Washington, Sept 28 (IANS) A protein may explain why Alzheimer’s patients often lose their sense of smell, say scientists.
‘Deficits in odour detection and discrimination are among the earliest symptoms of Alzheimer’s disease…,’ said Leonardo Belluscio from the National Institute of Neurological Disorders and Stroke, who led the study.
Researchers believed that protein plaques seen in the brains of Alzheimer’s victims were responsible for killing off nerve cells, causing memory disruptions – a hallmark of the disease, reports The Journal of Neuroscience, citing a statement from the institute.
The plaques are 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 nerve cells’ death.
Belluscio and colleagues genetically manipulated mice to produce high levels of a mutated version of human APP in olfactory nerve cells.
Researchers found that mice making mutant APP had four times as much olfactory nerve cell death by three weeks of age compared with normal mice.
Although the cells that produced mutant APP died, the neighbouring cells – that did not have mutant APP – survived.
