Cortico-basal ganglia mechanism of controlling forelimb movements in rodents

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03342
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 46030:Function of nervous system-related
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: Isomura Yoshikazu 東京医科歯科大学, 大学院医歯学総合研究科, 教授 (00415077)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 大脳皮質 / 大脳基底核 / 運動制御 / ラット / スパイク

Outline of Final Research Achievements

This study aimed to elucidate the mechanisms of neural circuits in the cerebral cortex and basal ganglia that control the expression of forelimb movements. We analyzed spike activity in these brain areas of head-fixed rats performing forelimb movement tasks. We found lateral dominance changes exhibited by primary and secondary motor cortex neurons with parkinsonian lesions caused by 6-OHDA. We also analyzed the motor- and reward-related activity of projection neurons in the substantia nigra pars compacta and striatum, as well as the timing of activity of hippocampal and entorhinal neurons. Moreover, we have developed automatized spike collision tests to identify the projection of recorded neurons, optimized photoactive opsins for the spike collision test, and established a new method for analyzing the timing of neural spike activity.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

私たちが手や足を意のままに動かす随意運動を実現する神経回路の仕組みはまだ十分には解明されていない。パーキンソン病などの神経疾患では大脳皮質-基底核回路に異常が生じて運動発現や制御に障害が出現する。本研究は独自に開発したラットの運動発現課題を活かし、さまざまな外界状況における大脳皮質や大脳基底核の神経細胞活動の特性を解明した。また、神経活動の定量的解析手法や領域間信号の計測法などの実験解析技術も開発した。これらの研究成果は神経科学の基礎的基盤を一層強固にするとともに、神経疾患の病態生理の理解にもつながると期待される。