A systematic representation of interaural intensity differences in the auditory cortex of the pallid bat

The current model of cortical processing of auditory spatial information is based on an orthogonal representation of frequency and binaural response properties, but how this arrangement leads to representation of space in the auditory cortex is unclear. This study describes the first evidence of a cortical substrate for the systematic representation of space in a region of primary auditory cortex of the pallid bat that subserves passive sound localization. The organizational feature of this region is a systematic shift in sensitivity to interaural intensity differences across the cortical surface, suggesting a topographic representation of horizontal space based on the distribution of activity within the neuron population.

[1]  T. Imig,et al.  Binaural columns in the primary field (A1) of cat auditory cortex , 1977, Brain Research.

[2]  G D Pollak,et al.  Neural mechanisms of sound localization in an echolocating bat. , 1984, Science.

[3]  W. O'Neill,et al.  The Bat Auditory Cortex , 1995 .

[4]  T. Imig,et al.  Functional organization of sound direction and sound pressure level in primary auditory cortex of the cat. , 1994, Journal of neurophysiology.

[5]  H. Heffner,et al.  Effect of auditory cortex ablation on localization and discrimination of brief sounds. , 1978, Journal of neurophysiology.

[6]  J. C. Middlebrooks,et al.  Binaural response-specific bands in primary auditory cortex (AI) of the cat: Topographical organization orthogonal to isofrequency contours , 1980, Brain Research.

[7]  G D Pollak,et al.  Binaural response organization within a frequency-band representation of the inferior colliculus: implications for sound localization , 1986, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[8]  D. Irvine,et al.  Topographic organization of interaural intensity difference sensitivity in deep layers of cat superior colliculus: implications for auditory spatial representation. , 1985, Journal of neurophysiology.

[9]  Z. M. Fuzessery,et al.  A representation of horizontal sound location in the inferior colliculus of the mustache bat (Pteronotus p. parnellii) , 1985, Hearing Research.

[10]  M. Merzenich,et al.  Role of cat primary auditory cortex for sound-localization behavior. , 1984, Journal of neurophysiology.

[11]  J. Kelly,et al.  Binaural organization of primary auditory cortex in the ferret (Mustela putorius). , 1994, Journal of Neurophysiology.

[12]  L. Aitkin,et al.  Azimuthal sensitivity of neurons in primary auditory cortex of cats. II. Organization along frequency-band strips. , 1990, Journal of neurophysiology.

[13]  K A Razak,et al.  Single cortical neurons serve both echolocation and passive sound localization. , 1999, Journal of neurophysiology.

[14]  N Suga,et al.  Aural representation in the Doppler-shifted-CF processing area of the auditory cortex of the mustache bat. , 1978, Science.

[15]  L. Aitkin,et al.  Sensitivity to interaural intensity differences of neurons in primary auditory cortex of the cat. I. types of sensitivity and effects of variations in sound pressure level. , 1996, Journal of neurophysiology.

[16]  A J King,et al.  Spatial response properties of acoustically responsive neurons in the superior colliculus of the ferret: a map of auditory space. , 1987, Journal of neurophysiology.

[17]  J. C. Middlebrooks,et al.  Functional classes of neurons in primary auditory cortex of the cat distinguished by sensitivity to sound location , 1981, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[18]  D. Irvine,et al.  Binaural interaction in high-frequency neurons in inferior colliculus of the cat: effects of variations in sound pressure level on sensitivity to interaural intensity differences. , 1990, Journal of neurophysiology.

[19]  Z. Fuzessery,et al.  Monaural and binaural spectral cues created by the external ears of the pallid bat , 1996, Hearing Research.

[20]  J. Kelly,et al.  Organization of auditory cortex in the albino rat: binaural response properties. , 1988, Journal of neurophysiology.

[21]  J. C. Middlebrooks,et al.  A neural code for auditory space in the cat's superior colliculus , 1984, The Journal of neuroscience : the official journal of the Society for Neuroscience.