Altered TRPV1 staining in paw skin tissue obtained from STZ-induced diabetic mice. A. Representative TRPV1 immunofluorescent pictures of paw skin sections from control non-diabetic (a), STZ-induced diabetic hyperalgesic (b), hypoalgesic mice (c) and non-diabetic TRPV1 knock-out mice (d). Arrows indicate the TRPV1-expressing fibers in dermis (De). Background staining was consistently observed in the epidermis (Ep) of all sections including TRPV1 knock-out mice. B. Summary graph showing increased (n = 8 sections from 4 mice, p < 0.05) and decreased (n = 9 sections, p < 0.05) mean gray values of TRPV1 staining in diabetic hyperalgesic and hypoalgesic fibers of the paw dermis layer as compared with control non-diabetic mice (n = 8 sections from 4 mice). Number in the parenthesis represents the number of TRPV1 stained sections and the asterisk (*) represents p < 0.05. Scale bar is 50 μm.