ABSTRACT
Objective To investigate the mechanisms of the inhibitory effects of peripheral electrical stimu- lation(PES)on chronic central pain(CCP)after spinal cord injury(SCI).Methods Twenty-four male Sprague- Dawley rats with CCP following SCI were randomly divided into three groups:a group without stainless steel needles implanted (NSSN group,n=8),a group with a stainless steel needle implanted but no peripheral electrical stimula- tion applied(NPES group,n=8)and a PES group(PES group,n=8).The rats' CCP was evaluated through ob- serving their response to nociceptive stimulation by means of the paw withdrawal pressure threshold(PWPT)and the paw withdrawal latency(PWL).Spontaneous pain behaviors including autophagia and scratching were observed at the same time.PES was applied via stainless steel needles inserted into standard acupoints on the hind limps and the back.The expression of the NMDA receptor 1(NR-1)subunit in the spinal cord horn was measured using immuno- chemical methods.Results Compared with the NSSN and NPES groups,CCP in the PES group was alleviated, PWPT and PWL were dramatically increased(P＜0.01)and the expression of NR-1 was obviously decreased (P＜0.01).Conclusion Peripheral electrical stimulation may alleviate chronic central pain after spinal cord injury in rats.