The effecTS of ReM Sleep depRIvaTIoN aNd ReM Sleep RebouNd oN hypocReTIN levelS IN MIce bRaINS

background and objective: Hypocretins (orexins) are recently discovered neuropeptides that are produced in a very restricted area of the lateral hypothalamus. These peptides were originally associated with feeding behavior, but have come to be viewed as essential in causing narcolepsy and regulating sleep. Narcolepsy is a sleep disorder associated with REM sleep abnormalities, and it is likely that hypocretins play a major role in regulation of this sleep stage. Methods: To verify the potential effects of REM sleep deprivation on the levels of hypocretins in the brain, we deprived mice of REM sleep for 96 h and measured the levels of hypocretins in whole brain preparations using an enzyme immunoassay. Results: Our results showed no difference in the levels of hypocretin 1 and 2 (orexin A and B) in REM sleep-deprived animals or in animals that had a sleep rebound after sleep deprivation. conclusions: These results corroborate data in the literature that show that sleep deprivation does not produce significant alteration in hypocretin levels in the mouse brain just after an active period.