Fig. 1.

Effects of menthol on human α3β4 nAChR-mediated [Ca²⁺] influx and nicotine-stimulated ⁸⁶Rb⁺ efflux. (A) Representative Fluo-4 fluorescence images of α3β4-expressing HEK293 cells captured during control, repeated application of 30 μM ACh (upper images), or application of 30 μM ACh alone and ACh plus 100 μM menthol (lower images). (B, upper trace) Mean Fluo-4 fluorescence during repeated application of ACh (n = 39 cells) or (B, lower trace) ACh and ACh plus menthol (n = 37 cells). The interstimulus interval was 5 minutes. (C) Inhibition of nicotine-stimulated ⁸⁶Rb⁺ efflux in the presence of menthol or (D) 10-minute preincubation with menthol; n = 3 independent assays.