effect of rapid changes of light/dark cycle on cholinesterase activity in the cerebellum and prefrontal cortex of rats

Background: spaceflight poses unique physiological stressors, including circadian rhythm disruption, which can impact astronaut health and brain function.objectives: this study investigated the effects of rapid day/night changes on cholinesterase activity in the rats' cerebellum and prefrontal cortex. methods: rats were divided into 2 groups (n = 8 per group): control and circadian disruption with a 45-minute light/45-minute dark cycle. after 14 days of intervention, the cerebellum and prefrontal cortex were harvested from each rat. the samples were washed in ice-cold normal saline solution, weighed, homogenized in phosphate buffer using 1 ml of buffer per 100 mg of tissue, and centrifuged. moreover, the supernatants were used for the measurement of cholinesterase activity by the photometric method. results: mean cholinesterase activity was significantly lower in rats exposed to circadian disruption than in the control group (p < 0.05). conclusions: it seems that cholinesterase activity in rats' cerebellum and prefrontal cortex reduces following exposure to rapid light/dark rhythm.