Cellular localization of transgene expression. Confocal microscopy demonstrated EGFP-expression in the nerve roots. The left panel provides an anatomic overview of a lumbar section through the spinal cord obtained with transmission light at a low magnification. The middle panel shows EGFP fluorescence (excitation wave length 488 nm, emission wave length 505–530 nm). The right image is a fusion of the fluorescence image with a transmission light micrograph of the same area. The insert depicts a detail at higher magnification. Images were obtained on an LSM 510 META confocal microscope.