Sniffing and whisking in rodents

Sniffing and whisking are two rhythmic orofacial motor activities that enable rodents to localize and track objects in their environment. They have related temporal dynamics, possibly as a result of both shared musculature and shared sensory tasks. Sniffing and whisking also constitute the overt expression of an animal's anticipation of a reward. Yet, the neuronal mechanisms that underlie the control of these behaviors have not been established. Here, we review the similarities between sniffing and whisking and suggest that such similarities indicate a mechanistic link between these two rhythmic exploratory behaviors.

► Sniffing and whisking serve to gather sensory information, and occur during reward expectation. ► These rhythmic activities affect both the coding and central processing of sensory inputs. ► As sniffing and whisking exhibit a fixed temporal relationship, they may share a common circuitry.