Investigating early formation of the cerebral cortex by in utero electroporation: Methods and protocols

Abstract

Cortical development requires a strict balance between neuronal proliferation, differentiation, and cellular migration within restricted developmental stages. The precise spatiotemporal gene manipulation used in developmental studies can be achieved by in vitro or ex vivo experiments or by the generation of transgenic animals. However, these approaches have significant limitations when trying to investigate the origin and molecular regulation of early cortical neurons. In utero electroporation (IUE) is an informative cell labeling technique that provides the ability to label neural progenitor cells and their progeny in vivo with promoterspecific reporter constructs as well as to induce or repress gene expression in a spatially and temporally specific manner. Technical improvements of this method have allowed the targeting of multiple neural cell types, as well as the precise transfection of subpopulations of neurons at increasingly earlier embryonic stages. Furthermore, neuronal projection studies and the use of multiple electroporations in the same embryo have made it possible to examine processes occurring at different developmental stages and/or cortical areas and link their anatomy to their function. In this chapter, we present the latest advances of the in utero electroporation technique for the study of early formation of the cerebral cortex, together with a description of the necessary tools