bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulatory actions of gamma aminobutyric acid (GABA) on GABA type a receptor subunit expression and function
Authors: Schousboe A. , Redburn D. A.
Published: January 2005

Gamma aminobutyric acid (GABA) is present in the central nervous system (CNS) during very early embryogenesis. It is therefore likely to play a role not only as a neurotransmitter but also as a signal molecule for neuronal differentiation, growth, and development. It has been firmly established that formation of synapses is strengthened by GABA, and the expression of certain subunits of the GABA type A (GABAA) receptor complex is clearly promoted by GABA. This latter effect of GABA may have profound implications for the functional activity of GABAergic synapses since the pharmacological properties of GABAA receptors are governed by the subunit composition of the receptor complex. Dynamic changes in GABAA receptor expression and diversity during development and differentiation may therefore play important roles for the inhibitory potential of the CNS during mature stages. © 1995 Wiley‐Liss, Inc.
Gene expression and oligodendrocyte development in the myelin deficient rat
Authors: Nadon N. L. , Duncan I. D.
Published: January 2005

The proteolipid proteins play a major role in the structure of the CNS myelin sheath, but they have also been implicated in the oligodendrocyte development leading to myelination. Mutations in the PLP gene result in severe dysmyelination and a paucity of mature oligodendrocytes. The myelin deficient (md) rat, carrying a Thr75? Pro substitution present in both isoforms of proteolipid protein (PLP and DM20), is the most severely affected of the PLP mutants described to date. The expression of myelin associated genes was quantitated to determine the effect of the mutation on oligodendrocyte development in vivo. At 5 days postnatal, gene expression in the and rat approximated that in age‐matched control rats, but as they matured, there was a progressive inhibition of gene expression in the and rats. The genes expressed late in the myelination program (PLP and MBP) were affected more dramatically than those expressed earlier in oligodendrocyte development (CNP and GPDH). The results indicate that the later stages of oligodendrocyte maturation and myelin elaboration are inhibited. © 1995 Wiley‐Liss, Inc.
Brain distribution of four rat homologues of the drosophila dunce cAMP phosphodiesterase
Authors: Engels P. , Abdel'Al S. , Hulley P. , Lübbert Hermann
Published: January 2005

We have analyzed the brain distribution of the rat cAMP‐specific phosphodiesterases (rPDEIV) which are closely related to the defective gene products of the drosophila melanogaster learning and memory mutant dunce. PCR analysis of rat brain cDNA was performed on the four known dunce‐like cAMP PDE rat isogenes (rPDE‐IV‐A, ‐B, ‐C, ‐D). High expression of three of these isogenes (rPDEIV‐A, ‐B, ‐D) highlighted their involvement in regulation of cAMP in the brain. Specific probes for all four isogenes were then used for in situ hybridization of rat brain sections. Distinct but overlapping expression patterns were observed for rPDEIV‐A, rPDEIV‐B, and rPDEIV‐D. Abundant expression of these subtypes was observed in the olfactory system, the hippocampus and the cerebellum, while no specific signals could be detected in most areas of the brain for the subtype rPDEIV‐C. © 1995 Wiley‐Liss, Inc.
Experimental strategies to promote central nervous system remyelination in multiple sclerosis: Insights gained from the Theiler's virus model system
Authors: Miller D. J. , Asakura K. , Rodriguez M.
Published: January 2005

The Destruction of central nervous system (CNS) myelin, the lipid‐rich insulator surrounding axons in the mammalian brain and spinal cord, is the primary pathological finding in multiple sclerosis. Myelin loss can result in a significant clinical deficit, and was originally thought to be permanent, similar to axonal destruction. However, myelin regeneration is now an established phenomenon in both human disease and animal models of CNS demyelination. In this review, the concept of remyelination in demyelinating deseases such as multiple sclerosis is discussed and the usefulness of animal models of CNS demyelination in developing experimental strategies to promote remyelination is examined Special emphasis is given to the Theiler's murine encephalomyelitis model, which has been the primary animal model used to investigate therapies designed specifically to stimulate myelin repair. © 1995 Wiley‐Liss, Inc.
Characterization of gonadotropin‐releasing hormone (GnRH)‐immunoreactive protein in the rat pineal gland
Authors: Park M. K. , Kogo H. , Kawashima S. , Wakabayashi K.
Published: January 2005

The aim of the present study was to characterize GnRH‐like substance(s) in the rat pineal gland using a monoclonal antibody, LRH13, as a probe. The epitope of LRH13 is between 2nd and 5th amino acid residues of the mammalian GnRH, and its immunological characters were previously defined by us. LRH13 could show strong immunological signal on the rat pineal gland. Immunoblot after SDS‐PAGE of the pineal gland preparations showed a LRH13 immunoreactive band with apparent mol wt 52 kiloDalton (kD), which is much bigger than that of hypothalamic GnRH precursor (10 kD). The 52 kD protein, however, was detected from insoluble fraction of the pineal homogenate and liberated from the fraction by Triton X‐100 (2%) treatment. On the other hand, NaCl (140 mM and 500 mM) or EDTA (10 mM) treatment failed to liberate. Two‐dimensional gel electrophoresis showed that the 52 kD protein is a mixture of two proteins with different isoelectric points (pI approximately 6.8 and 7.0). Both proteins showed identical patterns of peptide mapping by V8 protease digestion, and they might be originated from the same peptide. These results suggest that the rat pineal GnRH‐immunoreactive substance has a unique property as a membrane associate protein. © 1995 Wiley‐Liss, Inc.
Glial fibrillary acidic protein mRNA isotypes: Expression in vitro and in vivo
Authors: Galea E. , Dupouey P. , Feinstein D. L.
Published: January 2005

