Fig. 1

PACAP administration alleviates severe brain pathology upon T. gondii encephalitis. A Experimental design and PACAP administration schedule. Mice were infected with 2 cysts of T. gondii (type II strain ME49) and treated with 100 µg PACAP i.p. on alternating days starting at 3 weeks post-infection; yellow indicates acute infection, followed by an intermediated phase (2 to 3 weeks post-infection, not indicated), and green indicates chronic infection. B, D, F Histological brain sections from infected control animals (left column) and PACAP-treated animals (right column). B H&E staining and C bar charts show number of inflammatory foci quantified across 10 consecutive brain sections per mouse. D F4/80 staining and E bar charts show the mean of F4/80⁺ cells across 10 random cortical areas per mouse. F Caspase-3 (Casp3) staining and G bar charts show the mean of Casp3⁺ cells across 10 random cortical areas per mouse. Data show mean + SEM, n = 4, **p < 0.01, ***p < 0.001, ****p < 0.0001 (unpaired two-tailed t-test). Scale bars = 100 µm. (H) Parasite burden was determined by qPCR analysis of TgB1 abundance, and RT-qPCR of Sag1 and Bag1 gene expression in brain homogenate. (I) Parasite burden in peripheral organs determined by TgB1 abundance. Bar charts present results normalized to mean values of control group as mean + SEM obtained in two independent experiments and analyzed together, n = 4–5 (Mann–Whitney U-test); Control (black bars) and PACAP-treated (white bars)