Medical Research Council - London Institute of Medical Sciences

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Nose Limits

The brain's smell receptors determine how sensitive we are to individual smelly compounds

11 August 2018

Nose Limits

Smells guide us around the world – but amines, ammonia-containing odours found in fishy smells (and decaying flesh), are possibly ones to avoid. Looking down on this mouse’s nose, a high-powered microscope peers inside the olfactory bulb, where chemicals sniffed from the outside world turn into speedy signals for the brain, similarly to humans. This mouse is genetically modified, giving colour to some important cells – blue picks out the trails of calcium signals sent as neurons communicate; pink and yellow highlight two types of cell sensitive to amines. While these different types of trace amine-associated receptor (TAAR) are sensitive to amines in general, each has a particular favourite. It seems that among the hundreds of olfactory receptors in mice and humans, specific types set the bar for how sensitive we are to individual smelly compounds, perhaps shedding new light on disorders like hyperosmia – an abnormally acute sense of smell.

Written by John Ankers

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