Glial fibrillary acidic protein (GFAP) and its mRNA, primarily expressed in astrocytes, are also expressed in peripheral nervous system Schwann cells as well as in certain non‐neural tissues. Schwann cells express a GFAP mRNA (GFAP‐β) which differs from the CNStype mRNA (GFAP‐β) by the presence of an extended 5′ untranslated region. We have developed a polymerase chain reaction assay which allows distinction of these two GFAP mRNAs, as well as quantitative analysis of their levels. In the cultured rat Schwannoma cell line RT4‐D6, GFAP‐b̃ was the major GFAP mRNA species, accounting for at least 75% of total GFAP (α+β) mRNA. GFAP‐b̃ was also detected in primary rat astrocyte cultures, where it constituted approximately 5% of the total GFAP mRNA, as well as in RNA samples prepared from normal rat cerebral cortex, and from hamster and human brain. In rat cortex, the temporal expression of GFAP‐β mRNA paralleled that of total GFAP mRNA, with plateau levels reached between postnatal days 15 and 20. In astrocyte cultures, the relative levels of GFAP‐α and ‐β mRNAs were differentially regulated by exposure to interferon‐γ (10 to 25 units/ml), which caused an increase in GFAP‐β levels while at the same time no change or a small decrease in total GFAP levels. In rat brain cortical slices, 4 hr exposure to 25 units/ml interferon‐γ decreased total GFAP mRNA levels over tenfold, while GFAP‐b̃ levels were unaffected. These data indicate that a second form of the GF AP mRNA is expressed in astrocytes both in vivo and in vitro and provide evidence for independent regulation of these two GFAP mRNA species. © 1995 Wiley‐Liss, Inc.
Collagen implants and cortico‐spinal axonal growth after mid‐thoracic spinal cord lesion in the adult rat
Authors: Joosten E. A. J. , Bär P. R. , Gispen W. H.
Published: January 2005

We describe an experimental model to study regeneration of lesioned corticospinal tract (CST) fibers in the adult rat spinal cord. After transection of all CST fibers at mid‐thoracic level the gap is grafted with a sterile, cell‐free collagen matrix. Two methods of collagen‐application are used: (1) injection of a fluid collagen solution into the lesioned area which self‐assembles in situ and (2) implantation of a solid collagen gel. At 4 weeks post‐implantation CST axons are anterogradely labelled with horseradish‐peroxidase (HRP). The collagen implant is evaluated for ingrowth of CST axons. The histopathological reaction (gliotic response) around the lesion and within the matrix is also studied. After application of a fluid collagen solution into the lesion area HRP‐labelled CST axons can be visualized within the implant. In addition, astroglial and reactive microglial cells invade the collagen‐matrix. On the other hand, if collagen is implanted as an already self‐assembled gel, no ingrowth of labelled CST axons nor of astroglial/reactive microglial cells is observed. Both methods of collagenapplication result in a considerable reduction of the gliotic response as compared to the ungrafted animals.

We conclude that the method of application of collagen (i.e., fluid or gel) considerably affects the response of lesioned CST axons. The application of a fluid collagen graft which in situ self‐assembles is beneficial for the regrowth of lesioned CST axons in rat spinal cord. In this respect the formation ' of an astroglial scaffolding structure within the (fluid) collagen, probably due to optimal integration between host and graft, is very important. The inability of injured CST fibers to enter the solid collagen graft may be related to the absence of an astroglial scaffolding structure within the implant. © 1995 Wiley‐Liss, Inc.
Laminin oligopeptide derivatized agarose gels allow three‐dimensional neurite extension in vitro
Authors: Bellamkonda R. , Ranieri J. P. , Aebischer P.
Published: January 2005

The phenotypic expression of various neural cells is influenced by extracellular matrix (ECM) molecules. This study aims to develop a three‐dimensional gel tailored to support neurite extension from neural cells. Laminin‐derived (LN) oligopeptides CDP‐GYIGSR, a 19‐mer IKVAV containing sequence, GRGDSP, a cocktail of the three aforementioned LN peptides (PEPMIX), and a control peptide sequence GGGGG were covalently linked to an agarose hydrogel backbone using the bi‐functional coupling agent 1′1, carbonyldiimidazole. Embryonic day 9 chick DRGs and PC12 cells were suspended in three dimensions in underivatized and derivatized agarose gels and neurite extension was analyzed. Agarose gels derivatized with CDPGYIGSR and PEPMIX enhanced neurite outgrowth from DRGs while GRGDSP and IKVAV derivatized gels inhibited neurite extension when compared to underivatized agarose gels. The IKVAV derivatized gels significantly enhanced neurite outgrowth from PC12 cells in comparison to underivatized and other LN peptide derivatized gels. Agarose hydrogels carrying covalently immobilized LN oligopeptides thus evoke specific responses from cells which contain receptors to the peptides used. Agarose hydrogels derivatized with neurite promoting peptide sequences may find applications in various models of in vivo regeneration of nervous tissue. © 1995 Wiley‐Liss, Inc.
Syngeneic bone marrow transplantation eliminates Vβ8.2 T lymphocytes from the spinal cord of Lewis rats with experimental allergic encephalomyelitis
Authors: Burt R. K. , Burns W. , Ruvolo P. , Fischer A. , Shiao C. , Guimaraes A. , Barrett J. , Hess A.
Published: January 2005

Experimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis (MS), is a paralytic disease of the central nervous system (CNS) mediated by T‐lymphocytes reactive to myelin basic protein (MBP). Lewis rats actively immunized with fragment 68 to 82 of guinea pig MBP develop a monophasic disease with spontaneous recovery. Lymphocyte recognition of the primary encephalitogenic sequence of MBP (fragment 68 to 82) is Vβ8.2 T cell receptor (TCR) skewed [1–3].

