Perineural Capillary Plexus

The perineural vascular plexus surrounds the neural tube and is formed by angioblasts which migrate away from somites, in response to VEGF released by the neural tube. The first vessels constituting the primary perineural vascular developed on day 12–14 of mouse gestation and show sinusoidal characteristics, including: irregular thickness of the endothelial wall, and perforations by fenestrations or small holes. Immature capillaries which then sprout from the preexistent vessels begin to appear at about day 15 of mouse gestation.