Modulation of SI and ACC response to noxious and non-noxious electrical stimuli after the spared nerve injury model of neuropathic pain.
The current knowledge on the role of SI and ACC in acute pain processing and how these contribute to the development of chronic pain is limited. Our objective was to investigate differences in and modulation of intracortical responses from SI and ACC in response to different intensities of peripheral presumed noxious and non-noxious stimuli in the acute time frame of a peripheral nerve injury in rats.We applied non-noxious and noxious electrical stimulation pulses through a cuff electrode placed around the sciatic nerve and measured the cortical responses (6 electrodes in each cortical area) before and after the spared nerve injury model.We found that the peak response correlated with the stimulation intensity and that SI and ACC differed in both amplitude and latency of cortical response. The cortical response to both noxious and non-noxious stimulation showed a trend towards faster processing of non-noxious stimuli in ACC and increased cortical processing of non-noxious stimuli in SI after SNI.We found different response in SI and ACC to different intensity electrical stimulation based on two features and changes in these features following peripheral nerve injury. We believe that these features may be able to assist to track cortical changes during the chronification of pain in future animal studies.