FOS and migraine disorder: As we all know, preclinical studies related to migraine commonly use trigeminal nucleus caudalis in the brainstem where pain signals are transmitted to second-order neurons to determine c-Fos activation (Ramachandran et al., 2012) (Noghani et al., 2019) (Zhu et al., 2011) (Offenhauser et al., 2005).