Fig. 5: Structural and functional alterations in synapses of MG^4E mice.

a Schematic diagram of mPFC serial block-face scanning electron microscopy (SB-SEM). b Spine density in the mPFC of 6-week-old male control and MG^4E mice. Representative dendrites reconstructed from SB-SEM images show dendritic spines (gray) and presynaptic terminals (blue). Graphs show spine density, synaptic spine density and percentage of non-synaptic spines. 5 control mice, 40 dendrites and 1187 spines; 6 MG^4E mice, 30 dendrites and 1120 spines. Two-sided t-test (spine density, **p = 0.0017; synaptic spine density, *p = 0.0112; non-synaptic spine *p = 0.0253). Scale bar, 2 µm. c Spine volume and synaptic size. Representative dendrites reconstructed from SB-SEM images show dendritic spines (blue) and postsynaptic density (PSD, light yellow). Graphs show PSD size and spine volume. 5 control mice, 40 dendrites and 1098 spines; 6 MG^4E mice, 30 dendrites and 999 spines. Two-sided t test (PSD area, **p = 0.0044; spine volume, **p = 0.0037). Scale bar, 2 µm. d Density of asymmetric and symmetric synapses in the mPFC of 6-week-old male and female control and MG^4E mice. Images show representative asymmetric and symmetric synapses (arrows). n = 3 mice and 30 images per mouse for each group. **p = 0.0059 by two-sided t-test. Scale bar, 2 µm. e Spine density in mPFC layer 5 neurons and hippocampal CA1 neurons of 2-week-old (2 W) and 6-week-old (6 W) male control and MG^4E mice. 2 W, 6 mice per genotype; 6 W, 6 control mice and 7 MG^4E mice; 2–5 neurons in each brain region per mouse. *p = 0.0362, **p = 0.0012 and ***p < 0.001 by two-sided t-test. Scale bar, 5 µm. f Levels of neuroligin 1 (NLGN1) and neuroligin 2 (NLGN2) in the mPFC and hippocampus. n = 4 control mice and 5 MG^4E mice. Two-sided t test (mPFC, *p = 0.0409 for NLGN1 and *p = 0.0279 for NLGN2; hippocampus, *p = 0.0207 for NLGN1 and *p = 0.0229 for NLGN2). All data are shown as mean ± s.e.m. Source data are provided as a Source Data file.