Fig. 2.

Immunoperoxidase staining of ZIKV antigens in young adult mouse brain. a Representative images illustrating the distribution of ZIKV envelope antigens stained by immunoperoxidase in brain sections on days 3, 7, and 10 post-infection. ZIKV-positive staining and cresyl violet-colored cells appear brown and purple-blue, respectively. Images were selected from slide scans obtained at a magnification of 20 × using a NanoZoomer HT 2.0 slide scanner. Scale bars on the picture are equivalent to 1 mm. b Mean score of ZIKV antigen immunostaining in the dorsal hippocampus at different times post-infection. Results represent the mean ± SEM of 5–6 mice per time point. c Mean score of ZIKV antigen immunostaining in selected brain regions on day 10 post-infection. Results represent the mean ± SEM of 6 mice per brain region. H, hippocampus; vHPC, ventral hippocampus; dHPC, dorsal hippocampus; T, thalamus; HT, hypothalamus; A, amygdala; C, cortex. Statistical analyses were performed using a nonparametric Kruskal–Wallis test for ordinal variable with Dunn’s multiple comparison test. Results that are statistically different between indicated groups are shown as follows: ** P < 0.01; *** P < 0.001. d Schematic representation of the dorsal hippocampus and the dentate gyrus (DG). The cornu ammoni 1 (CA1), CA2, and CA3 as well as the stratum radiatum (SR) and the stratum lacunosum-moleculare (SLM) layers are shown