Table 3. Ultrastructural characteristics of the VZ in serial section reconstructions (intervals of 200 nm). Each cell is represented by a row, and each column shows which of the six ultrastructural features scored were present in each section: contact with ventricle, gray block; no contact with ventricle, white block; cillium, dot; centriole, X; radial process, triangle; tangential process, square. Eighty-four cells were contained within the studied sections.