Fig. 3From: Nitric Oxide-Dependent Penile Erection in Mice Lacking Neuronal Nitric Oxide Synthase Immunohistochemical localizations of nNOS in penes of wild-type and nNOS − mice In cross sections of the proximal penis of the wild-type (A) and nNOS− mouse (B), staining of dorsal penile nerves (arrow) is observed only in the wild-type penis. Counterstaining with hematoxylin facilitates visualization. Scale bars = 100 µm.Back to article page