Pituitary gland stalk, light micrograph. The neurosecretion of the posterior hypophysis (pituitary gland) is synthesized in neurons located in the hypothalamic nuclei (supraoptic-vasopressin and paraventricular-oxytocin). The axons of these neurons transport the secretory product through the pituitary stalk to the posterior lobe. This pituitary stalk is stained with the Gabe paraldehyde-fuchsin method to show neurosecretion in these axons, which occasionally show dilations filled with neurosecretory material, which are known as Herring bodies.