What whisker movement and limb movement have in common is that their rhythm is controlled by central pattern-generating networkslocated in the brain stem and the spinal cord, respectively (Brown,1914; Shik and Or lovsky, 1976; Grillner and Zangger, 1979; Gaoet al., 2001). It is thus conceivable that the two networks communicate in order to affect a temporal coupling between whisking and limb frequency. Such a coupling could be mediated by the breathingrhythm as it has been recently observed in running mice (Sofroniewet al., 2014). These authors identified a low-frequency component of whisking which was nearly equal to the frequency of stepping and respiration