishita M, Fukuyama H, Akiguchi I.
Localization in spatial vision. Clinical Neurology and
Neurosurgery 97, 249-252, 1995
15. Endo K, Makishita H, Yanagisawa N, Sugishita M.
Modality specific naming and gesture disturbances.
A case with optic aphasia, bilateral tactile aphasia,
optic apraxia and tactile apraxia. Cortex 32, 3-28,
1996
16. Sugishita M, Takayama Y, Shiono T, Yoshikawa K,
Takahashi Y. Functional maguetic resonance imaging(fMRI) during mental writing with phonograms.
Neuroreport 7, 1917-1921, 1996
17. Koike A, Simizu H, Suzuki I, Ishijima B, Sugishita M.
Preserved musical abilities following right temporal
lobectomy. Journal of Neurosurgery 85, 1000-1004,
1996
18. Nishiyama K,, Sugishita M, Kurisaki H, Sakuta M.
Reversible memory disturbance and intelligence
impairment induced by long-term anticholinergic
therapy. Internal Medicine 37, 514-518, 1998
19. Matsuda O, Saito M, Sugishita M. Cognitive deficits
of mild dementia: a comparison between dementia
of the Alzheimer’s type and vascular dementia.
Psychiatry & Clinical Neurosciences 52, 87-91, 1998
20. Kobayashi M, Takayama H, Mihara B, Sugishita M.
Partial seizure with aphasic speech arrest caused bywatching a popular animated TV program. Epilepsia
40, 652-654, 1999
21. Tanaka S, Kanzaki R, Yoshibayashi M, Kamiya T,
Sugishita M. Dichotic listening in patients with situs
inversus: brain asymmetry and situs asymmetry.
Neuropsychologia 37, 869-874, 1999
22. Ogiso T, Kobayashi K, Sugishita M. The precuneus inmotor imagery: a magnetoencephalographic study.
NeuroReport 11, 1345-1349, 2000
23. Takayama H, Kobayashi M, Sugishita M, Mihara B.
Diffusion-weighted imaging demonstrates transientcytotoxic edema involving the corpus callosum in apatient with diffuse brain injury. Clinical Neurology
and Neurosurgery 102, 135-139, 2000
24. Katanoda K, Yoshikawa K, Sugishita M. Neural substrates for the recognition of newly learned faces: afunctional MRI study. Neuropsychologia 38, 16161625, 2000
25. Katanoda K, Yoshikawa K, Sugishita M. A functional
MRI study on the neural substrates for writing.
Human Brain Mapping 13, 34-42, 2001
26. Sugishita M, Koike A, Shimizu H, Suzuki I, Ishijima
B: Right temporal lobe function. Journal of
Neurosurgery 95, 372, 2001
27. Sugishita M, Omura K. Learning Chinese characters
may improve visual recall. Perceptual and Motor
Skills 93, 579-594, 2001
28. Katanoda K, Matsuda Y, Sugishita M. A spatio-temporal regression model for the analysis of functional
MRI data. NeuroImage 16, in press, 2002

119Department of
Neuropsychiatry
Outline and Research Objectives
This department of neuropsychiatry has the longest history among all that of
Universities in Japan since 1886. In the past quarter century, unfortunately it had been in aunusual condition that two groups, “The Ward” and “The Clinic”, had made independent
clinical activities in this department and excluded each other. “The Ward” group was influenced by the movement “Anti-Psychiatry” in 1960. During this period the most part ofbudgets and personnel changes had been frozen. This unfortunate incident made the facilities of the ward and all laboratories of our department old-fashioned and obsolescent. In
1994, two groups had arrived a compromise with each other and started the care of patientsin the psychiatric ward and clinic together, however more several years were needed for theregeneration of the department. Now it has already been “normalized”, overwhelming thelong and difficult period of past quarter century and we have regenerated the productive
activities of neuropsychiatry.
Approximately 240 patients with various psychiatric disorders were admitted on lastyear (2001). Since 2002, new wards was established (34 beds in the secluded ward and 19
beds in the general ward) and this department became to be expected the more active roles
on clinical fields in this year. Occupational therapy, art therapy and group therapy are performed in the ward. For the outpatients, we have two “Day Hospital Units” in this department; Day Hospital for young patients with psychotic feature based on cognitive behavioral
approach and Day Care for autistic children using educational treatment models.
Research activities in this department are wide-ranged from social psychiatry to molecular biology. Main research activities in this department is as follows, 1) molecular biologicalstudies of psychiatric disorders, 2) neuroscientific studies of stress, 3) psychopathologlicalstudies of early schizophrenia, 4) psychophysio1ogical and neuropsychological studies ofschizophrenia and epileptic psychosis, 5) community-based psychosocial treatment ofchronic schizophrenia, 6) cognitive-developmental or pharmacological treatment of autism
and Tourette syndrome, 7) neuroimaging studies of psychiatric disorders, and 8) neuropathological studies of dementias. Starting 2000, a nation-wide Project with the Grant ofJapan Science and Technology Agency has organized under the management of thisDepartment, entitled “Molecular mechanisms underlying stress-induced brain dysfunctions
and development of diagnosis/treatment strategies on post-traumatic stress disorders(PTSD)”.

Faculties and Students
Professor and Chair
Associate Professor

Nobumasa Kato, M.D.（1998〜）
Nobuo Nakayasu, M.D.
Akira Iwanami, M.D.
Lecturer
Koichi Tsunashima, M.D.
Hitoshi Tsuda, M.D.
Rinmei Fukuda, M.D.
Associate ...............................10
Graduate Student..................13
Secretary .................................4

Past Research and Major Accomplishments
Research activity in our department ranges over
diverse fields in neuropsychiatry including biological120

and social psychiatry. Professor Kato has been conducting and supervising the researches on the effectof stress on brain using animal models. Especially,various stress-induced changes in hippocampus havebeen elucidated. Dr Nakayasu had conducted intensive psychopathological research on early symptomsof schizophrenia and proposed the notion of “incipient schizophrenia” in 1990, which could be fundamentally different from its full-blown counterpart. At
this early stage, he suggested that we could employ a
combination of specific pharmacotherapy and psychotherapy to prevent the outbreak of this devastating illness. Dr Iwanami has been utilizing event-related potentials (ERPs) to investigate the neural correlates of cognitive dysfunction in schizophrenia,
methamphetamine psychosis and other mental disor-

Grand mean ERP waveforms in patients with and without
thought disorder. (Iwanami et al. Schizophrenia Research, 2000)

Typical time courses of the NIRS variables during cognitive andphysiological tasks. (Matsuo et al. Psychological Medicine,
2002)

Future Prospects

Spatiotemporal excitation patterns of N100m sources and
SPECT imaging during musical hallucinations. (Kasai et al.
Lancet, 1999)

ders. He found that specific parameters of ERPs correlates the severity of the illness. In the field of social
psychiatry, our department was the first to introduce
Day Hospital unit in 1980s and made extensive
research on the efficacy of this treatment strategy.
Our efforts had significantly contributed to the following nationwide introduction of this treatment
approach in Japan.

Current Research
The primary activity in our department is the government-supported study in the pathogenesis ofstress-induced neuropsychiatric disorders, mainly,
post-traumatic stress disorder (PTSD). The development of novel treatment strategy will also be expected. As one of the patient population, victims of theTokyo subway sarin attack in 1995 kindly served
themselves. Especially, we employ multimodal neuroimaging techniques (electroencephalography, eventrelated potentials, magnetoencephalography, structural magnetic resonance imaging, functional magnetic
resonance imaging, magnetic resonance spectroscopy
and near infrared spectroscopy) to elucidate the individual vulnerability to this condition and the neurobiological aftereffects of psychological trauma. Other
research activities include 1) molecular genetics ofpsychiatric disorders, 2) basic neuroscience, 3) clinicaland basic psychopharmacology, 4) the development of
psychosocial treatment approach in autism, and 5)
neuropathological studies of dementias.

The Last ten years were “The Decade of Brain”.
Outstanding progress has been achieved in neuroscience in terms of scientific knowledge and technicalinnovation. In addition, the human genome project isalmost done. Now we are jumping into the 21st century, “The Century of Mind”. Psychological terms shouldbe translated into those of brain, which would provide the more solid basis for psychiatry as a branch ofneuroscience. In this context, our basic and clinicalresearch projects are in progress. For holistic understanding of patients suffering psychiatric disorders
and their treatments, multi-disciplinary studies
should be necessary under the collaboration withother neuroscience research groups.
As a university hospital, clinical practice is also
important. We should be always keen to the needs ofthe public. To meet them, we opened several specialized outpatient clinics, such as PTSD or Child andAdolescent clinic, in addition to regular services. The
teams for psychiatric emergency and palliative medicine are also being formed. In addition to clinical services, the public would expect the scientific outputs
obtained through clinical studies. The system recruiting subjects or volunteers should be established
immediately.
The curriculum for medical students and the training system for residents are now changing. Especially,
the “super-rotation” system will begin in a few years.
Our training system should be modified for residents
to acquire the better clinical clerkship.
We will continue to make our best efforts to fulfill
the three major missions of the university hospital,
that is, research, clinical service and education.

