Figure 7.

Dietary zinc supplementation increases cortico-striatal and thalamo-striatal synaptic SHANK2 expression in Shank3^{ex13–16−/−} mice. (A–D) Example overlaid images from WT and Shank3^{ex13–16−/−} mice fed normal (30 ppm) or high dietary zinc (150 ppm), immunostained for SHANK2 (green), VGluT1 (red) or VGluT2 (blue). Red triangles denote example synaptic SHANK2 puncta colocalized with VGluT1, blue triangles denote example synaptic SHANK2 puncta colocalized with VGluT2, open triangles denote example non-synaptic SHANK2 puncta. Scale bar 5 μm. (E) SHANK2 puncta intensity at cortico-striatal synapses, i.e., puncta co-localized with VGluT1, was significantly increased in $Shank{3}_{150\text{ ppm}}^{\text{ex168}3-16-/-}$ mice. (F) SHANK2 puncta intensity at thalamocostriatal synapses, i.e., puncta co-localized with VGluT2, was significantly increased in WT and Shank3^{ex13–16−/−} mice fed 150 ppm dietary zinc. (G) Total synaptic SHANK2, puncta co-localized with VGluT1 plus VGluT2, was significantly increased in both WT and Shank3^{ex13–16−/−}mice fed 150 ppm dietary zinc. (H) Non-synaptic SHANK2, i.e., puncta not co-localized with either VGluT1 or VGluT2, was not significantly different between WT and Shank3^{ex13–16−/−} mice fed either diet. Data represent mean ± SEM from six Shank3^{ex13–16−/−} mice and six WT mice. Statistical significance was determined by one-way ANOVA with Tukey’s multiple comparisons test. *p < 0.05, **p < 0.01. NS, not significant.