Tørstcentral

Tørstcentral, or the thirst center, refers to neural substrates in the brain that regulate the sensation of thirst and the motivation to drink. In humans and other mammals, the principal location is in the hypothalamus, especially in the region of the lamina terminalis, which includes the organum vasculosum lamina terminalis (OVLT) and the subfornical organ (SFO).

These areas contain osmoreceptors that monitor plasma osmolality. Increases in osmolality activate thirst pathways, prompting a behavioral drive to drink. The thirst center also responds to signals from the renin-angiotensin system; angiotensin II, generated during hypovolemia, stimulates thirst via the OVLT and SFO. The hypothalamic network integrates inputs from baroreceptors, gut stretch receptors, and higher cognitive centers to trigger the conscious urge to consume fluids. Release of vasopressin (antidiuretic hormone) from the posterior pituitary commonly accompanies thirst, promoting water reabsorption in the kidneys to restore fluid balance.

Conscious thirst is processed in cortical regions such as the insular and cingulate cortices, which translate homeostatic signals into the subjective urge to drink. The concept of the thirst center describes the coordinated hypothalamic control of fluid intake and vasopressin signaling, essential for maintaining extracellular fluid osmolality and blood volume.

Clinical considerations include lesions or dysfunction of the hypothalamic thirst network, which can cause adipsia or hypodipsia. Disturbances in thirst and vasopressin signaling occur in conditions such as diabetes insipidus and dehydration. Aging and certain illnesses can also alter thirst perception.

In Norwegian-language physiology, tørstcentral or tørstsentrum is used to refer to this concept.