Neurobiological basis of emergence from anesthesia

• Published in: Trends in neurosciences (Regular ed.) Vol. 47; no. 5; pp. 355 - 366
• Main Authors: Song, Xue-Jun, Hu, Jiang-Jian
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2024
• Subjects: Anesthesia - methods; Anesthesia Recovery Period; Anesthetics - pharmacology; Animals; Brain - drug effects; Brain - physiology; consciousness; Consciousness - drug effects; Consciousness - physiology; GABAA receptors; Humans; KCC2; neural circuits; NMDA receptors; sleep; sleep; consciousness; KCC2; NMDA receptors; neural circuits; GABAA receptors; GABA(A) receptors
• ISSN: 0166-2236; 1878-108X
• DOI: 10.1016/j.tins.2024.02.006

Anesthesia is proposed to have different underlying mechanisms in terms of molecular targets and neural circuits.Emergence from anesthesia is a dynamic process that is driven by the brain’s inherent abilities and can be partially controlled, in addition to being dependent on anesthetic elimination.Animal-model studies indicate that the recovery of consciousness from the minimally responsive state during anesthesia is a molecularly distinct process from the behavioral recovery observed after anesthesia is discontinued.There are similarities and differences in the nuclei, neural circuits, neurotransmitters, and arousal systems involved in emergence from anesthesia and awakening from sleep. The suppression of consciousness by anesthetics and the emergence of the brain from anesthesia are complex and elusive processes. Anesthetics may exert their inhibitory effects by binding to specific protein targets or through membrane-mediated targets, disrupting neural activity and the integrity and function of neural circuits responsible for signal transmission and conscious perception/subjective experience. Emergence from anesthesia was generally thought to depend on the elimination of the anesthetic from the body. Recently, studies have suggested that emergence from anesthesia is a dynamic and active process that can be partially controlled and is independent of the specific molecular targets of anesthetics. This article summarizes the fundamentals of anesthetics’ actions in the brain and the mechanisms of emergence from anesthesia that have been recently revealed in animal studies. The suppression of consciousness by anesthetics and the emergence of the brain from anesthesia are complex and elusive processes. Anesthetics may exert their inhibitory effects by binding to specific protein targets or through membrane-mediated targets, disrupting neural activity and the integrity and function of neural circuits responsible for signal transmission and conscious perception/subjective experience. Emergence from anesthesia was generally thought to depend on the elimination of the anesthetic from the body. Recently, studies have suggested that emergence from anesthesia is a dynamic and active process that can be partially controlled and is independent of the specific molecular targets of anesthetics. This article summarizes the fundamentals of anesthetics’ actions in the brain and the mechanisms of emergence from anesthesia that have been recently revealed in animal studies.