SPIKE DISCHARGES IN PYRAMIDAL SYSTEM DURING RECRUITMENT WAVES

Publisher Website
Google Scholar
Abstract
In the unanesthetized "pyramidal" cat, spike discharge of single units may be led with monopolar wire microelectrodes from the pyramidal decussation or from the layers of the motor cortex. Discharges studied are those observed only during the spontaneous spindle waves of the motor area. The pyramidal discharges are driven by low frequency stimulation of the diffuse thalamic projection system. Corticifugal volleys occur during each recruiting wave and follow the stimulus artefact after latencies of 10-12 msec, (primary discharge) and 20-40 msec, (secondary discharge). The cortical recruiting waves are also correlated with intracortical spike outbursts. The latter tend to be subdivided into primary and secondary groups. Latencies of 4-10 msec, and of 18-30 msec, were calculated, respectively. Confirming previous investigations, high frequency spike outbursts may be recorded from either the motor cortex or the pyramidal tract following local strychninization (0.2%) of the cerebral area. These spike outbursts are also driven by the intrathalamic stimuli. If the frequency of the recruiting potentials is raised to 12/sec, spike discharges and recruiting waves of the motor cortex exhibit alternation of effect. The convulsive waves and spike outbursts following more concentrated strychnine (1%) are no longer triggered by recruiting stimuli.

This publication has 4 references indexed in Scilit: