
Central nervous system and immune system
Quote:
>I have a question about the relationship between the immune system and
>the central nervous system. It is generally acknowledged that facing
>illness with good mental state helps fighting the disease whereas being
>depressed or anxious does inhibit natural defenses.
Quite true.
Oliver Wendell Holmes once provided rudimentary insight into the
processes:
"Healing is a living process, greatly under the influence of mental
conditions. It has often been found that the same wound received in
battle will do well in the soldiers that have beaten, that would prove
fatal in those that have just been defeated."
Quote:
>The problem is, as far as I understand, that there is no way by which
>the central nervous system communicates with the immune system which
>seems to be intrinsically autonomous and decentralized. So my question
>is : how does the nervous system act on the immune system ? (if it
>does!)
There is an extraordinary interactive relationship between the immune
and nervous systems.
Leroy Hood, Chairman of Caltech's biology division, inventor of the
DNA sequencer:
"It looks like we'll be able to say that our immune system is
constructed from elements that evolved from molecules originally
operating in the nervous system....in one immune gene superfamily, that
connection is absolutely explicit! It has eight multigene families and
twelve single-gene members identified so far. The genes fall into three
catagories: those connected only to the immune system, those primarily in
the nervous system, and those shared by both the immune and nervous
systems. And we have absolutely no idea what the shared sets do! But it's
a beautiful relationship..."
Dr. Paul J. Rosch, President of the American Institute of Stress:
"...they use the same chemical messengers to communicate, and both
have the ability to remember. Further links are likely, because there are
networks of nerve fibers in the thymus, spleen and lymph nodes, which
indicate that these important mediators of immune activity may actually
be hard-wired to the central nervous system."
Findings reported at the March 21, 1989 annual meeting of the
Federation of American Societies for Experimental Biology provided
further insight into brain-immune system links.
University of Alabama researchers (Raymond N. Hiramoto, prof. of
microbiology; Vithal Ghanta, assc. prof. of biology and microbiology; H.
Brent Solvasson, grad. student in microbiology dept.) have shown that at
least in mice, the brain can be taught to control part of the immune
system.
In the study, mice were exposed to the pungent mothball smell of
heated camphor for one hour. Immediately afterward, they were injected
with a drug called poly I:C, which mimics a viral infection and causes
certain immune system cells (natural killer cells) to become more active.
NK cells are "general purpose", first-line-of-attack responders and are
important in fighting viruses and tumors.
After only one lesson, the mice learned to connect the camphor smell
with what seemed to be a viral infection. When they were exposed to the
camphor again, without being injected, the "conditioned" mice were found
to have increased the activity of their natural killer cells by 20 to 100
percent. Mice that hadn't been conditioned or were not re-exposed to the
smell did not show increases in immune system activity.
Dr. Hiramoto:
"Since smell is perceived in the brain, the mice that raised their
immune system activity in response to the camphor odor had to be
communicating between brain and immune system. What we're showing, is
once the brain learns this response, it can direct the activity of the
immune system and the natural killer cells. This 'talk' had to go on, or
you wouldn't get an immune response. We've definitely established a link
between immune functions and processes in the brain."
Candace B. Pert, chief of the section on brain biochemistry in the
clinical neuroscience branch of the National Institute of Mental Health:
"Cells in the immune system that heal wounds, repair tissue and ingest
foreign bodies are shaped in such a way that they invite chemical
interaction with neuropeptides...there is a particularly strong
concentration of cells shaped to interact with neuropeptides in the
limbic system, the network of brain structures that controls emotion.
Research suggests that the immune system itself is one source of the
chemicals that control mood.
I believe the findings I have described indicate that we need to
start thinking about how consciousness can project into the body."
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Lance "Bo Knows Psychoneuroimmunology" Sanders