[Long-term changes in the efficiency of the excitatory and inhibitory connections in the neuronal micronetworks of the motor cortex induced by tetanization of the thalamic nuclei and the sensory cortex].

Assumption was verified that tetanization which produces long-term potentiation (LTP) and long-term depression (LTD) in the efficacy of thalamo-cortical inputs and the inputs from the sensory cortex to motor cortex results also in long-term modifications of the efficacy of interneuronal interactions in the motor-cortical networks. It was shown that monosynaptic excitation of one of the neighbouring neurons in the motor cortex by rhythmical stimulation of some thalamic nuclei or the sensory cortex resulted in LTP or LTD in the efficacy of excitatory and inhibitory transmission between the neurons of the network. The efficacy of the synapses formed by the terminals of one axon on the neighbouring cells could be variously modified. If the network contained the neurons with multiple convergent inputs the tetanization resulted in the LTP of most of them. In the neuronal networks which contained local feed-forward inhibitory circuits, LTP (LTD) of the inhibitory input to the target cell was accompanied by LTD (LTP) of the excitatory input to the same target cell. Different patterns of modified interneuronal connections were caused by tetanization of different brain structures (thalamic nuclei or sensory cortex).