VSV-G pseudotyped EF1α-EGFP lentivector-mediated gene transfer into dorsal root ganglion in adult rat. A, B. Representative images of immunostained EGFP expression (A) and EGFP-expressed neurons co-labeled with β3-tubulin (DRG neuronal marker, B) 4 weeks after injection of the LV2-EF1α-EGFP into a L5 DRG. C, D. Arrows point to weak EGFP expression in nerve roots proximal to the injection (C) and spinal nerve distal to the injection (D). No EGFP staining was detected in corresponding spinal cord (not shown) or in contralateral DRGs (E; the two vertical streaks are from wrinkles in the section). F. Bar graphs represent the percentage of immunostained EGFP positive neuronal cells per total DRG neurons observed in the sections of L5 ipsilateral DRGs injected with VSV-G LV1-EF1α-EGFP (n = 3) and VSV-G LV2-EF1α-EGFP (n = 4). Tissues were collected four weeks after vector injection. Scale bar = 200 μm for A, B, and E; 100 μm for C and D.