Sevoflurane-induced cognitive effect on α7-nicotine receptor and M1 acetylcholine receptor expression in the hippocampus of aged rats

BackgroundSevoflurane treatment increases the incidence of postoperative cognitive dysfunction (POCD), and patients with POCD show a decline in cognitive abilities compared to preoperative levels. ObjectivesThis study aimed to investigate whether the activation of alpha 7 nicotinic acetylcholine receptor (alpha 7nAChR) and the expression of M1 acetylcholine receptor (mAChR M1) in the hippocampus affects the cognitive function of aged rats. MethodsForty-eight Sprague-Dawley (SD) rats of 1-week- and 12-months-old were divided into eight groups: four groups for alpha 7nAChR and four groups for mAChR M1, respectively. All SD rats received 1.0-02% sevoflurane for alpha 7nAChR and 1.0-02% sevoflurane for mAChR M1 for 2-6 h, respectively. The Y-maze test was used to assess the ability to learn and memory after receiving sevoflurane for 7 days at the same moment portion. RT-PCR was used to determine the expression of alpha 7nAChR and mAChR M-1 in the hippocampus of rats. ResultsThe alpha 7nAChR mitigated the formation of sevoflurane-induced memory impairment by modulating the translocation of NR2B from the intracellular reservoir to the cell surface reservoir within the hippocampus. Next, sevoflurane-induced decline of cognitive function and significantly decreased mAChR M1 expression at mRNA levels. Conclusion alpha 7nAChR regulates the trafficking of NR2B in the hippocampus of rats via the Src-family tyrosine kinase (SFK) pathway. This regulation is associated with cognitive deficits induced by sevoflurane in hippocampal development. Sevoflurane affects the cognitive function of rats by suppressing the mAChR M1 expression at mRNA levels in the hippocampus.