Effect of IFN-γ on parasite multiplication. Microglial cells, endothelial cells and neurons were stimulated by IFN-γ before being infected with the RH or PRU strain of T. gondii for 24 h. Parasite burden was quantified by semi-quantitative RT-PCR in stimulated and infected cells (black) and in non-stimulated and infected cells (grey). Parasite quantification was evaluated as follows: final number of tachyzoites/initial number of tachyzoites. Comparison was performed using the Scheirer-Ray-Hare test. **p < 0.01.