Effects of general anesthesia on behavioral circadian rhythms and clock-gene expression in the suprachiasmatic nucleus in rats.

Tomoki Mizuno
Shimpei Higo
Nobutaka Kamei
Keisuke Mori
Atsuhiro Sakamoto
Hitoshi Ozawa

The suprachiasmatic nucleus (SCN) of the hypothalamus is a nucleus that regulates circadian rhythms through the cyclic expression of clock genes. It has been suggested that circadian-rhythm-related
 adverse postoperative events
 including sleep disturbances and delirium
 are partly caused by anesthesia-induced disruption of clock-gene expression. We examined the effects of multiple general anesthetics on the expression cycle of Period2 (Per2)
 one of the clock genes that regulate circadian rhythms in the SCN
 and on the behavioral rhythms of animals. Rats were treated with sevoflurane
 propofol
 and dexmedetomidine for 4?h. The expression of Per2 in SCN was analyzed using in?situ hybridization
 and the behavioral rhythm before and after anesthesia was analyzed. Per2 expression in the SCN decreased significantly immediately after anesthesia in all groups compared with corresponding control groups. However
 Per2 returned to normal levels within 24?h
 and there was no phase change in the gene expression cycle or behavioral rhythm. This study suggests that acute suppression of Per2 expression may be a general phenomenon induced by general anesthesia
 but that the molecular mechanism of the body clock is resilient to disturbances to some extent.

Histochemistry and cell biology

10.1007/s00418-022-02113-0

https://doi.org/10.1007/s00418-022-02113-0
https://www.ncbi.nlm.nih.gov/pubmed/35614272