ADH travels via the bloodstream to its target cells in the papillary ducts in the kidneys, enhancing water reabsorption.

[citation needed] In the cell bodies, the hormones are packaged in large, membrane-bound vesicles that are transported down the axons to the nerve endings.

[citation needed] Each neuron in the nucleus has one long axon that projects to the posterior pituitary gland, where it gives rise to about 10,000 neurosecretory nerve terminals.

[citation needed] Some other inputs come from the brainstem, including from some of the noradrenergic neurons of the nucleus of the solitary tract and the ventrolateral medulla.

The gene expression and electrical activity of supraoptic neurons has been studied extensively, in many physiological and experimental conditions.

[citation needed] These studies showed that the brain is much more "plastic" in its anatomy than previously recognized, and led to great interest in the interactions between glial cells and neurons in general.

Richard Dyball and his co-workers speculated that this pattern of activity, called "phasic firing", might be particularly effective for causing vasopressin secretion.

It is now thought that bursts of electrical activity might be generally important for releasing large amounts of peptide from peptide-secreting neurons.

Francoise Moos and Phillipe Richard first showed that the autoregulatory action of oxytocin is important for the milk-ejection reflex.

Oxytocin and vasopressin receptors are present in many other brain regions, including the amygdala, brainstem, and septum, as well as most nuclei in the hypothalamus.