{NEWS} Fear Stops Here... /more/...
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Posted by 2nd Lt Aimee
On 2002-11-10 14:18:15
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Source:
ABCNEWS.com
October 23, 2002
Nov. 7 In a time when the national terror alert rating lingers at yellow
and communities around Washington, D.C., are recovering from a series of sniper
shootings, fear has become a prominent part of Americans' lives. as an
append I'd have to say the worlds lives, aswell
But what, exactly, is fear, and how can people shrug off its often paralyzing
effects?
A study on rats is shedding light on the sensation that isn't just an emotion,
but a biological instinct designed to help us survive. By zeroing in on how the
brain processes fear and quells it scientists hope to develop treatments for
people with runaway fear responses.
"What was clinically interesting was we could reduce fear in rats by stimulating
a particular area of the brain," says Gregory Quirk, a physiologist at the Ponce
School of Medicine in Puerto Rico who authored the study in this week's issue of
Nature. "Someday we hope to use what we learn to help people with anxiety
disorders."
The Fear Center
For years scientists have believed that the so-called "hub" of fear lies in a
peanut-sized part of the brain called the amygdala. The amygdala assesses whether
a situation is dangerous, then fires signals to other parts of the brain. This
triggers the release of hormones, including cortisol, which causes reactions like
sweating and a tensing of the muscles.
Now Quirk and others have taken a closer look at another region of the brain
the prefrontal cortex where they believe one's sense of safety is generated.
To analyze this region, Quirk and his student Mohammed Milad trained rats to fear
a tone by following the sound with an electric shock to their feet. Rats
conditioned to fear the tone froze at the sound in anticipation of pain.
Next the team reconditioned some of the rats using the same tone followed by no
electric shocks. Over time most of these rats no longer froze when they heard the
tone. In another set of rats, Quirk and Milad did not retrain the animals so they
would no longer fear the tone, but instead electrically stimulated neurons in the
prefrontal cortex of the rats' brains.
Quirk says the rats whose brains had been stimulated "acted like they had never
been conditioned to fear the tone at all," even when the tone was repeatedly
followed by shocks.
"We know that fear is not erased it's always there," says Quirk. "Instead there
seems to be a system that actively inhibits the response. That's what we've
discovered."
Sending the 'All Clear'
What happens, Quirk believes, is when the brain senses conditions similar to ones
that previously produced fear, the prefrontal cortex assesses the situation and
if all seems OK, sends what he calls an "all clear" signal to the brain's fear
center. This signal reins in the fear response that would otherwise emanate from
the amygdala. The 'all clear' signal is likely based on the context of the
situation.
"If I yell 'Fire!' in a movie theater, people may run, but if I yell 'Fire!' in
an outside county fair, people are a lot less likely to feel afraid and react,"
explains Michael Bouton, a psychologist at the University of Vermont.
It's this soothing signal that people with anxiety disorders may have trouble
accessing. And just as Quirk was able to electrically stimulate the "all clear"
signal in rats, he hopes the same can be done in people using magnetic pulses.
Rats and people are a big leap apart, he admits, but those working with human
anxiety disorders say the research is promising.
"We're very interested in animal studies," says Thomas Neylan, medical director
of the Post Traumatic Stress Program at the San Francisco Veterans Affairs
Medical Center in California.
Neylan adds that current research is revealing that neurons in the prefrontal
cortexes of people with post-traumatic stress disorder are not as active as in
normal patients.
"If you can enhance frontal lobe function, it may have therapeutic effects,"
Neylan says. "But it is all speculative at this point."
Traumatic Times
Today about 5.2 million Americans suffer from PTSD and recent traumatic events
may well have caused that number to spike.
A post-Sept. 11 study done for the New York City Board of Education found that
10.5 percent of schoolchildren in the city show multiple symptoms consistent with
post-traumatic stress disorder. Among adults, a New York Academy of Medicine
survey in January found that 40 percent to 45 percent of New Yorkers have at
least one symptom of post-traumatic stress. Nearly 6 percent of Americans outside
of New York City reported post-traumatic stress symptoms six months after the
attacks according to a University of California at Irvine study.
A common method of treatment for post-traumatic stress is to have patients
repeatedly experience the conditions of a traumatic event through psychotherapy
in an effort to reprogram their associations. Neylan says that while the
treatment is often effective, it's usually not long lasting.
A treatment using magnetic stimulation of the brain might offer more long-term
cures, says Quirk. Still, he adds, nothing can completely erase the memory of
fear.
"It's not about erasing fear from memory, but replacing it with a memory of
safety," he says, adding, "It's good we can't erase fear, we need it. Fear keeps
you alive."
2nd.Lt.
Aimee
Contact
"I prayed so many nights that you would come my way
An angel from above to light my darkest day
A love so strong it can't be wrong
It's with you that i belong"
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RE: {NEWS} Fear Stops Here... /more/...
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Posted by Ker PixieLuv
On 2002-11-15 01:16:00
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it is scarey living here, you have no idea. but i do not let it get me down and keep me from doing what i love. death will come when you are hiding or not.
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i will not be living my life in fear. period -nt-
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Posted by Cpt Emrys
On 2002-11-11 19:35:23
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There is nothing to fear but fear itself. n/t
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Posted by Ker HeltahSkeltah
On 2002-11-11 07:19:57
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