LECTURE
Dynamics of calcium and its roles in the dendriteof the cerebellar Purkinje cell
Takafumi Inoue
Division of Molecular Neurobiology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan(Received for publication on April 24, 2003)

Abstract. The calcium ion (Ca 2B ) serves as an important cellular messenger with spatio-temporally
highly dynamic patterns. Not only Ca 2B entering from the plasma membrane but also Ca 2B released
from intracellular store sites play crucial roles in neurons as well as in other cell types. The cerebellar
Purkinje cell shows a variety of spatio-temporal Ca 2B dynamics in its rich arborization, and the Ca 2B
release mechanism mediated by IP3 receptors and ryanodine receptors has been shown to be crucial
for the induction of long-term depression, a form of synaptic plasticity, in this neuron. Purkinje cells ina model mouse line of human neurodegenerative disease, spinocerebellar ataxia type 1, showed abnormal Ca 2B release properties, which indicated tight regulation of Ca 2B dynamics in the wild type
Purkinje cell. Quantitative analysis of the complex Ca 2B dynamics in the Purkinje cell dendrite is stillin progress to elucidate the link between external stimuli and the resultant biochemical changes. (Keio J
Med 52 (4): 244–249, December 2003)
Key words: calcium, cerebellar Purkinje cell, dendrite, IP3 receptor, Ca release

Introduction
In contrast to their simple structure and ubiquity,
calcium ions (Ca 2þ ) are postulated to be potent intracellular signaling messenger molecules. Ca 2þ concentration ([Ca 2þ ]) in the cytosol ([Ca 2þ ]i ) is strictly maintained at about 50–100 nM in the resting state. This
low range of [Ca 2þ ]i is remarkable when compared tothe [Ca 2þ ] in the extra-cellular space (1–2 mM). The
plasma membrane forms a tight barrier against thischemical gradient. When channel proteins on theplasma membrane are opened by several signalingmechanisms on stimuli, Ca 2þ rushes into the cell fromthe outer space and [Ca 2þ ]i rises rapidly. Ca 2þ is also
stored intracellularly in certain kinds of organelles,
namely the endoplasmic reticulum (ER) and mitochondria. Ca 2þ stored in the ER is released upon stimulation
through the ER membrance Ca 2þ channels, namely
inositol 1,4,5-trisphosphate receptor (IP3 R) and theryanodine receptor. IP3 R opens when a second messenger molecule IP3 binds to it, which is generated
through the phospholipase C-activation pathway.1 Boththe IP3 R and ryanodine receptors are sensitive to cyto-

solic Ca 2þ concentration,2 which property adds a feature of ‘‘Ca 2þ -induced Ca 2þ release’’ to the functions ofthese receptors.3 The ability of Ca 2þ to stimulate theryanodine receptor is modulated by cyclic ADP ribose
in neurons4–6 as well as in other tissues.7 Since prolonged high [Ca 2þ ]i states lead to cytotoxic events,8 extrusion mechanisms for Ca 2þ immediately start to pumpout the excess Ca 2þ when cytosolic [Ca 2þ ] is raised bythese Ca 2þ channels on the plasma and ER membranes.
The extrusion mechanism for Ca 2þ includes Ca 2þ binding proteins in the cytosol and Ca 2þ pumps (e.g.,
Ca-ATPase and Naþ /Ca 2þ exchanger) on the plasma
membrane, ER and mitochondria. [Ca 2þ ]i is thus strictly
controlled, and [Ca 2þ ]i is actively increased to change
the cell’s state and its subsequent fate through affecting
the activities of Ca 2þ -dependent proteins. High [Ca 2þ ]iactivates numerous Ca 2þ -dependent enzymes, e.g., calcineurin, calmodulin-dependent protein kinases, protein kinase C, and many other important proteins. For
instance, calmodulin is activated by binding with up
to four Ca 2þ molecules and controls the activity ofnumerous channels and enzymes. Increase in [Ca 2þ ]iﬁnally leads to fertilization, proliferation, exocytosis,

