Figures
How drinking and eating alter the activity of AVP neurons.
AVP neurons (middle) help maintain osmolality by releasing a hormone called vasopressin, which reduces the amount of fluids excreted from the kidneys. Eating and drinking have been shown to alter the activity of AVP neurons before there are any detectable changes in blood osmolality. Water cues (such as the presence of a glass) and drinking suppress the release of vasopressin (red line) by activating inhibitory neurons (blue circle) in the MnPO and OVLT regions of the lamina terminalis. Eating, on the other hand, stimulates AVP neurons to release vasopressin (green line) through an unknown population of neurons (red circle) in the arcuate nucleus, the region of the brain that regulates hunger. These neural circuits allow the body to react quickly to the osmotic changes caused by eating and drinking before the balance of fluids in our blood is disrupted.
