Autoimmunity, Brain & Beyond

[Guest guest]

DR. KEVIN TRACEY SHARES HIS SCIENCE AT NIH

http://feinsteininstitute.typepad.com/feinsteinweblog/2007/10/dr-

kevin-tracey.html

It used to be dogma that the brain was shut away from the actions of

the immune system, shielded from the outside forces of nature. But

that's not 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 immune system, sending commands that control

the body's inflammatory response to infection and autoimmune

diseases. Understanding the intimate relationship is leading to a

novel way to treat diseases triggered by a dangerous inflammatory

response.

Dr. Tracey, director and chief executive of The Feinstein

Institute for Medical Research, gave the 2007 Stetten Lecture at the

National Institutes of Health on Wednesday, Oct. 24th. His talk –

Physiology and Immunology of the Cholinergic Anti-inflammatory

Pathway – highlighted the discoveries made in his laboratory and the

clinical trials underway to test the theory that stimulation of the

vagus nerve could block 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 regulating

inflammation, scientists believe that they can tap into the body's

natural healing defenses and calm the sepsis storm before it wipes

out its victims. Each year, 750,000 people in the United States

develop severe sepsis, and 215,000 will die no matter how hard

doctors fight to save them. Sepsis is triggered by the body's own

overpowering immune response to a systemic infection, and hospitals

are the battlegrounds for these potentially lethal conditions.

The vagus nerve is located in the brainstem and snakes down

from the brain to the heart and on through to the abdomen. Dr.

Tracey and others are now thinking about ways of altering the

brain's response or targeting the immune system itself as a way to

control diseases.

Dr. Tracey is a neurosurgeon who came into research through the

back door of the operating room. More than two decades ago, he was

treating a young girl whose body had been accidentally scorched by

boiling water and she 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 own cells that can do fatal damage. Dr.

Tracey discovered that the vagus nerve speaks directly to the immune

system through a neurochemical called acetylcholine. And stimulating

the vagus nerve sent commands to the immune system to stop pumping

out toxic inflammatory markers. " This was so surprising to us, " said

Dr. Tracey, who immediately saw the potential to use vagus

stimulation as a way to shut off abnormal immune system responses.

He calls this network " the inflammatory reflex. "

Research is now underway to see whether tweaking the brain's

acetylcholine system could be a natural way to control the

inflammatory response. Inflammation is key to many diseases - from

autoimmune conditions like Crohn's disease and rheumatoid arthritis

to Alzheimer's, where scientists have identified a strong

inflammatory component.

Dr. Tracey has presented his work to the Dalai Lama, who has

shown a great interest in the neurosciences and the mind-body

connection. He has also written a book called " Fatal Sequence, "

about the double-edge sword of the immune system.