Effect of basal forebrain somatostatin and parvalbumin neurons in propofol and isoflurane anesthesia
Shuang Cai, A. Tang, Tianyuan Luo, Shao‐Cheng Yang, Huanhuan Yang, Chengxi Liu, Yue Shu, Yunchao Pan, Yu Zhang, Liang Zhou, Tian Yu, Shouyang Yu
Abstract
Abstract Aims The basal forebrain (BF) plays an essential role in wakefulness and cognition. Two subtypes of BF gamma‐aminobutyric acid (GABA) neurons, including somatostatin‐expressing (GABA SOM ) and parvalbumin‐positive (GABA Parv ) neurons, function differently in mediating the natural sleep–wake cycle. Since the loss of consciousness induced by general anesthesia and the natural sleep–wake cycle probably share similar mechanisms, it is important to clarify the accurate roles of these neurons in general anesthesia procedure. Methods Based on two transgenic mouse lines expressing SOM‐IRES‐Cre and PV‐IRES‐Cre, we used a combination of genetic activation, inactivation, and chronic ablation approaches to further explore the behavioral and electroencephalography (EEG) roles of BF SOM and BF Parv neurons in general anesthesia. After a single intravenous injection of propofol and the induction and recovery times of isoflurane anesthesia, the anesthesia time was compared. The changes in cortical EEG under different conditions were also compared. Results Activation of BF GABA SOM neurons facilitates both the propofol and isoflurane anesthesia, manifesting as a longer anesthesia duration time with propofol anesthesia and a fast induction time and longer recovery time with isoflurane anesthesia. Moreover, BF GABA SOM ‐activated mice displayed a greater suppression of cortical electrical activity during anesthesia, showing an increase in δ power bands or a simultaneous decrease in high‐frequency power bands. However, only a limited and nuanced effect on propofol and isoflurane anesthesia was observed with the manipulated BF GABA Parv neurons. Conclusions Our results suggested that BF GABA SOM neurons play a critical role in propofol and isoflurane general anesthesia, while BF GABA Parv neurons appeared to have little effect.