Posted on 07/21/2008 5:51:12 PM PDT by Dysart
In a major step in understanding how the nervous system and the immune system interact, scientists at The Feinstein Institute for Medical Research have identified a new anatomical path through which the brain and the spleen communicate. The spleen, once thought to be an unnecessary bit of tissue, is now regarded as an organ where important information from the nervous reaches the immune system. Understanding this process could ultimately lead to treatments that target the spleen to send the right message when fighting human disease.
Mauricio Rosas-Ballina, MD, working with colleagues in the laboratory of Kevin J. Tracey, MD, figured out that macrophages in the spleen were making tumor necrosis factor, a powerful inflammation-producing molecule. When they stimulated the vagus nerve, a long nerve that goes from the base of the brain into thoracic and abdominal organs, tumor necrosis factor (TNF) production in the spleen decreased. This study complements previous research performed in Dr. Tracey’s laboratory, which showed that stimulation of the vagus nerve increases survival in laboratory models of sepsis.
The findings were published today in the Proceedings of the National Academy of Sciences. Many laboratories at The Feinstein Institute study the immune system in health and in disease. Every year, about 500,000 people develop severe sepsis, a syndrome triggered when the body’s immune system wages an attack on the body that is well beyond its normal response to an invader. Sepsis kills about 225,000 deaths in the United States each year.
A hundred years ago, the spleen (located in the upper quadrant of the abdomen) was thought to be only reservoir for blood. It has only been in recent years that scientists discovered that the spleen is a manufacturing plant for immune cells, and a site where immune cells and nerves interact. The spleen defends the body against infection, particularly encapsulated bacteria that circulate through the blood.
The hope is to modulate other immune functions like antibody production through the spleen (via vagus nerve stimulation) as a way to modify the course of infections and possibly some autoimmune disorders.
Dr. Rosas-Ballina began following the winding path of the vagus nerve to establish the route it follows to reach the spleen. He was trying, without much luck, to find fibers of the vagus nerve in this organ. And then he went a little further south to the splenic nerve, the nerve that innervates the spleen. Their results indicate that the vagus nerve inherently communicates with the splenic nerve to suppress TNF production by macrophages in the spleen.
According to the prevailing paradigm, the autonomic nervous system is anatomically and functionally divided in sympathetic and parasympathetic branches, which act in opposition to regulate organ function. “The division between the parasympathetic and sympathetic nervous systems is not clear cut,” said Dr. Rosas-Ballina, explaining that the vagus nerve (the major parasympathetic nerve) acts through the splenic nerve to modulate immune function. He said that results of this study suggest that there may be two separate ways the brain communicates with the spleen to regulate immune function. This points the way to a possible solution for treating sepsis. It may be more effective to take advantage of the central nervous system to control cells of the spleen. This way, “you know where the treatment is going,” said Dr. Rosas-Ballina.
About The Feinstein Institute for Medical Research Headquartered in Manhasset, NY, The Feinstein Institute for Medical Research is home to international scientific leaders in Parkinson's disease, Alzheimer’s disease, psychiatric disorders, rheumatoid arthritis, lupus, sepsis, inflammatory bowel disease, diabetes, human genetics, leukemia, lymphoma, neuroimmunology, and medicinal chemistry. The Feinstein Institute, part of the North Shore-LIJ Health System, ranks in the top 6th percentile of all National Institutes of Health grants awarded to research centers. Feinstein researchers are developing new drugs and drug targets, and producing results where science meets the patient. For more information, please visit www.FeinsteinInstitute.org or http://feinsteininstitute.typepad.com/feinsteinweblog
psychoneuroimmunology
I had no idea the spleen was good for something - although it stands to reason that's it's there for...well, a reason. Thanks for the link.
I wonder if that is the last of our “vestigial” organs.
Interesting ping
interesting, thanks for posting.
What I want to know is how the brain communicates with the organs to make someone a liberal!
Cheers!
Candace Pert, The Molecules of Emotion. Very interesting book.
Just for the record: There’s a whole lot more to psychoneuroendocrine function than just the spleen-vagus aspect mentioned in this report of a single study.
ping for later read
Dr. Pert was an amazing lady. One of my professors told a story of a conference he was participating in when all of a sudden Dr.Pert stood up in the middle of the presentation and said ‘Now I understand!. I understand why the females in Kenya die at a young age...’ She went on from this point to write her book.
Agreed. A must read IMHO.
Was? Did she die recently? As of last year I believe she was alive and working not too far away from me.
thanks, bfl
A much more interesting point to be made about TNF is that it is the inflammatory cytokline that causes PSD or Altzhiemer’s Disease. Every patient with a case of PSD has a medical history that includes instrumentation of the intrathecal space. Whether by needles, stimulators, catheters or shunts. They show almost a 100% correlation with development of AD. Thats a much more important issue.
That is absolutely fascinating, I had no idea. Could you expand just a little so I can do some googling?
And to the OP, thanks for posting this article.
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