Identification of neural circuit responsible social function in social isolation animal model : focusing on medial prefrontal cortex - pons - cerebellum

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K08078
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52030:Psychiatry-related
• Research Institution: Nara Medical University
• Principal Investigator: Yoshino Hiroki 奈良県立医科大学, 医学部, 研究員 (10347560)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 社会性 / 孤立 / 内側前頭前野 / 錐体細胞 / 興奮性 / 橋

Outline of Final Research Achievements

We previously found that juvenile isolated housing of mice decreased the excitability of specific pyramidal cells (characterized by producing h-current upon hyperpolarization) in layer 5 of the adult medial prefrontal cortex. As it is known that this specific pyramidal cell projects axons to the subcortical brain area, such as thalamus, striatum, pons, etc. we investigated which pyramidal cell projecting axons to subcortical area juvenile social isolation affect. Pyramidal cells that project axons to the thalamus, striatum, and pons were identified and electrophysiologically recorded after the juvenile isolated housing. The electrophysiological properties of the pyramidal cells with each axonal projection target were different in the healthy group, and the isolated housing affected the pyramidal cells projecting axon to pons.

Free Research Field

精神医学

Academic Significance and Societal Importance of the Research Achievements

幼若期に社会的刺激を奪うことで発達異常がみられる神経回路の一つとして前頭前野－橋を提示することができた。橋は小脳への入力の中継として機能しており、これまで社会的機能との関係が報告されてきた小脳が、社会的刺激によって発達すると今回提示できた前頭前野－橋の回路の先にあるのではないかと考えられた。ヒトにおいて幼少期にネグレクトを受けたり、もしくは社会的接触が減少しやすい発達の問題（自閉症スペクトラム障害）を抱えていると、今回示した神経回路の発達が十分行われずに成長し、大人になってから社会性を中心とした脳機能障害を抱える可能性について提示できた。