Figure 5.

Basal wedging. Basal wedging occurs in the medial and dorsolateral hinge points of the neural plate during neural tube closure. Cells in the pseudostratified neural plate are tightly packed and only bulge around the nucleus, which moves in an apicobasal direction as the cell cycle progresses and resides basally in S-phase. Cells at the hinge point remain in S-phase longer than their neighbours, therefore becoming wedge-shaped with basal nuclei, resulting in a fold at the hinge point. Blue, basal lamina; purple, nucleus.