Presented at the 1287th Meeting of the Keio Medical Society in Tokyo, November 1, 2002.
Reprint requests to: Dr. Takafumi Inoue, Division of Molecular Neurobiology, The Institute of Medical Science, The University of Tokyo, 4-6-1
Shirokanedai, Minato-ku, Tokyo 108-8639, Japan, e-mail: tinoue@ims.u-tokyo.ac.jp244Keio J Med 2003; 52 (4): 244–249

muscle contraction, cell death, and numerous otherconsequences.3 Thus Ca 2þ regulation is very important from the clinical point of view. Mutations in Ca 2þ
channels on the plasma membrane cause a variety ofsymptoms, e.g., migraine, ataxia and epilepsy, which
form a part of channelopathy.9 [Ca 2þ ]i needs to be
increased for cellular functions, but it has to be broughtback right away. Therefore a change of [Ca 2þ ]i is usually observed as a single transient or as multiple transients, the latter of which is sometimes referred to as
Ca 2þ oscillation or Ca 2þ wave according to the pattern.
Ca 2þ oscillation in an egg at fertilization is a very wellknown phenomenon that is crucial in commencing theinitial steps of ontogeny.10 The temporal pattern ofCa 2þ oscillation has been shown to be important for the
speciﬁcity of downstream targets for Ca 2þ increase.11
In this lecture, I will focus on the signiﬁcance anddynamics of [Ca 2þ ] in the cerebellar Purkinje cell. The
Purkinje cell in the cerebellar cortex is a neuron witha large dendritic arborization, which is very interesting in terms of Ca 2þ dynamics. Various types of Ca 2þ
dynamics are known in the Purkinje cell dendrite. The
Ca 2þ spike is a regenerative Ca 2þ inﬂux that repeats
periodically over the entire dendritic structure.12 Widespread Ca 2þ inﬂux is observed on activation of one of thetwo excitatory synaptic connections, the climbing ﬁber
input.13,14 Activation of the other excitatory synapse,
the parallel ﬁber-Purkinje cell synapse, results in Ca 2þ
increase in a relatively restricted area in the dendrite
mediated by Ca 2þ inﬂux and Ca 2þ release.14–16 Froma molecular biological point of view, many proteins
involved in Ca 2þ handling are abundantly expressed in
the Purkinje cell. Calbindin D28k and parvalbumin are
Ca 2þ -binding proteins, rich in the Purkinje cell, thatserve as Ca 2þ buffers. Calsequestrin, a well-known lowafﬁnity/high-capacity intraluminal ER protein, is notfound in neurons other than the Purkinje cell.17 Subtypes of ryanodine receptor are expressed.18 In particular, the IP3 receptor type 1 (IP3 R1) is predominantly
expressed in the Purkinje cell.19
IP3 receptor type 1 is required for Purkinje cell function
The molecular function and the expression pattern of
IP3 receptors had already been well-researched by themid 1990’s.1 It had been shown that IP3 receptors in the
Purkinje cell certainly release Ca 2þ from intracellular
Ca 2þ store sites in the neuron as well as in other cells byagonist stimulation20 or by means of caged-IP3 which
releases active IP3 molecules by UV-photolysis.21 The
molecular basis for the Ca 2þ release by IP3 R throughsynaptic stimulation had been well established by thisperiod. The excitatory synaptic transmitter, glutamate,activates a metabotropic type of glutamate receptor(mGluR),22 which activates phospholipase C through245

