2002 Fiscal Year Final Research Report Summary
Neural circuitry for precise hand movements
| Project/Area Number |
13680831
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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 |
Nerve anatomy/Neuropathology
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| Research Institution | Tokyo Metropolitan Organization for Medical Research |
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Principal Investigator |
TOKUNO Hironobu Tokyo Metropolitan Institoe for Neuroscience, Department of Brabi Structure, Senior Research Associate, 東京都神経科学総合研究所, 研究員 (40212071)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Spinal cord / Motoneuron / Cerebral Cortex / Basal ganglia / Striatum / Patch compartment / Interneuron |
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| Research Abstract |
Anatomical and physiological experiments were carried out to understand the brain mechanism for the control of precise hand movements. The neural circuitry in the the spinal cord, the basal ganglia, or the cerebral cortex was studied as follows.
1. Distribution of the motoneurons innervating ulnar, median or radial nerves was analyzed using retrograde triple labeling technique. Overlap of flexor and extesor motoneurons were clearly demonstrated.
2. Input organization of premotor cortical areas into the hindlimb region of the primary motor cortex was investigated after intracortical microstimulation mapping. Difference between hand and foot representations in the primary motor cortex was discussed.
3. Corticostriatal and striatopallidal/nigral projections related to the hand movements were studied using combined electrophysiological and anatomical examination.
4. Efferent projections from the striatal patch compartments were revealed after targeting of mu-opioid receptor expressing neurons followed by silver impregnation. It wa revealed that striatal patch neurons in the hand area send their axons to the globus pallidus, entopeduncular nucleus, and the pars compacta and reticulata of the substantia nigra.
5. Polysynaptic neurotransmission in the striato-entopeduncular pathway related to the forelimb movements was analyzed using single-unit recording after ablation of striatal interneurons expressing substance P receptors. The striatal interneurons were shown to play importamt roles to maintain spatial specificity in the basal ganglia circuitry.
6. Both injection system for deep brain structures under guidance of ultrasonography, and photographic system for fluorescence digital macrography were developed to carry out these experiments.
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