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

The cochleotopic organization of the second auditory cortex (AII) was investigated by means of focal potentials evoked by direct electrical stimulation of the cochlea in cats under nembutal anesthesia. It is shown that there are two independent projections of cochlea in AII. One of them is located in the dorsocaudal region of AII and the other--in ventrorostral one. These projections differ in the size and order of cochlear representation. The significant variability of cochlear representation in the auditory cortex was found. The analysis of the projectional maps shows that different cochlear regions are represented in the AII nonproportionally. The basal region projects to the larger cortical square than both the middle and the apical ones. It is suggested that basal cochlear coil is more important for perception and primary analysis of the auditory information.