trimeric G proteins, then IP3 is produced. However, thephysiological signiﬁcance of the IP3 receptor in theneuron was unclear. Ca 2þ increase in the Purkinje cell
dendrite was known to play an important role in the
induction of a form of synaptic plasticity, long-term
depression (LTD) at the parallel ﬁber-Purkinje cell
synapse.23,24 However, the amount of Ca 2þ entering
through Ca 2þ channels on the plasma membrane wasthought to sufﬁce for the formation of LTD, since Ca 2þ
inﬂux by synaptic activation was very large13 and there
had been no evidence showing that Ca 2þ release actually occurred by synaptic activation. On the assumptionthat IP3 R should have some physiological roles in the
Purkinje cell because of its Ca 2þ releasing function andits abundant amount of expression, our group generated an IP3 R1-deﬁcient mouse line by gene-targeting
to understand its physiological functions.25 Homozygous IP3 R1 deﬁcient (IP3 R1-/-) mice had severe
ataxia and tonic or tonic-clonic seizures and died by the
weaning period. These neurological symptoms indicatethat IP3 R1 is indeed an important molecule in the central nervous system. There was no obvious histologicalimpairment in the IP3 R1-/- brain. Purkinje cells in cerebellar slice preparations from IP3 R1-/- mice showednormal electrophysiological properties, e.g., Naþ spikeand Ca 2þ spike ﬁring, paired pulse facilitation of parallel ﬁber-Purkinje cell synapses, or paired pulse depression of the climbing ﬁber-Purkinje cell synapse.25
Combined electrophysiological and imaging experiments showed that not Ca 2þ inﬂux by evoked depolarization but Ca 2þ release evoked by ﬂush photolysis of
caged-IP3 was lost in the IP3 R1-/- Purkinje cell.26 All ofthese results indicate that the Purkinje cells in IP3 R1-/mice develop without signiﬁcant alteration in structure,
excitability or synaptic connections except for the IP3 induced Ca 2þ release activity. LTD experiments were
performed using these IP3 R1-/- Purkinje cells and it was
revealed that LTD was totally lost in these IP3 R1-/Purkinje cells.26 To further conﬁrm this result, another approach was taken. The monoclonal antibody
18A10 raised against IP3 R1 was shown to be a functionblocking antibody in vitro27 and in vivo.28 18A10 was
introduced into wild-type Purkinje cells in a slice
through a recording patch pipette, and an LTD experiment was performed. LTD was blocked by 18A10.26
Altogether, IP3 R1 was shown to be essential in theformation of LTD at the parallel ﬁber-Purkinje cell
synapse. This ﬁnding was the earliest study giving solid
evidence for a physiological role of IP3 R in the central
nervous system.
Ryanodine receptor is also important in LTD
Ryanodine receptors are another class of Ca 2þ release channel on the ER. Since ryanodine receptors are246

also expressed in the Purkinje cell dendrite,29 and theyfunction as a Ca 2þ -induced Ca 2þ release channel in the
Purkinje cell,30 they were also thought to be one of
the candidates responsible for the Ca 2þ signaling in the
LTD induction. To clarify this question, we performed
LTD experiments in Purkinje cells in primary culture
preparation with various blockers against ryanodine
receptors. A high concentration of ryanodine, whichkeeps the ryanodine receptor/channel open and blocks
the receptor activity, and ruthenium red, which inhibits
the ryanodine receptor, blocked the LTD induction,31
showing the possibility that ryanodine receptors arealso involved in LTD induction. Though it is still
unclear whether ryanodine receptors play a role in
LTD induction in slice preparation, ryanodine receptors could work in concert with IP3 Rs by enhancing
Ca 2þ released by IP3 Rs or enhancing Ca 2þ that entered
the cytoplasm through Ca 2þ channels on the plasma
membrane. Together with the importance of IP3 R in
LTD induction, Ca 2þ release mechanisms have beenshown to play an important role in neuronal function.
This view posed a question: What is the difference between the Ca 2þ dynamics generated solely by Ca 2þ inﬂux and those by the combination of Ca 2þ inﬂux andCa 2þ release? Ca 2þ inﬂux could have compensated for
Ca 2þ release with stronger stimulation, but it seemed not
to be the case. The answer was thought to come fromunderstanding the precise nature of the Ca 2þ dynamics
in various situations in the Purkinje cell dendrite.
Aberrant Ca 2þ release in Purkinje cells of the SCA1
model mouse
A mutant mouse line provided an example showingtight regulation of the patterns in Ca 2þ dynamics in
the Purkinje cell dendrite. Spinocerebellar ataxia type
1 (SCA1) is an autosomal dominant neurological disorder in humans characterized by ataxia and brain stem
dysfunction. Like several other neurodegenerative diseases, SCA1 is caused by the expansion of a CAG
trinucleotide repeat resulting in an expanded polyglutamine tract in its gene product, ataxin-1.32 In SCA1, theconsistent neuropathological ﬁnding is loss of Purkinje cells in the cerebellar cortex and loss of neurons
in the pontine nuclei.33 Lines of transgenic mice that
expressed the mutant form of the SCA1 gene developed
ataxia and Purkinje cell pathology. Importantly, theeventual development of ataxia is attributable not tocell death per se but to cellular dysfunction and morphological alterations that occur long before neuronal
death.34 It was found that several key neuronal genes
are speciﬁcally altered in the Purkinje cells of themutant cerebellum prior to any clinicopathologic manifestations.35 Some of these genes are important for
regulating intracellular Ca 2þ dynamics. Among them,Inoue T: Dynamics and role of Ca in Purkinje cell dendrite

