Fig. 4. Immunohistochemistry image showed the total expression of total NR2B subunit positive neurons (tNR2B) in laminae I-II on ipsilateral (i) and contralateral (c) sides of rat spinal cord at 40× magnification. (A) The positive control for NR2B subunit in the rat's brain (thalamus) whilst. (B) The negative control in the rat's spinal cord region. (C) Control group. (D) Diabetes mellitus group. (E) (I 0.5) group. (F) (I 1.0) group. Arrows indicate the dark staining of tNR2B subunit positive neuron expression.