Generating Inhibitory Neuron Diversity through Morphogenic Patterning: From in vivo Studies to New in vitro Models

The proper functioning of the central nervous system depends on the cooperation of distinct neuronal subtypes generated during development.

Here, we review new insights provided by recent research and technological advances into the mechanisms underlying the generation of the remarkable diversity of inhibitory GABAergic neurons (INs). INs are generated in the ventral telencephalon or subpallium and migrate long distances to populate multiple brain regions. INs exhibit considerable morphological, molecular, and electrophysiological diversity. This diversity is mediated by intrinsic and extrinsic factors, including secreted molecules (such as sonic hedgehog).

This review examines the role of extrinsic factors in the establishment of distinct subpallial domains and the subsequent emergence of IN diversity. We begin by summarizing the in vivo morphogenesis of this process and then highlight the new technologies that allow us to revisit the role of morphogens in subpallial development and IN specification.