IP3 R1 and sarco/endoplasmic reticulum Ca 2þ ATPase(SERCA2) are greatly reduced.35 Therefore, it was ofinterest to study the electrophysiological and synaptic
properties of SCA1 Purkinje cells, particularly thosethat affect stimulus-evoked [Ca 2þ ]i changes. Purkinjecells in SCA1 mice had Naþ spikes and Ca 2þ spikes,
electrical responses of the parallel and climbing ﬁbers,that were qualitatively similar to those recorded fromwild type mice.14 The membrane resistance of SCA1
Purkinje cells was 3.3 times higher than that of wild
type cells which correlated with the 1.7 times smaller
cell body size. mGluR-mediated parallel ﬁber-evoked
Ca 2þ release from intracellular stores was observed in
SCA1 Purkinje cells as well as in wild type Purkinjecells, and it was slightly easier to evoke the mGluRmediated [Ca 2þ ]i release in SCA1 Purkinje cells. In response to climbing ﬁber stimulation, most Purkinje cells
in mutant and wild type mice had rapid widespread[Ca 2þ ]i changes, recovering in less than 200 ms. Some
SCA1 Purkinje cells showed a slow, localized, secondary Ca 2þ transient following the initial climbing ﬁber
Ca 2þ transient, which may reﬂect release of Ca 2þ fromintracellular stores. Recently climbing ﬁber stimulation
was shown to activate IP3 production36 and to evoke
Ca 2þ release37 in the Purkinje cell dendrites. The latterstudy was performed by enhancing the mGluR activity
with a glutamate uptake inhibitor. The Ca 2þ releaseobserved in the SCA1 Purkinje cell is an exceptionalcase in that climbing ﬁber stimulation evoked apparent Ca 2þ release without pharmacological enhancement. In conclusion, the basic physiological propertiesof the mutant Purkinje cells other than Ca 2þ release
were similar to those of wild type neurons, even withthe dramatic alteration in their morphology. It was
furthermore surprising that Ca 2þ release activity was
more hyperactive than depressed in spite of the downregulation of Ca 2þ handling molecules. This study conversely suggests that the Ca 2þ release mechanism istightly regulated in wild type Purkinje cells.
Ca 2þ inﬂux in the Purkinje cell dendrite
Ca 2þ inﬂux from the extra-cellular space and Ca 2þ
release from the intra-cellular Ca 2þ store form a variety of Ca 2þ dynamics in the Purkinje cell dendrite. Thisvariation of Ca 2þ dynamics may result in different consequences in the dendrite, e.g., LTD or LTP in synaptic
efﬁcacy38 and protein synthesis.39 Furthermore, theCa 2þ increase events in the dendrite may be transmitted to the nucleus thereby affecting gene transcription
patterns. A potent candidate for such informationtransmission mechanism from synapse to nucleus is thecalmodulin (CaM)- Ca 2þ /CaM-dependent protein kinase IV (CaMK IV)- cAMP-response element-binding
protein (CREB; a transcription factor) pathway.40 It

