Scientists have discovered more details about how the vagus nerve interacts with the immune system, which may lead to treatment for autoimmune conditions like rheumatoid arthritis, Crohn’s disease and lupus. The researchers from the Feinstein Institute for Medical Research say they will have a much better understanding how “bioelectronic medicine” may treat painful diseases.
By mapping the mechanisms of the vagus nerve and identifying new neural pathways that the vagus nerve signals to the rest of the body, researchers can now focus their attention on using bioeletronic medicine to activate the newly revealed pathways and treat a wide variety of conditions and diseases. The results of this discovery are part of a new study published in Bioelectronic Medicine.
“We know from previous studies that the vagus nerve is a conduit for signals from many of our vital organs and that it has a role in reporting changes in inflammation to the brain,” said Feinstein Institute investigator Patricio T. Huerta, PhD, also associate professor of molecular medicine at Hofstra Northwell School of Medicine and corresponding author of the paper. “Our new finding clearly shows that the vagus nerve carries immune-related signals, which makes it a good target for bioelectronic treatment for autoimmune conditions such as rheumatoid arthritis, Crohn’s disease and lupus.”
The nervous system sends signals through the body to control organ and cell function. Nerves connect to different organs and send signals to the brain to maintain normal function and also to alert to issues such as infection and inflammation. The emerging field of bioelectronic medicine is looking to harness these neural signals to help the body heal itself.
The key to successfully tapping into these neural signals is having a full understanding of how different receptors within each nerve trigger different reactions in the body. This information can be used to identify the different mechanisms to treat a condition, while helping medical professionals to identify if their stimulation has an effect on other bodily functions.
In the study, titled Cytokine-specific Neurograms in the Sensory Vagus Nerve, Dr. Huerta looked at how the vagus nerve responds to the presence of elevated levels of cytokines in the body. Cytokines are small proteins that are especially important in the function of the immune system.
“In this study, we were looking to sharpen our understanding of what makes the vagus nerve sense the immune response,” said Dr. Huerta. “We devised an electrode setup to record down to the vagus fibers that are activated by the cytokines. We found that similar to how the brain perceives and interprets colors differently, each cytokine is perceived and interpreted by the vagus nerve differently.”
Dr. Huerta’s team profiled the vagus nerve’s reaction in an animal model to two pro-inflammatory cytokines — tumor necrosis factor (TNF) and interleukin-1β. The mice normally have very low levels of the cytokines being profiled in their bodies. Researchers put the cytokines into their bodies, which activated the vagus nerve, which in turn sent signals (called action potentials) regarding their elevated level to the central nervous system. Each cytokine activated signals at different frequencies within the nerve. Now having a method to record the different fibers of the vagus nerve, the scientists will continue to catalog the different signals of the vagus nerve and what they control in the body. These findings can all be used to find targets to treat disease with bioelectronic medicine devices.
“Dr. Huerta and his team’s method of recording signals and identifying pathways within the nerve fiber opens up many new possibilities for our research teams to apply bioelectronic medicine to these nerves and treat many diseases and conditions,” said Kevin J. Tracey, MD, president/CEO of the Feinstein Institute and associate dean for research at the School of Medicine.
Vagus nerve stimulation (VNS) is most often used to treat epilepsy when other treatments haven’t worked. VNS is also a treatment for hard-to-treat depression that hasn’t responded to typical therapies. Based on this new research, it appears that VNS therapy may move down a path towards treating autoimmune conditions, as well.