Fig 2: Overexpression of truncated trkB induces habits, makes them harder to “break,” and causes depression-like behavior.(a) We infused a lentivirus expressing truncated trkB (Trkb.t1) or GFP into the vHC and CeA. Large (red) and small (white) infusion sites are represented on images from the Mouse Brain Library [27]. All infusion sites are described in S3 Fig. At bottom right, representative lentiviral GFP expression in the CeA is shown (at gray arrows). The external capsule is highlighted in red, and the image is intentionally overexposed. (b) In Trkb.t1-expressing mice, p-ERK42/44 immunoreactivity was diminished at the infusion site. n = 7–8/group. (c) All mice acquired the instrumental responses. Response acquisition curves represent both responses/min. (d) Trkb.t1 in the vHC and CeA blocked sensitivity to instrumental contingency degradation. Thus, selective Trkb.t1 overexpression recapitulated the long-term effects of adolescent CORT exposure. n = 6–8/Trkb.t1 group; total control = 23. (e) Another group of mice was first trained using a fixed ratio schedule of reinforcement. Then, to build on our findings reported in (d), an RI schedule of reinforcement was applied, with no interruption in training and no differences in responding between groups. (f) In reaction to repeated instrumental contingency degradation training, control mice inhibited a response that was unlikely to be reinforced, their habits “breaking” (“degraded contingency,” right). By contrast, mice with vHC Trkb.t1 failed to inhibit responding. Response rates associated with an intact contingency were unaffected (left). Response rates are represented on 2 plots in the interest of clarity but were compared together by ANOVA. n = 9–10/group. (g) Finally, vHC Trkb.t1 overexpression also decreased responding on a progressive ratio schedule of reinforcement in adulthood, again recapitulating the long-term effects of adolescent CORT exposure. n = 9/group. Bars/symbols = means + SEMs, * p < 0.05, ** p ≤ 0.004. Raw data for this figure can be found in S1 Data. CeA, central nucleus of the amygdala; ERK42/44, Extracellular signal-Regulated Kinase 42/44; p-ERK, phosphorylated ERK; trkB, tyrosine kinase receptor B; trkB.t1, truncated trkB; vHC, ventral hippocampus.

Fig 3: Effect of hypoxia on MET phosphorylation and activation of the Akt and Erk downstream pathwaysHela (A), MDCK (B), and MCF10A (C) cells were incubated for 1 or 24 h under normoxic or hypoxic conditions and then treated or not for 10 minutes with 10 ng/mL HGF/SF. For each cell line, the same amount of protein was analyzed by western blotting with antibodies directed against the indicated phosphorylated residue(s) in the MET kinase domain, juxtamembrane domain, or C-terminal domain or against one of the following: the MET kinase domain, phosphorylated Akt, Akt, phosphorylated Erk, Erk2, or the hypoxia marker HIF1a or carbonic anhydrase IX (CAIX). The positions of prestained molecular weight markers are indicated. Arrows indicate the positions of precursor and mature full-length MET and Erk1/2 proteins. (D) GTL16 cells were placed under normoxic or hypoxic conditions for 1.5 h. Cell lysates were incubated for AlphaScreen specific phospho-MET quantitation. Error bars represent standard deviations (± SD). (E) MCF10A cells were placed under normoxic or hypoxic conditions for 1.5 h, then treated for 10 minutes with HGF/SF at 50, 30, 10, 3, 1, 0.3, or 0 ng/mL. Cell lysates were incubated for AlphaScreen specific phospho-Erk and phospho-Akt quantitation. Error bars represent standard deviations (± SD).

Fig 4: Upregulation of σ-1R and activation of JNK/p38 and Akt pathway in LPS-induced astrocyte activation. a Treatment of astrocytes with 100 ng/ml LPS significantly increased the expression of σ-1R. Representative immunoblots and the densitometric analysis from three separate experiments are presented. b-e Western blot analysis of time-dependent activation of JNK (b), p38 (c), ERK (d) and Akt (e) by LPS (100 ng/ml) in primary mouse astrocytes. All the data are presented as mean ± SEM of three individual experiments. *p < 0.05, **p < 0.01, and ***p < 0.001 vs. the control group

Fig 5: BOP caused the activation of extracellular signal-regulated kinase (ERK) in the mouse brain. Representative Western blots (A) and quantification analysis (B) revealed the activation of ERK after blast (n = 5/group). (Data are means ± SEM, * p < 0.05, ** p < 0.01; ns, non-significant).