Re-feeding and the restoration of odor attractivity, odor preference, and sexual receptivity in food-deprived female meadow voles

Food-deprived meadow voles were used to test predictions of two hypotheses associated with the recovery of sexual behaviors following re-feeding. Specifically, we tested between the body weight set point and metabolic fuels hypotheses. To do so, we determined whether the body weight of previously food-deprived female voles had to return to pre-food deprivation levels before they would recover their sexual behaviors. The body weight set point hypothesis predicts that food-deprived females that were re-fed will recover their sexual behavior after they return to their original body weight. In contrast, the metabolic fuels hypothesis predicts that food-deprived females that were re-fed will recover their sexual behavior before they return to their original body weight. That is, when the females are in positive energy balance. To distinguish between these two hypotheses, female voles were food deprived for 24 h, which is sufficient to inhibit all three components of sexual behavior. The food-deprived females were then supplied ad libitum food for 0 h, 24 h, 48 h, 72 h, or 96 h and weighed. Females were then tested for their sexual behaviors (odor attractivity, odor preference or proceptivity, sexual receptivity). Re-feeding for 48 h was sufficient to restore odor attractivity, 72 h was sufficient to restore odor preferences for opposite sex conspecific odors, and 96 h was sufficient to restore sexual receptivity to those similar to that of females that were not food deprived. The time-points that the behaviors were recovered were prior to voles recovering their initial body weight. Thus, the data support the metabolic fuels hypothesis.