H1N1 infection results in increased numbers of activated Iba-1 positive microglia in the substantia nigra <i>pars compacta</i> (SNpc) region of the brain.

<p>Representative images presented here of the SNpc from saline-treated (A-C) or H1N1 [21dpi (D-F) & 60 dpi (G-I)-infected] demonstrate Iba-1 positive microglia with different morphology (yellow arrowheads-resting; red arrowheads-activated). The inset box demonstrates the magnified regions of the SNpc (20X and 40X, respectively) to better demonstrate the morphology of Iba-1 positive microglia. Magnified images of Iba-1 positive microglia show resting (J) and activated morphology (K). Stereological estimates of Iba-1 positive activated microglia in the SNpc (L) and dentate gyrus of the hippocampus (M) are graphically represented. Graph demonstrates stereologically acquired numbers of activated morphology Iba-1 positive microglia in the SNpc following 21 dpi, 60 dpi and 90 dpi compared to saline administered controls (n = 5). All statistics were one-way ANOVA followed by Dunnett’s post-hoc comparisons. ***p≤0.001 compared to control, **** p≤0.0001 compared to control. Scale Bars: A,D,G 100 μm, B,E,F 20 μm, C,F,I, 10 μm, J,K 10 μm.