2005 Fiscal Year Final Research Report Summary
Involvement of reward system in acquisition and maintenance of alcohol independence.
| Project/Area Number |
14570928
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Psychiatric science
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| Research Institution | Kagawa University |
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Principal Investigator |
TAKEUCHI Yoshiki Kagawa University, Faculty of Medicine, Professor, 医学部, 教授 (20116619)
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| Co-Investigator(Kenkyū-buntansha) |
MIKI Takanori Kagawa University, Faculty of Medicine, Associate Professor, 医学部, 助教授 (30274294)
YOKOYAMA Toshihumi Kagawa University, Faculty of Medicine, Assistant Professor, 医学部, 助手 (10380156)
WATANABE Takemi Kagawa University, University Hospital, Assistant Professor, 医学部附属病院, 助手 (50304598)
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| Project Period (FY) |
2002 – 2005
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| Keywords | Alcohol / Dependence / Model animal / Rewards system / Hippocampus / Glial cells / Amino acids / Neurotrophic factors |
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| Research Abstract |
Wistar rats were exposed to a relatively high daily dose of ethanol at postnatal day 10-15 by placing them for 3 h/day in a chamber containing ethanol vapor. These ethanol-treated rats (blood concentration : approximately 430 mg/dl) were found to have slightly but significantly fewer pyramidal cell neurons. The present observations indicate that pyramidal cells in the hippocampus may be vulnerable to a relatively high dose of ethanol exposure during this short period of early postnatal life. In additional experiment, the effects on the frontal cortex and hilar neuron numbers, observed as a result of such short periods of ethanol treatment, appeared to be transitory.
With respect to colocalization of taurine and glial fibrillary acidic protein immunoreactivity in mouse hippocampus, induced by short-term ethanol exposure, quantitative analysis revealed that the merged area in ethanol-treated mice was twice that (71.6% vs. 35.8%) of control mice. Since taurine is involved in various neuroprotective functions, the present observations suggest that the expression of taurine immunoreactivity in reactive astrocytes after ethanol exposure might play an important role in neuroprotective processes.
Additional analysis was made to investigate the effects on expression of neurotrophic factors. The expression levels of brain- and glia-derived neurotrophic factors (BDNF and GDNF) in the hippocampus were analyzed by RT-PCR analysis. This study revealed that chronic ethanol consumption does not result in significant changes in expression levels of BDNF and GDNF mRNAs. However, it was characteristic in myelin-associated glycoprotein that expression levels of oligodendrocyte myelin glycoprotein (OMgp) mRNA were increased. This appears to be consistent with the neuropathological changes in alcoholics, which have relationship with demyelination.
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