title: Emergent properties of tactile scenes selectively activate barrel cortex neurons.
abstract: Rats discriminate objects by scanning their surface with the facial vibrissae, producing spatiotemporally complex sequences of tactile contacts. The way in which the somatosensory cortex responds to these complex multivibrissal stimuli has not been explored. It is unclear yet whether contextual information from across the entire whisker pad influences cortical responses. Here, we delivered tactile stimuli to the rat vibrissae using a new 24 whisker stimulator. We tested sequences of rostrocaudal whisker deflections that generate multivibrissal motion patterns in different directions across the mystacial pad, allowing to disambiguate local from global sensory integration. Unitary electrophysiological recordings from different layers of the barrel cortex showed that a majority of neurons has direction selectivity for the multivibrissal stimulus. The selectivity resulted from nonlinear integration of responses across the mystacial pad. Our results indicate that the system extracts collective properties of a tactile scene.
authors.affiliation: Unité de Neurosciences Intégratives et Computationnelles, Centre National de la Recherche Scientifique, Gif sur Yvette, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Jacob
authors.forename: Julie
authors.initials: J
authors.lastname: Le Cam
authors.forename: Valérie
authors.initials: V
authors.lastname: Ego-Stengel
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Shulz
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001931:Brain Mapping; D008297:Male; D015233:Models, Statistical; D009474:Neurons / Q000502:physiology*; D010812:Physical Stimulation; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000166:cytology*; D014110:Touch; D014738:Vibrissae