Fig. 2

Recurrent NTG injection induced hyperalgesia and upregulated the expression of CGRP, c-Fos. A, B Periorbital and paw mechanical threshold during the injection of NTG. C, D, E Diagram showing the mouse's trajectory in the light and dark boxes, the time spent in the light box, and the number of times it entered the lightbox. F, G, H Mouse trajectory graph in EPM, time spent in open arm, and number of entries in open arm. I, J Immunofluorescence staining images of CGRP and c-Fos in the SP5C. (K) Location of SP5C. (n = 6–8 in each group; scale bar = 50/100 μm; *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001 compared with the Control group)