Research Grants
1. 1999:Health Science Research Grants (Research on
Brain Science)¥18,000,000

121

2. 2000:Target Oriented Brain Science Promotion
Programsupported
by
the
MEXT
2000-2002¥194,493,000
3. 2001: Japan-US Cooperative Reserch Project“Cooperative Brain Reserch
2001-2002¥2,700,000
4. 2002: Health Science Research Grants (Research on
Health Service)¥36,000,000

Select Publications
Basic
1. Jinde S, Matsui A, Morinobu A, Takahashi Y,
Tsunashima K, Noda A, Yamada N, and Kato N.
Elevated neuropeptide Y and corticotropine-releasing
factor in the brain of an novel epileptic mutant rat:
Noda epileptic rat. Brain Research 833, 286-290,
1999.
2. Shirayama Y, Hashimoto K, Matsuki H, Tsunashima
K, Iyo M, Higuchi T, and Minabe Y. Increased
expression of zif268 mRNA in rat retrosplenial cortex following administration of phencyclidine. Brain
Research 839, 180-185, 1999.
3. Nagaki S, Fukumachi F, Sakamoto Y, Higuchi H,
Miki N, Ono M, Sadamatsu M, Kato N, and Osawa
M. Upregulation of brain somatostatin and neuropeptide Y following lidocaine-induced kindling in
the rat. Brain Research 852, 470-474, 2000.
4. Kohda K, Wang Y, and Yuzaki M. Mutation of glutamate receptor motif reveals its role in gating and d2
receptor channel properties. Nature Neuroscience 3,
315-322, 2000.
5. Nishiyama M, Hong K, Mikoshiba K Poo M-m, andKato K. Polarity and input specificity of synaptic
modification: critical role of Ca2+ release from internal
stores (underlined authors equally contributed).
Nature 408, 584-588, 2000.
6. Watanabe K, Ashby CR Jr, Katsumori H, and Minabe
Y. The effect of theacute administration of various
selective 5-HT receptor antagonists on focal hippocampal seizures in freely-moving rats. European
Journal of Pharmacology 398, 239-246, 2000.
7. Yasuda S, Ishida N, Higashiyama A, Morinobu S, andKato N. Characterization of audiogenic-like seizuresin naïve rats evoked by activation of AMPA andNMDA receptors in the inferior colliculus.
Experimental Neurology 164, 396-406, 2000.
8. Minabe Y, Hashimoto K, Watanabe K, and Ashby CR
Jr. Acute and repeated administration of the selective
5-HT(2A) receptor antagonist M100907 significantly
alters the activity of midbrain dopamine neurons: anin vivo slectrophysiological study. Synapse 40, 102112, 2001.
9. Imai H, Nishimura T, Sadamatsu M, Liu Y, Kabuto
M, and Kato N. Type II glucocorticoid receptors are
involved in neuronal death and astrocyte activationinduced by trimethyltin in the rat hippocampus.
Experimental Neurology 171, 22-28, 2001.

122

10. Nishimura T, Schwarzer C, Furtinger S, Imai H, Kato
N, and Sperk G. Changes in the GABAergic system
induced by trimethyltin application in the rat.
Molecular Brain Research 97, 1-6, 2001.
11. Takahashi J, Tanaka K, Morinobu S, Fujimaki K, Li
ST, Kato K, Ohkawa M, Yamawaki S, and Kato N.
Influence of restraint stress on the expression andthe serine/threonine phosphatase activity of calcineurin in the rat brain. Synapse 40, 130-6, 2001.
12. Tsutsumi S, Akaike M, Arimitsu H, Imai H, Kato N.
Circulating corticosterone alters the rate of neuropathological and behavioral changes induced bytrimethyltin in rats. Experimental Neurology 73, 8694, 2002.

Clinical (genetics)
13. Kato T, Honda M, Kuwata S, Juji T, Kunugi H, Nanko
S, Fukuda M, and Honda Y. A novel polymorphismin the promoter region of the tumor necrosis factor
alpha gene: No association with narcolepsy.
American Journal of Medical Genetics 88, 301-304,
1999.
14. Kunugi H, Hattori M, Nanko S, Fujii K, and Kato T.
Dinucleotide repeat polymorphism in the neurotrophin-3 gene and hippocampal volume in psychoses. Schizophrenia Research 37, 271-273, 1999.
15. Kunugi H, Ishida S, Kato T, Sakai T, Tatsumi M,
Hirose T, and Nanko S. No evidence for an association of polymorphism of the tryptophan hydroxylase
gene with affective disorders or attempted suicide
among Japanese patients. American Journal of
Psychiatry 156, 774-776, 1999.
16. Kunugi H, Ishida S, Kato T, Tatsumi M, Sakai T,
Hattori M, Hirose T, and Nanko S. A functional polymorphism in the promotor region of monoamineoxidase-A gene and mood disorders. Mol Psychiatry4, 393-395, 1999.
17. Sadamatsu M, Masui A, Sakai T, Kunugi H, Nanko S,
and Kato N. Familial paroxysmal kinesigenic
choreoathetosis: an electrophysiologic and genotypic
analysis. Epilepsia 40, 942-949, 1999.
18. Kato T, Kunugi H, Nanko S, and Kato N. Associationof bipolar disorder with the 5178 polymorphism inmitochondrial DNA. American Journal of Medical
Genetics 96, 182-186, 2000.
19. Narita K, Sasaki T, Akaho R, Okazaki Y, Kusumi I,
Kato T, Hashimoto O, Fukuda R, Koyama T, Matsuo
K, Okabe Y, Nanko S, Hohjoh H, and Tokunaga K.
Human leukocyte antigen and season of birth inJapanese patients with schizophrenia. American
Journal of Psychiatry 157, 1173-1175, 2000.
20. Tomita H, Nagamitsu S, Wakui K, Fukushima Y,
Yamada K, Sadamatsu M, Masui A, Konishi T,
Matsuishi Y, Aihara M, Shimizu K, Hashimoto K,
Mineta M, Matsushima M, Tsujita T, Saito M,
Tanaka H, Tsuji S, Takagi T, Nakamura Y, Nakano S,
Kato N, Nakane Y, and Niikawa N. Paroxysmal kinesigenic choreoathetosis locus map to chromosome
16p11.2-q12.1. American Journal of Human Genetics
65, 1688-1697, 2000.

21. Kato T, Kunugi H, Nanko S, and Kato N.
Mitochondrial DNA polymorphisms in bipolar disorder. Journal of Affective Disorders 62, 151-164, 2001.
22. Tatsumi M, Sasaki T, Iwanami A, Kosuga A, Tanabe
Y, Kamijima K. Season of birth in Japanese patientswith schizophrenia. Schizophrenia Research 54, 2138, 2002.

Clinical (pharmacology/neurobiology)
23. Fukuda R, Sasaki T, Kunugi H, and Nanko S. No
changes in paired viral antibody titers during thecourse of acute schizophrenia. Neuropsychobiology
40, 57-62, 1999.
24. Kato T and Kato N. Mitochondrial dysfunction in
bipolar disorder. Bipolar Disorder 2, 180-190, 2000.
25. Fukuda R. Factors affecting serum haloperidol levelassessed by longitudinal therapeutic monitoring.
Progress in Neuropsychopharmacology and BiologicalPsychiatry 24, 1299-1318, 2000.
26. Morita S, Shimoda K, Someya T, Yoshimura Y,
Kamijima K, and Kato N. Steady-state plasma levelsof nortriptyline and its hydroxylated metabolites inJapanese: the impact of CYP2D6 genotype on thehydroxylation of nortriptyline. Journal of ClinicalPsychopharmacology 20, 141-149, 2000.
27. Iwanami A, Okajima Y, Isono H, Shinoda J, Kasai K,
Hata A, Fukuda M, Nakagome K, Kamijima K. Effectsof risperidone on event-related potentials in schizophrenic patients. Pharmacopsychiatry 34, 73-79,
2001
28. Fujimaki K, Morinobu S, Takahashi J, Yamawaki S,
Kato N, Kanno M, Okuyama N, Kawakatsu S, Otani
K, Kusumi I, and Koyama T. Nucleotide sequence
analysis of the binding site on the inositol 1,4,5trisphosphate type-1 receptor in bipolar disordernegative study. Journal of Affective Disorders 65,
139-143, 2001.
Clinical (neuroimaging)
Magnetic resonance spectroscopy
29. Hamakawa H, Kato T, Shioiri T, Inubushi T, andKato N. Quantitative proton magnetic resonancespectroscopy in the bilateral frontal lobes of patientswith bipolar disorder. Psychological Medicine 29,639-644, 1999.
30. Murashita J, Kato T, Shioiri T, Inubushi T, and Kato
N. Age-dependent alteration of metabolic responseto photic stimulation in the human brain measured
by 31P MR-spectroscopy. Brain Research 818, 72-76,
1999.
31. Kato T, Inubushi T, and Kato N. Prediction of lithium response by 31P-MRS in bipolar disorder.
International Journal of Neuropsychopharmacology
3, 83-85, 2000.
32. Murashita J, Kato T, Shioiri T, Inubushi T, and Kato
N. Altered brain energy metabolism in lithium-resistant bipolar disorder detected by photic stimulated
31P-MR spectroscopy. Psychological Medicine 30,
107-115, 2000.

Near-infrared spectroscopy (NIRS)
33. Matsuo K, Kato T, Fukuda M, and Kato N. Alterationof hemoglobin oxygenation in the frontal region inelderly depressed patients measured by near-infrared
spectroscopy. Journal of Neuropsychiatry andClinical Neuroscience 12, 465-471, 2000.
34. Matsuo K, Kato N, and Kato T. Decreased cerebral
haemodynamic response to cognitive and physiological tasks in mood disorders as shown by nearinfrared spectroscopy. Psychological Medicine 32,1029-37, 2002.
Magnetic resonance imaging (MRI)
35. Kasai K, Shenton ME, Salisbury DF, Hirayasu Y, Lee
CU, Ciszewski A, Yurgelun-Todd D, Kikinis R, Jolesz
FA, McCarley RW. Progressive decrease of left superior temporal gyrus gray matter volume in firstepisode schizophrenia. American Journal of
Psychiatry, in press.
36. Gilbertson MW, Shenton ME, Ciszewski A, Kasai K,
Lasko NB, Orr SP, Pitman RK. Smaller hippocampal
volume predicts pathologic vulnerability to psychological trauma. Nature Neuroscience, in press.
37. Onitsuka T, Shenton ME, Kasai K, Nestor PG, Toner
SK, Kikinis R, Jolesz FA, McCarley RW. Fusiform
gyrus volume reduction and facial recognition inchronic schizophrenia. Archives of General
Psychiatry, in press.
38. Kubicki M, Shenton ME, Salisbury DF, Hirayasu Y,
Kasai K, Kikinis R, Jolesz FA, McCarley RW: Voxelbased morphometric analysis of gray matter in firstepisode schizophrenia. Neuroimage, in press.
39. Anderson JE, Wible CG, McCarley RW, Jakab M,
Kasai K, Shenton ME: An MRI study of temporal
lobe abnormalities and negative symptoms in chronic schizophrenia. Schizophrenia Research, in press.
40. Lee CU, Shenton ME, Salisbury DF, Kasai K,
Onitsuka T, Dickey CC, Yurgelun-Todd D, Kikinis R,
Jolesz FA, McCarley RW: Fusiform gyrus volume
reduction in first-episode schizophrenia: an MRI
study. Archives of General Psychiatry 59, 775-781,
2002.
Clinical (neurophysiology)
41. Kasai K, Yamada H, Kamio S, Nakagome K, Iwanami
A, Fukuda M, Yumoto M, Itoh K, Koshida I, Abe O,
Kato N. Neuromagnetic correlates of impaired automatic categorical perception of speech sounds inschizophrenia. Schizophrenia Research 2002, inpress.
42. Kasai K, Asada T, Yumoto M, Takeya J, Matsuda H:
Evidence for functional abnormality in the right
auditory cortex during musical hallucinations. Lancet
354: 1703-1704, 1999.
43. Kasai K, Okazawa K, Nakagome K, Hiramatsu K,
Hata A, Fukuda M, Honda M, Miyauchi M,
Matsushita M: Mismatch negativity and N2b attenuation as an indicator for dysfunction of the preattentive and controlled processing for deviance detection123

