Changes in food intake with electrical stimulation of the ventromedial hypothalamus in dogs.

Six adult dogs were implanted stereotaxically with chronic indwelling Medtronic platinum-tipped electrodes in the left ventromedial hypothalamic area (VMH); two dogs with electrodes placed in the subcortical white matter served as controls. Following 24 hours of food deprivation, VMH-stimulated dogs delayed their next meal for a period ranging from 1 to 18 hours. When not stimulated, however, each dog ate immediately upon receiving its food and consumed greater than average daily intake (p less than 0.005). The two control dogs ate immediately upon receiving food regardless of whether they were stimulated or not. Dogs that received 1 hour of VMH stimulation every 12 hours for 3 consecutive days maintained an average daily food intake of 35% of normal baseline levels (range 13% to 51%), and water consumption averaged 50% of baseline intake (range 29% to 67%). Both of these results were statistically significant (p less than 0.01). After cessation of stimulation, food and water intake returned to normal within 6 to 9 days, with no observable "rebound hyperphagia." The two animals that received subcortical electrodes showed no change in food or water intake with stimulation. Blood pressure, pulse, respiration, temperature, and gross behavior were not altered during or after stimulation. These results suggest that the use of electrical stimulation of the VMH may be a useful modality for regulating food intake, and deserves further examination as a potential alternative therapy for human morbid obesity.