Figure 13. Color-coded reconstructions from computerized densitometry of film autoradiographs of 125I-VIP binding in the coronal (A–F) and horizontal (G–I) planes of adult rat brain. Yellow = most dense binding. Red = moderately dense binding. Blue = least dense binding. Autoradiography was performed as described previously (1). (A–C,G) Total 125I-VIP binding pattern in brain. (D–F, H) 125I-VIP binding in the presence of 10 mM stable GTP analogue. (I) 125I-VIP binding in the presence of excess (1 mM) unlabeled VIP, to show specificity of binding. Arc, arcuate nucleus; BLA, basolateral amygdala; BNST, bed nucleus of the stria terminalis; Ce, cerebellum; CG, central gray; Cg, cingulate cortex; CPu, caudate-putamen; DG, dentate gyrus; Hip, hippocampus (Ammon's horn); IP, interpeduncular nucleus; LD, lateral dorsal thalamic nucleus; MD, medial dorsal thalamic nucleus; Me, medial amygdala; MG, medial geniculate thalamic nucleus; OB, olfactory bulb; OT, olfactory tubercle; Par, parietal cortex; Pir, piriform cortex; Pit, pituitary; PVA, paraventricular thalamic nucleus, anterior; Re, reuniens thalamic nucleus; S, septum [the precommissural septum (G) has many VIP binding sites; however, VIP binding is very low in the postcommissural septum (A)]; SCN, suprachiasmatic nucleus; SC, superior colliculus, superficial gray; SO, supraoptic nucleus; VP, ventral posterior thalamic nucleus; VPL, ventral posterolateral thalamic nucleus.