Neural Input and Hormonal Output:
oxytocin release and lactation
Supraoptic and paraventricular nuclei contain
magnocellular neurons that secrete oxytocin into
the general circulation in the posterior pituitary.
When a baby sucks on a mother’s nipples,
mechanoreceptors are stimulated.  These
receptors activate neurons that project to the
magnocellular hypothalamic neurons, causing
those cells to fire brief bursts, releasing oxytocin.
Oxytocin, in turn, increases contraction of
myoepithelial cells in the mamillary glands,
leading to milk ejection.