Role of CNS osmosensory networks in the regulation of cardiovascular function in health and disease.

Symposium — Tuesday, April 25, 2024 — 3:15 PM - 5:15 PM — , Room W196A
CNS Section — Chair: Javier E Stern — Co-Chair: Melina Pires da Silva

Osmoregulation is a fundamental process in mammals whereby complex patterns of neuroendocrine, autonomic and behavioral responses contribute to maintenance of fluid/electrolyte balance, in face of changes in extracellular fluid osmolality. These responses are mediated in large part by CNS osmosensitive circuits. Recent evidence indicates however, that chronic high levels of salt intake, commonly observed in modern society diets, impose a novel form of osmotic challenge that has been linked to a higher incidence of salt-sensitive cardiovascular diseases, including hypertension and heart failure. While an exaggerated sympathoexcitatory activity and neuroendocrine secretion (e.g., vasopressin) have been associated to the pathophysiology of salt-sensitive cardiovascular diseases, the precise mechanisms by which an excess of sodium contributes to altered central osmoregulatory mechanisms remains poorly understood. The goal of this symposium is to critically discuss recent findings that highlight novel mechanisms implicated in central osmosensory responses, with a particular emphasis on salt-sensitive cardiovascular diseases. The outstanding panel of international speakers (USA, Canada, Brazil), ranging from junior to well-recognized investigators, will present novel and thought-challenging findings and discuss future directions in this important research field. Dr. Bourque, CW (McGill University) will discuss novel evidence supporting the contribution of neuronal plasticity in central osmosensitive circuits to baroreflex regulation of vasopressin and salt-dependent hypertension. Dr. Toney, GM (University of Texas Health Science Center) will present recent findings that identify mechanisms that interface forebrain osmosensitive sympathoexcitatory networks and brainstem sympathetic rhythm generating network, and their contribution to salt-sensitive cardiovascular diseases.  Dr. Antunes, VR (University of Sao Paulo) will provide new mechanistic insight into purinergic and glutamatergic interactions within the hypothalamus in the control of the salt-induced sympathoexcitation and hypertension. Finally, Dr. Stern, JE (Augusta University) will discuss novel findings highlighting the impact of osmotically-driven dendritic release of vasopressin on hypothalamic neurovascular function and sympathetic outflow in cardiovascular disease states. We believe this is a timely proposal that will provide a needed update in the field, inspire critical discussions, and contribute to shape future investigation in this significant area of research.

Speakers

• Network plasticity in baroreceptor control of magnocellular vasopressin neurons.
  Charles Bourque — , McGill University


• Interfacing osmosensitive sympathoexcitatory neurons with the brainstem sympathetic rhythm generating network
  Glenn Toney — , University of Texas Helath Science Center


• Mechanistic insights into purinergic signaling at hypothalamus level in the control of salt-induced sympathoexcitation
  Vagner R Antunes — , University of Sao Paulo


• Osmotically-driven dendritic release of VP and its impact on hypothalamic  sympathetic outflow
  Javier E Stern — Department of Physiology, Georgia Regents University