How Nerve Injury Affects Pain Sensitivity in Neurons
Author Information
Author(s): Mo Gary, Grant Rebecca, O'Donnell Dajan, Ragsdale David S, Cao Chang-Qing, Séguéla Philippe
Primary Institution: Montreal Neurological Institute and The Alan Edwards Centre for Research on Pain, Department of Neurology & Neurosurgery, McGill University, Montreal, Canada
Hypothesis
The study aims to understand how P2X3 receptors and Nav1.3 voltage-gated sodium channels contribute to neuronal hyperexcitability in neuropathic dorsal root ganglion neurons.
Conclusion
Neuropathic injury causes primary sensory neurons to become hyperexcitable to ATP-evoked P2X receptor-mediated depolarization, which is sensitive to protein kinase C modulation and mediated by increased activity of voltage-gated sodium channels.
Supporting Evidence
- Increased expression of Nav1.3 channels was observed in neuropathic dorsal root ganglion neurons.
- PKC inhibition reduced the activity of sodium channels in neuropathic neurons.
- P2X receptor activation led to excessive firing in neuropathic DRG neurons.
Takeaway
When nerves get hurt, the cells that send pain signals become extra sensitive, making it easier for them to send pain messages. This happens because of changes in certain channels in the cells that help them respond to signals.
Methodology
The study used a spinal nerve ligation model in rats and whole-cell patch clamp recordings of dissociated dorsal root ganglion neurons to examine changes in excitability after nerve injury.
Participant Demographics
Sprague-Dawley male rats weighing 125-150 g for the neuropathic model and 340-400 g for neuronal culture.
Statistical Information
P-Value
p<0.0005
Statistical Significance
p<0.0005
Digital Object Identifier (DOI)
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