title: Two-dimensional coincidence detection in the vibrissa/barrel field.
abstract: Coincidence detection in visual and auditory cortex may also be critical for feature analysis in somatosensory cortex. We examined its role in the rat posteromedial barrel subfield (PMBSF) using high-resolution arrays of epipial electrodes. Five vibrissae, forming an arc, row, or diagonal, were simultaneously or asynchronously stimulated to simulate contact with a straight edge of different angles at natural whisking velocities. Results indicated supralinear responses for both slow-wave and fast oscillations (FOs, about 350 Hz) at intervibrissa delays <2 ms. FO represented the earliest and most precisely tuned response to coincident vibrissa displacement. There was little difference in the spatiotemporal pattern of slow-wave or FO responses in the row, arc, or diagonal. This equivalence of function suggests that the PMBSF may be capable of working as a two-dimensional integrative array, processing spatial features based on coincidence detection despite the direction that the vibrissae pass across an object.
authors.affiliation: Department of Psychology, University of Colorado, Boulder, CO 80309-0345, USA.
authors.forename: Krista M
authors.initials: KM
authors.lastname: Rodgers
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Benison
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Barth
mesh_terms: D000818:Animals; D004594:Electrophysiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D008297:Male; D010812:Physical Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013003:Somatosensory Cortex / Q000502:physiology*; D014738:Vibrissae / Q000502:physiology*