EARLY POSTNATAL EXPERIENCE MODIFIES ACTIVATION OF THE PITUITARY-TESTICULAR COMPLEX IN MALE HOUSE MICE (MUS MUSCULUS) EXPOSED TO THE ODOR OF RECEPTIVE CON- AND HETEROSPECIFIC FEMALES

For the first time, data were obtained proving the modification of the activation of the pituitary-testicular complex of male house mice under the influence of early postnatal experience and the maternal environment when exposed to the odor of receptive females of their own and closely related species. We have confirmed the conjugacy of the formation of behavioral and physiological mechanisms of precopulatory isolation in early ontogenesis. The serum level of free testosterone in males of closely related species M. spicilegus and M. m. wagneri differ, it is significantly lower in mound-building mice. The level of free testosterone of males fostered by a conspecific female was significantly lower when they exposed a heterospecific in comparison with a conspecific female odor. The rearing of M. m. wagneri males by females of a closely related species caused a decrease in the testosterone response of males to the exposure of chemosignals from a female (both con-and heterospecific) and led to the absence of differences in the serum level of free testosterone when they exposed to the odor of a female of their own or closely related species. The data obtained indicate a significant influence of the rearing conditions on the formation of hormonal mechanisms of reproductive isolation.