Neuronal mechanisms of propofol-induced alpha rhythm in rat cerebral cortex

2015 Fiscal Year Final Research Report

• Project/Area Number: 25463150
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Nihon University
• Principal Investigator: OI Yoshiyuki 日本大学, 歯学部, 教授 (60271342)
• Co-Investigator(Kenkyū-buntansha): KOBAYASHI Masayuki 日本大学, 歯学部, 准教授 (00300830) ; KOYANAGI Yuko 日本大学, 歯学部, 助教 (20609771)
• Research Collaborator: YOKOTA Eiko 日本大学, 歯学部・大学院
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: プロポフォール / 大脳皮質 / 脳波 / アルファ周波数帯 / fast-spiking細胞 / 抑制性シナプス伝達 / GABA(A)受容体 / ホールセル・パッチクランプ法

Outline of Final Research Achievements

The general anesthetic propofol raises frontal alpha rhythm at the dose that is sufficient to induce loss of consciousness. However, the neural mechanisms of propofol-induced alpha rhythm in the cerebral cortex remain unknown. Using dual whole-cell patch clamp technique, we found that the fast-spiking cell (FS) to pyramidal cell (Pyr) connections exhibited greater enhancement of unitary inhibitory postsynaptic current compared to FS→FS/non-FS and non-FS→Pyr/FS/non-FS connections. In addition, triple whole-cell patch clamp recordings were performed from one FS and two Pyr which were received inhibitory input from the FS. We found that propofol reduced the coefficient of variation of spike timing among postsynapic Pyr during FS activation. These results suggest that propofol facilitates Pyr firing synchrony by enhancing inhibitory inputs from FS. This synchrony of Pyr may induce the frontal alpha rhythm that associates with propofol-induced loss of consciousness.

Free Research Field

麻酔学