Fig. 1

a: Schematic timeline of the experimental design. The CFA/saline/IS/SIF treatment was considered as “0” timepoint. LCFA, LPHYS, 2IS, 2SIF, 4IS, 4SIF groups received lidocaine before the skin incision. 20 min after dural treatment, the surface of the dura was rinsed off with either saline or SIF. Animals in NAT and FRE groups were only anesthetized and placed in a stereotaxic frame (NAT) or left on a heating pad (FRE) as long as animals in other groups. b: Schematic figure of trigeminal pain pathway. Dermatome distribution of the trigeminal nerve divisions of the face. Trigeminal ganglion contains the first-order neurons, second-order neurons are found in the spinal cord and medulla. Schematic figure of the dorsal horn shows the somatotopic representation of the three branches of the trigeminal nerve. The ventral (darkest), intermediate and dorsal part of the dorsal horn considered to be equivalent to the area of the ophthalmic (V/1), maxillary (V/2), and mandibular (V/3) branch. Figure of the coronal brain section represents the third-order neurons in the thalamus (Th) and neurons in the primary somatosensory cortex (S1)