2007 Volume 30 Issue 10 Pages 1895-1897
Stress has been known to release corticotropin-releasing factor (CRF) and have an affect on sleep–wake patterns. However, there is no direct evidence of CRF receptor agonist and antagonist on sleep–wake patterns. Therefore, this study aimed to clarify this point by using radiotelemetry system in conscious rats. Wake, non-rapid eye-moving (NREM) sleep and rapid eye-moving (REM) sleep were analyzed by computer software, simultaneously measuring electroencephalogram and electromyogram. In the light period, urocortin (CRF receptor agonist: i.v.) significantly increased wake duration, and decreased NREM sleep duration. REM sleep was not affected. Astressin (CRF receptor antagonist: i.p.) significantly attenuated the changes induced by urocortin, although astressin itself did not affect the sleep–wake pattern in the light period at this dosage. These findings show that urocortin changes the sleep–wake pattern in the light period. Moreover, urocortin was found to change the sleep–wake pattern by acting on CRF receptor, as astressin significantly attenuated the urocortin-induced changes on sleep–wake patterns.
