A Direct Route From The Brain To The Immune System

[Guest guest]

RESEARCHScientists Discover A Direct Route From The Brain To The Immune System By Talan.http://www.eurekalert.org/pub_releases/2007-10/nsij-sda102307.php It used to be dogma that the brain was shut away from the actions ofthe immune system, shielded from the outside forces of nature. But that'snot how it is at all. In fact, thanks to the scientific detective work of Tracey, MD, it turns out that the brain talks directly to the immunesystem, sending commands that control the body's inflammatory response toinfection and autoimmune diseases. Understanding the intimate relationshipis leading to a novel way to treat diseases triggered by a dangerousinflammatory response. Dr. Tracey, director and chief executive of The Feinstein Institutefor Medical Research, will be giving the 2007 Stetten Lecture on Wednesday,Oct. 24, at the National Institutes of Health in Bethesda, MD. His talk -Physiology and Immunology of the Cholinergic Anti-inflammatory Pathway -will highlight the discoveries made in his laboratory and the clinicaltrials underway to test the theory that stimulation of the vagus nerve couldblock a rogue inflammatory response and treat a number of diseases,including life-threatening sepsis. With this new understanding of the vagus nerve's role in regulatinginflammation, scientists believe that they can tap into the body's naturalhealing defenses and calm the sepsis storm before it wipes out its victims.Each year, 750,000 people in the United States develop severe sepsis, and215,000 will die no matter how hard doctors fight to save them. Sepsis istriggered by the body's own overpowering immune response to a systemicinfection, and hospitals are the battlegrounds for these potentially lethalconditions. The vagus nerve is located in the brainstem and snakes down from thebrain to the heart and on through to the abdomen. Dr. Tracey and others arenow studying ways of altering the brain's response or targeting the immunesystem itself as a way to control diseases. Dr. Tracey is a neurosurgeon who came into research through the backdoor of the operating room. More than two decades ago, he was treating ayoung girl whose body had been accidentally scorched by boiling water andshe was fighting for her life to overcome sepsis. She didn't make it. Dr.Tracey headed into the laboratory to figure out why the body makes its owncells that can do fatal damage. Dr. Tracey discovered that the vagus nervespeaks directly to the immune system through a neurochemical calledacetylcholine. And stimulating the vagus nerve sent commands to the immunesystem to stop pumping out toxic inflammatory markers. "This was sosurprising to us," said Dr. Tracey, who immediately saw the potential to usevagus stimulation as a way to shut off abnormal immune system responses. Hecalls this network "the inflammatory reflex." Research is now underway to see whether tweaking the brain'sacetylcholine system could be a natural way to control the inflammatoryresponse. Inflammation is key to many diseases - from autoimmune conditionslike Crohn's disease and rheumatoid arthritis to Alzheimer's, wherescientists have identified a strong inflammatory component. Dr. Tracey has presented his work to the Dalai Lama, who has shown agreat interest in the neurosciences and the mind-body connection. He hasalso written a book called "Fatal Sequence," about the double-edge sword ofthe immune system.