Figure 1.

Representative images of observed CR3/43 immunoreactivity in the corpus callosum following TBI versus control subjects. (A–C) Representative images showing increasing CR3/43 reactivity with age as has been previously reported. (A) Virtually absent CR3/43 immunoreactivity in an 18-year-old female control subject who died as a result of leukaemia. (B) Minimal, highly ramified microglia observed in a 36-year-old female who died following a sudden cardiac event, and (C) numerous microglia with shortened, thickened processes and hypertrophy of the cell body, indicative of activation in a 92-year-old female who died as a result of bronchopneumonia. (D–E) Clusters of activated microglia with decreased ramifications in a (D) 23- and (E) 31-year-old male, who each died 4 weeks after TBI. Note the occasional cell displaying amoeboid morphology. In addition, cells can be seen arranging in parallel lines, likely along the length of an injured axon. (F–H) Extensive and densely packed amoeboid CR3/43 immunoreactive cells displaying minimal or no processes in (F) a 43-year-old male, 4 years post-TBI, (G) a 67-year-old male 8 months post-TBI and (H) a 64-year-old male 16 years post-TBI. All scale bars = 100 µm.