Supra-barrel Distribution of Directional Tuning for Global Motion in the Mouse Somatosensory Cortex

Abstract

Summary: Rodents explore their environment with an array of whiskers, inducing complex patterns of whisker deflections. Cortical neuronal networks can extract global properties of tactile scenes. In the primary somatosensory cortex, the information relative to the global direction of a spatiotemporal sequence of whisker deflections can be extracted at the single neuron level. To further understand how the cortical network integrates multi-whisker inputs, we imaged and recorded the mouse barrel cortex activity evoked by sequences of multi-whisker deflections generating global motions in different directions. A majority of barrel-related cortical columns show a direction preference for global motions with an overall preference for caudo-ventral directions. Responses to global motions being highly sublinear, the identity of the first deflected whiskers is highly salient but does not seem to determine the global direction preference. Our results further demonstrate that the global direction preference is spatially organized throughout the barrel cortex at a supra-columnar scale. : Using voltage-sensitive dye imaging of the mouse barrel cortex, Vilarchao et al. demonstrate the presence of direction selectivity to global motion generated by multi-whisker stimuli. Selectivity to global motion is spatially organized at the supra-columnar scale with an overrepresentation of selectivity to caudo-ventral directions. Keywords: tactile sensory processing, multivibrissal stimulation, primary somatosensory cortex, barrel cortex, voltage-sensitive dye imaging, mouse, extracellular electrophysiological recordings