The median preoptic nucleus: A major regulator of fluid, temperature, sleep, and cardiovascular homeostasis.

Located in the midline lamina terminalis of the anterior wall of the third ventricle, the median preoptic nucleus is a thin elongated nucleus stretching around the rostral border of the anterior commissure. Its neuronal elements, composed of various types of excitatory glutamatergic and inhibitory GABAergic neurons, receive afferent neural signals from (1) neighboring subfornical organ and organum vasculosum of the lamina terminalis related to plasma osmolality and hormone concentrations, e.g.

Integrating Competing Demands of Osmoregulatory and Thermoregulatory Homeostasis.

Mammals are characterized by a stable core body temperature. When maintenance of core temperature is challenged by ambient or internal heat loads, mammals increase blood flow to the skin, sweat and/or pant, or salivate. These thermoregulatory responses enable evaporative cooling at moist surfaces to dissipate body heat.

Neural Substrate Essential for Suppression of Vasopressin Secretion and Excretion of a Water Load.

Suppression of vasopressin secretion to very low levels is essential for the excretion of excess water. To investigate a role for the preoptic brain region in the suppression of vasopressin secretion and the excretion of a water load, lesions were made in the vicinity of the lamina terminalis in ewes (LTX-sheep) and responses to water-loading or reduction of cerebrospinal fluid NaCl by i.c.