title: Diurnal variation in performance of free-operant avoidance behavior of rats.
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology; D002940:Circadian Rhythm; D003216:Conditioning, Operant / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000502:physiology; D051381:Rats