Location and abundance of parasites in the brain following intranasal and subcutaneous inoculation. C57BL/6 mice were infected intranasally and subcutaneously with 25 × 103 parasites, sacrificed at day 25 (peak brain parasitism), and assayed for T. cruzi by quantitative PCR in the brain cortex (CX), basal ganglia (BG), and cerebellum (CB). The experiment was repeated four times, using two or three mice per region tested. *, P < 0.001.