Lewis rats in clinical remission at 1 month and 3 months after spontaneous resolution of EAE retain Vβ8.2 T‐lymphocytes in the CNS when analyzed by reverse transcriptase polymerase chain reaction or in situ hybridization. In contrast, I and 3 months after clinical remission from syngeneic bone marrow transplantation, Vβ8.2 T lymphocytes are absent from the CNS.

During clinically active EAE and inflammatory breakdown of the blood‐brain barrier, immune ablation and reconstitution with syngeneic bone marrow results in clinical tolerance of the new immune system to myelin. © 1995 Wiley‐Liss, Inc.
Spatial distribution of ω‐agatoxin IVA binding sites in mouse brain slices
Authors: Nakanishi S. , Fujii A. , Kimura T. , Sakakibara S. , Mikoshiba K.
Published: January 2005

A peptide toxin derived from funnel‐web spider venom, ω‐agatoxin IVA, blocks voltage‐sensitive calcium channels. Many pharmacological and electrophysiological studies have shown that these channels are widely distributed in both the central nervous system (CNS) and neuromuscular junctions. However, a direct morphological demonstration of the binding sites of this toxin is still lacking. To identify which cells have the binding sites, a biologically active, biotin‐conjugated ω‐agatoxin IVA was applied to mouse cerebellar and hippocampal slices. Confocal microscopy revealed that ω‐agatoxin IVA binding sites were distributed on the somata of Purkinje cells, cerebellar granule cells and interneurons, as well as on the dendrites of Purkinje cells. In the hippocampus, the binding sites were localized on the somata of pyramidal cells of the CA1–CA4 region and on the somata of granule cells in the dentate gyrus. A sequential competitive reaction confirmed the specificity of the binding in the cerebellum and CA1 pyramidal cells, and also suggested a difference in the binding affinity between CA1 and CA3 pyramidal cells. Since a high concentration of ω‐agatoxin IVA (2 μM) was needed for the present study, the ω‐agatoxin IVA binding sites presented in this study may represent “P‐type” and “Q‐type” calcium channels. © 1995 Wiley‐Liss, Inc.
Selective in vitro blockade of neuroepithelial cells proliferation by methylazoxymethanol, a molecule capable of inducing long lasting functional impairments
Authors: Cattaneo E. , Reinach B. , Caputi A. , Cattabeni F. , Di Luca M.
Published: January 2005

In order to characterize the antiproliferative effect of methylazoxymethanol neuroepithelial cells derived from the rat striata primordia at embryonic day 14 have been exposed to graded doses of this compound. It was found that methylazoxymethanol application to striatal neuroblasts elicits a blockade of cell proliferation at a dose which does not interfere with cell survival. By using synchronized cells and short term exposures to this compound, we found that the antiproliferative effect of methylazoxymethanol is strikingly correlated to the number of cells actively dividing in culture, thus indicating that the cells targeted by methylazoxymethanol must be in an active mitotic phase. To test for the selectivity of actien of Methylazoxymethanol for dividing neuroblasts either cultures composed of mature proliferating astrocytes or muscle cells have been subjected to the same treatment. It has been observed that astrocytes proliferation was not affected by the dose of methylazoxymethanol shown to be effective on neuroepithelial cells. Finally we demonstrated that methylazoxymethanol is able only transiently to interfere with smooth muscle cell division, further supporting its selectivity of action within the developing CNS. © 1995 Wiley‐Liss, Inc.
Expresgions of nerve growth factor and p75 low affinity receptor after transient forebrain ischemia in gerbil hippocampal CA1 neurons
Authors: Lee T.‐H. , Abe K. , Kogure K. , Itoyama Y.
Published: January 2005

Expressions of nerve growth factor (NGF) and low affinity p75 NGF receptor (p75 NGFR) in gerbil hippocampal neurons after 3.5‐min transient forebrain ischemia were studied. Most hippocampal CAI neurons were lost (neuronal density = 44 ± 12/mm) at 7 days after recirculation, while no cell death was found in the sham‐control neurons (220 ± 27/min). NGF immunoreactivity was normally present in the sham‐control hippocampal neurons. However, it decreased in hippocampal CAI neurons, and slightly decreased in the neurons of CA3 and dentate gyrus areas from 3 hr after recirculation. By 7 days, NGF immunoreactivity returned almost completely to the sham‐control level in the CA3 and dentate gyrus neurons but decreased markedly in the CAI neurons. In contrast, p75 NGFR immunoreactivity was scarcely present in the sham‐control hippocampal neurons but was induced from 1 hr after recirculation in the CAI and CA3 neurons and from 3 hr in the dentate gyrus. At 7 days, p75 NGFR immunoreactivity was expressed greatly in the surviving CAI neurons and the reactive astrocytes but was not seen in the other hippocampal neurons.

