The generation of cortical interneurons

The mammalian telencephalon is responsible for many functions, which range from processing sensory information to learning, decision-making, and modulating emotional responses. The capacity of telencephalon to perform such a variety of functions likely relies on its neuronal diversity. GABAergic inhibitory interneurons, with their enormous multiplicity of subtypes, are a major contributor to this repertoire as they have remarkable diversity in morphology, physiology, and function. The central goal of this manuscript is to survey our present knowledge of how cortical interneuron subtypes are generated during development. We will start by briefly addressing the mature properties that differentiate between different major populations of cortical interneurons. We will then review the progressive events in development involved in the generation of interneuron diversity, beginning with their origin and specification, within the different subdomains of the subpallium. We will then explore the mechanisms by which interneurons migrate and mature in the early postnatal cortex. Finally, we will conclude by calling the reader's attention to the devastating consequences resulting from developmental failures in the formation of inhibitory circuits within the cortex.