Lateral Hypothalamic Area Glutamatergic Neurons and Their Projections to the Lateral Habenula Modulate the Anesthetic Potency of Isoflurane in Mice / 神经科学通报·英文版

The lateral hypothalamic area (LHA) plays a pivotal role in regulating consciousness transition, in which orexinergic neurons, GABAergic neurons, and melanin-concentrating hormone neurons are involved. Glutamatergic neurons have a large population in the LHA, but their anesthesia-related effect has not been explored. Here, we found that genetic ablation of LHA glutamatergic neurons shortened the induction time and prolonged the recovery time of isoflurane anesthesia in mice. In contrast, chemogenetic activation of LHA glutamatergic neurons increased the time to anesthesia and decreased the time to recovery. Optogenetic activation of LHA glutamatergic neurons during the maintenance of anesthesia reduced the burst suppression pattern of the electroencephalogram (EEG) and shifted EEG features to an arousal pattern. Photostimulation of LHA glutamatergic projections to the lateral habenula (LHb) also facilitated the emergence from anesthesia and the transition of anesthesia depth to a lighter level. Collectively, LHA glutamatergic neurons and their projections to the LHb regulate anesthetic potency and EEG features.

Thalamic paraventricular nucleus mediates orexinergic neurons-induced promotion of emergence from general anesthesia in mice: evaluation using optogenetics method / 中华麻醉学杂志

Objective To evaluate whether the thalamic paraventricular nucleus mediates orexiner-gic ( orexin ) neurons-induced promotion of emergence from general anesthesia by using the optogenetics method in mice. Methods Twenty healthy male Hcrt-cre mice, aged 8-10 weeks, weighing 20-25 g, were divided into 4 groups ( n=5 each) using a random number table method: retrograde labeled viruses channelrhodopsin group ( R group) , anterograde labeled viruses channelrhodopsin group ( A group) , retro-grade labeled viruses control group ( RC group ) , and anterograde labeled viruses control group ( AC group) . The optogenetics technique was used in each group. Anesthesia was induced and maintained through inhaling 1％ isoflurane and pure oxygen 1. 0 L∕min. Electroencephalogram was monitored througout the procedure with the PowerLab monitoring system. The burst suppression ratio ( BSR) was recorded at 1 min before light stimulation and during light stimulation. Results Compared with RC group or the baseline at 1 min before light stimulation, the BSR was significantly decreased during light stimulation in R group ( P<0. 05) . Compared with AC group or the baseline at 1 min before light stimulation, the BSR was signifi-cantly decreased during light stimulation in group A ( P<0. 05) . Conclusion Optogenetics technique ap-plication once again confirms that orexin neurons can promote emergence from general anesthesia through thalamic paraventricular nucleus in mice.