in schizophrenia: a topographic event-related potential study. Schizophrenia Research 35: 141-156, 1999.
44. Iwanami A, Okajima Y, Kuwakado D, Isono H, Kasai
K, Hata A, Nakagome K, Fukuda M, Kamijima K.
Event-related potentials and thought disorder inschizophrenia. Schizophrenia Research 42, 187-191,
2000.
45. Kasai K, Nakagome K, Iwanami A, Fukuda M.
Neuropsychiatry and the auditory selective attention. Current Opinion in Psychiatry 14, 219-225,
2001.
46. Kamio S, Nakagome K, Murakami T, Kasai K,
Iwanami A, Hiramatsu K-I, Hata A, Watanabe A,
Fukuda M, Honda M, Kato N. Impaired suppressionof processing in schizophrenic patients suggested by
ERPs obtained in a selective attention task.
Schizophrenia Research 49, 213-221, 2001.
47. Kasai K, Nakagome K, Itoh K, Koshida I, Hata A,
Iwanami A, Fukuda M, Kato N. Impaired cortical network for preattentive detection of change in speechsounds in schizophrenia: a high-resolution eventrelated potential study. American Journal of
Psychiatry 159, 546-553, 2002.
48. Kasai K, Nakagome K, Iwanami A, Fukuda M, Itoh K,
Koshida I, Kato N. No effect of gender on tonal andphonetic mismatch negativity in normal adults
assessed by a high-resolution EEG recording.
Cognitive Brain Research 13, 305-312, 2002.
49. Kasai K, Yamada H, Kamio S, Nakagome K, Iwanami
A, Fukuda M, Yumoto M, Itoh K, Koshida I, Abe O,
Kato N. Do High or low doses of anxiolytics andhypnotics affect mismatch negativity in schizophrenic subjects? An EEG and MEG study. Clinical
Neurophysiology 113, 141-150, 2002.
50. Watanabe A, Kasai K, Nagakubo S, Kamio S,
Murakami T, Hata A, Iwanami A, Nakagome K,
Fukuda M, Kato N. Verbal and procedural memory inschizophrenia with milder symptoms: implications
for psychosocial intervention. Schizophrenia
Research 53, 263-265, 2002.

124

Department of
Neurology
Outline and Research Objectives
The Department of Neurology as a division of clinical service in The University Hospital
was established in 1964 separated from the third Department of Internal Medicine. The
facilities for research in neurology were provided from the Faculty of Medicine as a divisionof clinical research in the Institute for Brain Research until March 1997. In April 1997, ourdepartment was reorganized as a Department in the Division of Neuroscience, Graduate
School of Medicine.
Activities of our department include 1. clinical service in the out-patient clinic and theward in the University Hospital, 2. undergraduate and postgraduate education of neurology
in the Faculty of Medicine and Graduate School of Medicine, and 3. research in neuroscience in the Graduate School of Medicine. Besides a weekly ward round, a weekly clinicalconference is held for discussion on cases with difficult problems. A weekly neuroimaging
conference and journal club are also held. Moreover, a bimonthly ‘’Neuroscience Club” withstimulating discussions is held where informal lectures are given by invited distinguishedguests in the field of neuroscience from outside the University.
The Research Objectives of the Department of Neurology is to elucidate molecular mechanisms of neurological diseases and development of new therapeutic strategies based on our
understanding of molecular mechanisms of neurological diseases.

Faculties and Students
Professor and Chair Shoji Tsuji, MD, PhD (2002)
Associate Professors Shin Kwak, MD, PhD (1997)
Lecturer
Susumu Kusunoki, MD, PhD(1999)
Lecturer
Yoshikazu Ugawa, MD, PhD(1997)
Associate .................................4
Graduate student ..................18

Past Research and Major Accomplishments
The research activities have been focused on elucidation of molecular mechanisms of neurodegenerative
diseases based on molecular genetics approaches. We
took a strategy for collecting as many as families withvarious hereditary neurological diseases. We have conducted a number of projects that include linkage mapping and eventual positional cloning of the causative
genes. For the diseases in which we discovered thecausative genes, analyses of molecular mechanisms ofneurodegeneration have been conducted.
1. Identification of causative genes for neurodegenerative diseases
By linkage analysis, we have identified the loci for
Machado-Joseph disease (Nature Genet. 4:300-304,
1993), hereditary progressive dystonia (Segawa disease) (Ann. Neurol. 37:405-408, 1995) and autosomal

recessive Parkinsonism (AR-JP) (Am. J. Hum. Genet.
60:588-596, 1997). Furthermore we have identified
the causative gene for dentatorubral-pallidoluysian
atrophy (DRPLA) (Nature Genet. 6:9-13, 1994), hereditary progressive dystonia (Nature Genet. 8:236-242,
1994), spinocerebellar ataxia type 2 (SCA2), earlyonset ataxia with ocular motor apraxia and hypoalbuminemia (EAOH) (Nature Genet. 29: 184-188, 2001),
Charcot-Marie-Tooth disease type 2 (CMT2) (Cell
105:587-597, 2001) and SCA17 (Hum. Mol. Genet.
8:2047-2053, 1999, Hum. Mol. Genet. 10: 1441-1448,
2001).
2. Elucidation of molecular pathogenesis of neurodegenerative diseases
Based on identification of causative genes for theabovementioned neurodegenerative diseases, our laboratory further expanded our studies to elucidate themolecular mechanisms of neurodegeneration in these
diseases. Our major effort has been focused on molecular mechanisms of neurodegeneration in polyglutamine diseases caused by expanded CAG repeats coding for polyglutamine stretches. We have createdtransgenic mice having a full-length human mutant
DRPLA gene as a single copy, which carry various
lengths of polyglutamine stretches (Q76, Q113 andQ129 mice at the same insertion site). The expression
levels of the transgene were comparable to those ofendogenous mouse DRPLA gene. Q129 mice showed
severe neurological phenotype including ataxia,

125myoclonus and epilepsy with premature death by 16
weeks, while Q76 mice did not show any obvious
phenotypes. Q113 mice showed milder phenotypes
compared with those of Q129 mice. Given the factthat the insertion site of the transgene (human fulllength mutant DRPLA gene) is identical in these
Q129, Q113 and Q76 mice, these data strongly suggest that the variability in the phenotypes exclusively
depends on the length of the polyglutamine stretches.
Interestingly, neuronal loss was not evident in thebrains of these mice, suggesting that neuronal dysfunction not but neuronal death underlies the basic
pathophysiologic mechanisms of neurodegeneration.
Detailed analysis of these mice demonstrated that theearliest neuropathological change was intranuclear
accumulation of mutant proteins (diffuse nuclear
staining) with preferential involvement of cerebellar
nuclei, red nuclei, globus pallidus, subthalamic nuclei
and cerebral cortex. Similar findings were also confirmed in human autopsied brains of DRPLA patients.
These data strongly suggest that neuronal dysfunction is the basic molecular mechanisms of neurodegeneration in polyglutamine diseases.
Given the fact that nuclear dysfunction underlies
the molecular mechanisms of neuronal degenerationin polyglutamine diseases, we investigated nuclear
proteins that bind to expanded polyglutamine stretches. Employing yeast two-hybrid assays, we havefound TAF130 (TATA-binding protein associated factor) binds to expanded polyglutamine stretches. The
association was further confirmed by co-localizationof TAF130 and expanded polyglutamine stretches not
only in transient expression assays but also in human
autopsied brains of DRPLA and MJD patients. Since
TAF130 is involved in CREB-dependent transcriptional activation, association between TAF130 and
expanded polyglutamine stretches raised the possibilities that suppression of CREB-dependent transcription, which has been demonstrated to be essential forneuronal survival and plasticity, leads to neuronal126

dysfunctions. Suppression of CREB-dependent transcription by expanded polyglutamine stretches was
confirmed by a reporter assay, and, furthermore, bymonitoring endogenous cAMP responsive genes suchas c-FOS. Expression profiling of the Q129 mousebrains further demonstrated down-regulation of manycAMP responsive genes including c-FOS and EGR-1.
To develop therapeutic approaches for polyglutamine disease, we have investigated possibilities forabrogating suppression of CREB-dependent transcriptional activation. We found that increase in intracellular cAMP levels abrogate the suppression of the CREBdependent transcriptional activation. We have further
demonstrated that histone deacetylase (HDAC)
inhibitor has similar effects. Thus, stimulation of transcription by cAMP or HDAC inhibitors has potential
roles in therapeutic measures for polyglutamine diseases.

