Manifestation of brain activity basic principles on cellular level

It is known that cortical plasticity is a promising candidate in the construction of a model for associative memory and self-organisation of neural networks. The formation of a conditioned reflex (CR) is accompanied by a considerable increase in the interrelationship between the impulse activity of the neurons of the local, cortico-cortical and subcortico-cortical circuits. To elucidate the problem of the correspondence of phenomena proceeding in interneuron relationships to processes appearing at behavioral level at different forms of integral adaptive activity, it is important to investigate the spatial and temporal organisation of memory trace processes at cellular level. This report summarizes two groups of experimental data aimed at elucidating the changes that occur in waves amplitudes of pyramidal tract (PT) response as a result of conditioning and tetanic stimulation. It is known that a change in first direct wave (D) of PT response reflects a change in excitability of pyramidal tract neurones and a change in successive indirect (I) monosynaptic wave reflects a change in efficacy of intracortical synaptic connections.