HIV-1 structural and enzymatic proteins can deliver a heterologously packaged RNA to non-dividing cells in vivo. A. MLV/HIV RRE chimeric vector used to investigate transduction of mouse neurons in vivo following packaging into MLV or HIV-1 viral particles. B. Mouse brains were injected into the striatum with equivalent transducing units of MLV/HIV RRE vector packaged into either MLV (left panels), or HIV-1 (right panels), derived viral particles. Brain sections were imaged by confocal microscopy following co-staining for neurons (NeuN, red) and vector particles (GFP, green). Images depicting both vector and neurons can be seen for MLV (top left and low magnification) and HIV (left top and low magnification) viral particles. Independent images of vector and neurons are shown for MLV (top middle and top right, respectively) and HIV (left middle and left bottom, respectively) viral particles. C. The graph represents the total number of cells scored for GFP only (white bars), and colocalized GFP + NeuN (black bars) from 5 mice in each group. Error for bar graph is expressed as ±S.D.