Disruptions in the glia limitans are associated with reactive astrocytes. Immunofluorescent detection of nestin (red) and laminin (LM; green) in nestin-Cre/DG-null cerebellum at P3 (A). Immunofluorescent staining of glial fibrillary acidic protein (GFAP; red) and laminin (LM; green) in nestin-Cre/DG-null cerebella at P8 (B), P16 (C), and P21 (D). Reactive astrocytes (asterisms; ⁂) dominate areas where the basement membrane, demarcated by laminin staining, is severely disrupted or mostly absent. Scale bar: 20 μm.