Washington, Nov 21 - Researchers seem to have cracked the mystery of failing smell and how it is linked with Alzheimer's and Parkinson's disease and even normal ageing.

The findings by Donald A. Wilson, professor of child and adolescent psychiatry at New York University Langone Medical Centre, suggest possible ways to reverse the loss of smell due to ageing or disease.

"We located where in the brain loss of smell may happen... We showed that training can improve the sense of smell, and also make it worse," the journal Nature Neuroscience reports.

Wilson and Julie Chapuis, post-doctoral fellow, based their experiments on mice, according to a Langone statement.

"Our findings suggest that while olfactory impairment may reflect real damage to the sensory system, in some cases it may be a 'use it or lose it' phenomenon," says Wilson.

This opens the door for potential smell training therapies that could help restore smell function in some cases. "Odour training could help fix broken noses," he adds. (IANS)