Current Research
1. Molecular pathogenesis of polyglutamine diseases
Current research is being focused fo the following
points. 1. Detailed analyses of transcriptional dysregulation in polyglutamine diseases. 2. Development oftherapeutic measures based on the molecular pathogenesis of polyglutamine diseases.
For elucidating the mechanisms of transcriptional
dysregulation, detailed expression profiling analysesof the Q129, Q113 and Q76 mice are being conducted.
Similar expression profiling of human autopsied
brains of patients with polyglutamine diseases is also
being conducted. Abnormalities in CREB-dependenttranscriptional activation in vivo are also being investigated by generating double transgenic mice for
DRPLA and Cre-LacZ (Lac-Z gene was inserted under
the promoter containing CRE.),For development of therapeutic approaches, thepossibilities of increasing intracellular cAMP andadministration of HDAC inhibitors are being investigated. To further establish a sensitive assay system, asensitive assay system for CREB-dependent transcriptional activation using cultured cells is being developed.
2. Molecular pathogenesis of neurodegenerative
diseases caused by deficiently in DNA repair
We have recently identified the causative gene,aprataxin, for an autosomal recessive spinocerebellar
ataxia (early-onset ataxia associated with ocularmotor apraxia and hypoalbuminemia). Preliminary
studies suggest that aprataxin binds to XRCC-1, a key
molecule involved in single strand DNA break repair.
The hypothesis that XRCC-1 is involved in the single
strand DNA break repair is further supported by thefact that aprataxin has a polynucleotide kinase-likedomain.
Since a number of neurodegenerative diseases
with mutations in the DNA repair systems havealready been found, our finding further strengthens
the functional role of DNA repair system in neurodegenerative diseases. Since the role of single strand
DNA repair system in neurodegenerative diseases has
not been well established, the future research will befocused on the roles of single strand DNA breakrepair in neurodegenerative diseases. The fact that
hypoalbuminemia becomes evident only in adulthood
further raises the possibility that transcription-coupled repair of highly actively transcribed genes suchas albumin gene might be involved in this disease.
This hypothesis is intriguing, since brain is the organwith highly active transcription activities.
3. Molecular pathogenesis of neurodegenerative
diseases with complex trait
To elucidate molecular pathogenesis of sporadic
neurodegenerative disease, we are organizing a consortium to establish a nation-wide collaborative network. To elucidate the molecular pathogenesis of suchneurodegenerative diseases with complex trait, weneed to establish large databases and to collect as
many as samples. We are focusing on amyotrophic
lateral sclerosis (sporadic ALS, and ALS in Kii
Peninsula) and multiple system atrophy. Effort isbeing made to collect as many as multiples families
for ALS and multiple system atrophy. We are performing both linkage analysis based on multiplex
families and association studies (case-control studies).
These two strategies will complement each other.

Future Prospects
For future prospects, the following projects arebeing planned.

1. Development of therapeutic measures forpolyglutamine diseases.
For accomplishing this goal, various approaches
are being planned. Considering the cascade shown in
the above Figure, the therapeutic approaches should
be focused on 1. suppression of mutant gene expressions at the upstream cascade, and 2. enhancement of
CREB-dependent transcriptional activation at thedownstream cascade will be the two major targets.
2. Molecular pathogenesis of neurodegenerative
diseases caused by deficiently in DNA repair
Detailed reconstruction studies will be conductedto elucidate the physiological functions of aprataxin.
Knock-out mice for aprataxin gene are being generated, which should be essential not only for elucidationof molecular pathogenesis, but also development oftherapeutic approached.
3. Molecular pathogenesis of neurodegenerative
diseases with complex trait
To elucidate the molecular mechanisms of neurodegeneration of sporadic diseases, the following
strategies are being planned. 1. large-scale collectionof resources including database on clinical information and genomic DNAs based on a nation-wide consortium will be essential for future research. The collection of resources will be focused on a large scalecase and controls, as well as, intensive collection ofmultiplex families. For example, we have recently
identified 4 multiplex families with multiple system
atrophy (MSA), suggesting detailed genome-wide
analyses of these families may provide important
findings as to the genetic component involved inthese diseases. These two approaches (large scale
case-control studies and intensive analyses of multiplex families) should complement, and allow us to
identify the genes involved in the pathogenesis.

Research Grants
Grant for the Research for the Future Programfrom the Japan Society for the Promotion of Science, agrant from the Research Committee for Ataxic
Diseases, the Ministry of Health, Labor and Welfare,“Identification of Genes Involved in Brain
Diseases”
FY1996
94,998FY199775,682
FY199878,658FY199985,516
FY200076,286
FY200150,000FY200247,000in thousands of yen

127Grant for Scientific Research on Priority Areas (C) Advanced Brain Science Project- from the Ministry of
Education, Culture, Sports, and Science and Technology,
Japan “Molecular mechanisms of neurodegeneration”
FY2001
66,600FY2002/10/29 59,200
in thousands of yen
Grant for Scientific Research (A) from the Ministry of
Education, Culture, Sports, and Science and Technology,
Japan
FY2002
19,200FY2003
11,300in thousands of yen
Grant from the Ministry of Health, Labor and Welfare,Japan “Study for development of therapeutic measuresfor polyglutamine diseases!
FY199824,000
FY199924,000FY200016,000in thousands of yen

Select Publications
1

2

3

4

5

6

Naruse, S., Igarashi, S., Kobayashi, H., Aoki, K.,
Inuzuka, T., Kaneko, K., Shimizu, T., Iihara, K.,
Kojima, T., Miyatake, T. and Tsuj, S.: Mis-sense
mutaiton Val→Ile in exon 17 of amyloid precursor
protein gene in Japanese familial Alzheimers disease.
Lancet 337:978-979, 1991
Wakamatsu, N., Kobayashi, H., Miyatake, T. andTsuji, S.: A novel exon mutation in the human bhexosaminidase b subunit gene affects 3 splice site
selection. J. Biol. Chem. 267:2406-2413, 1992
Tsuji, S., Kobayashi, H., Uchida, Y., Ihara, Y. and
Miyatake, T.: Molecular cloning of human growth
inhibitory factor cDNA and its down-regulation in
Alzheimers disease. EMBO J. 11:4843-4850, 1992
Igarashi, S., Tanno, Y., Onodera, O., Yamazaki, M.,
Sato, S., Ishikawa, A., Miyatani, N., Nagashima, M.,
Ishikawa, Y., Sahashi, K., Ibi, T., Miyatake, T. andTsuji, S.: Strong correlation between the number of
CAG repeats in androgen receptor genes and the clinical onset of features of spinal and bulbar muscularatrophy. Neurol. 42:2300-2302, 1992
Takiyama, Y., Nishizawa, M., Tanaka, H.,
Kawashima, S., Sakamoto, H., Karube, Y., Shimazaki,
H., Soutome, M., Endo, K., Ohta, S., Kagawa, Y.,
Kanazawa, I., Mizuno, Y., Yoshida, M., Yuasa, T.,
Horikawa, Y., Oyanagi, K., Nagai, H., Kondo, T.,
Inuzuka, T., Onodera, O. and Tsuji, S.: The gene for
Machado-Joseph disease maps to human chromosome 14q. Nature Genet. 4:300-304, 1993
Koide, R., Ikeuchi, T., Onodera, O., Tanaka, H.,
Igarashi, S., Endo, K., Takahashi, H., Kondo, R.,
Ishikawa, A., Hayashi, T., Saito, M., Tomoda, A.,
Miike, T., Naito, H., Ikuta, F. and Tsuji, S.: Unstable
expansion of CAG repeat in hereditary dentatorubral-pallidoluysian atrophy (DRPLA). Nature
Genet. 6:9-13, 1994

128

7

Okuizumi, K., Onodera, O., Tanaka, H., Kobayashi,
H., Tsuji, S., Takahashi, H., Oyanagi, K., Seki, K.,
Tanaka, M., Naruse, S., Miyatake, T., Mizusawa, H.
and Kanazawa, I.: ApoE-ε 4 and early-onset
Alzheimers. Nature Genet. 7:10-11, 1994
8 Naruse, S., Igarashi, S., Furuya, T., Kobayashi, H.,
Miyatake, T. and Tsuji, S.: Structures of the humanand mouse growth inhibitory factor-encoding genes.
Gene 144:283-287, 1994
9 Ichinose, H., Ohye, T., Takahashi, E., Seki, N., Hori,
T., Segawa, M., Nomura, Y., Endo, K., Tanaka, H.,
Tsuji, S., Fujita, K. and Nagatsu, T.: Hereditary progressive dystonia with marked diurnal fluctuation
caused by mutations in the GTP cyclohydrolase I
gene. Nature Genet. 8:236-242, 1994
10 Burke, J. R., Ikeuchi, T., Koide, R. and Tsuji, S.:
Dentatorubral-pallidoluysian atrophy and Haw River
syndrome. Lancet 344:1711-1712, 1994
11 Ikeuchi, T., Koide, R., Tanaka, H., Onodera, O.,
Igarashi, S., Takahashi, H., Kondo, R., Ishikawa, A.,
Tomoda, A., Miike, T., Sato, K., Ihara, Y., Hayabara,T,. Isa, F., Tanabe, H., Tokiguchi, S., Hayashi, M.,
Shimizu, N., Ikuta, F., Naito, H. and Tsuji, S.:
Dentatorubral-pallidoluysian atrophy closely related
to unstable expansions of trinucleotide (CAG) repeat.
Ann. Neurol. 37:769-775, 1995
12 Kaneko, K., Miyatake, T. and Tsuji, S.: Rapid andreliable diagnosis of tuberculous meningitis by PCR.
Neurol. 45:1425-1426, 1995
13 Sanpei, K., Igarashi, S., Eguchi, I., Takiyama, Y.,
Tanaka, H. and Tsuji, S.: Direct detection of expanded (CAG/CTG) repeats in the myotonin-protein
kinase genes of myotonic dystrophy patients using ahigh-stringency hybridization method. Biochem.
Biophys. Res. Commun. 212:341-346, 1995
14 Okuizumi, K., Onodera, O., Namba, Y., Ikeda, K.,
Yamamoto, T., Seki, K., Ueki, A., Nanko, S., Tanaka,
H., Takahashi, H., Oyanagi, K., Mizusawa, H.,
Kanazawa, I. and Tsuji, S.: Genetic association of thevery low density lipoprotein (VLDL) receptor genewith sporadic Alzheimers disease. Nature Genet.
11:207-209, 1995
15 Onodera, O., Oyake, M., Takano, H., Ikeuchi, T.,
Igarashi, S. and Tsuji, S.: Molecular cloning of a fulllength cDNA for dentatorubral-pallidoluysian atrophy and regional expressions of the expanded allelesin the CNS. Am. J. Hum. Genet. 57:1050-1060, 1995
16 Takiyama, Y., Igarashi, S., Rogaeva, E. A., Endo, K.,
Rogaev, E. I., Tanaka, H., Sherrington, R., Sanpei, K.,
Liang, Y., Saito, M., Tsuda, T., Takano, H., Ikeda, M.,
Lin, C., Chi, H., Kennedy, J. L., Lang, A. E., Wherrett,J. R., Segawa, M., Nomura, Y., Yuasa, T.,
Weissenbach, J., Yoshida, M., Nishizawa, M., Kidd,
K. K., Tsuji, S. and St. George-Hyslop, P. H.: Evidence
for inter-generational instability in the CAG repeat in
the MJD1 gene and for conserved haplotypes atflanking markers amongst Japanese and Caucasiansubjects with Machado-Joseph disease. Hum. Mol.
Genet. 4:1137-1146, 1995

