Figure 5

Astrocytes were found to be the major source of iNOS expression. Confocal scanning laser microscopy studies of primary mixed human CNS monolayer cultures at 4 weeks in vitro revealed astrocytes to be the major sources of iNOS with rare neurons expressing iNOS. Immunofluorescence imaging by confocal microscopy was performed for detection of GFAP, MAP2 and iNOS antigens. Each panel of images shows individual fluorophores and merged fluorophores with colocalization represented in yellow. Gp120 exposed cultures show increased iNOS expression to colocalize extensively with the astrocytic marker GFAP (upper 3 panels) and rarely with the neuronal marker MAP2 (lower 3 panels). Bar = 10 μm.