"Deficits in odor detection and discrimination are among the earliest symptoms of Alzheimer's disease, suggesting that the sense of smell can potentially serve as a 'canary in the coal mine' for early diagnosis of the disease," said Leonardo Belluscio, PhD, of the National Institute of Neurological Disorders and Stroke, who led the study.
"The changes taking place in the olfactory system as a result of Alzheimer's disease may be similar to those in other regions of the brain but appear more rapidly" he
Researchers once thought that protein plaques commonly seen in the brains of people with Alzheimer's disease were responsible for killing off nerve cells, causing disruptions in memory - a hallmark of the disease.
The plaques are primarily derived from a protein called amyloid precursor protein (APP).
The new study suggests that APP alone - in the absence of the plaques - may be to blame for the death of nerve cells.
In the new study, Belluscio
colleagues genetically manipulated mice to produce high levels of a mutated version of human APP in olfactory nerve cells.
"Reducing APP production suppressed the widespread loss of nerve cells, suggesting that such disease-related death of nerve cells could potentially be stopped," Belluscio
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More information about Alzheimer's disease can be found in the Society's Research & Discoveries and Brain Briefings.