A and B, patch clamp recordings of trigeminal neurons in monoculture (A) and in co-culture with HaCaT keratinocytes (B). A, application of Javanol® (1 mm) did not induce currents in monocultured trigeminal neurons. ATP (20 μm) was used as a viability control. In co-cultures, Javanol® stimulation led to an inward current (B), which was not observed in the presence of 100 μm PPADS (C). D, quantification of the results presented in A–C. Javanol®-induced activation in percent for monocultured trigeminal neurons (Mono; n = 18 in 9 monocultures), co-cultured trigeminal neurons (CoCu; n = 26 neurons in 9 co-cultures), and co-cultured trigeminal neurons in the presence of PPADS (CoCu PPADS; n = 9 neurons in 3 co-cultures). ***, p < 0.001; Fisher's exact test.