Adrenocortical responses following sciatic nerve stimulation in rats with partial hypothalamic deafferentations.

Studies from this laboratory have demonstrated that the adrenocortical response following sciatic nerve stimulation is completely inhibited in rats with hypothalamic islands, indicating that this response depends entirely on the activation of afferent neural pathways to the hypothalamus. With the purpose of identifying the site of entry of these neural pathways into the mediobasal hypothalamus the effects of partial hypothalamic deafferentations were studied. It was found that in rats with posterior or posterolateral deafferentation the adrenocortical responses were similar to those obtained in intact rats, while anterior and anterolateral deafferentation resulted in a reduction of 62.3 and 53.3%, respectively. These results would indicate that the sciatic impulses which activate the adrenocortical response involve neural afferents which enter the mediobasal hypothalamus by an anterior pathway.