Ventral spinocerebellar tract

Ventral spinocerebellar tract
Anterior spinocerebellar tract is labeled in blue at right.
Diagram of the principal fasciculi of the spinal cord. (Ventral spinocerebellar fasciculus visible at center left.)
Latin tractus spinocerebellaris anterior, tractus spinocerebellaris ventralis
Gray's subject #185 761

The ventral spinocerebellar tract conveys proprioceptive information from the body to the cerebellum. It is part of the somatosensory system and runs in parallel with the dorsal spinocerebellar tract. Both these tracts involve two neurons. The ventral spinocerebellar tract will cross to the opposite side of the body then cross again to end in the cerebellum (referred to as a "double cross"), as compared to the dorsal spinocerebellar tract, which does not decussate, or cross sides, at all through its path.

The ventral tract (under L2/L3) gets its proprioceptive/fine touch/vibration information from a first order neuron, with its cell body in a dorsal ganglion. The axon runs via the fila radicularia to the dorsal horn of the grey matter. There it makes a synapse with the dendrites of two neurons: they send their axons bilaterally to the ventral border of the lateral funiculi. The ventral spinocerebellar tract then enters the cerebellum via the superior cerebellar peduncle. This is in contrast with the dorsal spinocerebellar tract (C8 - L2/L3), which only has 1 unilateral axon that has its cell body in the Clarke's nuclei (only at the level of C8 - L2/L3). The fibers of the ventral spinocerebellar tract then eventually enter the cerebellum via the superior cerebellar peduncle. This is one of the few afferent tracts through the superior cerebellar peduncle.

Originates from ventral horn at lumbosacral spinal levels. Axons first cross midline in the spinal cord and run in the ventral border of the lateral funiculi. These axons ascend to the pons where they join the superior cerebellar peduncle to enter the cerebellum. Once in the deep white matter of the cerebellum, the axons recross the midline, give off collaterals to the globose and emboliform nuclei, and terminate in the cortex of the anterior lobe and vermis of the posterior lobe.

Contents

Comparison with dorsal spinocerebellar tract

When the dorsal roots are cut in a cat performing a step cycle, the dorsal spinocerebellar tract has no activity with the loss of peripheral excitation, whereas the ventral spinocerebellar continues to show activity, implying that the dorsal spinocerebellar tract provides the spinocerebellum with sensory information during movement and the ventral spinocerebellar tract internally generated information about the movement. [Confusing sentence -- needs proofreading.] [1]

Synonyms

Additional images

References

  1. ^ Jessell, Thomas M.; Kandel, Eric R.; Schwartz, James H. (2000). Principles of neural science. New York: McGraw-Hill. ISBN 0-8385-7701-6. 

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