Neuropathic pain is a debilitating pain that occurs after nerve injury and is generally resistant to currently available treatments including morphine. Such pain involves aberrant excitability in dorsal horn neurons after nerve injury. Emerging evidence indicate that the enhanced activity of dorsal horn neurons requires a communication with microglia. Results of our laboratory have shown that activating P2X4R upregulated in spinal microglia after nerve injury contributes to neuropathic pain through a release of BDNF from microglia, which is a crucial factor to signal to dorsal horn neurons to cause neuronal hyp erexcitability. Activated spinal microglia also express P2Y 12R, and P2Y12R-KO mice display impaired neuropathic pain. The mechanisms of microglia activation are unknown, but our recent study shows that interferon-γ (IFN-γ) can be an important factor that causes spinal microglia activation after nerve injury. IFN-γ upregulates P2X 4R in microglia and causes P2X4R-dependent allodynia. These findings suggest that purinoceptors in spinal microglia is crucial for pathological intractable pain.
All Science Journal Classification (ASJC) codes
- Clinical Neurology