i will not be living my life in fear. period -nt- |
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 Cpt Emrys On 2002-11-10 14:18:15, Aimee wrote >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 > >
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