[Role of the paraventricular nucleus of the hypothalamus in facilitating responses of the pituitary-adrenocortical system to a stressor].

The role of the hypothalamic paraventricular nucleus (PVN) was studied in activation of pituitary-adrenocortical system in chronic experiments on rabbits. The activation was induced with immobilization or electrical stimulation of the skin and estimated by means of the blood corticosteroid levels. Lesion of the PVN resulted in reduction of amplitude and increase of the time of involvement of the stress-induced responses. The lesion did not alter the relationships between the strength of electrical stimulation and corticosteroid levels.