Preoptic area

The preoptic area is a region of the hypothalamus. According to the MeSH classification, it is considered part of the anterior hypothalamus. There are four nuclei in this region, according to Terminologia Anatomica (Medial, Median, Lateral, and Paraventricular).

Functions
The preoptic area is responsible for thermoregulation and receives nervous stimulation from thermoreceptors in the skin, mucous membranes, and hypothalamus itself.

This area propagates stimuli to either the heat-losing or the heat-promoting centers of the hypothalamus.

Median preoptic nucleus
The median preoptic nucleus is located along the midline in a position significantly dorsal to the other 3 preoptic nuclei, at least in the macaca fascicularis brain. It wraps around the top (dorsal), front, and bottom (ventral) surfaces of the anterior commissure.

The median preoptic nucleus generates thirst. Drinking decreases noradrenaline release in the median preoptic nucleus.

Medial preoptic nucleus
The medial preoptic nucleus is bounded laterally by the lateral preoptic nucleus, and medially by the preoptic periventricular nucleus. It releases gonadotropin-releasing hormone, controls copulation in males, and is larger in males than in females.

Lateral preoptic nucleus
The lateral preoptic nucleus is lateral to the medial preoptic nucleus. It also mediates non-REM sleep onset.

Preoptic periventricular nucleus
The preoptic periventricular nucleus is located along the midline and is medial to the medial preoptic nucleus.

Aging
Studies in female mice have shown that estrogen receptor-alpha declines in the pre-optic hypothalamus as they grow old. The female mice that were given a calorie-restricted diet during the majority of their lives, maintained higher levels of ERα in the pre-optic hypothalamus than their non-calorie-restricted counterparts.