Fig. 3: Synaptic alterations in adult mice expressing HERV-W ENV.

Synaptic densities were quantified the CA1, CA3, and DG subregions of the hippocampus from adult male transgenic CAG^HERV-Wenv mice (TG) and wild-type (WT) littermates. A The photomicrograph shows a representative double-immunofluorescence stain using VGLUT1 (green) as presynaptic and PSD-95 (red) as postsynaptic markers of excitatory neurons. Examples of VGLUT1⁺/PSD-95⁺ co-localizing synapses are highlighted by white circles in magnified sections. The scatter plots show the density (number/mm²) of VGLUT1⁺/PSD-95⁺ excitatory synapses in each subregion of the hippocampus from WT and TG mice. *p < 0.05 (CA1: t₍₁₂₎ = 2.35; CA3: t₍₁₂₎ = 2.32; DG: t₍₁₂₎ = 2.43), based on independent t-tests (two-tailed). B The photomicrograph shows a representative double-immunofluorescence stain using VGAT (green) as presynaptic and Gephyrin (red) as postsynaptic markers of inhibitory neurons. Examples of VGAT ⁺/Gephyrin⁺ co-localizing synapses are highlighted by white circles in magnified sections. The scatter plots show the density (number/mm²) of VGAT ⁺/Gephyrin⁺ inhibitory synapses in each subregion of the hippocampus from WT and TG mice. All scatter plots show individual mice with overlaid group means ± s.e.m.; n = 7 per genotype.