In a finding that could alter pain treatment,
British scientists have found that undamaged nerve fibers,
not injured ones, cause ongoing spontaneous pain.
The unexpected finding that may help in the development
of new treatments for back problems and other conditions
that involve chronic pain. Previous research into chronic
pain focused on nerve fibers damaged due to injury or
illness, and largely overlooked intact nerve fibers.
"The cause of this ongoing pain and why it arises
spontaneously was not understood before," Sally Lawson,
of the University of Bristol, said in a prepared statement.
"Now that we know the type of nerve fibers involved,
and especially that it is the undamaged nerve fibers that
cause this pain, we can examine them to find out what
causes them to continually send impulses to the brain.
This should help in the search for new analgesics that
are effective for controlling ongoing pain."
The findings appear in the current issue of the Journal
of Neuroscience.
Lawson and her colleagues identified nerve cells called
nociceptors (damage detectors) that, when activated by
disease or injury, send out electrical impulses that are
sent to the brain. The faster these undamaged nociceptors
fire electrical impulses, the stronger the ongoing pain.
The firing of these nociceptors seems to be caused by
inflammation within the nerves or tissues, caused by dying
or degeneration of the injured nerve fibers within the
same nerve, the researchers said.
