Figure 8

Visualization of the timecourse of neutrophil and inflammatory monocyte infiltration during acute infection. Uninfected mice (A-E) or mice infected with Theiler's murine encephalomyelitis virus (TMEV) for 12 h (F-J), 24 h (K-O), or 48 h (P-T) were killed by intracardiac perfusion of 4% paraformaldehyde and vibratome sections of brain were prepared and stained with CD45 (A, B, F, G, K, L, P, Q), CD11b (C, H, M, R), Gr1 (D, I, N, S), or 1A8 (E, J, O, T). No staining for any of the markers was observed in the uninfected brain (A-E). The number of CD45-labeled cells increased within the hippocampal region through 12, 24, and 48 hpi (F, K, P). Higher magnification of a cross section showing the corpus callosum and alveus (top of each image), the CA1 pyramidal neuron layer (middle of each image), and the hippocampal fissure (bottom of each image) (B-E, G-J, L-O, Q-T) confirms the increasing density of the CD45⁺ infiltrate and also reveals that the Gr1⁺ population peaks at 24 h (N) while the 1A8⁺ population continues to increase through time (J, O, T). The scale bar in P is 1 mm and refers to (A), (F), and (K). The scale bar in T is 200 μm and refers to the remaining panels. Results are representative of more than five mice at each timepoint.