Figure 6. Forty-micron slice of sheep spinal cord stained for nicotinamide adenine dinucleotide phosphate diaphorase. Low power view demonstrates selective labeling in superficial dorsal horn (DH) and intermediolateral cell column (IML), with minimal staining in ventral horn (VH). High power views demonstrate fiber and cell staining in DH and IML, but few fibers stained in VH. The boxes represent areas that were dissected in other preparations for nitric oxide synthase activity assessment in vitro.