A: Drawing indicates location of images shown in other panels. B: zRalDH mRNA expression by in situ hybridization, level similar to A. C–G: zRalDH protein detection through immunohistochemistry. C: HVC and RA, as well as the fiber tracts extending from HVC to RA (arrows) are labeled. D: lMAN and surrounding nidopallium, as well as Area X, are labeled; labeling in Area X is diffuse and not in somata. Thus, besides HVC and lMAN, which express zRalDH mRNA, protein is present in two song nuclei (X and RA) that lack zRalDH transcript (white arrows in B). E: Detail view of zRalDH protein in RA; labeling is diffuse and not in somata. F: Detail view of zRalDH protein in HVC, somata are labeled. G: High power view of zRalDH in lMAN, somata are labeled. In all panels, frontal is to the right, and dorsal is up. For abbreviations, see table 1.Scale bars for C = 0.5 mm; D–F = 100µm, G = 50µm.