A new study by a team of neuroscientists at the University of California, Berkeley, has determined that we learn new smells in an area of our brains, not just in our noses, which have neural receptors previously thought to be solely responsible for a person's ability to detect new odors.

This finding has prompted the team, led by graduate student Joel Mainland and Noam Sobel, assistant professor of psychology, to conclude that the adult brain has more capabilities to change than previously thought. The study appears in the Oct. 24 issue of Nature.

The discovery may have implications for how the brain recovers from injury. Lately, there has been a lot of evidence that activity in damaged regions of the body results in regeneration in the brain. For example, in stroke patients, tying down the unaffected limbs to force patients to try use their affected arms or legs has resulted in recovery of some use of those limbs.

The researchers conducted their work through a very simple mechanism using the chemical androstenone. Androstenone cannot be detected by approximately 30 percent of the population.

However, about half of such non-detectors can develop the capability to detect the odorant following repeated exposure to it. For those who can smell it, there is a wide range of reactions to its odor. The people who are most sensitive to it find the smell extremely foul and reminiscent, Sobel said, "of dirty laundry."

Sobel and his colleagues conducted an extensive screening to find subjects who could not detect this smell. The screening yielded 12 people. In the test subjects, one nostril was completely blocked, and the open nostril was exposed to androstenone every day for 21 days. After the 21 days, both nostrils were tested for detection. Both nostrils doubled their detection accuracy due to
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Contact: Carol Hyman
cph@pa.urel.berkeley.edu
510-643-7944
University of California - Berkeley
23-Oct-2002