The markedly decreased NGF and greatly induced p75 NGFR immunoreactivity found in the CAI neurons after transient forebrain ischemia suggests that NGF and p75 NGFR may be involved in the mechanism of delayed neuronal death. © 1995 Wiley‐Liss, Inc.
GapIII, a new brain‐enriched member of the GTPase‐activating protein family
Authors: Baba H. , Fuss B. , Urano J. , Poullet P. , Watson J. B. , Tamanoi F. , Macklin W. B.
Published: January 2005

Ras GTPase‐activating proteins (GAPs) are negative regulators of ras, which controls proliferation and differentiation in many cells. Ras GAPs have been found in a variety of species from yeast to mammals. We describe here a newly identified mammalian GAP, GapIII, which was obtained by differential screening of a rat oligodendrocyte cDNA library. GapIII putatively encodes a 834 amino acid protein with a predicted molecular weight of 96 kDa, which contains a consensus GAP‐related domain (GRD). The protein encoded by this cDNA has high homology with Gap1m, which was recently identified as a putative mammalian homolog of Drosophila Gapl. These proteins contain three structural domains, an N‐terminal calcium‐dependent phospholipid binding domain, GRD, and a C‐terminal PH/Btk domain. Because of the sequence homology and the structural similarities of this protein with Gaplm, we hypothesize that GapIII and Gap1m may be members of a mammalian GAP gene family, separate from p120GAP, neurofibromin (NF1), and IQGAP. To confirm the GapIII protein activity, constructs containing different GapIII‐GRD domains were transformed into iral mutant yeast to determine their relative ability to replace IRA1 functionally. Constructs that contained essentially the full‐length protein (all three domains), the GRD alone, or the GRD plus PH/Btk domain suppressed heat shock sensitivity of iral, whereas constructs that contained the GRD with part of the PH/Btk domain had only a weak ability to suppress heat shock sensitivity. These results suggest that the GapIII GRD itself is sufficient to down‐regulate ras proteins in yeast. Expression of GapIII mRNA (4.2 kb) was examined by Northern analysis and in situ hybridization. This mRNA was expressed at highest levels in the brain, where its expression increased with development. Lower levels of the mRNA were expressed in the spleen and lung. Among neural cells, GapIII mRNA was expressed in neurons and oligodendrocytes, but not in astrocytes. Interestingly, the expression pattern in brain is reminiscent of type 1 NF1 expression reported by Gutmann et al. (Cell Growth Differ in press, 1995). We propose that in addition to p120GAP and neurofibromin, the GapIII/Gaplm family may be important for modulating ras activity in neurons and oligodendrocytes during normal brain development and in particular in the adult brain. © 1995 Wiley‐Liss, Inc.
Neurotoxicity of the human immunodeficiency virus type 1 Tat transactivator to PC12 cells requires the Tat amino acid 49‐58 basic domain
Authors: Weeks B. S. , Lieberman D. M. , Johnson B. , Roque E. , Green M. , Loewenstein P. , Oldfield E. H. , Kleinman H. K.
Published: January 2005

The acquired immunodeficiency syndrome (AIDS) frequently involves the central nervous system (CNS) and manifests as dementia due to encephalitis or diffuse neurodegeneration. Human immunodeficiency virus type 1 (HIV‐1) proteins, potentially transported into the CNS by mononuclear inflammatory cells, have been implicated in the etiology of this HIV‐1 associated neurological dysfunction. Here we investigate the neurotoxicity of the essential HIV‐1 regulator protein Tat in vivo after microinfusion into the rat brain and in vitro using PC12, NG108‐15, and GT17 neuronal cell lines. Infusion of either chemically synthesized Tat (Tat86) or recombinant Tat (rTat) into the striatal gray matter in Sprague‐Dawley rats resulted in postural deviation ipsilateral to the infusion, a clinical presentation in rats associated with complete striatal dysfunction. Histologic examination 3 days after infusion revealed massive necrosis in the area of the distribution of the infusion. Infusion of heat denatured rTat, peptide Tat49‐58, or peptide Tat57‐86 did not result in clinically or histologically detectable brain damage. After 3 days incubation in vitro, the lethal dose for half (LD50) of PC 12 cells due to rTat was 5 μg/ml. The LD50 for Tat86 under the same conditions was 10 μg/ml. Tat49‐58 and Tat57‐86 peptides were not toxic in vitro even at 10‐fold higher doses. At 5 μg/ml, rTat was toxic to 100% of GT17 cells after 24 hr. At 5 μg/ml, Tat86 was toxic to 90% of the NG108‐15 cells after 7 days of treatment. Prior experiments have shown Tat49‐58 is specifically recognized by a cell surface protein that mediates Tat uptake. Here we show that Tat toxicity is inhibited by cotreatment with excess Tat49‐58, suggesting Tat neurotoxicity requires binding to its surface ligand. Chloroquine, which increases nuclear accumulation of Tat, enhances Tat toxicity to PC 12 cells, suggesting that Tat internalization is a required step in the mechanism of its toxicity. © 1995 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Distribution of transforming growth factor‐β isoforms in the mammalian retina
Authors: Anderson D. H. , Guerin C. J. , Hageman G. S. , Pfeffer B. A. , Flanders K. C.
Published: January 2005

The distribution of transforming growth factor‐beta (TGF‐β) was examined in the posterior segment of the monkey, human, and feline eye using antisera to TGF‐β, TGF‐β, or TGF‐β. A number of different antibodies, tissue processing methods, immunolocalization techniques, and microscopic imaging systems were used in an attempt to gain a more comprehensive picture of TGF‐β isoform distribution in the retina and retinal pigmented epithelium (RPE). The results are generally consistent in identifying one or more of the three TGF‐β isoforms in the cytoplasm of a small, overlapping subset of cells. RPE cells, photoreceptors, Mueller cells, ganglion cells, hyalocytes, and cells associated with choroidal and retinal vessels are all represented in this immunoreactive population. No evidence of extracellular labeling was noted. The intracellular distribution of the three isoforms is distinctly different in photoreceptors. Anti‐TGF‐β precursor and anti‐TGF‐β immunoreactivity is confined primarily to rod outer segments, whereas anti‐TGF‐β immunoreactivities are restricted to mitochondria within inner segments. In the RPE, clusters of anti‐TCF‐β positive cytoplasmic granules are located near the cells' lateral borders, whereas anti‐TGF‐β labeling is concentrated apically. These results provide baseline information from which new hypotheses regarding the function(s) of TGF‐β isoforms in the retina can be formulated. © 1995 Wiley‐Liss, Inc.
Insulin‐like growth factor I is an afferent trophic signal that modulates calbindin‐28kD in adult Purkinje cells
Authors: Nieto‐Bona M. P. , Busiguina S. , Torres‐Aleman I.
Published: January 2005

