RESUMO
<p><b>OBJECTIVE</b>To observe the role of NB127914, a CRF R1 receptor antagonist, in the regulation of neonatal sleep/wake cycle.</p><p><b>METHODS</b>Rat pups were surgically implanted with electrodes at postnatal day(PN) 13. At PN 14, 6 hours polysomnographic recording data were continuously collected before and after administration of various doses of NBI 27914, atropine and the same amount of saline.</p><p><b>RESULTS</b>Compared with baseline, rapid eye movement (REM) sleep was significantly reduced and was replaced primarily by non-REM (NREM) sleep in all groups treated with NBI, but not with dimethyl sulfoxide/saline. Atropine suppressed REM sleep significantly and increased wakefulness simultaneously.</p><p><b>CONCLUSION</b>Blockage of corticotropin-releasing factor (CRF) R1 receptors deprives neonatal rat REM sleep.</p>