LONDON, Jan 14: A little-known region of the brain may play a key role in high blood pressure, researchers in New Zealand have claimed.

The lateral parafacial region, a bundle of nerves in the brainstem that controls automatic functions such as digestion, breathing, and heart rate, was previously known to activate during activities such as laughing, exercising, or coughing. Now, scientists say activating the region can also trigger nerves that tighten blood vessels, potentially raising blood pressure and contributing to hypertension.

In laboratory experiments on rats, researchers activated and inhibited nerves in the region while monitoring blood pressure. They found that blood pressure rose when the lateral parafacial region was active and fell when it was inhibited.

Dr. Julian Paton, a physiologist at the University of Auckland who led the research, said in a statement: “We’ve unearthed a new region of the brain that is causing high blood pressure. Yes, the brain is to blame for hypertension! We discovered that, in conditions of high blood pressure, the lateral parafacial region is activated and, when our team inactivated this region, blood pressure fell to normal levels.”

The study, published in the journal Circulation Research, used viruses to excite or calm the nerves in the lateral parafacial region. Scientists also tracked signals from the rostral ventrolateral medulla, another brainstem area that controls blood pressure. Activating the parafacial region triggered forced exhalations and activated nerves that constrict blood vessels, part of the sympathetic nervous system responsible for the body’s “fight-or-flight” response. Inhibiting these nerves returned blood pressure to normal without affecting normal breathing.

Researchers noted that the study was conducted in rats, and further research will be needed to determine whether the findings apply to humans. It is also unclear what proportion of high blood pressure cases may be caused by this mechanism, as lifestyle factors such as a high-salt diet, stress, obesity, and alcohol consumption remain major contributors.

Hypertension is the most common medical condition in the United States, affecting an estimated 120 million adults, or nearly half the population, according to the Centers for Disease Control and Prevention (CDC). Normal blood pressure is considered less than 120/80 mmHg, while readings above that are classified as high.

Doctors warn that uncontrolled high blood pressure can damage blood vessels and increase the risk of stroke, heart attack, dementia, and other serious conditions. About one in six deaths in the U.S. is linked to the condition, with the CDC reporting approximately 664,470 related deaths annually. Treatment generally includes medications that relax blood vessels, as well as lifestyle measures such as maintaining a healthy weight, exercising regularly, and eating a balanced diet.

Previous research has also suggested a link between the brain and high blood pressure. A study by MD Anderson Cancer Center published last year found that overactivity in the hypothalamus, a brain region that controls the sympathetic nervous system, can raise blood pressure and increase the risk of heart disease and dementia. Researchers found that normally a protein called calcineurin calms brain signals, but another protein, RCAN1, can block calcineurin and trigger overactivity in the hypothalamus, disrupting normal blood pressure regulation.

The New Zealand study adds to a growing body of evidence that brain activity, alongside lifestyle factors, may play a critical role in the development and management of hypertension.