| Abstract: | Objective: To study sympathetic-sensory coupling in chronically compressed dorsal root ganglion (DRG) neurons in rats. Methods: In chronically compressed DRG model, the spontaneous activity of single fiber from the injured DRG neuron was recorded, and lumbar sympathetic trunk was electrical stimulated to study the sympathetic modulation of spontaneous activities in injured DRG neurons. Results: Fifty-seven percent of spontaneous active neurons of injured DRG responded to sympathetic stimulation. The responses included simple excitation, excitation followed by inhibition and simple inhibition. The responses enhanced with the increase of sympathetic stimulation time. The responses to sympathetic stimula- tion could be blocked by intravenously injection of phentolamine, a-adrenorecepor antagonist. Fifty-three percent of injured DRG responded to norepinephrine (NE). The responses to NE were similar to those induced by sympathetic stimulation. Conclusion: Sympathetic-sensory coupling is virtually present in chronic compressed DRG neurons. NE released from sympathetic nerve terminals acts on a-adrenorecepor to influence spontaneous activities of injured DRG neurons. |
