Abstract:
Neurological, anatomical and electrophysiological techniques have been combined
in a sequence of studies designed to elucidate further the nature and characteristics
of the influx ascending the neuraxis to the cerebellum. The form and course
of the electrical activity initiated in the cerebellum by these various components
are included in the study as is the distribution of their terminations within
the cerebellum. This study includes the cerebellopetal flows from the ventral
spino-cerebellar tract, the inferior olives, and the lateral reticular nuclei.
Characterization of the ventral spino-cerebellar system has been completed. This
pathway causes, primarily in the lobulus centralis, the very late component of
the cerebellar electrical activity evoked by stimulation of the afferent nerves from
the lower limbs. This response is ipsilateral and occurs at approximately 20 msec.
after stimulation of the sciatic nerve. It is abolished by section of the anterolateral
column of the contra1ater)al spinal cord, or of the ipsilateral superior
cerebellar peduncle. Section of these pathways, while eliminating the late potential
does not affect the earlier sequence known to arise from activity of the dorsal
spino-cerebellar tract. Similar analyses of the influence of other ascending systems
on the cerebellum are in process and will be presented in terms of the electrophysiological
findings and the anatomical relations.
