Physiological and anatomical evidence for multisensory interactions in auditory cortex
Single Paper Presentation

Jennifer Bizley
Department of Physiology, Anatomy and Genetics, University of Oxford

Fernando Nodal
Department of Physiology, Anatomy and Genetics, University of Oxford

Victoria Bajo
Department of Physiology, Anatomy and Genetics, University of Oxford

Israel Nelken
Department of Neurobiology, Hebrew University

Andrew King
Department of Physiology, Anatomy and Genetics, University of Oxford

     Abstract ID Number: 27
     Full text: Not available
     Last modified: March 1, 2006
     Presentation date: 06/20/2006 11:30 AM in Hamilton Building, McNeil Theatre
     (View Schedule)

Abstract
Recent studies, conducted almost exclusively in primates, have shown that several cortical areas usually associated with modality-specific sensory processing are subject to influences from other senses. Here we demonstrate using single-unit recordings that visually-responsive units are widespread in the auditory cortex of anesthetized ferrets. In many cases, these units were also acoustically responsive and frequently transmitted more information in their spike discharge patterns in response to paired visual-auditory stimulation than when either modality was presented by itself. Visually-responsive units were present throughout the depth of the cortex. They were particularly common in non-tonotopic areas on the anterior ectosylvian gyrus, but were also found in tonotopic areas, including the edges of the primary auditory fields on the middle ectosylvian gyrus. Within each auditory cortical field, the pure tone response properties of neurons sensitive to visual stimuli did not differ in any systematic way from those of visually-unresponsive neurons. Neural tracer injections revealed direct inputs from different areas of visual cortex to both primary and non-primary auditory fields, indicating a potential source of origin of the visual responses in auditory cortex. These data suggest that multisensory convergence and integration are features common to all auditory cortical areas.