Loss of Smell Could Be Early Sign of Alzheimer's

In mice, even small amount of amyloid plaques affected olfactory sense

January 12, 2010 RSS Feed Print

TUESDAY, Jan. 12 (HealthDay News) -- New research in mice suggests that loss of smell could serve as an early indicator of Alzheimer's disease.

People with Alzheimer's are already known to suffer from loss of smell. But the new research pinpoints a direct link between development of amyloid plaques -- the bits of gunk in the brain that cause Alzheimer's disease -- and a worsening sense of smell.

The findings are reported in the Jan. 13 issue of the Journal of Neuroscience.

Researchers found that the plaques first develop in the part of the mouse brain that's devoted to the sense of smell. When tested, the mice with the plaques had to spend more time sniffing odors to remember them, and they had a hard time telling the difference between odors.

"What was striking in our study was that performance of the mouse in the olfactory behavior test was sensitive to even the smallest amount of amyloid presence in the brain as early as 3 months of age (equivalent to a young adult)," study co-author Daniel W. Wesson, of New York University School of Medicine and the Nathan S. Kline Institute for Psychiatric Research in Orangeburg, N.Y., said in a university news release.

"This is a revealing finding because, unlike a brain scan, a laboratory-designed olfactory test may be an inexpensive alternative to early diagnosis of Alzheimer's," Wesson said.

More information

The Alzheimer's Association has more on Alzheimer's disease.