Tenascin-R Restricts Posttraumatic Remodeling of Motoneuron Innervation and Functional Recovery after Spinal Cord Injury in Adult Mice

The Journal of Neuroscience, 2006 · DOI: 10.1523/JNEUROSCI.1526-06.2006 · Published: July 26, 2006

Simple Explanation

This study investigates how a protein called Tenascin-R (TNR) affects recovery after spinal cord injury in adult mice. TNR is known to influence nerve development and plasticity in the central nervous system. The researchers compared mice lacking TNR (TNR-/-) with normal mice (TNR+/+) after spinal cord compression. They assessed motor functions using behavioral tests and motion analysis. The findings suggest that TNR limits functional recovery by restricting the remodeling of synapses, which are connections between nerve cells, around motoneurons after the injury.

Study Duration

6 weeks

Participants

Adult mice (TNR-deficient and wild-type littermates)

Evidence Level

Not specified

Key Findings

1
TNR-deficient mice showed better recovery in open-field locomotion compared to wild-type mice after spinal cord compression.
2
Functions requiring lower levels of supraspinal control, such as plantar stepping, improved more in TNR-deficient mice.
3
Spinal cord repair in TNR-deficient mice was associated with an increase in GABAergic and a decrease in glutamatergic puncta around motoneurons, which was not observed in wild-type mice.

Research Summary

This study aimed to determine if the absence of Tenascin-R (TNR) has beneficial effects on recovery from spinal cord injury (SCI) in adult mice. The researchers used TNR-deficient mice and wild-type littermates in a compression SCI paradigm. The results indicated that TNR-deficient mice showed better functional recovery, particularly in tasks requiring less supraspinal control. This improvement was not attributed to enhanced tissue sparing or axonal regrowth. The study suggests that TNR restricts functional recovery after SCI by limiting the posttraumatic remodeling of synapses around motoneuronal cell bodies, where TNR is normally expressed in perineuronal nets.

Practical Implications

Therapeutic Target

TNR could be a potential therapeutic target for promoting functional recovery after spinal cord injury.

Synaptic Remodeling

Understanding the role of TNR in synaptic remodeling may lead to new strategies for enhancing plasticity and repair in the injured spinal cord.

Rehabilitation Strategies

Rehabilitation strategies could be designed to promote specific types of motor function that are more responsive to the absence of TNR, such as plantar stepping.

Study Limitations

1
The study was conducted only in mice, and the results may not be directly applicable to humans.
2
The study focused on a specific type of spinal cord injury (compression), and the findings may not generalize to other types of SCI.
3
The mechanisms underlying the enhanced synaptic remodeling in TNR-deficient mice were not fully elucidated.

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