Fluctuations in the vagal and sympathetic tone connected with the circadian cycle and the wakefulness-sleep cycle.
D000818:Animals; D002415:Cats; D002940:Circadian Rhythm; D004594:Electrophysiology; D012890:Sleep / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*