17 Ikeuchi, T., Igarashi, S., Takiyama, Y., Onodera, O.,
Oyake, M., Takano, H., Koide, R., Tanaka, H. andTsuji, S.: Non-Mendelian transmission in dentatorubral-pallidoluysian atrophy and Machado-Joseph
disease: The mutant allele is preferentially transmitted in male meiosis. Am. J. Hum. Genet. 58:730-733,
1996
18 Takano, H., Onodera, O., Takahashi, H., Igarashi, S.,
Yamada, M., Oyake, M., Ikeuchi, T., Koide, R.,
Tanaka, H., Iwabuchi, K. and Tsuji, S.: Somatic
mosaicism of expanded CAG repeats in brains ofpatients with dentatorubral-pallidoluysian atrophy:
Cellular population-dependent dynamics of mitotic
instability. Am. J. Hum. Genet. 58:1212-1222, 1996
19 Ishikawa, A. and Tsuji, S.: Clinical analysis of 17
patients in 12 Japanese families with autosomalrecessive type juvenile parkinsonism. Neurol. 47:160166, 1996
20 Shimizu, N., Yamami, T., Nakayama, M., Ikeuchi, T.,
Koide, R. and Tsuji, S.: A sporadic case of dentatorubral pallidoluysian atrophy (DRPLA) with CAG
repeat expansion but no clinical abnormalities in thefather. J. Neurol. Neurosurg. Psychiat. 61:113-114,
1996
21 Igarashi, S., Takiyama, Y., Cancel, G., Rogaeva, E.A.,
Sasaki, H., Wakisaka, A., Zhou, Y.-X., Takano, H.,
Endo, K., Sanpei, K., Oyake, M., Tanaka, H.,
Stevanin, G., Abbas, N., Durr, A., Rogaev, E.I.,
Sherrington, R., Tsuda, T., Ikeda, M., Cassa, E.,
Nishizawa, M., Benomar, A., Julien, J., Weissenbach,J., Wang, G.-X., Agid, Y., St. George-Hyslop, P.H.,
Brice, A. and Tsuji, S.: Intergenerational instability of
the CAG repeat of the gene for Machado-Joseph disease (MJD1) is affected by the genotype of the normal chromosome: implications for the molecularmechanisms of the instability of the CAG repeat.
Hum. Mol. Genet. 5:923-932, 1996
22 Okuizumi, K., Onodera, O., Seki, K., Tanaka, H.,
Namba, Y., Ideda, K., Saunders, A. M., PericakVance, M. A., Roses, A. D. and Tsuji, S.: Lack ofassociation of very low density lipoprotein receptor
gene polymorphism with Caucasian Alzheimers disease. Ann. Neurol. 40:251-254, 1996
23 Sanpei, K., Takano, H., Igarashi. S., Sato, T., Oyake,M., Sasaki, H., Wakisaka, A., Tashiro, K., Ishida, Y.,
Ikeuchi, T., Koide, R., Saito, M., Sato, A., Tanaka, T.,
Hanyu, S., Takiyama, Y., Nishizawa, M., Shimizu, N.,
Nomura, Y., Segawa, M., Iwabuchi, K., Eguchi, I.,
Tanaka, H., Takahashi, H. and Tsuji, S.:
Identification of the spinocerebellar ataxia type 2
gene using a direct identification of repeat expansion
and cloning technique, DIRECT. Nature Genet.
14:277-284, 1996
24 Oyake, M., Onodera, O., Shiroishi, T., Takano, H.,
Takahashi, Y., Kominami, R., Moriwaki, K., Ikeuchi,T., Igarashi, S., Tanaka, H. and Tsuji, S.: Molecularcloning of murine homologue dentatorubral-pallidoluysian atrophy (DRPLA) cDNA: Strong conservation of a polymorphic CAG repeat in the murine
gene. Genomics 40:205-207, 1997

25 Matsumine, H., Saito, M., Shimoda-Matsubayashi,S., Tanaka, H., Ishikawa, A., Nakagawa-Hattori, Y.,
Yokochi, M., Kobayashi, T., Igarashi, S., Takano, H.,
Sanpei, K., Koike, R., Mori, H., Kondo, T., Mizutani,Y., Schaffer, A. A., Yamamura, Y., Nakamura, S.,
Kuzuhara, S., Tsuji, S. and Mizuno, Y.: Localizationof a gene for an autosomal recessive form of juvenile
parkinsonism to chromosome 6q25.2-27. Am. J.
Hum. Genet. 60:588-596, 1997
26 Ikeuchi, T., Asaka, T., Saito, M., Tanaka, H.,
Higuchi, S., Tanaka, K., Saida, K., Uyama, E.,
Mizusawa, H., Fukuhara, N., Nonaka, I., Takamori,
M. and Tsuji, S.: Gene locus for autosomal recessive
distal myopathy with rimmed vacuoles maps tochromosome 9. Ann. Neurol. 41:432-437, 1997
27 Takiyama, Y., Sakoe, K., Soutome, M., Namekawa,
M., Ogawa, T., Nakano, I., Igarashi, S., Oyake, M.,
Tanaka, H., Tsuji, S. and Nishizawa, M.: Single
sperm analysis of the CAG repeats in the gene for
Machado-Joseph disease (MJD1): evidence for nonMendelian transmission of the MJD1 gene and forthe effect of the intragenic CGG/GGG polymorphismon the intergenerational instability. Hum. Mol.
Genet. 6:1063-1068, 1997
28 Ikeuchi, T., Takano, H., Koide, R., Horikawa, Y.,
Honma, Y., Onishi, Y., Igarashi, S., Tanaka, H.,
Nakao, N., Sahashi, K., Tsukagoshi, H., Inoue, K.,
Takahahsi, H. and Tsuji, S.: Spinocerebellar ataxia
type 6: CAG repeat expnasion in α1A voltagedependent calcium channel gene and clinical variations in Japanese population. Ann. Neurol. 42:879884, 1997
29 Koide, R., Onodera, O., Ikeuchi, T., Kondo, R.,
Tanaka, H., Tokiguchi, S., Tomoda, A., Miike, T.,
Isa, F., Beppu, H., Shimizu, N., Watanabe, Y.,
Horikawa, Y., Shimohata, T., Hirota, K., Ishikawa, A.
and Tsuji, S.: Atrophy of the cerebellum and brainstem in dentatorubral pallidoluysian atrophy.
Influence of CAG repeat size on MRI findings.
Neurol. 49:1605-1612, 1997
30 Saito, M., Hayashi, Y., Suzuki, T., Tanaka, H.,
Hozumi, I. and Tsuji, S.: Linkage mapping of thegene for Charcot-Marie-Tooth disease type 2 to chromosome 1p (CMT2A) and the clinical features of
CMT2A. Neurol. 49:1630-1635, 1997
31 Shimohata, T., Date, H., Ishiguro, H., Suzuki, T.,
Takano, H., Tanaka, H., Tsuji, S. and Hirota, K.:
Ataxia with isolated vitamin E deficiency and retinitis pigmentosa. Ann. Neurol. 43:273, 1997
32 Igarashi, S., Koide, R., Shimohata, T., Yamada, M.,
Hayashi, Y., Takano, H., Date, H., Oyake, M., Sato,T., Sato, A., Egawa, S., Ikeuchi, T., Tanaka, H.,
Nakano, R., Tanaka, K., Hozumi, I., Inuzuka, T.,
Takahashi, H. and Tsuji, S.: Suppression of aggregate
formation and apoptosis by transglutaminase
inhibitors in cells expressing truncated DRPLA protein with an expanded polyglutamine stretch. Nature
Genet. 18:111-117, 1998
33 Onodera, O., Idezuka, J., Igarashi, S., Takiyama, Y.,
Endo, K., Takano, H., Oyake, M., Tanaka, H.,

