EFFECT OF PREOPTIC AND ANTERIOR HYPOTHALAMIC LESIONS ON BEHAVIORAL THERMOREGULATION IN COLD

Studied the ability of 26 adult male Sprague-Dawley rats to regulate body temperature in a cold environment by behavioral means following hypothalamic lesions using a heat-reinforced operant procedure. The most consistent consequence of preoptic and anterior lesions was an increased rate of response for radiant heat reinforcement; in spite of this, posttest rectal temperature was often low. Transient or minor changes were noted in some Ss with preoptic or anterior lesions, and in those with posterior and septal lesions. Data indicate that: (1) deficits in physiological regulation in the cold can be obtained following rostral hypothalamic damage, (2) the effective lesion site is primarily but not exclusively the medial preoptic region, and (3) behavioral compensation for an impaired regulatory ability occurs. (24 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.