[The baseline gamma oscillations in neural networks with interhemispheric connections].

The evidence obtained from the studies of EEG high-frequency components and computer simulation which determined the necessary conditions for occurrence of oscillations were compared with some features of spontaneous gamma oscillations, which had been revealed by us in interconnections of neurons located in symmetrical loci of both hemispheres of motor cortex of anaesthetized rats. Based on the similarity of the most expressed high-frequency EEG components and dominant frequencies of gamma oscillations, we proposed that gamma oscillations could underlie the appearance of the high-frequency EEG components. Taking into account the obtained by us results that interhemispheric oscillations occurred 1.5 times more frequently than ipsilateral and the evidence from computer simulation experiments that reciprocal inhibition underlies oscillations in neural networks, we suggested that transcallosal inhibition was more effective than inhibition between the neighbouring cells. Parameters of simultaneously revealed spontaneous oscillations caused by interhemispheric and ipsilateral interactions and in individual cell activity could be different. It was assumed that functional variability of local neocortical networks and participation of different inhibitory neurons underlie distinctions in oscillation parameters.