Figure 3: Effects of in vivo electroporation.

(a) Images of an area close to the ganglion transfected with EGFP. Note that both EGFP-positive axons and non-neuronal cells were identified, showing that in vivo electroporation of dorsal root ganglion (DRG) targets both neurons and non-neuronal cells. The white arrow indicates an axon labelled with EGFP. The yellow arrow indicates an EGFP-positive cell that is also positive for S100, the marker for Schwann cells. (b) Haematoxylin and eosin staining showing that neither plasmid injection nor electroporation had any detectable effects on the general histology of the DRG. (c) Representative immunostaining of the DRG injected with staurosporine. At 3 h after staurosporin injection, DRG was fixed and immunostained for active caspase-3 (red) and a neuronal marker Tuj1 (green). (d) Representative immunostaining of the DRG electroporated with EGFP. At 3 days after electroporation, DRG was fixed and immunostained for active caspase-3 (red). Note that electroporation of the DRG with EGFP caused no obvious apoptosis, indicated by the lack of active caspase-3 staining. (e) Representative immunoblots showing that the level of active caspase-3 (Act-cas3) in the DRG was not affected by electroporation (Elec.) when the DRG was subjected to western blot analysis at 1 day (Elec. 1d) or 3 days (Elec. 3d) after electroporation. By contrast, injection of staurosporine (STS) for 3 h increased the level of active caspase-3. Scale bars, a,b, 160 μm; c,d, 100 μm.