Self-stimulation and body weight in rats with lateral hypothalamic lesions.

KEESEY, RICHARD E., AND TERRY L. POWLEY. Self-stimulation and body weight in rats with lateral hypothalamic lesions. Am. J. Physiol. 224(4) : 970-978. 1973.-Electrical self-stimulation of the posterior hypothalamus and ventral tegmentum was either eliminated or severely depressed in male rats following placement of lateral hypothalamic lesions. Though the rate of responding increased over the next 2-3 weeks, the terminal level of self-stimulation (expressed as a proportion of the stable postlesion to prelesion rate) averaged only 55y0 and was inversely related to the extent of lateral hypothalamic destruction (Y = -. 79). Body weight also declined in the postlesion period and a new maintenance level (83% of normal) was reached in the third postlesion week. This reduced level of weight maintenance was also inversely related to the percentage of lateral hypothalamic damage (Y = .86) and directly related to the chronic reduction in selfstimulation rate (Y = +. 79). A model relating central reward to the regulation of body weight is discussed.