Effects of medial preoptic-anterior hypothalamic lesions on development of sociosexual behavior in dogs

Bilateral medial preoptic-anterior hypothalamic lesions in adult male dogs eliminate or impair copulatory behavior and reduce urine-marking responses but do not affect aggressive behavior. The present study examined the emergence of the adult forms of these same male sociosexual behavioral patterns when the lesions were made prior to puberty. 18 beagle puppies were allowed to interact with male peers during development. Ss with lesions had reduced frequency of juvenile mounting and an almost total absence of male copulatory activity in adulthood. Urine-marking and aggressive behavior in the juvenile and adult periods were not affected by the lesions. Findings reveal a sparing of function with regard to urine-marking but not sexual behavior. (PsycINFO Database Record (c) 2006 APA, all rights reserved).