Effect Of Circadian Disruption On Behavior,health,and The Expression Of Clock Genes In Mice

The synchronization of the internal clock with the external clock is essential to the normal operation of the body.When body clock is disturbed by abnormal light/dark schedules,the body usually needs several days to adjust the internal clock to synchronize with the external clock.However,it is not well known how repeated shifts in a short period affect the re-entrainment capacity,and the impact on health is not yet clear;at the same time,in another common circadian disruption,constant darkness environment,the dynamic oscillation process of endogenous circadian clock genes in various tissues in mice is also unclear.The research contents of this article are as follows:(1)In two months,C57BL/6 mice were treated multiple 6-hour phase advance shift(+6,which is equivalent to eastward crossing 6 time zones)and then delayed by 6 hours(-6,which is equivalent to westward crossing 6 times zones,or give reverse phase shift processing,realtime monitoring of mice running wheel movement.The results showed that in the same direction repeated phase shift,the number of days of re-entrainment decreased gradually irrespective of the shift direction.In the second stage,however,during which mice were treated with reversed 6-hour shifts,re-entrainment in the mice treated with advance shifts,but not delay shifts,were significantly prolonged.(2)After various phase shift treatments,mice were given intraperitoneal injection of bacterial lipopolysaccharide(LPS)to induce a sepsis model to monitor the health of the mice to understand whether different types of phase shift have different effects on health.The results obtained that the short-term multiple +6 phase shift treatments have a higher lethality in sepsis model mice than multiple-6 phase shift treatments.Among them,the +6 phase shift group,which was set by shorten the light time instead of the dark time had the highest mortality rate.(3)In constant darkness environment,the dynamic changes of the expression oscillations of 7 core circadian clock genes in mouse liver,white adipose tissue and brown adipose tissue were detected.Finally,after the mice are placed in a constant darkness environment for 6 weeks,per3 gene in the liver and bmal1 gene in white adipose tissue can still maintain a certain rhythm.But the amplitude,phase and period of their oscillations have changed;and the remaining part of the clock genes and all the circadian clock genes in brown adipose tissue disappeared.These results indicate that:(1)adaptation to multiple phase shifts in a short period was...