129

Inuzuka, T., Hayashi, T., Yuasa, T., Ito, J., Miyatake,T. and Tsuji, S.: Progressive atrophy of cerebellum
and brainstem as a function of age and the size ofthe expanded CAG repeats in the MJD1 gene in
Machado-Joseph disease. Ann. Neurol. 43:288-296,
1998
34 Takano, H., Cancel, G., Ikeuchi, T., Lorenzetti, D.,
Mawad, R., Stevanin, G., Didierjean, O., Durr, A.,
Oyake, M., Shimohata, T., Sasaki, R., Koide, R.,
Igarashi, S., Hayashi, S., Takiyama, Y., Nishizawa,M., Tanaka, H., Zoghbi, H., Brice, A., Tsuji, S.: Close
associations between prevalence rates of dominantly
inherited spinocerebellar ataxias with CAG-repeat
expansions and frequencies of large normal CAG
alleles in Japanese and Caucasian populations. Am. J.
Hum. Genet. 63:1060-1066, 1998
35 Koide, T., Igarashi, S., Kikugawa, K., Nakano, R.,
Inuzuka, T., Yamada, M., Takahashi, H. and Tsuji,
S.: Formation of granular cytoplasmic aggregates incells expressing mutant Cu/Zn superoxide dismutase
associated with familial amyotrophic lateral sclerosis.
Neurosci. Lett. 257:29-32 1998
36 Okuizumi, K., Takano, H., Seki, K., Onishi, Y.,
Horikawa, Y. and Tsuji, S.: Genetic polymorphism of
the tau gene and neurodegenerative diseases with
tau pathology among Japanese. Ann. Neurol. 44:707,
1998
37 Sato, T., Oyake, M., Nakamura, K., Nakao, K.,
Fukusima, Y., Onodera, O., Igarashi, S., Takano, H.,
Kikugawa, K., lshida, Y., Shimohata, T., Koide, R.,
Ikeuchi, T., Tanaka, H., Futamura, N., Matsumura,R., Takayanagi, T., Tanaka, F., Sobue, G., Komure,O., Takahashi, M., Sano, A., Ichikawa, Y., Goto, J.,
Kanazawa, I., Katsuki, M. and Tsuji, S.: Transgenic
mice harboring a full-length human mutant DRPLA
gene exhibit age-dependent intergenerational andsomatic instabilities of CAG repeats comparable tothose in DRPLA patients. Hum. Mol. Genet. 8:99106, 1999
38 Takano, H., Koike, R., Onodera, O., Sasaki, R. andTsuji, S.: Mutational analysis and genotype-phenotype correlation of 29 unrelated Japanese patientswith X-linked adrenoleukodystrophy (ALD). Arch.
Neurol. 56:295-300, 1999
39 Ikeuchi, T., Shimohata, T., Nakano, R., Koide, R.,
Takano, H. and Tsuji, S.: A case of primary torsion
dystonia in Japan with the 3-bp (CAG) deletion in
the DYT1 gene with a unique clinical presentation.
Neurogenetics 2:189-190, 1999
40 Sato, A., Shimohata, T., Koide, R., Takano, H., Sato,
T., Oyake, M., Igarashi, S., Tanaka, K., Inuzuka, T.,
Nawa, H. and Tsuji, S.: Adenovirus-mediated expression of mutant DRPLA proteins with expanded
polyglutamine stretches in neuronally differentiated
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1999
41 Koide, R., Kobayashi, S., Shimohata, T., Ikeuchi, T.,
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and Tsuji, S.: A neurological disease caused by an

130

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Hum. Mol. Genet. 8:2047-2053, 1999
42 Schilling, G., Wood, J. D., Duan, K., Slunt, H. H.,
Gonzales, V., Yamada, M., Cooper, J. K., Margollis, R.
L., Jenkins, N. A., Copeland, N. G., Takahashi, H.,
Tsuji, S., Price, D. L., Borchelt, D. R. and Ross, C. A.:
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Neuron 24:275-286, 1999
43 Shibasaki, Y., Tanaka, H., Iwabuchi, K., Kawasaki, S.,
Kondo H., Uekawa, K., Ueda, M., Kamiya, T.,
Katayama, Y., Nakamura, A., Takashima, H.,
Nakagawa, M., Masuda, M., Utsumi, H., Nakamuro,T., Tada, K., Kurohara, K., Inoue, K., Koike, F., Sakai,T., Tsuji, S. and Kobayashi, H.: Linkage of autosomal
recessive hereditary spastic paraplegia with mental
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44 Maruyama, M., Ikeuchi, T., Saito, M., Ishikawa, A.,
Yuasa, T., Tanaka, H., Hayashi, S., Wakabayashi, K.,
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I, Nagatsu, T, Takiyama, Y, Nishizawa, M, Goto, J,
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and Tsuji, S.: Expanded polyglutamine stretches
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46 Zhao, C., Takita, J., Tanaka, Y., Setou, M.,
Nakagawa, T., Takeda, S., Yang, H.W., Terada, S.,
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KIF1Bβ. Cell 105:587-597, 2001
47 Nakamura, K., Jeong, S.E., Uchihara, T., Anno, M.,
Nagashima, K., Nagashima, T., Ikeda, S., Tsuji, S.
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T., Awaya, Y., Sakai, T., Takahashi,T., Nagatomo,
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29: 184-188, 2001
49 Takahashi T., Igarashi S., Kimura T., Hozumi I.,
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131

Department of
Neurosurgery
Outline and Research Objectives
The Department of Neurosurgery focuses its academic activities on patient care,research, and education. Services of the Neurosurgical Clinic are devoted to the care ofpatients who suffer from brain tumors, cerebrovascular disorders, head injuries, spinal diseases, malformations of the central nervous system, and functional disturbances of thebrain. The research objectives of the department are based on these neurosurgical diseases.
Clinical research has been performed by analyzing many neurosurgical cases. The attempts
to develop new neurosurgical techniques are ongoing. Since the first Gamma-knife unit inthis country was installed in 1991, many studies have been conducted which analyze theoutcome of patients treated by this modality. To solve problems encountered in a clinicalsetting, cell biology and molecular biology of ischemic brain injury and brain tumors havebeen pursued as the two major research subjects. The research on ischemic brain damage
has been carried out using rodent ischemia models. The objective of the research has been
to determine the molecular mechanism underlying delayed neuronal death in the hippocampus following ischemia, but it has recently shifted toward the research on neuronal regeneration in the hippocampus by activation of endogenous progenitor cells. The research on
brain tumors has mainly focused on the genetic analysis of tumor specimens obtained during neurosurgery. This research strategy has particularly employed the genetic analysis ofmalignant brain tumors.

Faculty and Students
Professor and Chair Takaaki Kirino, M.D., Ph.D. (1992~)
Associate Professor Akio Morita, M.D, Ph.D.
Lecturer
Nobutaka Kawahara, M.D., Ph.D.
Lecturer
Tomoki Todo, M.D., Ph.D.
Associates ...............................8
Graduate Students ..................7
Research Students...................3
Secretaries ...............................5
Research assistants .................2
Residents.................................6

Past Research and Major Accomplishments
The research performed by our department has
been divided into three categories: clinical research,basic research on ischemic brain damage, and basic
research on brain tumors.
Research of clinical materials has been encouraged
since it may be effective in improving current andfuture patient care. Most clinical publications by thisdepartment are case studies, such as the rupture of
intracranial aneurysms (16, 17, 22, 25, 34, 41), arteriovenous or venous malformations (11, 32, 46), brain
tumors (8, 15, 21), and other disorders (13). The
results of Gamma-knife radiosurgery (6, 10, 12, 14, 19,
20, 33, 43) and the theoretical or technical aspect ofneurosurgical treatment (18, 23, 38, 50) have also132

been published. Thirty-two case reports have been
published by this department in English (not listed in
the references).
Our department has been continuously undertaking basic research as well. Currently, our basic
research consists mainly of studies on ischemic brain
damage and brain tumors. In our neurosurgical laboratory, one of the features is in vivo experiment using
our microsurgical techniques on small animals.
Another advantage of our laboratory is the availabilityof various specimens that are obtained during neurosurgical operations. In addition, we are rapidly
expanding our research facility to take advantage ofstate-of-the-art techniques in cell and molecular biology. We collaborate with various laboratories of basic
science and departments of engineering in an attempt
to expand our future possibilities in clinical andresearch activities. Some of the major accomplishments in basic research in our department have beenpossible by mutual collaborations with such laboratories.
Research on ischemic brain damage
When the brain is subjected to transient ischemia,
the first detrimental event in the brain tissue is depletion of ATP and it is followed by anoxic depolarization of the neuronal membrane and a massive
increase in the extracellular glutamate level.
Glutamate is believed to be the major factor that

Figure 1: A small, but significantly higher number of mature neurons in the CA1 are seen at Day 28 (c, c’, h). When FGF-2 and EGF
are infused into the lateral ventricle of ischemic animals, CA1 pyramidal neurons degenerates extensively at Day 7 (d, d’), but the number of neurons later after ischemia markedly increases (e, e’, j). (Cited and modified from Nakatomi et al. Cell 110:429-441,2002 5)

injures the brain tissue during the early phase of cerebral ischemia. We attempted to examine the validityof this hypothesis by inducing focal cerebral ischemia
in mice deficient in the ε1 (NR2A) subunit of the
NMDA receptor (39) in collaboration with Dr.
Mishina of the Department of Molecular
Neurobiology of this Graduate School. This experiment revealed that the brain deficient in glutamate
neurotransmission is less vulnerable to ischemic
insult.
The precise mechanism underlying ischemic brain
injury that follows the initial extracellular glutamate
surge and influx of Ca2+ remained unclear. Since a very
brief ischemic insult can induce ischemic tolerance inthe hippocampus (37), we postulated that the underlying mechanism is related to events induced by neuronal stress response. We found that significant
changes in hsp70 and ubiquitin expression occur following brief transient ischemia (28, 49). The hsp70
message and protein levels increase in toleranceinduced brain tissue. Ubiquitin expression pattern isvery similar to that of hsp70. When CA1 neurons die
following ischemia, free ubiquitin is severely depleted,and at the same time, the level of conjugated ubiquitin increases. These findings led to the hypothesisthat a disturbance in proteasomal function is the initial event that leads to neuronal apoptosis. We confirmed that under culture conditions proteasomal
inhibitors induce cytochrome-c- and caspase-3-likeprotease-induced apoptosis (24). Then, we directly
measured the proteasomal activity in the hippocampal
CA1 region. This study demonstrated the selective
proteasomal dysfunction in the CA1 sector after transient cerebral ischemia (1). This finding indicates thatthe protein-degrading system plays a major role inischemic neuronal death following brief cerebral
ischemia.

