Inhibition of discharge rates of neurons via electroacupuncture at Shenshu (BL23), Huantiao (GB30) , Weizhong (BL40) and Yanglingquan (GB34) to alleviate inflammation-induced discogenic sciatica

Abstract

Sciatica is closely related to the disease symptoms of lumbar disc herniation. Previous studies exhibited that electroacupuncture (EA) can effectively relieve chronic low back pain and sciatica. However, the mechanism underlying the analgesic effects of EA on discogenic sciatica is still largely confusing. In this study, model rats of discogenic sciatica were established to avoid causing direct compression. Male SD rats were randomly divided into sham operation group (FM), model group (M), electroacupuncture group (EA), electroacupuncture sham point group (NA) and sham operation electroacupuncture group (SEA). EA with low-frequency electronic pulse was adjusted to continuous wave (2Hz, 1mA) mode, and applied to the specified fixed acupuncture points (BL23, GB30, BL40, GB34) for 20 min on odd days for 4 weeks. After EA treatment for 4 weeks, the sensory neurons in the dorsal horn of the spinal cord in FM and SEA groups remained silent throughout the recording time, while the firing rates of neurons in M and NA groups stayed active at 20 ~ 30 sparks/10s. The EA group had a significantly lower firing rate during the EA intervention process compared to the M and NA groups. EA intervention can effectively reverse the abnormal excitability of sensory neurons in the dorsal horn of the spinal cord, improve the plantar mechanical pain threshold and inflammatory factors depending on the accurate selection of acupuncture points in discogenic sciatica rat models.