Zones of hypothalamus
Rostrocaudally oriented regions of the hypothalamus characterized by their position and cell groups. The periventricular zone (zona periventricularis) is a thin sheet of small neurons located in the wall of the third ventricle. The medial zone (zona medialis) lies between the periventricular zone and a rostrocaudal line drawn between the mammillothalamic tract and the postcommissural fornix, and consists of supraoptic, tuberal, and mammillary regions. The lateral zone (zona lateralis) is lateral to the medial zone, and contains the tuberal nuclei and the fibers of the medial forebrain bundle.