FIGURE 1.

Notch1 signaling is activated in reactive astrocytes in vitro. (A) Experimental design: astrocytes were isolated from the cortex of postnatal day six (PND6) C57BL/6J mice and cultured until confluency in 13 mm coverslips. Astrocyte reactivity was induced by scratch assay, and expression of the reactivity marker GFAP was analyzed 3 days post lesion (3dpl) by immunocytochemistry and confocal imaging. (B) Scratch-induced astrocytes are GFAP⁺ and show reactive morphology. Scale bar: 50 μm. (C) Representative confocal images of NICD1 staining in control and reactive astrocytes. Dashed line indicates the scratch border. Scale bar: 20 μm. (D) Normalized fluorescence analysis of nuclear NICD1 immunostaining revealed increased NICD1 nuclear localization in reactive astrocytes compared to control (***p ≤ 0.001); unpaired Student’s t-test, n = 154 nuclei in scratch / 217 nuclei in control, three culture replicates. Data are mean ± SEM. Nuclei were stained with 4’,6-diamidino-2-phenylindole (DAPI; blue).