ELECTROPHYSIOLOGICAL STUDIES ON OCULOMOTOR NEURONS OF THE CAT

Publisher Website
Google Scholar
Abstract
Glass micropipettes were inserted into the oculomotor nucleus of the cat and electrical activities and properties of the neurons were studied with intracellular recordings. The properties of ocular motoneurons were, in many respects, alike to those of lumbar spinal motoneurons. However, when compared with the latter, several characteristics of ocular motoneurons were noted; rather smaller time constant, shorter duration of after-hyperpolarization, lack or scarcity of collateral inhibition, much more frequent rates of tonic and phasic discharges and so on. Local reflex activity in the oculomotor system was rarely observed, but a few cases were encountered that seemed to be like those of proprioceptive responses in the spinal motor system. Synaptic potentials in ocular motoneurons due to the VIIIth nerve stimulations were visualized by intracellular recording, and their relations with focal potentials in the oculomotor nucleus and with discharges to the IIIrd nerve, elicited by the same stimulation, were examined in relation with the vestibulo-ocular reflex.