A scientist’s team of NYU Langone Medical Center performs a new animal study to prove that the impairment in sense of smell due to disease or aging can be reversed by training, which is published online on 20 November 2011 in “Nature Neuroscience”.
The team is lead by Donald A. Wilson, who is senior psychology research scientist at the Nathan S. Kline Institute and Emotional Brain Institute and professor of child and adolescent psychiatry at NYU Langone Medical Center.
Wilson and Julie Chapuis, a post-doctoral fellow kept thirsty rats in boxes having a small hole on its three walls. The rats are exposed to three different smells including a mixture of 10 chemicals, another identical mixture with the absence of one chemical and again the same mixture with one replaced chemical. The rats are exposed to smells through a middle hole and a sip of water is supplied through the left and right side holes.
The researchers found that the rats can distinguish between smells when one chemical is replaced, but fails to distinguish when one chemical is removed. The Electrodes are inserted into the anesthetized rat’s brain to record the electrical activity. It is found that each smell produced non-identical patterns within the olfactory lobe. But in the rat’s piriform cortex, the smells that are distinguished and not distinguished by them generate distinct activity and identical patterns.
Wilson and Chapuis trained a new set of rats to distinguish between the smells, which was not done by the first set of rats, by providing more sips of water for choosing corresponding holes. They found that the activity pattern in the piriform cortex of the trained rats showed difference, which is not attainable in the previously tested rats. Similarly, the researchers trained a third set of rats by supplying water at the same hole, which resulted in identical patterns for both the smells.
Wilson said that the researcher’s findings suggest that the olfactory impairment might cause damage to the sensory system. He also added that this research creates awareness about the potential odor training therapies to retain smell function in specific cases.
Source: http://www.med.nyu.edu/