The effect of 5 days successive i.t. vehicle or FA administration on pERK-LI cells in Vc and C1-C2 in CNX rats. Photomicrographs of pERK cells following mechanical stimulation (60 g) of the lateral facial skin with i.t. administration of vehicle (A) and FA (B). C: mean number of pERK-LI cells following 15 g and 60 g mechanical stimulation of the lateral facial skin in CNX rats. *: p < 0.05, **: p < 0.01.