[Convergence and divergence of interneuronal functional connections].

Multiunit activity was recorded in the auditory and motor cortex of cats with implanted electrodes, impulses with highest and lowest amplitudes being isolated by means of an amplitude discriminator. Crossinterval histograms were obtained for two simultaneous records. Functional relationships between neurons under different electrodes were evaluated by statistical interdependence of isolated trains. In the auditory cortex, neurons with high amplitude spikes mainly produced connections of excitatory type whereas neurons with low amplitude spikes produced connections of inhibitory type. In the motor cortex neurons producing heterogenous effect were predominant.