Recent evidence suggests that Purkinje cells are specific targets of insulin‐like growth factor I (IGF‐I) through their entire life span. During development, Purkinje cell numbers and their calbindin‐28kD content increase after IGF‐I treatment in culture. In the adult, part of the IGF‐I present in the cerebellum is transported from the inferior olive, and modulates Purkinje cell function. We investigated whether IGF‐I produced by inferior olive neurons and transported to the contralateral cerebellum through climbing fibers may modulate the levels of calbindin‐28kD in the cerebellum of adult animals. Twenty‐four hr after injection of an antisense oligonucleotide of IGF‐I into the inferior olive, both IGF‐I and calbindin‐28kD levels in the contralateral cerebellar lobe were significantly reduced, while the number of calbindin‐positive Purkinje cells was unchanged. The effect of the antisense on IGF‐I levels was fully reversed 3 days after its injection into the inferior olive, with a postinhibitory rebound observed at this time, while calbindin‐28kD levels slowly returned to control values. A control oligonucleotide did not produce any change in either IGF‐I or calbindin‐28kD content in the cerebellum. These results indicate that normal levels of IGF‐I in the inferior olive are necessary to maintain appropriate levels of IGF‐I in the cerebellum and of calbindin‐28kD in the Purkinje cell. These results also extend our previous findings on the existence of an olivo‐cerebellar IGF‐I‐containing pathway with trophic influence on the adult Purkinje cell. © 1995 Wiley‐Liss, Inc.
Cloning and characterization of MVP17: A developmentally regulated myelin protein in oligodendrocytes
Authors: Kim T. , Fiedler K. , Madison D. L. , Krueger W. H. , Pfeiffer S. E.
Published: January 2005

The remarkable quantities of myelin membrane produced by oligodendrocytes has led us to examine the mechanisms involved in the sorting and transport of proteins and lipids during myelinogenesis. Noting that it has been proposed that proteins destined for the apical surface of polarized epithelial cells co‐cluster with glycolipid‐rich microdomains during sorting and transport from the trans‐Golgi network (Simons and van Meer: Biochemistry 27:6197‐6202, 1988; Simons and Wandinger‐Ness: Cell 62:207‐210, 1990), we hypothesized that the glycolipid‐rich oligodendrocytes may adopt this mechanism for myelinogenesis. Protein‐lipid complexes from oligodendrocytes and myelin were isolated utilizing detergent insolubility and two‐dimensional gel electrophoresis. A developmentally regulated protein, MVP17 (myelin vesicular protein of 17 kDa), was identified. Microsequencing of the N‐terminal peptide revealed a high homology to human T‐cell MAL protein (Alonso and Weissman: Proc Nati Acad Sci USA 84:1997‐2001, 1987). The corresponding MVP17 cDNA was isolated from an oligodendrocyte cDNA library. The predicted protein sequence showed 88.9% identity with MAL, and the hydrophobicity profile suggested four transmembrane domains. In vitro translation demonstrated a signal at the deduced Mr of 17 kDa. Northern analyses indicated that MVP17 mRNA expression is restricted to brain and kidney and that this expression is up‐regulated in oligodendrocytes and brain during the period of active myelination. These data suggest that MVP17 is involved in myelin biogenesis and/or myelin function. © 1995 Wiley‐Liss, Inc.
Characterization of a novel oligodendrocyte cell surface molecule
Authors: Zhou L. , Szigeti V. , Miller R. H.
Published: January 2005

Cell‐type‐specific reagents have proven useful in the analysis of central nervous system (CNS) development and function. Most markers of oligodendrocytes are components of myelin sheath, which in the CNS is the specific product of oligodendrocytes. We have isolated a novel monoclonal antibody termed 2B10 which was raised against embryonic rat spinal cord tissue. In adult rat cerebrum, cerebellum, and spinal cord, 2B10 immunoreactivity is predominantly localized in white matter. 2B10 immunoreactivity is absent from peripheral nerve, suggesting that in the nervous system the 2B10 antigen is restricted to the CNS. Dissociated cell culture studies indicate that 2B10 labels a cell surface molecule, and its cellular distribution is coincident with O1 and myelin basic protein‐positive oligodendrocytes. By contrast, 2B10 does not label GFAP‐positive astrocytes. These data suggest that in the CNS the 2B10 antigen is expressed specifically on oligodendrocytes. Biochemical analysis indicates that 2B10 recognizes a protein with an apparent molecular weight of approximately 79,000 in reducing sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. Developmentally, 2B10 immunoreactivity is detectable in rat spinal cord at as early as embryonic day 14. The relative abundance of this molecule decreases during myelination, but is maintained at a sustained level throughout adulthood. The 2B10 antigen appears not to be a myelin‐associated protein since it is not detected in purified myelin fractions. 2B10 immunoreactivity is not detectable in extracts of rat sciatic nerve, heart, kidney, muscle, and skin, but is detectable in extracts of spleen and thymus. These data suggest that the 2B10 antigen is a novel cell surface molecule that is expressed on oligodendrocyte lineage cells throughout development. © 1995 Wiley‐Liss, Inc.
Blockade of K+ channels induced by AMPA/kainate receptor activation in mouse oligodendrocyte precursor cells is mediated by NA+ entry
Authors: Borges K. , Kettenmann H.
Published: January 2005

