INFLUENCE OF IONTOPHORETIC APPLICATION OF ACETYLCHOLINE ON INTERNEURONAL CONNECTIONS IN THE RABBITS MOTOR CORTEX

The multiunit activity of the neurons in the motor cortex was recorded in 8 rabbits under conditions of acetylcholine (or physiological sali ne) iontophoretric application. Crosscorrelation analysis of pulse tra ins was carried out. It was found out that acetylcholine activated the intracortical connections. Its application led to an increase in inte nsity of permanently existing short-latency interneuronal connections (i.e. the stable ones). Moreover, it led to a formation of the long-la tency unstable connections, However, the obtained data do not suggest that acetylcholine promotes the formation of new short-latency connect ions between neurons. The modulatory influence of acetylcholine is dis cussed on the network activity of cortical neurons.