Figure 7.
Long-term effect of IAV infection on dendritic spine density of hippocampal neurons. A, Representative images of Golgi-stained hippocampus sections. Scale bars, 200 μm, 2.5× hippocampal neurons; 20 μm, 20× and dendritic spines in hippocampal CA1 apical neurons after infection with IAV; 2 μm, 63×. B–E, After infection with H3N2 and H7N7 IAV, the spine density of apical dendrites of CA1 (B) and CA3 (C) hippocampal neurons decreased at 30 dpi; only H7N7 IAV infection reduced dendritic spine density of dentate granule cells located in the superior (D) and inferior (E) blade of the granule cell layer. At 60 dpi, a partial recovery occurred in the DG and CA3 hippocampal subregions of infected animals and, at 120 dpi, the dendritic spine density fully recovered in all regions of the hippocampus. Data are presented as mean ± SEM (n = 4–5 and number of dendrites in each group = 40–50), one-way ANOVA of data and post hoc Bonferroni's multiple-comparisons test were performed. *p < 0.05 and ***p < 0.001 compared with control; ##p < 0.01 and ###p < 0.001 compared with 30 dpi time point.