The Human Hypothalamus
3C: LEVEL 3 CELLS: Prominent at this level are the paraventricular and supraoptic nuclei. These are the darkly staining large-celled ("magnocellular") nuclei, which produce oxytocin and vasopressin which are secreted through the posterior pituitary. Axons from cells of these nuclei, carrying the neurohormones, travel behind the optic chiasm to form the infundibular stalk leading to the pituitary. The infundibulum (funnel) consists of the stalk and immediately neighboring tissue, and the front edge of the infundibulum is just visible below the optic chiasm at this level. Scattered cells of the anterior hypothalamic area lie between the magnocellular nuclei and the basal nucleus of Meynert which lies outside the hypothalamus.