The Reactions of Glial Cells and Endoneurial Macrophages in the Dorsal Root Ganglion and Their Contribution to Pain-Related Behavior After Application of Nucleus Pulposus Onto the Nerve Root in Rats

Activation of DRG glial cells and endoneurial macrophages plays an important role in the pathogenesis of the neuropathic pain state. TNF-alpha actively released from activated glial cells and endoneurial macrophages in the DRG might initiate and maintain the neuropathic pain together with TNF-alpha derived from the applied NP. In the recovery phase, persistent expression of GDNF from activated satellite glial cells might play an important role to restore the function of damaged neurons and recover from neuropathic pain.