Étudiante-chercheuse étoile August 2015



Katrina Choe

PhD student in Neuroscience at the Research Institute of the McGill University Health Centre and current postdoctoral fellow at University of California, Los Angeles
RI-MUHC


Award-winning publication: High Salt Intake Increases Blood Pressure via BDNF-Mediated Downregulation of KCC2 and Impaired Baroreflex Inhibition of Vasopressin Neurons

Published in: Neuron
 

Abstract

"A majority of hypertensive individuals are salt-sensitive, but the mechanisms linking high plasma sodium (pNa) to blood pressure (BP) elevations remain unestablished. Vasopressin (VP) is a potential candidate for mediating the salt-mediated elevations in BP, because high pNa strongly stimulates its release, and the hormone has both antidiuretic and vasoconstrictive properties. Our study shows that a week of increased sodium intake in rats results in an override of gamma-Aminobutyric acid (GABA) synaptic inhibition. This ultimately leads to an excessive amount of circulating VP, sufficient to produce BP elevation. We further showed that this effect is due to a collapse in the chloride gradient of VP neurons, via a mechanism involving a neurotrophin signaling pathway. These results serve as demonstration that VP neurons of the hypothalamus play an important role in salt-sensitive BP elevations. The significance of our findings has been highlighted by Nature Reviews Neuroscience and Science Signaling."

Hypertension is a major global health issue, currently affecting a third of the world's population. Katrina Choe's study provides evidence that high dietary salt intake induces a ‘reprogramming' of a neural circuit to promote salt-sensitive increases in blood pressure. These findings have gathered an enormous amount of interest from the media, including international sources such as Radio Canada International and The Huffington Post. Making a significant impact on public health, this study will reinforce awareness in the general public and health practitioners about the dangers that high sodium consumption may present. This may motivate both healthy and hypertensive individuals to decrease the amount of sodium in their diets and contribute to an eventual decrease in the incidence of hypertension.