Abstract: Objective To study the effects of acetylcholine(ACh) on spontaneous discharges of compressed rat dorsal root ganglion(DRG) neurons.Methods In chronically compressed DRG model,the spontaneous discharge of a single fiber from the DRG neuron in response to ACh treatment was recorded.Results Active spontaneous discharges were recorded in the injured DRG,and 77.9% of the injured DRG neurons responded to Ach treatment in the manner of simple excitation,or excitation followed by inhibition.The responses were enhanced with the increase of Ach concentration.Conclusion Injured DRG remains active in spontaneous discharges,which can be significantly influenced by ACh treatment.