Figure 1.

Addition of LPS-activated MG on enriched astrocyte cultures reduces GJC and increases membrane permeability in astrocytes. a_1–4, Representative pictures of immunofluorescence staining in astrocyte cultures and cocultures with MG. GFAP-positive cells (red) correspond to astrocytes, and isolectine B4-positive cells (green) correspond to MG in cultures of astrocytes alone (Astrocytes, a_1–2) and in astrocyte-MG cocultures (+Microglia; a_3–4), both treated or not with LPS (10 ng/ml; 24 h). Scale bar, 50 μm. a_5–12, Representative pictures for SL/DT with LY (a_5–8) and EthBr uptake (a_9–12) to measure the functional states of GJC or hemichannels, respectively. Experiments were performed with similar culture models and treatments as described above. Scale bar, 100 μm. b, c, Graphs corresponding to the quantification of LY diffusion through astrocytic gap junctions (b) and the EthBr uptake (c) either in enriched astrocyte cultures (Astrocytes) or in astrocyte-MG cocultures (+Microglia). Both culture models were treated (LPS), or not (C, control), with LPS (10 ng/ml) for 24 h. Each plotted number corresponds to the mean ± SEM of three independent experiments. **p < 0.01, ***p < 0.001; n.s., no significant difference compared with control astrocyte group; ^δδδp < 0.001, compared with the astrocyte-LPS group.