 TA lists four nuclei in this region, (medial, median, lateral, and periventricular).The preoptic area is responsible for thermoregulation and receives nervous stimulation from thermoreceptors in the skin, mucous membranes, and hypothalamus itself.The median preoptic nucleus is located along the midline in a position significantly dorsal to the other three preoptic nuclei, at least in the crab-eating macaque brain.