Fig. 1

Regional and sex-differences in the level of two main endocannabinoids, 2AG and AEA. Regional and sex-differences of 2-AG and AEA levels were observed in CNS areas (cortex, PAG, Vc, and TG) harvested from naïve female and male SD rats. A Comparison of ratio of 2-AG:AEA between sexes and across CNS regions. Within PAG, ratio of 2-AG:AEA was significantly increased in males as compared to females (**p = 0.0049). Female ratio of 2-AG:AEA within Vc was significantly greater than the ratio observed in males (***p < 0.0001). No significant differences observed within V1M cortex or TG. B Comparison of AEA and 2-AG levels between sexes within V1M cortex. Female AEA concentration observed as significantly greater than male AEA concentration (*p = 0.035). No significant sex difference observed for 2-AG concentration. C Comparison of AEA and 2-AG levels between sexes within periaqueductal grey (PAG). Female AEA concentration within PAG was significantly greater than male AEA concentration (**p = 0.0035), Female 2-AG concentration observed to be significantly decreased as compared to male 2-AG concentration within PAG (*p = 0.015). D Comparison of AEA and 2-AG levels between sexes within Vc. Female 2-AG concentration was detected at significantly higher levels than male 2-AG concentration (****p = 0.0008). No significant differences observed for AEA concentration between sexes. E Comparison of AEA and 2-AG levels between sexes within trigeminal nerve (TG). Female AEA concentration was significantly greater than male AEA concentration (***p = 0.0056), Female 2-AG concentration also observed as significantly greater than male 2-AG concentration (***p = 0.004). AEA concentrations reported as picomole/gram tissue, 2-AG concentrations reported as nanomole/gram tissue. n = 5 for all male regions, n = 20 females (5/estrous stage) for all female regions