Keio J Med 2003; 52 (4): 244–249

247

Fig. 1 Ca 2þ dynamics in the Purkinje cell dendrite. A. Molecular mechanisms underlying Ca 2þ dynamics in the parallel ﬁber-Purkinje cell
synapse are shown. Excitatory synaptic transmitter, glutamate (glu; ﬁlled triangle), released from the parallel ﬁber terminal activates the
AMPA-type glutamate receptor (AMPAR) and metabotropic glutamate receptor type 1 (mGluR1). AMPAR depolarizes the membrane potential by passing Naþ . The depolarization then opens the P/Q type voltage-gated Ca 2þ channel (P/Q). Activated mGluR1 produces IP3 anddiacylglycerol (DAG) through the trimeric G protein (G) and phospholipase C pathway. IP3 then opens IP3 R on the ER and Ca 2þ is released
from the ER. The ryanodine receptor (RyR) is another Ca 2þ release channel on the ER which is activated by high [Ca 2þ ]. B. Time course of[Ca 2þ ]i in a small area of the Purkinje cell dendrite evoked by parallel ﬁber stimulation. Upper panel: when the parallel ﬁber is modestly
stimulated (50 Hz  5 times), Ca 2þ transient shows a biphasic pattern. The ﬁrst phase derives from Ca 2þ inﬂux and the second phase from Ca 2þ
release, since the ﬁrst phase was blocked by CNQX, an AMPAR antagonist (broken line) and the second phase was blocked by MCPG, anantagonist against mGluR1 (dotted line).15 Lower panel: when the parallel ﬁber is intensively stimulated (50 Hz  50 times), the Ca 2þ transient
becomes very large in intensity and monotonous. Ca 2þ inﬂux mostly contributes to this large Ca 2þ increase, because CNQX diminished theCa 2þ transient but MCPG affected it little.47 The ordinate of the plots ([Ca 2þ ]i ) are scaled. Stimulation patterns are indicated at bottoms of theplots (stim).

has been shown that the activation of CREB depends
on the stimulation pattern and types of Ca 2þ inﬂux
pathway.40–42 Thus it is important to describe the pattern of Ca 2þ dynamics in the dendrite before discussing the relationship between Ca 2þ changes and biological consequences. So far, numerous studies have been
performed on the Ca 2þ dynamics in this particular
neuron. The dynamic change of Ca 2þ in the Purkinje
cell dendrite was measured optically by means of Ca 2þ sensitive dyes in the late 1980’s by the pioneering
attempts of Ross’s43 and Llinas’s groups.44 Since then,with reﬁnement of the technique, various aspects of
Ca 2þ dynamics in Purkinje cell dendrite have been
described. A Ca 2þ spike was found to be a synchronized Ca 2þ transient over the entire dendrite of the Purkinje cell.12 Climbing ﬁber input induces widespreadCa 2þ transients similar to a Ca 2þ spike while parallelﬁber input results in a local Ca 2þ increase.13 In the late1990’s, spatial resolution of the imaging technique was
improved by means of the confocal microscope to resolve single spines on dendrites where parallel ﬁbers
from synapses. Ca 2þ increase was observed in thespine.45 Ca 2þ release was measured by parallel ﬁber
stimulation in ﬁne dendrites (Fig. 1).15,16 However, thecurrent knowledge about Ca 2þ dynamics in this particular neuron is insufﬁcient in the quantitative point due
to technical difﬁculties in estimating absolute [Ca 2þ ] insmall structures such as neuronal dendrites,46 which isessential to discuss the link between Ca 2þ dynamics andthe resultant biochemical consequences. To approach
this issue, we started with a quantitative analysis of
Ca 2þ dynamics in the Purkinje cell dendrite.
Whole-cell patch clamp and imaging with ﬂuorescent
Ca 2þ and Naþ indicators were performed in mouse248