AMPA/kainate receptor activation in cultured oligodendrocyte precursor cells from embryonic mouse cortex leads to a blockade of delayed rectifying K+ currents. In the present study, we provide evidence using the patch‐clamp technique in the whole‐cell configuration that the mechanism linking kainate receptor activation and K+ conductance blockade is due to the receptor‐mediated Na+ entry: (1) The blockade was not observed in Na+ ‐free bathing solution nor when intracellular [Na+] was elevated by dialzying the cell with a pipette solution containing high [Na+]. (2) Elevation of intracellular [Na+] alone led to a blockade of outward currents in contrast to cells dialyzed by sucrose. High [Li+]i also reduced the outward currents, and in Li+‐containing bathing solution the kainate‐induced blockade of K+ channels was more pronounced. Probably, Li+ accumulates intracellularly after permeation through the receptor pore due to slower extrusion mechanisms. Experiments with GTPγS or GDPβS and pertussis toxin indicated that GTP‐binding protein‐mediated mechanisms were not of importance for the kainate‐induced K+ conductance blockade. Our data suggest that in glial precursor cells AMPA/kainate receptor activation leads to an intracellular [Na+] increase which blocks delayed rectifying K+ channels. © 1995 Wiley‐Liss, Inc.
Serum‐free B27/neurobasal medium supports differentiated growth of neurons from the striatum, substantia nigra, septum, cerebral cortex, cerebellum, and dentate gyrus
Authors: Brewer G. J.
Published: January 2005

Two fundamental questions about neuron cell culture were addressed. Can one serum‐free medium that was developed for optimum growth of hippocampal neurons support the growth of neurons from other regions of the brain? Is the region specific state of differentiation maintained in culture? To answer these questions, we isolated neurons from six other rat brain regions, placed them in culture in B27/NeurobasalTM defined medium, and analyzed their morphology and growth dependence on cell density after 4 days in culture. Neuronal identity was confirmed by immunostaining with antibodies to neurofilament 200. Neurons from each brain region maintained distinctive morphologies in culture in the virtual absence of glia. Cells isolated from embryonic day 18 cerebral cortex by digestion with papain showed the same high survival as hippocampal neurons, e.g., 70% survival for cells plated at 160/mm2. At this age and density, neurons from the septum showed slightly lower survival, 45%. Survival of dentate granule neurons from postnatal day four brains was 30‐40%, significantly lower, and relatively independent of plating density. This suggests an absence of dependence on trophic factors or contact for dentate granule neurons. Growth of cerebellar granule neurons isolated from postnatal day 7, 8, or 9 brains in B27/Neurobasal was compared to growth in BME/10% serum. Viability in serum‐free medium at 4 days was much better than that in serum, did not require KCI elevated to 25 mM, and occurred without substantial growth of glia. Cerebellar granule neurons plated at 1,280 cells/mm2 were maintained in culture for three weeks with 17 of the original cell density surviving. Survival of cells isolated from embryonic day 18 substantia nigra was 50% at 160 cells/mm2 after 4 days, similar to that of striatum, but slightly less than hippocampal neuron survival. The dopaminergic phenotype of the substantia nigral neurons was maintained over 2 weeks in culture as judged by immunoreactivity with antibodies to tyrosine hydroxylase. During this time, immunoreactivity was found in the processes as they grew out from the soma. Together, these studies suggest that B27/Neurobasal will be a useful medium for maintaining the differentiated growth of neurons from many brain regions. Potential applications of a common growth medium for different neurons are discussed. © 1995 Wiley‐Liss, Inc.
Increase in dopamine turnover and tyrosine hydroxylase enzyme in hippocampus of rats fed on low selenium diet
Authors: Castaño A. , Ayala A. , Rodriguez‐Gomez J. A. , De La Cruz C. P. , Revilla E. , Cano J. , Machado A.
Published: January 2005

We have studied the turnover of dopamine, noradrenaline, and serotonin and their metabolites in hippocampus of adult female rats that were fed control or selenium‐deficient diets during 15 days. Under these circumstances, there was an increase of dopamine turnover (4‐fold) in rats fed with selenium‐deficient diet with respect to controls and also an increase in the tyrosine hydroxylase activity (75.8%), which was the result of the increase of the amount of the enzyme (2‐fold), without significant change in the phosphorylation of the tyrosine hydroxylase.

In addition the glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase activities have been studied. After selenium‐deficient diet, the enzymatic activities of superoxide dismutase and catalase did not show change with respect to the controls; however glutathione reductase and glutathione peroxidase significantly decreased 15% and 29%, respectively.

It is concluded that the increase in dopamine turnover seems to be associated with the induction of tyrosine hydroxylase enzyme. In these conditions the decrease in antioxidant capacity may produce a cascade of events, which accelerates the degenerative process, since the increase in dopamine turnover produces an increase in oxygen radical by monoamine oxidase activity. © 1995 Wiley‐Liss, Inc.
Detection of tenascin‐C in the nervous system of the tenascin‐C mutant mouse
Authors: Mitrovic N. , Schachner M.
Published: January 2005

