Ependymal denudation and subcortical heterotopias. A. Nestin staining of the aqueduct of a SBA fetus of 21 weeks GA. Arrowheads indicate intact (I) and denuded (II) ependymal lining. At the denuded area, the figure shows reduction of nestin-positive cells (brown; DAB) indicative of progenitor cell loss. Scale bar = 100 μm. B. Haematoxylin-eosin staining of the telencephalon of a fetus with MMC (16 weeks GA). Arrowheads indicate subcortical heterotopias associated with ependymal denudation of the lateral ventricle. Scale bar = 500 μm.