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

Abstract

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 emergence of the adult forms of these same male sociosexual behavioral patterns were examined when the lesions were made prior to puberty. The subjects were allowed to interact with male peers during development. Animals 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. A sparing of function with regard to urine-marking but not sexual behavior was discussed.