FIGURE 6.

TRPA1 expression on nerve fibers in the trachea and skin of guinea pigs, as detected by immunofluorescence and confocal microscopy. (A,B) Representative TRPA1 expression (shown as red fluorescence) and PGP9.5 positive nerve fiber distribution (shown as green fluorescence) in the skin (A) and trachea (B) of guinea pigs with cough (model); guinea pigs with cough, the trunk-limbs of which were exposed to a cold environment (model, trunk-limb cold exposure); and guinea pigs with cough that were exposed to a cold environment, but with HC-030031-pretreated skin (model, skin pretreated). Positive fluorescence (white arrow) was primarily distributed on the epithelia. (C,D) Digital quantitative presentation of TRPA1 expression on the nerve fibers in the skin (C) and trachea (D) of different groups of guinea pigs. Results are presented as the mean ± SD (n = 5; **p < 0.01, ***p < 0.001).