Regulation mechanisms of the critical period by endocannabinoid

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K06523
• 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: Tottori University
• Principal Investigator: HATA Yoshio 鳥取大学, 医学部, 教授 (40212146)
• Co-Investigator(Kenkyū-buntansha): 亀山 克朗 鳥取大学, 医学(系)研究科(研究院), 助教 (80446517)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 神経回路 / 視覚系 / 臨界期 / 内因性カンナビノイド

Outline of Final Research Achievements

Ocular dominance plasticity of the mammalian visual system is a representative plasticity of the cerebral cortex. In animals lacking the endogenous cannabinoid synthase DGLα, the timing of the critical period of ocular dominance plasticity is accelerated. Since the maturation of inhibitory neuronal circuits is involved in the initiation of the critical period, we examined the possibility that the maturation of inhibitory neuronal circuits is earlier in DGLα-deficient animals. We found that the frequency of mIPSCs, which represent inhibitory synaptic transmission, increased in DGLα-deficient animals before the critical period, and that pharmacological suppression of GABA receptor function abolished ocular dominance plasticity. These results suggest that the endogenous cannabinoid system may be involved in the control of critical period timing through the maturation of inhibitory neural circuits.

Free Research Field

発達神経科学

Academic Significance and Societal Importance of the Research Achievements

脳発達の臨界期の開始には大脳皮質の抑制性神経回路の成熟が関わることが知られているが、その制御メカニズムは不明な点が多い。今回、内因性カンナビノイド合成酵素の欠損が抑制性神経回路の早期成熟につながることを見出した。この成果は臨界期制御の理解を深めるとともに、シナプス伝達の調節因子として知られる内因性カンナビノイドの、抑制性神経回路の成熟を介して脳発達にかかわるという新しい役割を提示する。