The brain’s ability to prioritize voluntary behaviors is essential for species propagation and self-survival. Initiating and sustaining exploratory behavior to seek mates or resources requires goal-directed locomotion, a process made more efficient by suppression of other voluntary behaviors, including urination and defecation, both of which are time-consuming and spatially restricted (as highlighted in the image above).
In this preprint (Link), 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. Our study illustrates how a hormone-responsive brain node optimizes an essential voluntary behavior for evolutionary fitness.
Photo from the 2026 SF Marathon, courtesy of Archana's mother.