Estrogen Drives Melanocortin Neurons To Reduce Sedentary Behavior

Estrogen depletion in both rodents and humans leads to inactivity, unhealthy fat accumulation, and metabolic syndrome, underscoring the conserved metabolic benefits of estrogen signaling that inevitably decline with aging. Here, we uncover a hypothalamic node that integrates estrogen and melanocortin-4 receptor (MC4R) signaling to drive episodic bursts in activity prior to ovulation. Skirting the estrogen-dependent gating of this node by CRISPR activation of Mc4r reduces sedentary behavior long-term in both males and females. Our findings expand the impact of MC4R signaling beyond food intake regulation and rationalize reported sex-differences in melanocortin signaling including increased disease severity for women with MC4R-insuffciency. This newly identified hormone-dependent activity node illustrates the potency of estrogen in maintaining an active lifestyle.