Fig. 6. Immunohistochemical staining of spinal cord for inducible nitric oxide synthase (iNOS) (magnification ×40) and histogram of average intensity of iNOS expression in ventral gray matter. ( A ) A representative picture of the Control group. Positive staining for iNOS is green. Note that iNOS expression was found in proliferated glia cells ( arrow ) and that motor neurons were obviously swollen without iNOS expression ( asterisk ). ( B ) A representative picture of the Cooling group. Positive staining for iNOS is green. Note that iNOS was expressed in motor neurons ( asterisk ), which have normal architecture, and that no proliferation of glia cells was found. ( C ) Histogram of average intensity of iNOS expression in ventral gray matter of spinal cord. Average intensity in the Cooling group was significantly augmented versus the Control group ( P = 0.01275).