Given the positive correlation of BDNF, TrkB, p-ERK and p-CREB with NTG-induced migraine, which was confirmed by this and other studies (Fischer et al., 2012; Isensee et al., 2014; Zhang et al., 2013), these factors are probably involved in the actions of estrogen contributing to migraine, as described in the Fig. 8. This evidence concerns the gene MAPK1 and migraine disorder.