Microphotographs showing the distribution of occludin immunoreactivity in sagittal sections of the tuberal region of the hypothalamus. A: Low magnification photomontage of Hoechst fluorescence showing the different brain structures. B–D: High magnification images showing the honeycomb pattern of occludin-immunoreactivity (green) in cuboidal ependymal cells (B) and tanycytes of the median eminence (C), whereas tanycytes of the arcuate nucleus display an unorganized pattern of immunoreactivity for occludin (D). 3V, third ventricle; OCh, Optic Chiasma; ME, median eminence; Pit, pituitary gland. Scale bar = 500μm in A; 20μm in D.