Figure 3. Schematic illustration of the autonomic neural pathways and effectors activated as a consequence of trigeminal nerve stimulation trigged either by peripheral signals from ophthalmic, maxillary, and mandibular branches or central cerebral vascular stimulus (figure modified from Buchholz’s publication [18]). The central TCR, which was stimulated by DMSO/ Onyx injection in the central vessel, induces a strong depressive response by a reciprocal activation of the parasympathetic system and an inhibition of the sympathetic system (red symbols). The peripheral TCR, which was stimulated by DMSO/Onyx injection in the peripheral vessels, involves simultaneous co-activation of both autonomic limbs (blue symbols).