SLOW POTENTIAL WAVES PRODUCED IN THE CUNEATE NUCLEUS BY CUTANEOUS VOLLEYS AND BY CORTICAL STIMULATION

Abstract

There has been a systematic study of the extracellular fields produced in and around the cuneate nucleus by afferent volleys from fore-limb nerves and by stimulation of the contralateral soma-tosensory areas of the cerebral cortex. The P wave has almost the same topographical features whether it is produced by an afferent volley or by cortical stimulation of somatosensory areas I and II and is attributed to a prolonged depolarization of the synaptic terminals of the cuneate tract fibers. The earlier and briefer N-wave produced by an afferent volley has a depth configuration that can be satisfactorily explained by a synaptically induced depolarization of the cuneate cells by the ascending volley in the dorsal column.