The role of the paraventricular nucleus of the hypothalamus in control of cardiac and renal sympathetic nerve activity

Abstract

Previous studies have indicated an important role for the paraventricular nucleus of the hypothalamus (PVN) in mediating the renal sympathetic nerve activity (RSNA) response to volume expansion. We have recently shown that in conscious animals volume expansion also inhibited cardiac sympathetic nerve activity (CSNA), but the role of the PVN in this response is unknown. We hypothesized that the similar decreases in CSNA and RSNA induced by volume expansion would be blocked by inhibition of neurons in the PVN. To test this hypothesis, microinjection guide tubes were surgically implanted into the PVN and 2 weeks later, recording electrodes were implanted to record CSNA and RSNA. Experiments wer..