[Postactivation inhibition of processes in interneurons transmitting the activity of lateral "descending" systems]

After-discharge depression of excitability is found in the interneurons specialized on transmission of activities from "lateral" descending systems. Many of these cells are propriospinal units sending axons to the lateral funicle (LF). Anti- und orthodromic spike potentials in these cells are followed by significant hyperpolarization. In some cells post-activation depression increased with a rise in intensity of LF stimulation that evoked antidromic discharge; inhibitory post-synaptic potentials were recorded in several units after LF stimulation subthreshold for evoking such discharges. Existance of inhibitory synaptic connections between neurons of the investigated group similar to recurrent connections in the motoneuronal pools is supposed.