Effect of Rapid Changes of Light/Dark Cycle on Cholinesterase Activity in the Cerebellum and Prefrontal Cortex of Rats

Spaceflight poses unique physiological stressors, including circadian rhythm disruption, which can impact astronaut health and brain function.

This study investigated the effects of rapid day/night changes on cholinesterase activity in the rats’ cerebellum and prefrontal cortex.

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.

Mean cholinesterase activity was significantly lower in rats exposed to circadian disruption than in the control group (P < 0.05).

It seems that cholinesterase activity in rats’ cerebellum and prefrontal cortex reduces following exposure to rapid light/dark rhythm.