Human AG explants and arachnoidal cells in culture. Human AG tissue was obtained at autopsy, usually within 24 hours post-mortem and explanted into cell culture plates coated with fibronectin. A: Cells were seen migrating from the explant within 7–10 days. Bar = 200 μm. B: Arachnoidal cells grown from AG explants in confluent cultures exhibited polygonal cell morphology. Confluent cultures of arachnoidal cells packed in quite densely and displayed a cobblestone-like appearance common to epithelial cells in culture. Bar = 200 μm.