| Project/Area Number |
05670569
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurology
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| Research Institution | Jichi Medical School |
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Principal Investigator |
FUJIMOTO Ken-ichi Faculty of Medicine, Jichi Medical School Assistant, 医学部, 講師 (50238614)
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| Project Period (FY) |
1993 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1993: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Striatum / Interneuron / GAP-43 / Putamen / Dystonia / Bicuculline / Pedunculopontine nucleus / Ibotenic acid / ドーパミン / 黒質 / DOPAC / HPLC / 基底核 / コリン作動性神経細胞 / choline acetyltransferase / mRNA / in situ hybridization / 大脳基底核 / in situhybridization / ドパミン レセプター / ジスキネジア / bicuculline |
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| Research Abstract |
About 2% of striatal neurons are of the so-called large, aspiny or sparsely spiny interneurons. In these interneurons, mRNA of both ChAt and growth-associated protein-43 (GAP-43) was observed. Many studies have implicated GAP-43 in development, axonal growth and synaptic plasticity. After the destruction of dopaminergic afferents by the injection of 6-hydroxydopamine into the medial forebrain bundle, mRNA of GAP-43 in the striatal interneuron did not change.
Microinjection of GABA_A antagonist bicuculline into the unilateral putamen of the cat resulted in periodic occurrence of contralateral movement of the head (dystonia). Corresponding to this dystonic movement, repetitive spikes of the field potential occurring in the putamen of the injected side and strong inhibition of the extracellularly recorded unit discharges in the neurons of the substantia nigra pars reticulata of the same side were observed.
After the injection of ibotenic acid (IBO) into the pedunculopontine nucleus (PPN), dihydroxyphenyl acetic acid (DOPAC) in the striatum increase gradually and reached almost 160% of the initial value after 90 min. Under the perfusion with scopolamine into the substantia nigra, no increase of DOPAC was observed. The level of depamine in the striatum was not changed before and after the injection of IBO into the PPN.Spontaneous discharges of the nigral dopaminergic cells were decreased after the injection of IBO into the PPN.Cholinergic input from the PPN is expected to increase not the release but the synthesis of dopamine in the nigral neurons. This process does not depend on the increase of action potential in the dopaminergic neurons.
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