Why stronger sniffing catches weak odors...

Grosmaitre et al. report in Nature Neuroscience that up to half of mammalian olfactory sensory neurons respond to mechanical stimulation through air-pressure changes, as well as to specific smells. The responses seem to share the same cellular pathway, with increased air pressure raising the firing rate of neurons that have been weakly stimulated by odorants. This mechanism may help to synchronize the firing of neurons in the olfactory bulb with breathing.