LONG-TERM POSTTETANIC CHANGES OF THE NEUR ONAL 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 affer ent inputs to these neurons. Consecutive or conjoint conditioning of t he thalamo-cortical and the cortico-cortical inputs could induce diffe rent changes in the efficiency of the synaptic inputs to the neighbbou ring neurons the effect depending on the modality of the conditioned i nput, the parameters of tetanization, the pattern of distribution of t he afferent terminals on the dendritic tree and the character of the l ocal circuits formed by the neurons under study and connected with the m excitatory and inhibitory interneurons. As a result of such changes the new patterns of interneuronal connections could appear and be stab le for tens of minutes. It was shown that in the same neuronal network the different types of modifiable synapses could function simultaneou sly. The results might be used for construction of models of learning and memory.