Our ability to image neurons and other brain structures depends on whether we can introduce fluorescent proteins or dyes into them. One problem for in vivo imaging is that the widely used GFP transgenic mice (thy1) do not express GFP in pyramidal neurons until after the 3rd postnatal week. Because we are interested in the development of dendrites and, in particular, the role of dendritic filopodia, we use in utero electroporation to transfect subsets of Layer 2/3 cortical neuron precursors at embryonic day 16.

Another advantage of in utero electroporation is that we can over-express or knock-down (using ssRNA) any gene of interest.