Midbrain GABAergic neurons control several aspects of behaviour, including mood and motivation, but what controls their development? On , Kala and colleagues identify the transcription factor Gata2 as a tissue-specific post-mitotic selector gene for these neurons in developing mouse brains. During neurogenesis, selector gene activation in post-mitotic neural precursors drives the selection of particular neuronal phenotypes from among distinct alternatives. The researchers show that Gata2 is expressed in developing midbrain GABAergic neurons as they exit the cell cycle and differentiate. Tissue-specific inactivation of Gata2, they report, switches all the inhibitory GABAergic neural precursors in the embryonic midbrain to an excitatory glutamatergic phenotype without affecting neural progenitor proliferation or early neurogenic processes. The inactivation of Gata2 also switches all the GABAergic neurons in neonatal brains to a glutamatergic fate, except for those associated with the ventral dopaminergic nuclei. These results identify Gata2 as an essential post-mitotic selector gene for midbrain GABAergic neurons and provide insights into the generation of regional identities in distinct GABAergic neuron subpopulations.
