CROSS-CORRELATIONAL ANALYSIS OF THE FUNCT IONAL CONNECTIONS IN THE SENSORIMOTOR CORTEX IN DOGS

Multiunit activity of sensorimotor cortes was recorded from chronicall y implanted semimicroelectrodes in two dogs. Functional interneuronal connections between neuronal spike trains of 6-8 neurons selected from background multiunit activity were studied by the method of cross-cor relation analysis. Bin widths 0,5, 1, 2, 3 and further up to 40 ms by step of 1 ms were used. The cross-interval connections were characteri zed by complete absence of the shared input (central symmetrical peaks ) and signs of inhibitory interrelations. The temporal interrelations between selected neurons were characterized by unilateral and bilatera l nonsymmetrical excitatory connections - ultra-narrow peaks with shor t (1-10 ms), middle (10-80 ms) and long (80-2000 ms) delays. The exist ence of such ultranarrow peaks contradicts <<classical>> conceptions o n the character of cross-interval connections based on model experimen ts on simple nervous systems. We suppose that special mechanism of syn chronization with high temporal accuracy exists in the cortex.