Effective gene delivery to adult neurons by a modified form of electroporation

Non-viral methods of transfection of cDNAs into adult neurons and other post-mitotic cells are generally very inefficient. However, the recent development of Nucleofector technology developed by Amaxa Biosystems allows direct delivery of cDNAs into the nucleus, enabling transfection of non-dividing cells. In this study, we describe a reliable method for culturing large numbers of retinal cells from adult rats and using Nucleofection, we were able to transfect cDNA-encoding GFP (jellyfish green fluorescent protein) into retinal ganglion cells (RGCs) with relatively high efficiency (up to 28%). Neuronal GFP expression was observed within 18 h and continued for up to 14 days. This compares with values up to 60% of RGCs expressing GFP following infection with an HSV-1 vector. Adult rat dorsal root ganglion (DRG) neurons were also successfully transfected. Thus, in summary, Nucleofection provides the possibility for a fast and efficient method for cDNA delivery and study of gene function in adult mammalian neurons.