Immunohistochemical and real-time (RT) PCR analyses. (A) Immunohistochemical assessment of microglial density in mid-frontal cortex (MFCx), hippocampus (HI), entorhinal cortex (ECx) and white matter (WM), expressed as the Iba-1-positive area fraction. No differences were seen in any brain area between immunized (n = 10) and non-immunized aged non-human primates (NHPs) (n = 6). Bars represent mean ± SD. (B) Quantitative RT-PCR analysis of expression of microglial (CD68 and Iba-1) and astrocytic (GFAP) markers as well as indicators of classical (CXCL10, CXCL9, indoleamine 2,3 dioxygenase (IDO), CCR7, prostaglandin-endoperoxide synthase 2 (PTGS2)) and alternative (CCL17, mannose receptor 1 (MRC1) microglia activation. No significant differences were seen between immunized and non-immunized NHPs for any marker. Mean ± SD.