Fig. 3

Spatiotemporal characteristics of reactive astrocytes and reactive astrocyte-derived BDNF after TBI, and close relationship with migrating neuroblasts. Coronal sections of forebrain were immunostained with anti-GFAP antibody (green, reactive astrocytes), anti-BDNF antibody (red or green, BDNF-positive cells) and DAPI (blue, nucleus). A photomicrograph showing the distribution of GFAP ⁺ cells at different TBI time courses (1, 3, 7, 14 and 21 days after TBI) and sham control. Scale bar = 5 μm (A1–A6), Scale bar = 50 μm (a1–a6). B photomicrograph showing the distribution of BDNF⁺/GFAP ⁺ cells at different CCI time courses (1, 3, 7, 14 and 21 days after TBI) and sham control. Scale bar = 5 μm (B1–B6), Scale bar = 50 μm (b1–b6). C Images of BDNF⁺/GFAP ⁺/DAPI⁺ cells on day 7 post-CCI. Scale bar = 5 μm (C1), Scale bar = 50 μm (c1–c2). D The number of BDNF+/GFAP+/DAPI+ cells in cortex at different CCI time courses (1, 3, 7, 14 and 21 days after CCI) and sham control. E1, e1 Images of DCX+/GFAP+ cells on day 7 post-CCI showing DCX+ and GFAP immunoreactivity as merged image. Scale bar = 25 μm (E1), Scale bar = 100 μm. (e1). E2, e2 Images of BDNF+/DCX+ cells on day 7 post-CCI showing DCX+ and GFAP immunoreactivity as merged image. Scale bar = 25 μm (E2), Scale bar = 100 μm (e2). E3, e3 Images of BDNF+/DCX+/GFAP+cells on day 7 post-CCI showing BDNF+, DCX+ and GFAP immunoreactivity as merged image. Scale bar = 25 μm (E3), Scale bar = 200 μm (e3, e3-1, e3-2, e3-3). The results revealed that the DCX-positive cells, BDNF-positive cells and GFAP-positive cells were accompanied at different time points post-CCI and showed a peak trend on day 7 post-CCI. Data are expressed as the mean ± SEM, n = 6 for each time-point. *, P < 0.05; one way ANOVA with Tukey’s multiple comparisons test. CCI: controlled cortical impact; TBI: traumatic brain injury; SVZ: subventricular zone; DAPI: 4,6-Diamidino-2-phenylindole; CC: corpus callosum