Figure 2.

Hypoxic-ischemic insult is associated with increased microglial activation in cortical and subcortical regions of interest. (A–F) Representative images of Iba-1 expression in the frontal cortex (FC) piglet brains. (A’–F’, G’–M’) Illustrate the typical morphology of microglia observed in the respective groups. Control I group microglia displayed a resting state with long branching processes (A’, G’; triangles). In the 2H group, cell bodies were relatively similar, though processes were much shorter’(B’ H’; thin tailed arrows). Piglets in the 4H group had microglia that were bushy in appearance and covered a much smaller area than the C group’(C’ I’; marked with an asterisk). In 8H, 12H, and 24H groups, the Iba-1 + cells were round and appeared larger (D’–F’ J’ M’; thick-tailed arrows). Morphological classification revealed significantly more activated microglia in the frontal cortex (N) and putamen (O) with fewer resting microglia. There was a significant difference in the total number of microglia in the frontal cortex, but no differences between groups were significant at the post-hoc level, no significant difference was observed in the putamen (P). Individual data points are the average aggregation of 4 separate fields from 3 technical replicates. Columns illustrate the mean with error bars at one standard deviation. Statistical comparisons refer to ordinary one-way analysis of variance test with a two-stage linear step-up procedure of Benjamini, Krieger and Yekutieli. Statistical significance was accepted at q < 0.05 (^∗∗q < 0.01, ^∗∗∗∗q < 0.0001). High magnification image scale bar = 25 μm; low magnification image scale bar = 100 μm. C control group; FC frontal cortex; (number)H group culled hours post injury; Iba-1 ionized calcium binding adaptor molecule 1; PUT putamen.