We have investigated the expression of tenascin‐C (TN‐C) in the somatosensory cortex of early postnatal mutant mice in which lacZ was reported to be expressed in place of tenascin (Saga et al.: Genes Dev 6:1821‐1831, 1992). At both the mRNA and protein levels, TN‐C was detected at levels lower in the mutant than in wild type animals by in situ hybridization and by immunocytochemistry using several poly‐ and monoclonal antibodies directed against mouse TN‐C. The distribution of TN‐C immunoreactivity in coronal sections was abnormal in that the barrel field boundaries in layer 4 of the somatosensory cortex could not be detected in the mutant mice. Furthermore, TN‐C was detected intracellularly in most cell bodies, including possibly also neurons. Western blot analysis of homogenates of brain tissue from early postnatal animals showed an abnormal pattern of protein bands immunoreactive for TN‐C in mutant animals while β‐galactosidase migrated at its expected molecular weight without incorporation into fusion proteins with TN‐C, suggesting disturbed splicing mechanisms. No gross disturbances in the patterning of barrel fields could be detected in the mutant mice as shown by Nissl staining. Our observations show that the mutant mouse designed to be nully disrupted for TN‐C expression shows detectable and abnormal TN‐C expression. © 1995 Wiley‐Liss, Inc.
Immunological identification of A1 adenosine receptors in brain cortex
Authors: Ciruela F. , Casadó V. , Mallol J. , Canela E. I. , Lluis C. , Franco R.
Published: January 2005

The A1 adenosine receptor from pig brain cortex has been identified by means of two antipeptide antibodies against two domains of the receptor molecule: PC/10 antiserum was raised against a part of the third intracellular loop, and PC/20 antiserum was raised against a part of the second extracellular loop. PC/10 antibody was able to recognize a 39‐kDa band that corresponded to the Al receptor, as demonstrated by immunoblotting and by immunoprecipitation of the molecule cross‐linked to [125I](R)‐2‐azidoN2‐p‐hydroxy(phenylisopropyl)adenosine. Besides the 39‐kDa band, PC/20 also recognized a 74‐kDa form that does not seem to correspond to a receptor‐G protein complex. The occurrence of the two bands was detected and analyzed in samples from different species and tissues showing a heterogeneous distribution of both. The 74‐kDa form can be converted into the 39‐kDa form by treatment with agonists or antagonists of Al adenosine receptors. These results suggest that A1 adenosine receptor can occur in dimers and that the dimer–monomer conversion might be regulated by adenosine as the physiological ligand. Since the 74‐kDa aggregates were not recognized by PC/10, it is likely that part of the third intracellular loop participates in the protein–protein interaction. ©1995 Wiley‐Liss, Inc.
Experimental allergic encephalomyelitis: Characterization of T lymphocytes that bind myelin basic protein and synapsin
Authors: de Santis M. L. , Roth G. A.
Published: January 2005

The immuno phenotypic profile of the mononuclear cells that bind myelin basic protein (MBP) and synapsin was investigated in lymph node cells from rats with experimental allergic encephalomyelitis induced by injection with MBP. Using a double immunofluorescent labeling technique, purified cells that bind one or both antigens were analyzed in different stages of the disease. The total MBP‐bound lymphocytes increased at 14 days post‐inoculation (dpi), had a CD4+/CD8+ ratio of two and were present until 29 dpi. Conversely, the apportionment of cells specific for MBP that also recognize synapsin reached a maximum value at 14 dpi coincidentally with the expression of the paralysis symptoms and then, they disappeared when the animal began to recover. This population amounted to about 40% of the total lymph node MBP‐bound cells and had a CD4+/CD8+ ratio of one, indicating that the lymphocytes with MBPsynapsin crossreactivity could be principally implicated in a cytotoxic or suppressor activity. © 1996 Wiley‐Liss, Inc.
Dietary β‐alanine results in taurine depletion and cerebellar damage in adult cats
Authors: Lu P. , Xu W. , Sturman J. A.
Published: January 2005

We have used the taurine analogue, β‐alanine, to perturb the taurine concentrations in taurine‐supplemented and taurine‐deprived adult cats. By using 5 % β‐alanine in the drinking water for 20 weeks, both groups of cats had greatly reduced brain taurine concentrations. Taurine‐supplemented cat brain accumulated relatively small amounts of β‐alanine whereas taurine‐deprived cats accumulated large amounts of β‐alanine. The cerebellum of cats treated with β‐alanine had a number of pathological changes compared with similar cats drinking water alone. The changes were more severe in the taurine‐deprived cats, and included reduced numbers of granule and Purkin je cells, with many of those remaining appearing pyknotic and dying. Long swollen fibers were seen in the white matter, resembling Rosenthal fibers described in some human cerebellar diseases. There was also prominent gliosis. Using antibodies to β‐alanine and taurine, β‐alanine was localized in Purkinje cell soma and dendrites, in Golgi II cells, and in some granule cells, especially in taurine‐deprived cats treated with β‐alanine. Taurine appears to have been virtually eliminated from Purkinje and granule cells, and concentrated in Golgi II cells and glia. We conclude that β‐alanine is responsible for these neuro toxic pathological changes. © 1996 Wiley‐Liss, Inc.
Nitrogen fertilizer and seed rate effects on Hagberg falling number of hybrid wheats and their parents are associated with α‐amylase activity, grain cavity size and dormancy
Authors: Kindred Daniel R , Gooding Mike J , Ellis Richard H
Published: January 2005

