Neuroplasticity of brain circuits of reward and socio-sexual in female wistar rats

Abstract

Sexual behavior and exercise are motivated behaviors that induce behavioral, plastic, and physiological changes. Paced mating is a strategy employed by the female to exercise control over copulatory contacts. A body of research has previously demonstrated that both behaviors promote the formation of new neurons. However, the combined effect of these behaviors has not yet been analyzed. The present study evaluated the plastic alterations induced by female-regulated copulation and wheel running in the same session. This evaluation was conducted using magnetic resonance imaging (MRI) and immunohistochemistry with BrdU. The subjects were divided into five groups: experimental design included two distinct control groups: the first group was subjected to a paced mating protocol, and the second group participated in a wheel running exercise followed by a paced mating session. The experimental design involved a ten-week exercise regimen, five days a week, complemented by one copulation session per week. The study found that the female subjects could engage in both behaviors without experiencing any impairment in either one. No significant variations were detected in the intensity of lordosis or the interval between intromissions. Magnetic resonance imaging (MRI) analysis revealed alterations in the socio-sexual circuit within the paced mating group. In contrast, the Wheel Running Exercise plus paced mating group demonstrated augmented signal intensity in the reward circuit. Furthermore, an increase in BrdU-positive cells was observed in the olfactory bulb of the paced mating, Wheel Running Exercise plus paced mating, and Wheel Running Exercise groups. These findings demonstrate that motivated behaviors induce
plastic changes in the brain, activating reward and socio-sexual circuits.