THE ARISING · Longevity & Healthspan
Brainstem Neurons Keep Blood Pressure Steady as Rats Wake and Move
Blood pressure is usually judged by its average. A rat study published earlier this year in rats points to a small group of brainstem cells that keeps it steady from moment to moment, and shows that average pressure can look normal while that steadiness is lost.
The work, published in Circulation Research on February 13, 2026, was done in freely behaving rats. A team led by Stephen Abbott at the University of Virginia School of Medicine studied neurons in a brainstem region called the rostral ventrolateral medulla. These are known as C1 neurons.
The researchers note that short-term swings in blood pressure are increasingly recognized as an independent predictor of cardiovascular and cerebrovascular risk. Yet the brain circuits that control those swings, especially across different behavioral states, have been poorly defined.
To find out how the C1 neurons behave, the team recorded their activity using genetically targeted fiber photometry, a method that tracks the activity of selected cells. The neurons changed with the animal's state. They switched on rapidly when the rats woke from non-rapid eye movement sleep. They stayed active during rapid eye movement sleep. They were recruited further during physical activity.
The cells also respond to feedback from the body. The baroreflex is the arterial sensor system that reports blood pressure back to the brain. When the researchers removed this input through sinoaortic denervation, it altered how the C1 neurons responded. According to the study, baroreflex input contributed to the modulation of C1 activity by drug-induced changes in blood pressure and by the shift from non-rapid eye movement to rapid eye movement sleep.
The key test was removing the cells. Selective genetic ablation of the C1 neurons did not change mean blood pressure. It did produce marked blood pressure instability during arousal and movement.
The authors conclude that these neurons stabilize blood pressure when behavior changes, by combining arousal-related drive from the brain with feedback from the baroreceptors. They describe the findings as a potential neural mechanism underlying pathological blood pressure instability.
For anyone thinking about healthy aging, the finding fits a broader shift in how blood pressure is viewed. A single average can hide how well the body handles the daily transitions between sleeping, waking and moving.
The next step to watch is whether the same neurons and the same swings can be linked to blood pressure instability in people, and whether that opens the way to treatments aimed at reducing harmful fluctuations.