Gestational environmental enrichment shapes maternal motivational strategies in postpartum rats

Maternal motivation arises from the integration of hormonal state, neural circuitry, and prior experience, all of which are influenced by environmental conditions. While environmental enrichment during pregnancy modifies maternal care and neural activity, its specific impact on core maternal motivation remains unknown. In the present study, we examined whether gestational environmental enrichment can persistently reshape motivational priorities after parturition using two paradigms that impose competitive or risky conditions for interaction with the offspring. Nulliparous female rats were housed under standard (STD) or enriched (EE) conditions exclusively during gestation. Maternal motivation was assessed during postpartum estrus, 12 h after parturition, using an offspring versus male test that elicits simultaneous maternal, aggressive, and sexual behaviors. On postpartum day 4, risk-related maternal motivation was assessed using a pup retrieval test on the elevated plus maze. Maternal care in the home cage was also evaluated to examine its relationship with motivational performance. In the offspring versus male test, EE dams exhibited increased maternal aggression and sexual motivation, including elevated proceptive behaviors and sexual receptivity, while spending less time in passive offspring care. In the pup retrieval test, EE dams retrieved pups more rapidly and reliably to protected locations, reflecting enhanced risk-taking behavior. Our findings demonstrate that environmental conditions restricted to gestation are sufficient to induce enduring, experience-dependent changes in maternal motivational strategies. Gestational enrichment promotes active defense of the offspring, elevated sexual motivation, and adaptive risk-taking, revealing pregnancy as a critical period for shaping postpartum motivational systems.