Fig. 4: The activity of the PI3K/AKT signaling pathway within the septum differs between mice with successful and unsuccessful extinction, and is altered by Meg3-ex10 knockdown.

A–G Protein and phosphorylation levels were measured at 3 h after social fear extinction training in unconditioned mice (SFC−/Ext+), and in conditioned mice with successful (SFC+/Ext+/suc) and unsuccessful (SFC+/Ext+/unsuc) social fear extinction. B SFC+/Ext+/unsuc mice displayed higher phosphorylation levels of P85 than SFC−/Ext+ (pP85, *p < 0.05) and (E) higher phosphorylation levels of AKT Ser473 than SFC−/Ext+ and SFC+/Ext+/suc mice (*p < 0.05, one-way ANOVA, Bonferroni multiple comparison tests). F Total AKT protein was significantly degraded in SFC+/Ext+/suc mice (*p < 0.05, one-way ANOVA, Bonferroni multiple comparison tests). C, D, G No differences were found for the phosphorylation levels of AKT Thr308, total P85 and PTEN. H–N Meg3-ex10 knockdown was induced 24 h after social fear acquisition in groups of SFC−/Ext+ and SFC+/EXT+ mice, and extinction training was performed 72 h thereafter. Protein and phosphorylation levels were measured in control and Meg3-ex10 knockdown animals at 90 min after social fear extinction training. I Phosphorylation levels of P85 were upregulated in SFC+/Ext+ control mice (*p < 0.05 vs. SFC−/Ext+ control, separate statistics: unpaired t-test). Meg3-ex10 knockdown increased baseline activity in SFC−/Ext+ knockdown mice by trend ((#)p = 0.06 vs. SFC−/Ext+ control, separate statistics: unpaired t-test). J–N Phosphorylation levels of AKT Ser473 and AKT Thr308, and total P85, AKT and PTEN levels were neither affected by social fear extinction nor by Meg3-ex10 knockdown. Data are presented as mean fold changes + SEM. Group sizes (left site; 3 h): n = 5–10. Group sizes (right site; 90 min): n(SFC−/Ext+ control) = 7–10; n(SFC+/Ext+ control) = 9–11; n(SFC−/Ext+ knockdown) = 9–10; n(SFC+/Ext+ knockdown) = 9–12.