Electroacupuncture Alleviates Hyperalgesia by Regulating CB1 Receptor of Spinal Cord in Incisional Neck Pain Rats

Figure 4

Effect of EA on the immunoactivity of endocannabinoid receptor CB1 at 24 h after modeling in neck incisional pain rats. Double immunolabeling of CB1 receptor and glial fibrillary acidic protein (GFAP, marker of astrocytes) in the superficial layer (laminae I and II) of cervical spinal dorsal horns (DHs): (a). CB1 positive labeling (red), scale bar, 50 μm; (b) GFAP-positive labeling (green), (c) double-labeled cells(yellow). (d): Histograms showing the intensity of the immunoactivity of CB1 receptors in the 5 groups. One-way ANOVA revealed that the expression level of CB1 was notably downregulated in the model group (vs the control group) and significantly upregulated in both EALI18 and EALI4-PC6 groups but not in the EAST36-GB34 group (vs the model group). Data are expressed as means ± SD (n = 5).  < 0.05, vs the control group, ^{^} < 0.05, vs the model group.