The Journal of Neurophysiology Vol. 83 No. 5 May 2000, pp. 3123-3132
Copyright ©2000 by the American Physiological Society

Topographic Analysis of Epidural Pure-Tone-Evoked Potentials in Gerbil Auditory Cortex

Department of Molecular and Cell Biology, Division of Neurobiology, University of California, Berkeley, California 94720

Ohl, Frank W., H. Scheich, and Walter J. Freeman. Topographic Analysis of Epidural Pure-Tone-Evoked Potentials in Gerbil Auditory Cortex. J. Neurophysiol. 83: 3123-3132, 2000. This study investigated the tonotopic organization of pure-tone-evoked middle latency auditory evoked potentials (MAEPs) recorded at the auditory cortical surface in unanesthetized gerbils. Multielectrode array recording and multiple linear regression analysis of the MAEP demonstrated different degrees of tonotopic organization of early and late MAEP components. The early MAEP components P1 and N1 showed focal topography and clear dependence in location and size of cortical area covered on pure-tone frequency. The later components P2 and N2 showed a widespread topography which was largely unaffected in location and size of cortical area covered by pure-tone frequency. These results allow delimitation of the neural generators of the early and late MAEP components in terms of the spectral properties of functionally defined neural populations.