Neurodegeneration induced by astrocyte responses to BDNF depends on astrocyte TrkB. (A) Double immunofluorescence for TrkB and GFAP in mouse cultured astrocytes. DAPI was used to stain for nuclei. Bars, 20 µm. (B) Assay performed as in Fig. 5 on mouse astrocytes. Graphs show quantification of β-tubulin MFI and the percentage of apoptotic cells in neuronal cultures exposed to ACM from GFAP-cre:TrkBflox/flox and TrkBflox/flox astrocytes treated as indicated. Data were obtained in three independent experiments and are represented as mean ± SEM. Statistics refer to comparisons with relative sNT (nontreated). *, P < 0.05; ***, P < 0.001; ****, P < 0.0001.