title: Effects of various photoperiods on the temporal distribution of paradoxical sleep in rats.
mesh_terms: D000818:Animals; D001143:Arousal; D002540:Cerebral Cortex / Q000502:physiology; D003213:Conditioning, Psychological; D003624:Darkness; D004569:Electroencephalography; D005260:Female; D006624:Hippocampus / Q000502:physiology; D008027:Light; D008032:Limbic System / Q000502:physiology; D009799:Ocular Physiological Phenomena; D010870:Pineal Gland / Q000502:physiology; D051381:Rats; D012894:Sleep Stages; D012895:Sleep, REM; D013016:Sound; D013997:Time Factors