Inoue T: Dynamics and role of Ca in Purkinje cell dendrite

Purkinje cells in slice preparation.47 Membrane potentials, [Ca 2þ ] and [Naþ ] were observed simultaneously.
High frequency parallel ﬁber stimulation (50 Hz 3–50
times) depolarized Purkinje cells and caused a large increase in [Ca 2þ ] at anatomically expected sites in dendrites for seconds that turned out to reach @200 mM of
Ca 2þ . This amplitude of [Ca 2þ ]i was much higher thanever reported in the neuron by synaptic activation. The[Ca 2þ ] increase was conﬁned to a small area in thedendrite and sustained for a longer period of time as
more stimuli were applied. However increase in [Naþ ]was sustained for tens of seconds and diffused awayfrom the activated site. Ca 2þ release was observed as aseparate delayed peak to the preceding peak formed by
Ca 2þ inﬂux at fewer parallel ﬁber stimuli (3–5 times),
and the delayed peak was hidden by the initial Ca 2þ
inﬂux at larger numbers of parallel ﬁber stimuli (Fig. 1).
It was shown by pharmacological experiments that not
Ca 2þ release but rather Ca 2þ inﬂux contributes to mostof the large Ca 2þ increase brought about by 50 shocksof parallel ﬁbers. Although it had already been reported
that the AMPA-type glutamate receptor (AMPA receptor)48 and the P/Q-type Ca 2þ channel are major
players at the postsynaptic side of the parallel ﬁberPurkinje cell synapse, pharmacological interventions
with this simultaneous Naþ and Ca 2þ imaging study
clearly demonstrated that the AMPA receptor and the
P/Q-type Ca 2þ channel exclusively pass Naþ and Ca 2þ
respectively, at the very distal end of the dendritic tree.
Ca 2þ concentration had a linear relationship with thenumber of parallel ﬁber stimuli. Thus, at a smaller
number of parallel ﬁber stimuli, Ca 2þ dynamics werecomprised a complex of Ca 2þ inﬂux and Ca 2þ release,and at intensive stimuli, Ca 2þ dynamics became simple
and followed the number of parallel ﬁber stimuli. Thus
different patterns of parallel ﬁber input produce different patterns of Ca 2þ dynamics, which difference
could lead to different biochemical consequences. Observing changes in localizations and activities in Ca 2þ dependent proteins with such a variety of Ca 2þ dynamics will link the variety of stimuli and the variety of cell
responses and fates.
Conclusion
Ca 2þ plays an important role as a messenger withvery dynamic spatial-temporal patterns in the neuron as
well as other cells. The fact that Ca 2þ release is a requisite for the induction of LTD in cerebellar Purkinje
cell provides an example of the complex nature of Ca 2þ
signaling. Different types and combinations of stimuli
yield a variety of Ca 2þ signaling patterns, which in turnlead to differential biochemical effects. To clarify thisﬂow of information process, a precise description of the
Ca 2þ dynamics is indispensable.

References
1. Berridge MJ: Inositol trisphosphate and calcium signalling. Nature 1993; 361: 315–325
2. Bezprozvanny I, Watras J, Ehrlich BE: Bell-shaped calciumresponse curves of Ins(1,4,5)P3 - and calcium-gated channels
from endoplasmic reticulum of cerebellum. Nature 1991; 351:
751–754
3. Berridge MJ, Lipp P, Bootman MD: The versatility and universality of calcium signalling. Nat Rev Mol Cell Biol 2000; 1: 11–21
4. Hua SY, Tokimasa T, Takasawa S, Furuya Y, Nohmi M, Okamoto H, Kuba K: Cyclic ADP-ribose modulates Ca 2þ releasechannels for activation by physiological Ca 2þ entry in bullfrog
sympathetic neurons. Neuron 1994; 12: 1073–1079
5. Mothet JP, Fossier P, Meunier FM, Stinnakre J, Tauc L, Baux G:
Cyclic ADP-ribose and calcium-induced calcium release regulate
neurotransmitter release at a cholinergic synapse of Aplysia. J
Physiol 1998; 507: 405–414
6. Morikawa H, Khodakhah K, Williams JT: Two intracellular pathways mediate metabotropic glutamate receptor-induced Ca 2þ
mobilization in dopamine neurons. J Neurosci 2003; 23: 149–157
7. Lee HC: Physiological functions of cyclic ADP-ribose and
NAADP as calcium messengers. Annu Rev Pharmacol Toxicol
2001; 41: 317–345
8. Nicotera P, Orrenius S: The role of calcium in apoptosis. Cell
Calcium 1998; 23: 173–180
9. Pietrobon D: Calcium channels and channelopathies of the central nervous system. Mol Neurobiol 2002; 25: 31–50
10. Miyazaki S, Shirakawa H, Nakada K, Honda Y: Essential role ofthe inositol 1,4,5-trisphosphate receptor/Ca 2þ release channel in
Ca 2þ waves and Ca 2þ oscillations at fertilization of mammalianeggs. Dev Biol 1993; 158: 62–78
11. Dolmetsch RE, Xu K, Lewis RS: Calcium oscillations increase
the efﬁciency and speciﬁcity of gene expression. Nature 1998;
392: 933–936
12. Lev-Ram V, Miyakawa H, Lasser-Ross N, Ross WN: Calcium
transients in cerebellar Purkinje neurons evoked by intracellular
stimulation. J Neurophysiol 1992; 68: 1167–1177
13. Miyakawa H, Lev-Ram V, Lasser-Ross N, Ross WN: Calcium
transients evoked by climbing ﬁber and parallel ﬁber synaptic
inputs in guinea pig cerebellar Purkinje neurons. J Neurophysiol
1992; 68: 1178–1189
14. Inoue T, Lin X, Kohlmeier KA, Orr HT, Zoghbi HY, Ross WN:
Calcium dynamics and electrophysiological properties of cerebellar Purkinje cells in SCA1 transgenic mice. J Neurophysiol
2001; 85: 1750–1760
15. Takechi H, Eilers J, Konnerth A: A new class of synaptic
response involving calcium release in dendritic spines. Nature
1998; 396: 757–760
16. Finch EA, Augustine GJ: Local calcium signalling by inositol1,4,5-trisphosphate in Purkinje cell dendrites. Nature 1998; 396:
753–756
17. Takei K, Stukenbrok H, Metcalf A, Mignery GA, Sudhof TC,
Volpe P, De Camilli P: Ca 2þ stores in Purkinje neurons: endoplasmic reticulum subcompartments demonstrated by the heterogeneous distribution of the InsP3 receptor, Ca2þ -ATPase, andcalsequestrin. J Neurosci 1992; 12: 489–505
18. Furuichi T, Kohda K, Miyawaki A, Mikoshiba K: Intracellularchannels. Curr Opin Neurobiol 1994; 4: 294–303
19. Nakanishi S, Maeda N, Mikoshiba K: Immunohistochemical
localization of an inositol 1,4,5-trisphosphate receptor, P400 , inneural tissue: studies in developing and adult mouse brain. J
Neurosci 1991; 11: 2075–2086
20. Yuzaki M, Mikoshiba K: Pharmacological and immunocytochemical characterization of metabotropic glutamate receptors
in cultured Purkinje cells. J Neurosci 1992; 12: 4253–4263

