[Inhibitory interactions in neuronal networks including cells of the auditory cortex and the medial geniculate body]

Cross-correlation method was used for revealing effective inhibitory interactions in neural networks containing simultaneously recorded neurons from different loci of auditory cortex (A1) and medial geniculate body (MGB). It was shown that (i) inhibitory connections were "divergent", i. e., one neuron in A1 (MGB) depressed activity of neurons in different loci of A1 and MGB simultaneously; (ii) inputs to inhibitory neuron were "convergent", i.e., one neuron in A1 (MGB) was excited by neurons from different loci of A1 and MGB simultaneously. There were inhibitory neurons which selectively depressed activity of only one neighbouring neuron. The results allow to suggest that the same inhibitory neuron may be involved in afferent and feedback inhibition. We supposed that the principles of organization of inhibitory connections in thalamo-cortical networks underlie the observed exceptions to mapping (tonotopic) principle of organization of receptive fields of A1 and MGB.