The decrease in the free ubiquitin level following
brief cerebral ischemia may be attributed to protein
degradation by activation of intracellular proteases, bydirect protein denaturation, or by an increase in thelevel of nascent protein molecules as a result of disturbed protein synthesis. We have confirmed the disturbance of protein ubiquitination and, at the sametime, inhibition of proteasomal function in CA1 neurons following brief cerebral ischemia. The mechanism of this dysfunction, however, is yet to be clarified. We hypothesized that activation of calcineurin,
an intracellular protein phosphatase, is somehow
related to proteasomal dysfunction since calcineurin
inhibitor FK506 protects CA1 neurons following
ischemia (47) and overexpression of calcineurin kills
cultured glial cells and neurons (27). This hypothesis
has not been fully tested.
Following brief ischemia, most of CA1 pyramidalcells die during 3-4 days following ischemia. The area
becomes almost devoid of neurons and finally falls inclassic gliosis. However, a close observation of thisregion for several weeks revealed a small but significant increase in the number of neurons in the CA1
subfield. Dr. Nakatomi (a graduate student of ourdepartment at that time) and Dr. Nakafuku (associate
professor, Department of Neurobiology of thisGraduate School) examined the possibility that theincreased neurons are derived from endogenous neural progenitor cells (5). The result was positive. In
addition, intraventricular infusion of FGF-2 and EGF
resulted in a more than 40% increase in neuronal population in the CA1 region. The regenerated hippocampi by this procedure exhibited electrical activity
when examined using slice preparations. The animals
that had regenerated hippocampi performed better inthe Morris water-maze task than the controls. We presented evidence that endogenous neural progenitors133

can be induced in situ to replace the hippocampal
neurons lost by ischemia. We further showed thatregenerated neurons contribute to ameliorating
ischemia-induced deficits in spatial cognitive functions, thus expanding the possibility of a novel neuronal replacement therapy for stroke. The neuronalchanges in the CA1 sector are shown in Figure 1.
We have published other experimental results on
cerebral ischemia (2, 26, 29) and on the cell biology of
cerebral blood vessels (9, 31, 48).
Research on brain tumors
Basic research on brain tumors conduced by ourdepartment has been based on specimens obtained
during surgery and those donated by affiliated hospitals. A portion of these specimens were fixed in aldehyde fixatives (formalin) and embedded in paraffin.
These materials were used for cellular analyses by
MIB-1 staining and other immunostaining techniques.
The remaining specimens were stored frozen until use
for genetic analysis. We have examined many types ofbrain tumors such as meningiomas, oligodendrogliomas, and neurinomas in NF2 (neurofibromatosis type 2) patients.
Mutation of the NF2 genes was detected in 20-30%
of sporadic meningiomas, whereas loss of heterozygosity (LOH) at chromosome 22q was found at amuch higher frequency (35). To determine the correlation of merlin loss with NF2 genetic alteration, we
performed a molecular genetic analysis of 50 sporadic
meningiomas. Findings of this study strongly support
the notion that NF2 is the sole target of 22q LOH in
meningiomas and that the loss of merlin expression isalways caused by alteration of NF2 gene, according to
the classic “two hit” theory. Oligodendrogliomas frequently, but not always, show sensitivity tochemotherapy. Recent studies demonstrated thatallelic loss of chromosome 1p is highly associatedwith this chemosensitivity. To clarify the molecularmechanism of this correlation, we examined comprehensive gene expression profiles of oligodendrogliomas with and without 1pLOH along with normal brain tissue using oligonucleotide microarray(GeneChip) (4). This study showed that biological differences between genetic subsets of oligodendroglioma are indeed reflected on the gene expression
profile. We encountered a very rare case of malignant
transformation of vestibular schwannoma following
stereotactic radiosurgery. Genotyping of this tumor
showed a TP53 mutation in the recurrent tumor that
did not exist in the original tumor, suggesting thatradiosurgery induced the malignant transformation(6). We performed molecular genetic analysis on nonselected gliomas and found that molecular genetic
analysis of 1p/19q/10q/TP53 has significant diagnostic
value, especially in detecting oligodendroglial tumors.

134

In addition, 1pLOH and TP53 mutations in gliomas
may be markers of oligodendroglial and astrocytic
pathways, respectively (7). We reported a case ofendolymphatic sac tumor, a rare adenomatous tumorof the temporal bone, in a patient with von HippelLindau (VHL) disease. Sequencing and microsatellite
analysis of DNA samples indicated that VHL gene
inactivation contributed to the oncogenesis ofendolymphatic sac tumor (30).
We examined brain tumor specimens to analyze
MEN1 gene mutation (36), telomerase activity (40),
MIB-1 in central neurocytoma (42), and proliferationof chordoma (44). We also published experimental
data on cultured glioma cells (3, 45).

Current Research
We are continuously conducting clinical researches
to improve neurosurgical technologies and future
patient care in the neurological field. The department
places strong emphasis on publishing clinical reports
and particularly encourages young colleagues to do so.
The objective of current clinical research in neurosurgery is gradually shifting to the improvement ofless invasive neurosurgical procedures using microendoscope, navigation and robotic manipulators. This
is now under way in collaboration with several
departments in the Faculty of Engineering of our university. The department is involved in the nationwide epidemiological study of the incidentally-discovered unruptured cerebral aneurysms (Unruptured
Cerebral Aneurysm Study of Japan, or UCAS Japan),and functions as the central office of this study.
We have been involved in experiments on themolecular mechanism underlying delayed neuronal
death found in the hippocampal CA1 region following
ischemia. Although we believe that this is a goodmodel system for studying neuronal protection,
experimental results obtained by us and other groups
suggest that neuronal protection is extremely difficult
and we are so far unable to propose clinically applicable methods of treatment. On the other hand, itturned out to be possible to induce practically meaningful regeneration of neurons in the hippocampal
CA1 region by activating endogenous neural progenitor cells. Given these experimental results, we are
now attempting to focus our experimental resourceson experiments of regeneration of CA1 neurons.
We have been engaged in the genetic analysis ofbrain tumors. This strategy has been particularly
effective for this department since comprehensive
genetic analysis has been rapidly introduced and we
can collect sufficient amounts of specimens during
neurosurgical operations. This strategy is being continued but the focus on brain tumor experiments isnow shifting toward research on treatment of malig-nant brain tumors because Dr. Todo who has expertise in this field has just joined our department inJanuary, 2003. He plans to start a clinical trial withgenetically engineered retrovirus for the treatment ofmalignant brain tumors.

5. Research grant from SORST (Solution Oriented
Research for Science and Technology) by Japan
Science and Technology Corporation "Neuronal
regeneration in the hippocampus following delayed
neuronal death", 2002-, ¥75,000,000

Future Prospects

Selected Papers (1995-2002)

We will continue to carry out our three major
research projects: i.e., clinical research, research on
ischemic brain damage, and research on brain tumors.
However, the main focus of each project may change.
The future projects that we expect to conduct in thenext 4-5 years are:

1. Asai A, Tanahashi N, Qiu JH, Saito N, Chi S,
Kawahara N, Tanaka K, Kirino T. Selective proteasomal dysfunction in the hippocampal CA1 region after
transient forebrain ischemia. J Cereb Blood Flow
Metab 22, 705-710, 2002
2. Kawahara N, Kawai K, Toyoda T, Nakatomi H,
Furuya K, Kirino T. Cardiac arrest cerebral ischemia
model in mice failed to cause delayed neuronal deathin the hippocampus. Neurosci Lett 322, 91-94, 2002
3. Mochizuki T, Asai A, Saito N, Tanaka S, Katagiri H,
Asano T, Nakane M, Tamura A, Kuchino Y, Kitanaka
C, Kirino T. Akt protein kinase inhibits non-apoptotic programmed cell death induced by ceramide. J Biol
Chem 277, 2790-2797, 2002
4. Mukasa A, Ueki K, Matsumoto S, Tsutsumi S,
Nishikawa R, Fujimaki T, Asai A, Kirino T,
Aburatani H. Distinction in gene expression profilesof oligodendrogliomas with and without allelic lossof 1p. Oncogene 21, 3961-3968, 2002
5. Nakatomi H, Kuriu T, Okabe S, Yamamoto S, Hatano
O, Kawahara N, Tamura A, Kirino T, Nakafuku M.
Regeneration of hippocampal pyramidal neurons
after ischemic brain injury by recruitment of endogenous neural progenitors. Cell 110, 429, 2002
6. Shin M, Ueki K, Kurita H, Kirino T. Malignant transformation of a vestibular schwannoma after gamma
knife radiosurgery. Lancet 360, 309-310, 2002
7. Ueki K, Nishikawa R, Nakazato Y, Hirose T, Hirato J,
Funada N, Fujimaki T, Hojo S, Kubo O, Ide T, Usui
M, Ochiai C, Ito S, Takahashi H, Mukasa A, Asai A,
Kirino T. Correlation of histology and molecular
genetic analysis of 1p, 19q, 10q, TP53, EGFR, CDK4,
and CDKN2A in 91 astrocytic and oligodendroglial
tumors. Clin Cancer Res 8, 196-201, 2002
8. Asano S, Ueki K, Suzuki I, Kirino T. Clinical featuresand medical treatment of male prolactinomas. Acta
Neurochir (Wien) 143, 465-470, 2001
9. Hoya K, Asai A, Sasaki T, Kimura K, Kirino T.
Expression of smooth muscle proteins in cavernousand arteriovenous malformations. Acta Neuropathol(Berl) 102, 257-263, 2001
10. Kawai K, Suzuki I, Kurita H, Shin M, Arai N, Kirino
T. Failure of low-dose radiosurgery to control temporal lobe epilepsy. J Neurosurg 95, 883-887, 2001
11. Kurita H, Shin M, Ueki K, Kawamoto S, Kirino T.
Congestive brain oedema associated with a pial arteriovenous malformation with impaired venous
drainage. Acta Neurochir (Wien) 143, 339-342, 2001
12. Kurita H, Kawahara N, Asai A, Ueki K, Shin M,
Kirino T. Radiation-induced apoptosis of oligodendrocytes in the adult rat brain. Neurol Res 23, 869874, 2001

1. Clinical research
The aim will be the technical improvement of lessinvasive neurosurgical procedures using micro-endoscope, navigation, robotic manipulators as well asother devices. We will continue large-scale clinicalstudies such as UCAS Japan. Clinical studies on neurosurgical cases will be continuously encouraged.
2. Research on ischemic brain damage:The main objective will be regeneration of hippocampal neurons following brief cerebral ischemia.
We will focus on the feasibility of activation of endogenous neural progenitors under a clinical setting. The
research on the mechanism underlying ischemic brain
damage and ischemic tolerance will be continued.
3. Research on brain tumors:
We will continue genetic analysis of brain tumor
specimens. Along with this investigation, we will
start clinical research on the treatment of malignant
brain tumors.

