A Neuroendocrine Circuit That Suppresses Excretion and Pelvic Pain During Activity.

Mate-seeking during peak sexual receptivity is tightly coupled with exploratory movement, a process made more efficient by transient suppression of excretion. Here, we define a functional hypothalamic-hindbrain circuit in mice that promotes locomotion while eliminating urination and defecation for hours. Chemogenetic stimulation of excitatory estrogen-melanocortin-responsive MC4R + neurons in the ventrolateral ventromedial hypothalamus (VMHvl) effectively silences bladder and colonic visceral reflexes, even at noxious distension pressures, underscoring the potency of this anti-excretion circuit. Pelvic sensations and excretion are restored only after ablating inhibitory GABAergic neurons in the Barrington's nucleus/locus coeruleus (BAR/LC) hindbrain region or after antagonizing endogenous endorphin signaling. Our study illustrates how a hormone-responsive brain node prioritizes movement over excretion and blunts pelvic discomfort, thereby optimizing an essential voluntary behavior for evolutionary fitness.