[Changes in the accessory group of hypothalamic neurosecretory cells following stimulation of the supraoptic nucleus].

Changes of an accessory neurosecretory cell group were investigated in acute experiments on cats under chloralose anesthesia. The unilateral stimulation of the supraoptic nuclei (with vasoconstrictory effect) caused activation of cells of the accessory group at the side of stimulation, and increase of the nucleolar size. No changes in the paraventricular nuclei were observed, whereas cells of the supraoptic nuclei were activated. The identity of the main and the accessory neurosecretory group reaction and literature data on histochemistry suggest that both cell groups produced vasopressin stored in the posterior lobe of the hypophysis, and acted partially as a mediator outside the hypothalamus.