New Study Links Brain Region to High Blood Pressure

A recent study suggests that a particular area of the brain might be connected to some forms of high blood pressure, and, interestingly, there may be a way to reverse this effect.

Conducted by researchers from the University of São Paulo in Brazil and the University of Auckland in New Zealand, the study focuses on the lateral parafacial (pFL) region of the brain. This area is known for its role in regulating breathing, especially in scenarios that involve forceful exhalations during activities like exercise, coughing, or even laughing.

In experiments on rats, the team discovered that the pFL region could also prompt blood vessels to constrict. They theorize that this interplay between breathing and blood vessel control could be a factor in hypertension. This might shed light on why a significant portion of the population—around 40%, according to some estimates—struggles with high blood pressure, even while on medication.

The findings imply that neurons in the pFL may connect subtle changes in breathing patterns to heightened activity in the sympathetic nervous system. This system plays a key role in blood pressure regulation and aligns with earlier research linking hypertension to neural activity.

“It’s estimated that about 50% of individuals with hypertension have a neurogenic aspect, so understanding the mechanisms that lead to this sympathetic activation is essential,” the authors mentioned in their report. They point out that such insights could guide the development of new treatment strategies.

In their rat studies, researchers manipulated pFL neurons and monitored the effects on breathing, sympathetic nerve activity, and blood pressure. They found that activating these neurons led to stimulation of brain circuits that ultimately raised blood pressure in the animals.

Moreover, they mapped the interactions between the pFL neurons and other brainstem activities, comparing hypertensive rats to those without high blood pressure. The results indicated that pFL neurons were not only involved in breathing control but also in constricting blood vessels—opening up potential new avenues for treatment.

“We found that in cases of high blood pressure, the pFL region becomes active, and when it’s inactivated, blood pressure returns to normal levels,” noted physiologist Julian Paton from the University of Auckland.

The research may also help explain why individuals with sleep apnea, who experience breathing difficulties at night, face an increased risk of hypertension. The pFL neurons respond to high carbon dioxide or low oxygen levels—both of which are common during sleep apnea episodes.

However, it’s crucial to remember that this study is based on animal models. While it’s likely that similar neural pathways exist in humans, this hasn’t been definitively proven yet.

With a substantial number of people globally grappling with high blood pressure—many of whom have limited access to effective medication—the urgency for new treatment options cannot be overstated. Uncontrolled hypertension significantly raises the risk of heart conditions and has been associated with numerous other health issues, including dementia.

The researchers are exploring ways to design drugs that specifically target pFL neurons without negatively affecting other brain functions. They’ve identified carotid bodies, which are clusters of cells that act as sensors in the neck and influence pFL neurons, as a potential target for new treatments.

“Our aim is to focus on the carotid bodies using a new drug we’ve repurposed to safely deactivate the pFL region without the need for it to penetrate the brain,” Paton explained.

While this approach may seem straightforward, it will still involve a significant amount of testing.

The research findings have been published in Circulation Research.