Double Immunofluorescence staining was performed on fixed frozen brain sections as previously described.17 (link) The 8-μm thick slides were rinsed with PBS, and permeabilized with 0.3% Triton X-100 for 15min at room temperature. Next, slides were incubated with blocking solution (95% PBS, 5% normal donkey serum, and 0.05% Triton X-100) for 2 hours. Then, the slides were incubated using the following: goat anti-NeuN (neuronal nuclei; 1:300), mouse anti-Iba1 (ionized calcium-binding adaptor molecule 1; 1:300), rabbit anti-FKN (1:100), rabbit anti-CX3CR1 (1:100), rabbit anti-CD68 (cluster of differentiation 68; 1:150), rabbit or goat anti-CD206 (the mannose receptor; 1:200), goat anti-CD206 (1:200), rabbit anti-CD163 (1:100) or rabbit antihemoglobin (1:100; Abcam) at 4 °C overnight. After 3 consecutive washes in PBS (10 minutes each time), the sections were incubated with appropriate fluorescent-conjugated secondary antibodies (1:200; Jackson ImmunoResearch) for 2 hours at room temperature. The number of CD68+Iba1+ or CD206+Iba1+ positive cells in 3 different fields of the right basal cortex was identified and counted from 5 random coronal sections per rat, and positive cells were quantified under microscope fields at ×400 magnification.