Quantitative analysis confirmed gp120 induced astrocytic hypertrophy and reduced dendritic complexity. Representative immunofluorescent images from 4-week monolayer control cultures (a) and cultures exposed to gp120 for 72 hours (b) stained for MAP2 (green) and GFAP (red). All bars = 20 μm. Quantitative immunofluorescent analysis of the effect of 72 hour gp120 exposure on MAP2 and GFAP expression (normalized to nuclear staining) using confocal scanning laser microscopic images is shown in (c). Bars represent normalized mean pixel intensities from 12 random fields +/- SEM. Gp120 treated cultures demonstrate a 37% decrease in MAP2 immunoreactivity (p < 0.02) and a 43% increase in GFAP immunoreactivity (p < 0.01) in comparison with controls. Error bars: +/- 1 standard error.