Auditory input to the external globus pallidus neurons and it's functions in the basal ganglia network

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K06532
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 46030:Function of nervous system-related
• Research Institution: Hokkaido University (2021); Doshisha University (2018-2020)
• Principal Investigator: Hirai Yasuharu 北海道大学, 医学研究院, 博士研究員 (30648431)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 大脳基底核 / 聴覚 / 淡蒼球外節 / ラット / 電気生理学

Outline of Final Research Achievements

The basal ganglia are well studied from the aspect of somato-motor functions. However, the anatomical and physiological features of special sense processing of the basal ganglia is mostly unknown. We obtained in vivo unit recordings from rat external globus pallidus (GPe) neurons and found most of them responded to the sound excitatory. The sound responded neurons were limited to the caudo-lateral part of GPe. Retrograde tracer injections revealed that the prospective origins of the excitatory responses were lateral part of the subthalamic nucleus, medial division of the medial geniculate thalamic nucleus and lateral cortical areas including higher-order auditory and limbic areas, where are the parts of “non-lemniscal auditory pathway”. Furthermore, we confirmed that caudo-lateral GPe projected to the lateral part of the substantia nigra (SNpl). It indicated that the sound-responded GPe neurons may contribute to the function of saliency responded dopamine neurons in the SNpl.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

大脳基底核はほぼ全ての大脳皮質領野から入力を受けており、運動、認知、情動、学習など多くの機能に関わっている。淡蒼球外節は線条体から抑制性の入力を受け、大脳基底核全体に脱抑制により情報を伝達するとされる間接路の主要神経核である。聴覚を含む特殊感覚が淡蒼球外節を介して大脳基底核の活動にどのように影響を与えるのかについてはまだほとんどわかっていない。本研究では、従来の大脳基底核スキームと反した、興奮性の音刺激応答や、音応答する淡蒼球外節領域の主要な入出力経路を明らかにできた。これらは今後、パーキンソン病患者でしばしば見られる幻聴の発生機序の解明やその対策に寄与する基礎情報となることが期待できる。