Salt and high BP: Blame it on your brain

An international team led by scientists at McGill University has found that excessive salt intake "reprogrammes" the brain, interfering with a natural safety mechanism that normally prevents the body's arterial blood pressure from rising. By studying the brains of rats, a team led by Prof. Charles Bourque of McGill's faculty of medicine discovered that ingesting large amounts of dietary salt causes changes in key brain circuits.

"We found that a period of high dietary salt intake in rats caused a biochemical change in the neurons that released vasopressin (VP) into the systemic circulation", Bourque explained This change prevents the inhibition of these particular neurons by other cells.

The team found that high salt intake prevents the inhibition of VP neurons by the body's arterial pressure detection circuit. The disabling of this natural safety mechanism allows blood pressure to rise when a high amount of salt is ingested over a long period of time.

While the team's discovery advances the understanding of the link between salt intake and blood pressure, more work is needed to define new targets that could potentially be explored for therapeutic intervention, the authors pointed out. "Meanwhile, the message is clear: limit dietary salt," Bourque concluded. The paper appeared in the journal Neuron.