SAN DIEGO, Jan 28:  Researchers at the University of California San Diego (UCSD) have discovered a neural pathway linking the brain and immune system that could help reduce damage from heart attacks, according to a study published Tuesday in the journal Cell.

The team found that disabling specific neurons in the vagus nerve—a bundle of fibers connecting the brain to organs—significantly improved outcomes in mice with experimentally induced heart attacks. UCSD neuroscientist Vineet Augustine, who led the study, said, “The injury almost disappears” when these neurons are blocked.

The research focused on TRPV1-expressing neurons, which carry signals from the heart to the hypothalamus, a deep-brain structure regulating temperature, hunger, sleep, and other functions. These signals trigger an immune protein that drives inflammation, worsening heart damage. Blocking any of the three points in the heart-brain-immune loop relieved complications and improved heart function in the lab animals.

The experiments involved complex procedures, including real-time echocardiography and targeted manipulation of brain cells. Postdoctoral researcher Saurabh Yadav described the work as “technically demanding” and said small errors could have compromised the study. The team’s success in blocking TRPV1 neurons produced “striking improvements” in heart-pumping efficiency and electrical signaling.

The findings build on decades of research linking the nervous and immune systems to cardiovascular health. Past studies have shown that vagus nerve stimulation can curb harmful inflammation, and implantable stimulators have been approved to treat autoimmune diseases such as rheumatoid arthritis.

Experts note that fight-or-flight signals from the brain, while protective in emergencies, can trigger harmful inflammation over time, leading to arrhythmias and heart failure. Dr. Kalyanam Shivkumar, a UCLA cardiac electrophysiologist, said these responses illustrate the heart’s vulnerability during stress events like earthquakes or major sporting events.

Cameron McAlpine, a neuroimmunologist at Mount Sinai not involved in the study, called the findings “quite impressive,” highlighting new genetic and neuroscience tools that allow precise manipulation of specific nerve cell groups.

Future studies will investigate how the TRPV1 neurons sense and communicate with the heart, and how the heart-brain-immune circuit interacts with other physiological pathways.

The research highlights a growing scientific focus on the interplay between the nervous and immune systems, which affects a wide range of body functions and may hold keys to novel treatments for cardiovascular and inflammatory conditions.