GABAergic neurons in the dorsomedial hypothalamus regulate states of consciousness in sevoflurane anesthesia

The neural inhibitory gamma-aminobutyric acid (GABA) system in the regulation of anesthetic consciousness is heterogeneous, and the medial hypothalamus (MH), consisting of ventromedial hypothalamus (VMH) and dorsomedial hypo-thalamus (DMH), plays an important role in sleep and circadian rhythm. However, the role of MH GABAergic neurons (MHGABA) in anesthesia remains unclear. In this study, we used righting reflex, electroencephalogram (EEG), and arousal behav-ioral score to evaluate the sevoflurane anesthesia. Activation of MHGABA or DMHGABA neurons prolonged the anesthesia induction time, shortened the anes-thesia emergence time, and induced EEG arousal and body movement during anesthesia; meanwhile, VMHGABA neurons activated only induced EEG changes during 1.5% sevoflurane anesthesia. Furthermore, inhibition of DMHGABA neu-rons significantly deepened sevoflurane anesthesia. Therefore, DMHGABA neu-rons exert a strong emergence-promoting effect on induction, maintenance, and arousal during sevoflurane general anesthesia, which helps to reveal the mechanism of anesthesia.

Automated summary

The GABA system in the central nervous system plays a crucial role in regulating anesthetic consciousness. The medial hypothalamus, including the ventromedial hypothalamus and dorsomedial hypothalamus, is involved in sleep and circadian rhythm. However, the specific role of GABAergic neurons in the medial hypothalamus in anesthesia is still unknown.