Exogenous Androgen and Non-Directed Hyperexcitability in Castrated Male Guinea Pig.

Abstract

An apparently non-directed hyperexcitability, inversely dependent on the level of androgen, occurs in male guinea pigs. The behavior is described as a sudden straightening of the limbs, a jumping off the floor and frequently, by a turning of the head. Intact males display it sporadically, but the frequency increases after castration and reaches a peak when copulatory behavior becomes least. Following injections of 25 [mu]g or more testosterone propionate per 100 g body wt. daily the frequency of hyperexcitability decreased sharply. Within a week display of the behavior reached the level seen in the intact controls. Injn. of 12.5 [mu]g of the hormone did not eliminate the increase which followed castration.