Rubrospinal Tract [Neurosurgery Wiki]

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====== Rubrospinal Tract ======

The **rubrospinal tract** is a descending motor pathway that originates in the **red nucleus** of the midbrain and plays a role in **facilitating flexor muscle tone**, particularly in the upper limbs. Though prominent in quadrupeds, its role in humans is limited and partially redundant with the corticospinal tract.

=== Origin ===
- **Red nucleus (nucleus ruber)**, specifically its magnocellular part, located in the **midbrain tegmentum**.

=== Course ===
- Fibers **decussate immediately** in the **ventral tegmental decussation**.
- Descend **contralaterally** through the **lateral funiculus** of the spinal cord, anterior to the lateral corticospinal tract.
- Most projections are to **cervical and upper thoracic levels**.

=== Termination ===
- Synapses primarily in **laminae V–VII** of the spinal cord gray matter.
- Influences **interneurons** and **motor neurons** controlling flexor muscles of the upper extremity.

=== Function ===
- Facilitates **flexor tone** and inhibits extensor tone (especially in upper limbs).
- Involved in **fine motor control**, though minimal in humans.
- May contribute to **motor recovery** post-stroke via plastic reorganization.

=== Clinical relevance ===
- **Redundant with corticospinal tract** in humans.
- Its function may become more relevant in **compensatory plasticity** after corticospinal damage.
- Damage rarely produces isolated clinical signs but may be involved in **decorticate rigidity**.

=== Comparative anatomy ===
- **Highly developed in quadrupeds**, contributing to limb coordination in locomotion.
- In humans, **vestigial** but potentially important in motor plasticity.

=== Related entries ===
  * [[lateral_corticospinal_tract|Lateral Corticospinal Tract]]
  * [[vestibulospinal_tract|Vestibulospinal Tract]]
  * [[reticulospinal_tract|Reticulospinal Tract]]