Research Grants
1. Research grant from CREST (Core Research for
Evolutional Science and Technology) by Japan
Science and Technology Corporation"Molecular mechanism of delayed neuronal death",
1998-2002, ¥265,201,000
2. Research grant of 21st century medical development
and promotion by the Ministry of Health, Labor andWelfare "Follow-up study of unruptured cerebral
aneurysms diagnosed by brain check-up clinics",
1999-2001, ¥24,000,000
3. Research Grants in Natural Sciences by the
Mitsubishi Foundation "Study of ischemic neuronal
death and ischemic tolerance based on functional
genomic/proteomic analysis", 2001, ¥7,000,000
4. Grant-in-Aid for Scientific Research (A) "Mechanismof ischemic cerebral damage by systematic expression analysis of genome and proteome", 2001-,¥30,000,000

13513. Oya S, Tsutsumi K, Ueki K, Kirino T. Reinduction ofhyponatremia to treat central pontine myelinolysis.
Neurology 57, 1931-1932, 2001
14. Shin M, Kurita H, Sasaki T, Kawamoto S, Tago M,
Kawahara N, Morita A, Ueki K, Kirino T. Analysis oftreatment outcome after stereotactic radiosurgery forcavernous sinus meningiomas. J Neurosurg 95, 435439, 2001
15. Sora S, Ueki K, Saito N, Kawahara N, Shitara N,
Kirino T. Incidence of von Hippel-Lindau disease inhemangioblastoma patients: the University of Tokyo
Hospital experience from 1954-1998. Acta Neurochir(Wien) 143, 893-896, 2001
16. Tsutsumi K, Ueki K, Kirino T. Recurrent subarachnoid hemorrhage. J Neurosurg 94, 541-542, 2001
17. Tsutsumi K, Ueki K, Morita A, Usui M, Kirino T. Riskof aneurysm recurrence in patients with clipped cerebral aneurysms: results of long-term follow-up
angiography. Stroke 32, 1191-1194, 2001
18. Fujimaki T, Kirino T. Combined transhorizontalsupracerebellar approach for microvascular decompression of trigeminal neuralgia. Br J Neurosurg 14,
531-534, 2000
19. Kurita H, Ueki K, Shin M, Kawamoto S, Sasaki T,
Tago M, Kirino T. Headaches in patients with radiosurgically treated occipital arteriovenous malformations. J Neurosurg 93, 224-228, 2000
20. Kurita H, Kawamoto S, Sasaki T, Shin M, Tago M,
Terahara A, Ueki K, Kirino T. Results of radiosurgery
for brain stem arteriovenous malformations. J Neurol
Neurosurg Psychiatry 68, 563-570, 2000
21. Matsuno A, Katakami H, Nagashima T, Teramoto A,
Osamura RY, Kirino T. Growth hormone-releasing
hormone expression in pituitary somatotroph adenomas, studied by immunohistochemistry and in situ
hybridization using catalyzed signal amplification
system. Hum Pathol 31, 789-794, 2000
22. Nakatomi H, Segawa H, Kurata A, Shiokawa Y,
Nagata K, Kamiyama H, Ueki K, Kirino T.
Clinicopathological study of intracranial fusiform anddolichoectatic aneurysms : insight on the mechanismof growth. Stroke 31, 896-900, 2000
23. Nishihara T, Teraoka A, Morita A, Ueki K, Takai K,
Kirino T. A transparent sheath for endoscopic surgery and its application in surgical evacuation of
spontaneous intracerebral hematomas. Technicalnote. J Neurosurg 92, 1053-1055, 2000
24. Qiu JH, Asai A, Chi S, Saito N, Hamada H, Kirino T.
Proteasome inhibitors induce cytochrome c-caspase3-like protease-mediated apoptosis in cultured cortical neurons. J Neurosci 20, 259-265, 2000
25. Tsutsumi K, Ueki K, Morita A, Kirino T. Risk of rupture from incidental cerebral aneurysms. J Neurosurg
93, 550-553, 2000
26. Zhu L, Saito N, Abe O, Okubo T, Yamada H,
Kawahara N, Asai A, Kirino T. Changes in the apparent diffusion coefficient of water and T2 relaxation
time in gerbil hippocampus after mild ischemia.
Neuroreport 11, 3333-3336, 2000

136

27. Asai A, Qiu J, Narita Y, Chi S, Saito N, Shinoura N,
Hamada H, Kuchino Y, Kirino T. High level calcineurin activity predisposes neuronal cells to apoptosis. J Biol Chem 274, 34450-34458, 1999
28. Ide T, Takada K, Qiu JH, Saito N, Kawahara N, Asai
A, Kirino T. Ubiquitin stress response in postischemic hippocampal neurons under nontolerant andtolerant conditions. J Cereb Blood Flow Metab 19,
750-756, 1999
29. Kawahara N, Mishima K, Higashiyama S, Taniguchi
N, Tamura A, Kirino T. The gene for heparin-binding
epidermal growth factor-like growth factor is stressinducible: its role in cerebral ischemia. J Cereb Blood
Flow Metab 19, 307-320, 1999
30. Kawahara N, Kume H, Ueki K, Mishima K, Sasaki T,
Kirino T. VHL gene inactivation in an endolymphatic
sac tumor associated with von Hippel-Lindau disease. Neurology 53, 208-210, 1999
31. Kim P, Yoshimoto Y, Nakaguchi H, Mori T, Asai A,
Sasaki T, Kirino T, Nonomura Y. Increased sarcolemmal permeability in the cerebral artery during chronic spasm: an assessment using DNA-binding dyes
and detection of apoptosis. J Cereb Blood Flow
Metab 19, 889-897, 1999
32. Kurita H, Kirino T. A longitudinal study of patientswith venous malformations. Neurology 52, 11091110, 1999
33. Kurita H, Sasaki T, Tago M, Kaneko Y, Kirino T.
Successful radiosurgical treatment of arteriovenous
malformation accompanied by venous malformation.
AJNR Am J Neuroradiol 20, 482-485, 1999
34. Tsutsumi K, Ueki K, Usui M, Kwak S, Kirino T. Riskof subarachnoid hemorrhage after surgical treatmentof unruptured cerebral aneurysms. Stroke 30, 11811184, 1999
35. Ueki K, Wen Bin C, Narita Y, Asai A, Kirino T. Tight
association of loss of merlin expression with loss ofheterozygosity at chromosome 22q in sporadic
meningiomas. Cancer Res 59, 5995-5998, 1999
36. Wenbin C, Asai A, Teramoto A, Sanno N, Kirino T.
Mutations of the MEN1 tumor suppressor gene insporadic pituitary tumors. Cancer Lett 142, 43-47,
1999
37. Kawahara N, Ide T, Saito N, Kawai K, Kirino T.
Propentofylline potentiates induced ischemic tolerance in gerbil hippocampal neurons via adenosine
receptor. J Cereb Blood Flow Metab 18, 472-475,
1998
38. Kim P, Wakai S, Matsuo S, Moriyama T, Kirino T.
Bisegmental cervical interbody fusion using hydroxyapatite implants: surgical results and long-term
observation in 70 cases. J Neurosurg 88, 21-27, 1998
39. Morikawa E, Mori H, Kiyama Y, Mishina M, Asano
T, Kirino T. Attenuation of focal ischemic brain
injury in mice deficient in the epsilon1 (NR2A) subunit of NMDA receptor. J Neurosci 18, 9727-9732,
1998
40. Sano T, Asai A, Mishima K, Fujimaki T, Kirino T.
Telomerase activity in 144 brain tumours. Br J
Cancer 77, 1633-1637, 1998

41. Tsutsumi K, Ueki K, Usui M, Kwak S, Kirino T. Riskof recurrent subarachnoid hemorrhage after complete obliteration of cerebral aneurysms. Stroke 29,
2511-2513, 1998
42. Fujimaki T, Matsuno A, Sasaki T, Toyoda T,
Matsuura R, Ogai M, Kitanaka C, Asai A, Matsutani
M, Kirino T. Proliferative activity of central neurocytoma: measurement of tumor volume doubling time,
MIB-1 staining index and bromodeoxyuridine labeling index. J Neurooncol 32, 103-109, 1997
43. Kurita H, Sasaki T, Kawamoto S, Taniguchi M,
Terahara A, Tago M, Kirino T. Role of radiosurgery
in the management of cavernous sinus meningiomas.
Acta Neurol Scand 96, 297-304, 1997
44. Matsuno A, Sasaki T, Nagashima T, Matsuura R,
Tanaka H, Hirakawa M, Murakami M, Kirino T.
Immunohistochemical examination of proliferative
potentials and the expression of cell cycle-related
proteins of intracranial chordomas. Hum Pathol 28,714-719, 1997
45. Mishima K, Asai A, Kadomatsu K, Ino Y, Nomura K,
Narita Y, Muramatsu T, Kirino T. Increased expression of midkine during the progression of humanastrocytomas. Neurosci Lett 233, 29-32, 1997
46. Furuya K, Sasaki T, Suzuki I, Kim P, Saito N, Kirino
T. Intramedullary angiographically occult vascularmalformations of the spinal cord. Neurosurgery 39,1123-1130, 1996
47. Ide T, Morikawa E, Kirino T. An immunosuppressant, FK506, protects hippocampal neurons from
forebrain ischemia in the mongolian gerbil. Neurosci
Lett 204, 157-160, 1996
48. Kim P, Yoshimoto Y, Iino M, Tomio S, Kirino T,
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