Altered TRPV1 staining in spinal cord dorsal horn of diabetic mice. A. Representative pictures of TRPV1 and NeuN staining from a control (a, b, c), STZ-induced diabetic hyperalgesic (d, e, f)), hypoalgesic (g, h, i), and non-diabetic TRPV1 knock-out mice (j, k, l). An enlarged segment of Af is shown in Am. B. Mean gray values of TRPV1 staining in dorsal horn was significantly increased (n = 14 sections from 3 mice, p < 0.01) in hyperalgesic mice and significantly decreased (n = 16 sections from 3 mice, p < 0.01) in hypoalgesic mice as compared to age matched control non-diabetic mice. Number in the parenthesis represents the number of TRPV1 stained sections and the asterisks (**) represents p < 0.01 obtained from student unpaired t-test. Scale bar is 50 μm.