Elucidating the network mechanisms controlling flexible neuronal activity in the striatum

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06418
• 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
• Principal Investigator: Okada Ken-ichi 北海道大学, 医学研究院, 助教 (80790956)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 大脳皮質－大脳基底核ループ / 線条体 / 行動選択 / 眼球運動 / 霊長類

Outline of Final Research Achievements

The basal ganglia play a pivotal role in adaptive behavioral control. The long-term changes in the striatal neuronal activity are known to be associated with the changes in cortico-striatal transmission. However, it remains unknown whether similar changes can occur rapidly within each trial. To address this, in monkeys performing oculomotor tasks, we electrically stimulated the supplementary eye field (SEF) and assessed the strength of cortico-striatal transmission by measuring local field potentials and single neuron activities in the caudate nucleus. Many caudate neurons responded to SEF stimulation with a short latency (23.8 ± 4.3 ms), and the stimulation effect was dependent on the phase and amplitude of striatal beta oscillations. These results suggest that cortico-striatal transmission is dynamically regulated by local oscillatory activity, which may underlie the rapid changes in striatal neuronal activity for different task demands.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

これまでに、数日程度の長い時間スケールで起こる強化学習において、皮質線条体経路のシナプス効率やLFP相関の変化が報告されてきた。より短い時間スケールにおいても線条体LFPに伴い機能結合が調整されるという本研究の成果は、時間スケールに関わらず神経活動を変化させる共通のメカニズムが働いていることを示唆している。また、パーキンソン病では大脳基底核でのβ律動の亢進がみられ、柔軟なルール切替えに障害がある。β律動と行動選択の関係を示した本研究の成果をもとに、更なる病態の解明が進むことが期待される。