Axin stabilization increases dendritic spine density and synaptic transmission.

<p>(A) Treating hippocampal neurons (17 DIV) with the Axin stabilizer XAV939 for 3 days significantly increased the density of mature dendritic spines and total protrusions. Scale bar: upper panels = 20 μm, lower panels = 10 μm; Student’s <i>t</i>-test, <i>n</i> = 24, *<i>p</i> < 0.05. (B) XAV939 treatment increased PSD-95–positive puncta along dendrites. Left panels: representative images showing the dendritic morphology of control and XAV939-treated neurons. Right panels: quantitation of PSD-95 puncta density and intensity. Scale bar: 10 μm; Student’s <i>t</i>-test, <i>n</i> = 15, *<i>p</i> < 0.05, **<i>p</i> < 0.01. (C) Representative mEPSC traces of control and XAV939-treated neurons. (D) XAV939 treatment increased the frequency but not the amplitude of mEPSCs in hippocampal neurons. One-way ANOVA, <i>n</i> = 22, **<i>p</i> < 0.01 vs DMSO for 72 h. (E) Cortical neurons were treated with XAV939 for the indicated times. Enhanced GluA1 phosphorylation at Ser831 was observed from 0.5–72 h after treatment. (F) Live imaging demonstrated that XAV939 treatment did not induce an obvious change in the formation rate of dendritic spines but significantly reduced their elimination rate. Left panels: representative images showing spine morphology in cultured neurons. Right panels: quantitative results of spine formation/elimination rate. Scale bar: 10 μm; Student’s <i>t</i>-test, <i>n</i> = 21, ***<i>p</i> < 0.001.