Description:

Rhythmic sniffing is considered intrinsic to active olfaction among terrestrial mammals. However, mice are known to briefly hold food under their nares while feeding, suggesting coordination of oromanual dexterity, breathing, and olfaction for non-rhythmic single sniffs. Here we recorded kinematics and breathing as mice foraged and fed, finding that mice indeed, with clockwork-like dexterity and millisecond timing, synchronize a single inspiration with rapid head and hand movements. These solitary sniffs override and abruptly reset the breathing rhythm, differ from stereotypical rhythmic sniffing, and exhibit behavioral modulations. Olfactory and motor circuit manipulations demonstrate cortical dependence and volitional rather than reflexive neural control. Our study redefines the concept of active olfaction to include dexterous, volitionally driven single sniffs, identifying these as a common, naturally occurring form of hypothesized discrete “snapshot” olfaction. 

Mang Gao PhD, 
Postdoctoral Researcher 
Shepherd Lab 
Department of Neuroscience