Fig. 1

Repeated NTG administration causes hyperalgesia in female mice. A. The schematic diagram illustrates the establishment of the CM mouse model and behavioral assessments through repeated NTG administration. B. In the NTG mice, the mechanical thresholds in the hind paw were significantly decreased compared to the VEH mice both before and after NTG administration. C. The thermal thresholds in the hind paw of NTG mice were significantly decreased compared to the VEH mice both before and after NTG administration. D. On the 9th day, after NTG administration, the mechanical threshold in the periorbital region of NTG mice showed a significant decrease compared to the VEH mice. Two-way ANOVA with the Tukey post hoc tests, * p < 0.05, **p < 0.01, n = 10 /group, Abbreviations: NTG, nitroglycerin; CM, chronic migraine; VEH, vehicle