Fig. 4: SLAMR facilitates dendritic arborization and transient structural plasticity in mouse hippocampal neurons.

A Experimental timeline for morphology studies. B Confocal projection images of hippocampal neurons. Scale Bar = 40 µm. C Quantification of dendritic morphology using Sholl analysis of intersections per 10-µm step size. Changes compared between SLAMR constitutive and inducible (TET) KD and NC-GFP(negative control) (NC-GFP n = 9, SLAMR-KD n = 10, TET-SLAMR n = 11 neurons; Two-way ANOVA + Tukey’s test; mean ± SEM). D Confocal projection images showing region analyzed for spine morphology and enlarged image in the inset for spine details. Cell Body Scale Bar=40 µm. Dendrite inset Scale bar=2 µm. E, F SLAMR KD did not induce significant changes in the total number of spines or their different subtypes. (n = 13 dendrites each; E One-way ANOVA. F Two-way ANOVA + Tukey’s Test; mean ± SEM). G Experimental timeline of hippocampal primary culture, inducible shRNA plasmid transfection, and doxycycline treatment for two-photon imaging with glutamate uncaging. H Representative fluorescence images of SLAMR shRNA-EGFP (TET-SLAMR) and scrambled shRNA-EGFP (NC-GFP) before and after glutamate uncaging pulse (30 pulses, 0.5 Hz). Scale bar, 2 μm. H–K Glutamate uncaging analysis of spine changes in volume with slow rate imaging (I) shows a significant decrease in TET-SLAMR condition compared with NC-GFP control at the transient phase (J) (NC n = 12 neurons, TET-SLAMR n = 13 neurons; Two-way or One-way ANOVA +Tukey’s test; (K) NC pre v. post ***p = 1.65E-07, TET-SLAMR pre v. post ***p = 1.18E-09; mean ± SEM). L, M Fast rate analysis of the spine volume during glutamate uncaging (NC n = 12 neurons, TET-SLAMR n = 11 neurons; Two-tailed Mann-Whitney U test, mean ± SEM).