Figure 4

Microglial phenotypes in human dACC gray matter are characterized by significant changes in the cell body and processes. Primed microglia display a cell body of greater area (a) and of decreased roundness (b), as reflected by a significantly increased difference between the maximum and minimum feret (max-min feret) (c) compared to the ramified phenotype. The cell body morphology of reactive microglia appears statistically similar in area (a), roundness (b) and max-min feret (c) as primed microglia, but presents a decrease in roundness (b) when compared with amoeboid microglia. A reconstruction of a primed microglia shows the shortest (blue arrow; min) and longest chord (violet arrow, max) representing the maximum and minimum feret, respectively, and the ramification patterns represented by the ends and nodes of the processes (d). Ramified and primed microglia project similar numbers of primary (e) and higher-order processes (f-g). Reactive microglia display fewer first-order (and overall) branches (e-g), as well as shorter total process length (h) and volume (i). Amoeboid microglia have a significant decrease of primary and higher order branches (f-g), as well as a significant decrease in total process length (h) and volume (i) compared to reactive microglia, *P <0.01, **P <0.001, ***P <0.0001.