Recovery of anticipatory activity to restricted feeding in rats with ventromedial hypothalamic lesions.
Entrainment of circadian activity rhythms to a fixed daily mealtime was measured in intact and ventromedial hypothalamic (VMH) lesioned rats housed in tilt-cages. Intact rats showed a clear increase in activity for 2-3 hr prior to the 2 hr daytime feeding period. Anticipatory activity in lesioned rats was attenuated or absent during restricted feeding 5-9 weeks after surgery, but was evident in all rats, even those bearing apparently total VMH damage, during a second restricted feeding schedule 14-21 weeks after surgery. These results show recovery of function and argue against a necessary role for the VMH in food entrained rhythms.
D000818:Animals; D001143:Arousal / Q000502:physiology*; D001835:Body Weight; D001931:Brain Mapping; D002940:Circadian Rhythm; D003216:Conditioning, Operant / Q000502:physiology; D004435:Eating; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005508:Food Deprivation; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule; D014697:Ventromedial Hypothalamic Nucleus / Q000502:physiology*