Figure 3.

Transfection of central neurons and a longitudinal muscle cell by particles coated with a plasmid encoding EGFP-Act1 and injection of two different lipophilic dyes. (For the details of microscopy, see supplemental material, available at www.jneurosci.org). A, Superimposed stack of fluorescence confocal sections of a dorsal region of an embryonic ganglion, 48 h after a shot. Cell nuclei were counterstained with a nonspecific nucleophilic compound (Hoechst, blue). Expression of EGFP-Act1 is clearly seen in the cell bodies and neurites of three neurons (there were two other expressers in different focal planes). Scale bar, 10 μm. Inset, Superimposed stack of reflected confocal sections taken in the same planes of the same ganglion; arrows indicate particles. B, Longitudinal muscle cell expressing EGFP-Act1, imaged with a confocal microscope 48 h after a shot. Inset, Magnified image of a fragment of the same cell taken with a transmission filter; one can see a particle in the cell nucleus (red arrow). Scale bar, 10 μm. C, Fluorescence image showing superposed stacks of confocal sections taken at conditions optimized for detection of green and red fluorescence in a dorsal region of an E10 embryo containing two segmental ganglia. The imaging was performed 2 h after particles coated with green (DiO) and red (DiI) fluorescent dyes were shot into the upper and lower ganglia, respectively. One can see some diffusion of dyes within cells. Scale bar, 100 μm. Inset, The same type of confocal image taken in a ganglion of an E10 embryo immediately after particles coated with the red and green dyes were shot into it; the gun was displaced by ∼100 μm between the shots.