Course of spinocerebellar axons in the ventral and lateral funiculi of the spinal cord with projections to the posterior cerebellar termination area: an experimental anatomical study in the cat, using a retrograde tracing technique.

The course of retrogradely labeled spinocerebellar fibers in the ventral and lateral funiculi of the spinal cord was studied following injections of wheat germ agglutinin-conjugated horseradish peroxidase into the posterior spinocerebellar termination area in the cat. Fibers labeled from unilateral injections into the paramedian lobule were found on the same side in the dorsal part of the lateral funiculus (DLF), corresponding to the dorsal spinocerebellar tract (DSCT), but contralaterally in the ventral part of the lateral funiculus (VLF) and in the ventral funiculus (VF), corresponding to the ventral spinocerebellar tract (VSCT). Following injections into the posterior vermis, labeled fibers were less numerous. Most of them were found in the DSCT and only very few in the VSCT. Previously identified cells of origin of these spinocerebellar tracts were labeled in these experiments and counted. They correlated well with the extents and the locations of the injections that had been made into the two termination sites. These results represent novel detailed information on the location of axons projecting to the two main posterior spinocerebellar termination sites in the spinal white matter in the cat.