[Cochleotopic organization of the primary auditory region of the cerebral cortex in cats].

The cochleotopic organization of the primary auditory cortex (AI) was investigated by means of focal potentials evoked by direct electrical stimulation of the cochlea in cats under nembutal anesthesia. Two foci of maximal activity (dorsal and ventral) which were more prominent in the rostral and medial parts of AI appeared in 85% of animals in response to local stimulation of different cochlear regions. The analysis of the projectional maps shows that different cochlear regions are represented in AI nonproportionally. The basal region is projected to a larger cortical area than both the middle and apical ones. Significant variability was found for cochlear representation in the auditory cortex of different cats.