Figure 3
Representative immunofluorescence (gray scale) for Iba-1+ microglia (white) in layers IV-V of the somatosensory cortex of control (A, C) and HIV-1 Tg rats (B, D) and within the dentate gyrus of the hippocampus of control (E, G) and HIV-1 Tg (F, H) rats at 7 months of age. Images represent compiled z-stack images collected throughout a 50 micron section. Higher magnification of individual representative cells demonstrates diminished arborization of Iba-1+ microglia primarily within the hippocampus. Microglia within defined regional areas were randomly selected (10/section/animal) and the projection distance of the processes was determined using a modified Sholl analysis. In the control brain, 90% (± 10%) of the processes projected past the 4th Sholl while in the HIV-1 Tg rat this was decreased to only 40% (± 18%). Estimates of complexity of the dendritic branching were generated by counting the number of processes originating at cell body. The number of processes was not statistically different from the number in the HIV-1 Tg rat hippocampus, ranging between 5 and 6 in Tg rats and between 7 and 8 in controls, although complexity and secondary branching appeared lower.