Keio J Med 2003; 52 (4): 244–249
21. Khodakhah K, Ogden D: Functional heterogeneity of calcium
release by inositol trisphosphate in single Purkinje neurones,
cultured cerebellar astrocytes, and peripheral tissues. Proc Natl
Acad Sci USA 1993; 90: 4976–4980
22. Anwyl R: Metabotropic glutamate receptors: electrophysiological properties and role in plasticity. Brain Res Brain Res Rev
1999; 29: 83–120
23. Sakurai M: Calcium is an intracellular mediator of the climbing
ﬁber in induction of cerebellar long-term depression. Proc Natl
Acad Sci USA 1990; 87: 3383–3385
24. Ito M: Cerebellar long-term depression: characterization, signaltransduction, and functional roles. Physiol Rev 2001; 81: 1143–
1195
25. Matsumoto M, Nakagawa T, Inoue T, Nagata E, Tanaka K,
Takano H, Minowa O, Kuno J, Sakakibara S, Yamada M, et al:
Ataxia and epileptic seizures in mice lacking type 1 inositol 1,4,5trisphosphate receptor. Nature 1996; 379: 168–171
26. Inoue T, Kato K, Kohda K, Mikoshiba K: Type 1 inositol 1,4,5trisphosphate receptor is required for induction of long-term
depression in cerebellar Purkinje neurons. J Neurosci 1998; 18:
5366–5373
27. Nakade S, Maeda N, Mikoshiba K: Involvement of the Cterminus of the inositol 1,4,5-trisphosphate receptor in Ca 2þ release analysed using region-speciﬁc monoclonal antibodies. Biochem J 1991; 277: 125–131
28. Miyazaki S, Yuzaki M, Nakada K, Shirakawa H, Nakanishi S,
Nakade S, Mikoshiba K: Block of Ca 2þ wave and Ca 2þ oscillation by antibody to the inositol 1,4,5-trisphosphate receptor in
fertilized hamster eggs. Science 1992; 257: 251–255
29. Kuwajima G, Futatsugi A, Niinobe M, Nakanishi S, Mikoshiba
K: Two types of ryanodine receptors in mouse brain: skeletal
muscle type exclusively in Purkinje cells and cardiac muscle typein various neurons. Neuron 1992; 9: 1133–1142
30. Llano I, DiPolo R, Marty A: Calcium-induced calcium release in
cerebellar Purkinje cells. Neuron 1994; 12: 663–673
31. Kohda K, Inoue T, Mikoshiba K: Ca 2þ release from Ca 2þ stores,
particularly from ryanodine-sensitive Ca 2þ stores, is required forthe induction of LTD in cultured cerebellar Purkinje cells. J
Neurophysiol 1995; 74: 2184–2188
32. Orr HT, Chung MY, Banﬁ S, Kwiatkowski TJ Jr, Servadio A,
Beaudet AL, McCall AE, Duvick LA, Ranum LP, Zoghbi HY:
Expansion of an unstable trinucleotide CAG repeat in spinocerebellar ataxia type 1. Nat Genet 1993; 4: 221–226
33. Gilman S, Sima AA, Junck L, Kluin KJ, Koeppe RA, Lohman
ME, Little R: Spinocerebellar ataxia type 1 with multiple systemdegeneration and glial cytoplasmic inclusions. Ann Neurol 1996;
39: 241–255
34. Clark HB, Burright EN, Yunis WS, Larson S, Wilcox C, Hart-

