[Plastic transformation of the activity of cortical neurons upon pairing a signal stimulus with microiontophoresis or electrocutaneous stimulation].

Substantial differences have been found in the plastic reorganizations of neuronal activity of the rat sensorimotor cortex at local and systemic reinforcements. In nineteen (95%) out of 20 neurones stable and one-type changes of response to CS (electrical stimulation of the cortex) developed in the course of pairings with local ionophoretic application of L-glutamate in the vicinity of the studied neurone. Twenty two units were studied during the pairings of electrical stimulation of the cortex with pain electrocutaneous stimulation: plastic reorganizations in response to CS were revealed only in eight (36.4%) units; they were, however, of long duration and were more diverse in pattern, than in the series with local reinforcement. It is assumed that different plastic reorganizations in these two model situations of learning depend on the number and reactive properties of the participating units.