Labeling of microglia with Alexa Fluor 488 conjugated lectin IB4. (A) Hippocampus slice of P7 rat stained immediately after sectioning. Microglia demonstrate typical "resting", ramified morphology with small cell bodies and branching processes (arrows). (B) After 1 DIV, the microglia started to revert to a more intermediate "reactive" form with larger cell bodies and thicker branches (arrow) and by 4 DIV a number of cells appeared with a rounded "amoeboid" phenotype (C, arrows), but also more pleomorphic cells with projections were visible (C&D, dashed arrows). Note also labeling of vascular endothelium (arrowheads in A and C). Scale bar equals 50 μm.