DOGS鈥� extraordinary ability to sniff out anything from cocaine to cancer turns out to owe much to the gunk inside their nose.
Dogs have many more nerve cells in their nasal cavities than we do and a wider variety of receptors to latch on to odour molecules. Now a team led by Brent Craven of Pennsylvania State University in University Park has shown that the complex network of snot-coated tubes in a dog鈥檚 nose also 鈥減re-sorts鈥� smells, which may make it easier for the brain to identify them.
Before odour molecules can reach smell receptors, they must get through a layer of mucus 鈥� and some molecules are absorbed quicker than others. To find out how this might affect smell perception, Craven鈥檚 team used MRI images of a dog鈥檚 nasal airways to develop computer models of how air travels along them. The team found that different molecules are first picked up at different points in the airway network.
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Until now, research has focused on how receptors pick up different chemicals. 鈥淲e鈥檝e shown that the sorting out of the different odorants before they even get to the receptors is also important,鈥� says Craven. The team presented its results this week at a meeting of the American Physical Society鈥檚 division of fluid dynamics in San Antonio, Texas.
