Brain, Immune System Linked

Scientists used to believe that the brain doesn't have anything to do with the immune system and that the immune system responds without any help from the brain, but a research conducted by Kevin Tracey, MD shows that there is a direct connection from the brain to the immune system and that the brain actually controls the body's inflammatory response to infection. Dr. Tracey's research could provide ways of treating diseases triggered by dangerous inflammatory response such as the sepsis condition.

Dr. Tracey went about his research almost a decade ago when a little girl died in his operating room, trying to overcome sepsis. The little girl was accidentally burned by boiling water and suffered septic shock. Dr. Tracey then tried to figure out why the body makes cells that can very well lead to its own damage. It was then that Dr. Tracey discovered that the vagus nerve can directly communicate with the immune system through a neurochemical called acetylcholine. When the vagus nerve is stimulated, it can send a command to the immune system to stop pumping harmful inflammatory markers. Dr. Tracey said he immediately saw the vagus nerve's potential to shut off abnormal immune system response.

The vagus nerve can be found in the brainstem and curves down from the brain to the heart and through the abdomen. Scientists are hopeful that with this new understanding of the vagus nerve in regulating the immune system's response, they can use the body's natural healing defenses to calm the sepsis storm before it can affect its victims. Sepsis is a condition triggered when the body's immune system overly responds to a systemic infection. According to Feinstein Institute for Medical Research, each year, 750,000 people in the United States alone develop severe sepsis and 215,000 of those suffering will die even if doctors fight hard enough to save them. Dr. Tracey together with other researchers are now studying different ways of altering the brain's response or even the immune system itself to control diseases. One of the methods that the scientists will try is tweaking the brain's acetylcholine system to see if it could produce a natural way of controlling the inflammatory response.

Dr. Tracey presented the highlights of his discoveries at the 2007 Stetten Lecture last Wednesday. Clinical trials will soon by underway to test Dr. Tracey's theory that stimulation of the vagus nerve will block dangerous inflammatory response and treat a number of diseases.

SOURCE:

Feinstein Institute for Medical Research, "Scientists Discover a Direct Route from the Brain to the Immune System."