Sleep deprivation and sleep recovery modifies connexin36 and connexin43 protein levels in rat brain.

Gap junctional communication is mainly mediated by connexin36 and connexin43 in neurons and astrocytes, respectively. It has been suggested that connexin36 allows electrical coupling between neurons whereas connexin43 participates in several process including release of ATP. It was recently reported that blockage of gap junctional communication mediated by connexin36 can disrupt the sleep architecture of the rat. However, there is no experimental approach about effects of sleep deprivation on connexins expression. Therefore, we examined in adult male Wistar rats whether protein levels of connexin36 and connexin43 change in pons, hypothalamus, and frontal cortex after 24 h of total sleep deprivation and 4 h of sleep recovery. Western blot revealed that total sleep deprivation significantly decreases the levels of connexin36 in the hypothalamus and this decrease maintains after sleep recovery. Meanwhile, connexin43 is not altered by total sleep deprivation but interestingly the sleep recovery period induces an increase of this connexin. These results suggest that electrical coupling between hypothalamic neurons could be altered by sleep deprivation and that sleep recovery drives changes in connexin43 expression probably as a mechanism related to ATP release and energy regulation during sleep.