Dynamic Correlation between Whisking and Breathing Rhythms in Mice

Abstract

Sniffing, a high frequency, highly rhythmic inhalation and exhalation of air through the nose, plays an important role in rodent olfaction. Similarly, whisking, the active rhythmic movement of whiskers plays an important role in rodent tactile sensation. Rodents whisk and sniff during exploratory behavior to sample odorants and surfaces. Whisking is thought to be coordinated with sniffing and normal respiratory behavior but the precise temporal relationships between these movements are not known. Here, using direct measurements of whisking and respiratory movements, we examined the strength and temporal dynamics of the correlation between large amplitude whisker movements and respiratory rhythm in mice. Whisking movements were detected using an optical sensor, and respiration was monitored with a thermistor placed close to the nostril. Our measurements revealed that breathing and whisking movements were significantly correlated only when the whisking rhythm was below 5 Hz. Only a fraction (~13%) of all large amplitude whisker movements occurred during episodes of high frequency (>5 Hz) respiration typically associated with sniffing. Our results show that that the rhythms of respiratory and whisking movements are correlated only during low frequency whisking and respiration. High frequency whisking and sniffing behaviors are not correlated. We conclude that whisking and respiratory rhythms are generated by independent pattern generating mechanisms.

Altered resonance properties of somatosensory responses in mice deficient for the schizophrenia risk gene Neuregulin 1

“…In WT mice, mean firing rates peaked in the 8 Hz condition (Fig. 2d, inset), indicating resonance effects at a frequency where whisking behavior typically occurs in mice (Cao et al 2012; Söhnchen et al 2010). In contrast, sustained firing rates in NRG1 (+/−) mutants increased from 1 to 8 Hz and leveled off at 8–15 Hz, without showing an identifiable peak.…”

“…In particular, an increase in firing rate and phase locking (i.e. the temporal precision of neuronal responses with respect to the stimulus) during 5–10 Hz whisker stimulation have previously been described in rats (Garabedian et al 2003; Melzer et al 2006), suggesting neuronal band-pass or resonant characteristics in the frequency range at which whisker motion occurs during exploratory behavior in rodents (Cao et al 2012; Carvell and Simons 1990). …”

How the brainstem controls orofacial behaviors comprised of rhythmic actions

“…Since Welker’s initial qualitative observations, synchronous sniffing and whisking has been more completely described 18, 19 and quantified 20, 21 in a number of subsequent studies in rats. There is also evidence that high-frequency sniffing and whisking are phase locked in mice 20 ; however, one study reports a lack of such coordination in this species 22 . Nonetheless, all of the recent studies of whisking behavior found that whisking, like licking, can also occur during basal respiration 20–22 .…”

“…There is also evidence that high-frequency sniffing and whisking are phase locked in mice 20 ; however, one study reports a lack of such coordination in this species 22 . Nonetheless, all of the recent studies of whisking behavior found that whisking, like licking, can also occur during basal respiration 20–22 . The separable timing of the whisking and basal breathing motor outputs indicates that these actions are paced by separate rhythm generators (Fig 2c).…”

Phenotypic And Electrophysiologic Characterization of a Mouse Model of Fragile X Syndrome

“…In our previous study, we found that the rhythms of respiratory and whisking movements were correlated during low-frequency whisking and respiration (Cao et al 2012). In the present study we also collected breathing data while recording LFP from the whisker barrel cortex of both WT and KO mice.…”