[Facilitation and depression, under the influence of the iontophoretic application of acetylcholine, of the different components of the neuronal reactions in the cat motor cortex during the performance of a conditioned reflex of placing the paw on a lever]

Abstract

The iontophoretic application of acetylcholine onto the motor cortex of cats during the execution of conditioned placing reaction caused an increase in neuronal excitability and facilitation of "extrinsic" connections (manifested as an enhancement of primary responses to electrical stimulation of the parietal cortex) and independent effect of suppression, which could be seen only in the response components with longer latency. The functional significance of these oppositely directed effects of acetylcholine application is corroborated by statistically significant changes in the motor response latency of the same directions as the changes in neuronal responses. Such a correlation was observed in a number of experiments.