249

35.

36.

37.

38.

39.
40.

41.

42.

43.

44.

45.

46.

47.

48.

man B, Matilla A, Zoghbi HY, Orr HT: Purkinje cell expressionof a mutant allele of SCA1 in transgenic mice leads to disparate
effects on motor behaviors, followed by a progressive cerebellar
dysfunction and histological alterations. J Neurosci 1997; 17:7385–7395
Lin X, Antalffy B, Kang D, Orr HT, Zoghbi HY: Polyglutamine
expansion down-regulates speciﬁc neuronal genes before pathologic changes in SCA1. Nat Neurosci 2000; 3: 157–163
Okubo Y, Kakizawa S, Hirose K, Iino M: Visualization of IP3
dynamics reveals a novel AMPA receptor-triggered IP3 production pathway mediated by voltage-dependent Ca 2þ inﬂux inPurkinje cells. Neuron 2001; 32: 113–122
Dzubay JA, Otis TS: Climbing ﬁber activation of metabotropic
glutamate receptors on cerebellar purkinje neurons. Neuron
2002; 36: 1159–1167
Lisman J: A mechanism for the Hebb and the anti-Hebb processes underlying learning and memory. Proc Natl Acad Sci
USA 1989; 86: 9574–9578
Richter JD, Lorenz LJ: Selective translation of mRNAs at synapses. Curr Opin Neurobiol 2002; 12: 300–304
Deisseroth K, Heist EK, Tsien RW: Translocation of calmodulin
to the nucleus supports CREB phosphorylation in hippocampal
neurons. Nature 1998; 392: 198–202
Deisseroth K, Bito H, Tsien RW: Signaling from synapse tonucleus: postsynaptic CREB phosphorylation during multiple
forms of hippocampal synaptic plasticity. Neuron 1996; 16: 89–
101
Dolmetsch RE, Pajvani U, Fife K, Spotts JM, Greenberg
ME: Signaling to the nucleus by an L-type calcium channelcalmodulin complex through the MAP kinase pathway. Science
2001; 294: 333–339
Ross WN, Werman R: Mapping calcium transients in the dendrites of Purkinje cells from the guinea-pig cerebellum in vitro. J
Physiol 1987; 389: 319–336
Tank DW, Sugimori M, Connor JA, Llinas RR: Spatiallyresolved calcium dynamics of mammalian Purkinje cells in
cerebellar slice. Science 1988; 242: 773–777
Eilers J, Augustine GJ, Konnerth A: Subthreshold synaptic Ca 2þ
signalling in ﬁne dendrites and spines of cerebellar Purkinje
neurons. Nature 1995; 373: 155–158
Maravall M, Mainen ZF, Sabatini BL, Svoboda K: Estimating
intracellular calcium concentrations and buffering without wavelength ratioing. Biophys J 2000; 78: 2655–2667
Kuruma A, Inoue T, Mikoshiba K: Calcium dynamics evoked byparallel ﬁber stimulation in cerebellar Purkinje cell dendrites.
Jpn J Physiol 2002; 52(suppl): S125
Nakanishi S: Molecular diversity of glutamate receptors andimplications for brain function. Science 1992; 258: 597–603