Cerebrospinal fluid contacting nucleus and its 5-HT: A new insight into the regulation mechanism of general intravenous anesthesia

• Published in: Brain research 2023-01, Vol.1798, p.148168-148168, Article 148168
• Main Authors: Zhai, Xiaomeng, Yuan, Yumin, Xu, Lingling, Jiang, Jun, Li, Ying, Yan, Yao, Zhang, Licai
• Format: Article
• Language: English
• Subjects: 5-HT; Anesthesia, Intravenous; Anesthetics, Intravenous - pharmacology; Animals; Cell Nucleus; Cerebrospinal fluid contacting nucleus (CSF-contacting nucleus); General anesthesia; Propofol - pharmacology; Rats; Serotonin
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2022.148168

[Display omitted] •“Knockout” CSF-contacting nucleus increased the number of LF δ waves and decreased HF β waves.•During recovery from general anesthesia, CSF-contacting nucleus “knockout” prolonged the RORR time.•Activation 5-HT neurons in the CSF-contacting nucleus promoted recovery from general anesthesia.•CSF-contacting nucleus and its 5-HT neurons participate in regulating the effect of general anesthesia. General anesthesia is one of the most common clinical anesthesia methods. Many studies have suggested that 5-HT plays an important role in the mechanism of general anesthesia, but its basic principle is still unclear. The cerebrospinal fluid (CSF)-contacting nucleus, which we identified 30 years ago, contains a large number of 5-HT neurons. In the brain, many of the nuclei involved in regulating the effects of general anesthesia send projections to the CSF-contacting nucleus. Does the CSF-contacting nucleus and its 5-HT neurons participate in regulating the effect of general anesthesia? This is a new and interesting scientific question. To answer this question, rats underwent general anesthesia by intravenous injection of propofol. During the maintenance of and recovery from general anesthesia, the protein expression of c-Fos in the CSF-contacting nucleus was significantly increased. “Knockout” of this nucleus significantly increased the of number of low-frequency δ waves, which are indicative of deep anesthesia, during general anesthesia maintenance; however, the number of high-frequency β waves, which indicate consciousness, was significantly decreased. During recovery from general anesthesia, the recovery of the righting reflex (RORR) time of rats with CSF-contacting nucleus ablation was significantly prolonged; activation of 5-HT neurons in the CSF-contacting nucleus promoted recovery from general anesthesia, while inhibition of 5-HT neurons in the CSF-contacting nucleus delayed recovery from general anesthesia. The above results suggest that the CSF-contacting nucleus and its 5-HT neurons play a key role in regulating the effect of intravenous anesthesia, especially during recovery from general anesthesia.