LONG-TERM POSTTETANIC CHANGES OF THE NEURONAL REACTIONS IN MICROAREAS OF THE CATS MOTOR CORTEX

The long-term posttetanic changes of mono- and polysynaptic reactions of the neighbouring neurons in the microareas of the motor cortex were studied before and after conditioning tetanization of different afferent inputs to these neurons. Consecutive or conjoint conditioning of the thalamo-cortical and the cortico-cortical inputs could induce different changes in the efficiency of the synaptic inputs to the neighbbouring neurons the effect depending on the modality of the conditioned input, the parameters of tetanization, the pattern of distribution of the afferent terminals on the dendritic tree and the character of the local circuits formed by the neurons under study and connected with them excitatory and inhibitory interneurons. As a result of such changes the new patterns of interneuronal connections could appear and be stable for tens of minutes. It was shown that in the same neuronal network the different types of modifiable synapses could function simultaneously. The results might be used for construction of models of learning and memory.