The track in the white matter contains islands distinct from the surrounding tissue (A,B). The cells within the islands (C,D). Sparse nestin‐positive cells (E). The immunostaining of myelin basic protein (F) and neurofilaments (G) stops at the edge of the island. Fibronectin antibody stains the vessel walls. The * marks the island. Scale bar: 100 µm (A,B,F,H); 50 µm (G); 20 µm (C,D,E). Abbreviation: MBP = myelin basic protein.