Rats that eat too much salt for a week have overactive brain cells that pump out more of a hormone that tightens blood vessels, causing their blood pressure to rise — but if you block that hormone, the pressure doesn’t go up as much.

When rats eat too much salt, the brain cells that release a hormone to raise blood pressure start firing faster, and this directly causes their blood pressure to go up.

When rats eat too much salt, their body releases a hormone that tightens blood vessels — blocking that hormone’s effect cuts the blood pressure rise in half.

When rats eat too much salt, their brain’s natural blood pressure control system flips — instead of slowing down when blood pressure rises, the neurons that release the pressure-raising hormone get even more active.

When rats eat too much salt for a week, their brain cells that control blood pressure stop responding to the body’s natural 'slow down' signal, because a key chloride pump gets turned down, making the signal backfire and push blood pressure higher.

Salt makes brain cells release a chemical called BDNF, which turns off a safety switch (KCC2) that normally calms down blood pressure neurons — blocking BDNF stops this from happening.