Biomedical subjects
Publications and source records attributed to M F Sarna.
The companion paper has described a new, fully automatic device for the sorting of action potential waveforms in real time. We present here a brief comparison of performance between this new device and several of the older, more traditional devices used for this purpose. We include in the comparison the performance of 3 human observers.
Spontaneous and evoked activities of nucleus interpositus neurons (IN) of the cerebellum were examined before and after cerebellar paravermal cortex lesions in cats anesthetized with alpha-chloralose. It was found that spontaneous activity increased dramatically following cortical ablation: before the lesion only 4% of cells encountered fired at a rate exceeding 80 impulses/sec., whereas up to 40% discharged at this rate postoperatively. Responses to paw stimulation were also altered: the initial excitation was lengthened from 8.5 to 15.8 msec; narrow; trough causing segmentation in this excitation, which seems to result from Purkinje cell inhibition, was absent; and the succeeding inhibitory period was reduced in duration by 50%. Also after the lesion there was a strong tendency for the neurons to discharge in bursts. It is suggested that changes in cell activity in the IN following cortical lesion unveil neural mechanisms of motor disturbances in lesioned cats.