Cellular composition of mixed and neuronal-enriched cultures. Confocal immunofluorescence microscopy was performed on mixed and neuronal-enriched cultures that were stained with neuronal specific antibody MAP-2 (green) and either the astrocyte-specific marker GFAP (red) (A and B) or the microglia marker F4/80 (red) (C and D), nuclei were stained with PI and appear blue. Prominent GFAP staining in mixed cultures is indicated with an arrow (A) and the rare astrocyte in the neuronal-enriched culture is shown with an arrow (B). Microglia were prominent in mixed cultures (C) and two examples were marked with an arrow. Microglial staining could not be detected in the neuronal-enriched cultures (D). Images were captured at 10× magnification for A and B, 60× for C and 40× for D. Magnification bars are 100 μm for A and B, 20 μm for C and D.