FIG. 1.

RA treatment significantly increases the survival of JEV-infected mice. (A) Survival of mice infected with 3 × 10⁵ PFU of JEV was significantly increased in groups that received RA treatment (15 mice for each group). Treatment with RA alone has no significant effect on survival. Observation of animal survival experiments was performed in a masked manner to avoid bias toward any one group of animals. (B to E) Cryostat sections from control (B), JEV-infected (C), and JEV-infected and RA-treated (D) mouse brains were processed for Iba-1. While the control sections exhibited only resting microglia (B; arrow), the infected brains showed the presence of activated microglia (C; arrowheads). The group of JEV-infected and RA-treated mice had mostly resting microglia (D; arrow). Scale bar, 25 μm. (E) Iba-1-positive activated microglia were counted and plotted as a graph. Values represent the means ± standard errors of the means (SEM) from five random fields in three animals in each group (P < 0.001).