Word: braine
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...studying brain-damaged patients can teach scientists only so much. They would also like to know how anxiety works in normal, intact brains. For this, brain scans have proved invaluable...
...also be that an entirely different part of the brain holds the key to understanding anxiety. Michael Davis, a behavioral neuroscientist at Emory University in Atlanta, has spent six years studying a pea-size knot of neurons located near the amygdala with an impossible name: the bed nucleus of the stria terminalis, or BNST. Rats whose BNST has been injected with stress hormones are much jumpier than those that have got a shot in their amygdala. Could the BNST be at the root of all anxiety disorders? The clues are intriguing, but as scientists are so fond of saying, more...
...course, what you would really like to know is whether any of the work done in rats applies to humans. Clearly researchers can't go around performing brain surgery on the amygdalas of living patients to see if it affects their anxiety levels. But the fascinating case of a woman known only by her research number, SM046, suggests that when it comes to fear, rodents and hominids really aren't so different...
Owing to an unusual brain disorder, SM046 has a defective amygdala. As a result, her behavior is abnormal in a very particular way. When scientists at the University of Iowa show SM046 pictures of a series of faces, she has no trouble picking out those that are happy, sad or angry. But if the face is displaying fear, she cannot recognize the feeling. She identifies it as a face expressing some intense emotion, but that is all. Her unusual condition strongly suggests that even in Homo sapiens, fear takes hold in the amygdala...
...years, doctors have used CAT scans and MRIs to help them diagnose strokes, brain tumors and other neurological conditions. But as the technology has become more sophisticated, researchers have started to employ it to tease out some of the subtle changes associated with mental illness. "We're not yet able to use these scans in a diagnostic way," says Dr. David Silbersweig of the Weill Cornell Medical College in New York City. "But we're getting pretty specific about the areas of the brain that are implicated in a number of psychiatric disorders...