Morphological Analysis of Control vs. Repopulated Microglia.

<p>A–G) All morphological markers were examined in control (n = 10), 14 d repopulation (n = 5, “14d Repop”), and 21 d repopulation (n = 10, “21d Repop”) treatments to examine the change in microglia morphology over time. A) Changes in the number of microglia were observed in the cortex, but not the hippocampus during repopulation. B) Cell body area was much larger in 14 d repopulation microglia than either controls or 21 d repopulation in both the cortex and hippocampus. C, D) Microglial process diameter (C) and length (D) varied according to brain region and treatment, with some recovery apparent over time. E) Total process length/microglia did not vary due to brain region or treatment. F, G) The number of primary, secondary, and tertiary (or above) branches/microglia varied due to brain region and treatment, where secondary and tertiary (or above) branches were reduced in the cortex at 14 d repopulation, but had recovered by 21 d repopulation (F). While in the hippocampus, a reduction in the number of tertiary (and above) microglial branches were reduced over the course of repopulation (G). Data were analyzed using unpaired student’s t-tests and are presented as raw means ± SEM. Statistical significance is represented as *P<0.05.