A new approach to manipulate the fate of single neural stem cells in tissue.

A challenge in the field of neural stem cell biology is the mechanistic dissection of single stem cell behavior in tissue. Although such behavior can be tracked by sophisticated imaging techniques, current methods of genetic manipulation do not allow researchers to change the level of a defined gene product on a truly acute time scale and are limited to very few genes at a time. To overcome these limitations, we established microinjection of neuroepithelial/radial glial cells (apical progenitors) in organotypic slice culture of embryonic mouse brain. Microinjected apical progenitors showed cell cycle parameters that were indistinguishable to apical progenitors in utero, underwent self-renewing divisions and generated neurons. Microinjection of single genes, recombinant proteins or complex mixtures of RNA was found to elicit acute and defined changes in apical progenitor behavior and progeny fate. Thus, apical progenitor microinjection provides a new approach to acutely manipulating single neural stem and progenitor cells in tissue.