Spread of damage produced by electrolytic lesions in the hypothalamus.

Demonstrated, in 2 experiments with 13 female albino Sprague-Dawley rats, the progressive and systematic expansion of behavioral deficits caused by electrolytic lesions in the hypothalamus. The effects continued to develop over several hours of testing after lesioning. The expansion affected electrical brain stimulation. Thresholds for positive and aversive brain stimulation rose and the intensity-response functions for self-stimulation changed progressively. The effects appear unrelated to general debility since contralateral stimulation was unaffected. Exp II showed systematically developing deficits in ingestive behavior. Immediate or quickly developing deficits in water drinking were followed by rejection of liquid food and less palatable solid food. Motor coordination progressively deteriorated. The phenomena provide a tool for systematic analysis of deficits and perhaps prediction of the course of recovery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)