Electrophysiological correlates of diurnal feeding rhythm disruption in rats.

Electrical activity was recorded simultaneously from Ventromedial (VMH) and Lateral Hypothalamus (LH) in chronically prepared rats before and during one hour gustation tests as also during and after food intake in Group I (ad lib feeding) and Group II (3-hour food schedule) animals. The VMH/LH activity designated as Response Ratio (RR) was calculated and gave a better index of the food related behaviour. The basal RR was higher in Group I as compared to Group II rats but the response to glucose and saccharin ingestion showed a differential pattern of decrease after glucose intake in Group I and an increase in Group II. By contrast, on saccharin intake, Group I showed an increase. RRs after food intake did not show a significant change in both Group I and II rats.