Field experiments were carried out to assess the effects of nitrogen fertilization and seed rate on the Hagberg falling number (HFN) of commercial wheat hybrids and their parents. Applying nitrogen (200 kg N ha−1) increased HFN in two successive years. The HFN of the hybrid Hyno Esta was lower than either of its parents (Estica and Audace), particularly when nitrogen was not applied. Treatment effects on HFN were negatively associated with α‐amylase activity. Phadebas grain blotting suggested two populations of grains with different types of α‐amylase activity: Estica appeared to have a high proportion of grains with low levels of late maturity endosperm α‐amylase activity (LMEA); Audace had a few grains showing high levels of germination amylase; and the hybrid, Hyno Esta, combined the sources from both parents to show heterosis for α‐amylase activity. Applying nitrogen reduced both apparent LMEA and germination amylase. The effects on LMEA were associated with the size and disruption of the grain cavity, which was greater in Hyno Esta and Estica and in zero‐nitrogen treatments. External grain morphology failed to explain much of the variation in LMEA and cavity size, but there was a close negative correlation between cavity size and protein content. Applying nitrogen increased post‐harvest dormancy of the grain. Dormancy was greatest in Estica and least in Audace. It is proposed that effects of seed rate, genotype and nitrogen fertilizer on HFN are mediated through factors affecting the size and disruption of the grain cavity and therefore LMEA, and through factors affecting dormancy and therefore germination amylase. Copyright © 2004 Society of Chemical Industry
Quilt Venoplasty Using Recipient Saphenous Vein Graft for Reconstruction of Multiple Short Hepatic Veins in Right Liver Grafts
Authors: Hwang Shin , Lee Sung-Gyu , Park Kwang-Min , Kim Ki-Hun , Ahn Chul-Soo , Moon Deok-Bog , Ha Tae-Yong
Published: January 2005

Major short hepatic veins (SHV) are indicated for vascular reconstruction to prevent excessive hepatic venous congestion of right liver grafts. As separate anastomoses of multiple small SHVs are vulnerable to stenosis or regeneration-related torsion, a conjoined large opening of SHVs may be better than multiple separate anastomoses. We devised an innovative method to reconstruct SHVs through a patchwork quilt using autologous greater saphenous vein (GSV). We applied this method to 3 different configurations of multiple SHVs. For double SHVs in alignment, 2 GSV fragments were stitched longitudinally to wrap 2 SHVs, forming the cuff shape of an ovoid bowl. For double SHVs not in alignment, a central patch of GSV was placed between 2 SHVs to offset the alignment gap, and the outer fence of a long GSV fragment was anastomosed to make a common cuff. For complex anatomy of quadruple SHVs, the central patch was designed to contact with 4 SHVs altogether and the outer fence was similarly created. Although this method was applied to only 4 right liver grafts, there was no disturbance of SHV drainage during 4 months of follow-up. In conclusion, we think that this quilt venoplasty technique using autologous GSV may be applicable for reconstruction of multiple or variant SHVs.
Brain energy metabolism and dopaminergic function in Huntington's disease measured in vivo using positron emission tomography
Authors: Leenders K. L. , Frackowiak R. S. J. , Quinn N. , Marsden C. D.
Published: January 2005

A 48‐year‐old man with typical Huntington's disease was investigated with computed tomography (CT) and positron emission tomography. Regional cerebral blood flow, oxygen extraction, oxygen and glucose utilisation, L‐Dopa uptake, and dopamine (D2) receptor binding were measured using several positron‐labelled tracers. CT showed slight atrophy of the head of caudate but no cortical atrophy, although distinct frontal lobe dysfunction was present on psychometric testing. Oxygen and glucose metabolism and cerebral blood flow were decreased in the striata and to a lesser extent in frontal cortex. Cerebral blood flow was in the low normal range throughout the remainder of the brain. A normal metabolic ration was found in all regions, since the changes in glucose utilisation paralleled those in oxygen consumption. The capacity of the striatum to store dopamine as assessed by L‐[18F]‐fluorodopa uptake was normal, but dopamine (D2) receptor binding was decreased when compared to normal subjects.
The effect of single and repeated administration of bromocriptine on monoamine metabolism in rat brain and [3H]spiroperidol binding to striatal membranes
Authors: Muradas V. , Bazan E. , Gervas J. J. , Mena M. A. , de Yebenes J. G.
Published: January 2005

Administration of a single high dose of bromocriptine decreased synthesis and release of dopamine and serotonin in several brain regions, most notably in the striatum. Bromocriptine modified the kinetics of [3H]spiroperidol binding to striatal membranes, but these changes were not prominent 2 h after injection when modifications of monoamine metabolism were evaluated. After injection of the same dose of bromocriptine daily for 10 days, the decrease in dopamine synthesis persisted, while other aspects of monoamine metabolism, presumably controlled by dopamine autoreceptors, returned to normal values. This adaptation was not caused by decreased blood levels of bromocriptine, since bromocriptine accumulated in plasma after repeated drug administration. This study provides evidence that different aspects of dopamine cell function, presumably controlled by autoreceptors, show different patterns of adaptation after chronic administration of dopamine agonists.
Long‐term followup computed tomography and magnetic resonance imaging findings in hepatolenticular degeneration: Case report and summary of the literature
Authors: Metzer W. Steven , Angtuaco Edgardo
Published: January 2005

Pretreatment and long‐term followup computed tomography (CT) findings were reported in a patient with successfully treated Wilson's disease. Results of magnetic resonance imaging (MRI) are correlated with followup CT findings, with MRI being more specifically sensitive than CT. The literature of CT and MRI findings in Wilson's disease is reviewed and summarized.
Natural history and treatment of tardive dystonia
Authors: Kang Un Jung , Burke Robert E. , Fahn Stanley
Published: January 2005

We retrospectively reviewed the clinical course and response to treatment of 67 patients with tardive dystonia. The age at onset ranged from 13 to 72 years without predilection to any particular age group or sex. Patients developed tardive dystonia even after relatively short duration of exposure to dopamine antagonists (21% within one year). Five of 42 patients withdrawn from these drugs remitted. Overall clinical improvement occurred in 52% of patients. Tetrabenazine and reserpine were most effective (>50% response rate) in controlling dystonia. Anticholinergic drugs diminished dystonia in 46% of patients.