The rubrospinal tract is one of the descending tracts of the spinal cord. It is a motor control pathway that originates in the red nucleus. It is a part of the lateral indirect extrapyramidal tract.
The rubrospinal tract fibers are efferent nerve fibers from the magnocellular part of the red nucleus. (Rubro-olivary fibers are efferents from the parvocelluar part of the red nucleus).
It is functionally less important in humans. It is involved in motor control of distal flexors of the upper limbespecially of the hand and fingersby promoting flexor tone while inhibiting extensors. It terminates primarily in the cervical and thoracic portions of the spinal cord, suggesting that it functions in upper limb but not in lower limb control.
It is small and rudimentary in humans. In some other primates, however, experiments have shown that over time, the rubrospinal tract can assume almost all the duties of the corticospinal tract when the corticospinal tract is lesioned.
See also
- Upper motor neuron