Bilateral movement training promotes axonal remodeling of the corticospinal tract and recovery of motor function following traumatic brain injury in mice

Cell Death and Disease, 2013 · DOI: 10.1038/cddis.2013.62 · Published: March 7, 2013

Simple Explanation

Traumatic brain injury (TBI) often leads to motor function impairment, with recovery being incomplete. Rehabilitative training aims to restore the injured neural network, promoting functional recovery. This study explores the impact of different training types on corticospinal tract (CST) plasticity and motor recovery in mice with unilateral motor cortex contusion. The research compared single pellet-reaching (simple repetitive training) and rotarod tasks (bilateral movement training) to evaluate forelimb motor function recovery using various tests. Results showed that the rotarod group exhibited better performance in most forelimb motor tasks, while the reaching group only improved in the single pellet test. The study found that bilateral movement training effectively promotes axonal rewiring and motor function recovery. In contrast, simple repetitive training had limited effects. The contralateral CST formed sprouting fibers into the denervated side of the cervical spinal cord, with significantly more fibers in the rotarod group, suggesting enhanced neural plasticity.

Study Duration

4 weeks

Participants

Adult male C57BL/6J mice

Evidence Level

Not specified

Key Findings

1
Bilateral movement training (rotarod) enhances motor function recovery more effectively than simple repetitive training (reaching) after TBI in mice.
2
Bilateral movement training promotes axonal rewiring of the corticospinal tract, leading to increased sprouting fibers in the denervated side of the cervical spinal cord.
3
Bilateral movement training increases neuronal activity in the cervical cord, specifically in laminae VII, VIII, and X, suggesting involvement of spinal interneurons in recovery.

Research Summary

This study compared the effects of unilateral repetitive and bilateral movement training on motor function recovery in a mouse model of TBI, focusing on corticospinal tract (CST) rewiring. The results indicate that bilateral movement training improves motor function recovery and facilitates axonal rewiring of the CST, while simple repetitive training provides only limited improvement. The study suggests that bilateral movement training enhances neural plasticity and motor recovery by modulating intraspinal systems and promoting CST axonal rewiring.

Practical Implications

Rehabilitation Strategies

Bilateral movement training should be considered as a more effective rehabilitative approach for motor function recovery after traumatic brain injury compared to simple repetitive training.

Neural Plasticity

Understanding the mechanisms underlying bilateral movement training's effect on CST rewiring can lead to the development of targeted therapies to enhance neural plasticity and promote recovery.

Clinical Translation

The findings support the use of bilateral movement therapies in clinical settings for patients with CNS injuries, potentially improving upper limb function and overall motor recovery.

Study Limitations

1
The study uses a mouse model of TBI, and the extent of CST plasticity and underlying mechanisms might differ between mice and humans.
2
The specific molecular mechanisms mediating training-induced rewiring remain unclear, requiring further investigation to identify key molecules involved in the process.
3
The study did not observe enhanced recovery on the rotarod test in the rotarod training group, potentially due to the test's limited sensitivity in evaluating recovery in this TBI model.

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