Fig. 2.
RU486 blocked DEX-decreased PLC-γ activation, glutamate release, and GR expression. (Ai) RU486 (RU, a GR antagonist) blocked DEX-decreased PLC-γ activation. DEX (1 μM) and RU486 (1 μM) were coapplied at DIV 4. Subsequently, 48 h later, BDNF was added for 1 min. (ii) Quantification of pPLC-γ. Data represent mean ± SD. (n = 4). Normalization to the level in BDNF-stimulated PLC-γ with no pretreatment. ***P < 0.001 (t test). (B) RU486 blocked the inhibitory effect of DEX on BDNF-induced glutamate release. Data represent the mean ± SD. (n = 4). ***P < 0.001 (t test). (C) Time-course of DEX-decreased GR expression. DEX (1 μM, at DIV 4) was applied for 10 min or 1–48 h. (Di) Dose-dependency of DEX on GR down-regulation. After DEX (0.01–100 μM, at DIV 4) exposure for 48 h, GR, MR, and TUJ1 were detected. (ii) Quantification of the GR. Data represent mean ± SD. (n = 5). Normalization to the level in 0 μM. ***P < 0.001 (t test). (Ei and iv) Immunostaining with anti-MAP2 and (ii and v) anti-GR antibodies. (iii and vi) Merged images. Upper: control. Lower: DEX-treated. DEX (1 μM, at DIV 4) was applied for 48 h. (Scale bar, 50 μm.) (vii) GR immunoreactivities of randomly selected regions from cell bodies or neurites. Normalization to the level in Con. N indicates the number of selected regions. At least 20 neurons from 6 coverslips were examined. (Fi) RU486 inhibited GR down-regulation by DEX. TUJ1 is the control. (ii) Quantification of the GR. Data represent mean ± SD. (n = 5). Normalization to the level in no treatment. ***P < 0.001, **P < 0.01 (t test).