DCX expression in the hypothalamus. Broadly, DCX expression (green) is highest in the Papez circuit structures and decreases progressively in surrounding zones; however, it occurs throughout the hypothalamus. Indeed, the fornix (Figure (G)), the upper part of the mammillary body (mb) and the tracts superior to it (asterisks) (Figure (J)) display dense areas of DCX staining. A higher-magnification view of the mammillothalamic tract (mt) (Figures (C) and (M)) reveals that fibers running through the posterior hypothalamus (ph) toward the thalamus entangle with fibers running antero-posteriorly to the boundary between the hypothalamus and the zona incerta (zi) (Figure (M)). GFAP expression (red) studied in an adjacent section shows another pattern of staining for this astrocyte marker (Figures (H), (K) and (N)) that confirms that the detected DCX staining is not an artifact. (A), DCX positive cell body (arrowhead) and fiber (arrow) in the boundary between the septum nuclei and the anterior hypothalamus; (B), the arrowhead points to a DCX-positive cell with neuroblast characteristics near the mammillary body. Images of the negative controls are from the counterpart zones of the single staining studies. Note the autofluorescence of red blood cells forming a readily identifiable pattern. Scale bars: (A), (B), (D), (E) = 50 μm; (C), (F), (M–O) = 100 μm; (G–I) = 200 μm; (J–L) = 500 μm.