Tactile allodynia can occur in the spared nerve injury model in the rat without selective loss of GABA or GABAA receptors from synapses in laminae I–II of the ipsilateral spinal dorsal horn
2008

Tactile Allodynia and GABA in Spinal Dorsal Horn After Nerve Injury

Sample size: 11 publication 10 minutes Evidence: moderate

Author Information

Author(s): Polgár E., Todd A.J.

Primary Institution: University of Glasgow

Hypothesis

Does spared nerve injury (SNI) lead to a depletion of GABA from GABAergic axon terminals in the spinal dorsal horn?

Conclusion

The study found no significant loss of GABAergic boutons or GABA levels in the spinal dorsal horn after spared nerve injury.

Supporting Evidence

  • Behavioral testing showed significant differences in paw withdrawal thresholds between ipsilateral and contralateral sides after SNI.
  • Immunolabeling indicated no significant difference in GABA levels between the two sides.
  • Confocal microscopy confirmed that GABAA receptor β3 subunit levels were similar on both sides.

Takeaway

When a nerve is injured, it can cause pain even from light touches. This study looked at whether the brain's 'off switch' for pain, called GABA, was missing after the injury, but it found that it wasn't.

Methodology

The study used immunogold labeling and confocal microscopy to analyze GABA levels and GABAA receptor presence in rat spinal dorsal horn tissue after spared nerve injury.

Potential Biases

The analysis was performed by individuals who were blind to the side of the sections being analyzed, reducing potential bias.

Limitations

The study did not analyze tissue from sham-operated animals, which could provide a baseline for comparison.

Participant Demographics

Adult male Sprague-Dawley rats, weighing 250–330 g.

Statistical Information

P-Value

p=0.08

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1016/j.neuroscience.2008.07.009

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