Fig. 1

Non-apoptotic or autophagic death of reactive astrocytes after SCI in mice. a Immunohistochemistry of GFAP and the size of spinal cavity at different time points after SCI. The spinal cavity enlarges gradually with reactive astrocytes at its border, and reaches plateau at 14 days post-injury in our model. Bar = 200 μm (b, c) Strategy for astrocytes labeling and Double-staining of YFP with apoptotic marker (TUNEL) and autophagic markers (Lamp2a, LC3 and Beclin-1) at 5 dpi. GFAP-CreER : ROSA-YFP mice were used, and Tamoxifen was injected for 5 successive days before SCI to label astrocytes by YFP. Notice that No double-staining of YFP/TUNEL was found. Only few YFP-positive cells express autophagic markers. Bar = 25 μm. d Schematic drawing of morphological quantification area. For quantification of immunostainings, immunoreactivities within two adjacent areas which were 400 μm rostral or caudal to the cavity border in each spinal section were analyzed. e 3-D reconstruction of combined PI-labeling and immunohistochemistry of GFAP, and quantification of GFAP- and PI-positive cells. Arrows in C and E point to double positive cells. Bar = 5 μm. **P <0.01. n = 3