Sexual interactions of maturing male guinea pigs with their mothers, sisters, and unfamiliar adult females in the home cage

Abstract

During observations in the home cage in the light and dark on days 5, 15, 25, 35, and 45, male guinea pigs mounted and exhibited anogenital investigation of the mother, though appropriately directed mounting occurred infrequently and was not shown by all males. Mothers nipped and kicked advancing males. No mounting of a female sibling was observed. When behavioral interactions of approximately 35-day-old males with the mother or an unfamiliar adult female were compared during 1-hr tests in the home cage, males exhibited much higher levels of mounting and anogenital investigation, and received many more nips and kicks, when with the unfamiliar female. The results 1) demonstrate that limited maternally directed sexual behavior occurs in the home cage, 2) support earlier findings indicating that continuous housing with the mother suppresses maternally directed sexual behavior in periadolescent guinea pig males, and 3) suggest that sexual behavior toward female siblings also is suppressed.

Prenatal glucocorticoid exposure alters hypothalamic–pituitary–adrenal function and blood pressure in mature male guinea pigs

“…We suggested that the increase in hippocampal MR expression, combined with the increase in plasma testosterone, which is known to inhibit HPA function in the rat (Viau et al 1999), resulted in reduced HPA function. Male guinea pigs are sexually mature by approximately 8 weeks of age (Hennessy et al 2003). Castration of male guinea pigs, rats and hamsters has been shown to increase ACTH and cortisol production as well as CRH and arginine vasopressin (AVP), while androgen replacement reversed this effect (El Hani et al 1980; Viau & Meaney, 1991; Handa et al 1994; McCormick et al 1998).…”

Social Preferences of Developing Guinea Pigs (Cavia porcellus) From the Preweaning to the Periadolescent Periods.

“…& Pitstick, 2003). Similarly, the females can exhibit adultlike social behavior and sometimes reach sexual maturity by this age (Young, 1969).…”

“…Although offspring maintained with the mother several weeks after weaning appear to treat her much as do preweaning pups, sexual motivation is emerging at this age (i.e., ∼5–7 weeks). The males readily direct courtship and sexual behavior toward unfamiliar adult females (Hennessy, Reed, Wilson, & Pitstick, 2003). Similarly, the females can exhibit adultlike social behavior and sometimes reach sexual maturity by this age (Young, 1969).…”