neurohormone

A neurohormone is a chemical messenger that a nerve cell makes and then releases straight into the bloodstream, so it can travel to and act on body parts far away. Most nerve cells whisper to a neighbor across a tiny gap, like passing a note to the person sitting next to you. A neuron that makes a neurohormone does something bolder: instead of handing the note to a neighbor, it drops its message into the blood, the body's shared delivery system, where it can reach distant organs minutes later — more like mailing a letter that anyone downstream can pick up.

This is the brain's way of sending body-wide commands rather than point-to-point signals. A famous example happens in the hypothalamus, a control hub deep in the brain: certain neurons there make hormones such as oxytocin and vasopressin, send them down to the pituitary gland just below, and release them into the blood. From there oxytocin can trigger labor contractions in the womb or milk release during nursing, and vasopressin tells the kidneys to hold on to water. So a thought, a stress, or a body rhythm sensed by the brain can be turned into a chemical order that reshapes what happens in organs all over the body.