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Afferent renal nerve stimulation excites RVLM projecting PVN neurons in rats
Author(s) -
Xu Bo,
Zheng Hong,
Patel Kaushik P
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.697.3
Subject(s) - rostral ventrolateral medulla , baroreflex , stimulation , medicine , denervation , endocrinology , phenylephrine , medulla oblongata , chemistry , neuroscience , heart rate , blood pressure , biology , central nervous system
Recently renal denervation in hypertensive patients has proven to be very successful, however the underlying mechanism is not entirely clear. To determine if pre‐autonomic neurons in the paraventricular nucleus of the hypothalamus (PVN) are responsive to afferent renal nerve stimulation (ARN‐Sti), extracellular recording was used to investigate the contribution of the rostral ventrolateral medulla (RVLM) projecting PVN (PVN‐RVLM) neurons to ARN‐Sti. We also examined if these same neurons were responsive to baroreflex (BR) (i.v. injection of phenylephrine), or cardiac sympathetic afferent reflex (CSAR) (epicardial bradykinin). In 109 spontaneously active neurons recorded in the PVN of anesthetized rats, 25 units were antidromically activated from the RVLM. Among units classified as RVLM projecting PVN neurons, 84% (21/25) were activated by ARN‐Sti and the baseline discharge rate was significantly higher in them compared to those that were not activated by ARN‐Sti (16%, 4/25). In addition, almost all of neurons sensitive to ARN‐Sti were sensitive to BR (95%) and CSAR (100%). Among the non‐evoked neurons (not responding to stimulated from the RVLM) in the PVN, 23% respond to ARN‐Sti while 77% did not; most of the ARN sensitive neurons (83%) were responsive to baroreflex stimulation. Non of the non‐evoked neurons respond to CSAR. These results demonstrate that sensory information originating in kidney is integrated at the level pre‐autonomic neurons within the PVN, providing a novel mechanistic insight for use of renal denervation in modulation of sympathetic outflow in disease states such as hypertension and heart failure. Supported by NIH 62222.