Development of GABAergic Interneurons in the Human Cerebral Cortex

GABAergic interneurons are critical regulators of information processing in the cerebral cortex. They constitute a heterogeneous group of neurons with unique spatial and temporal capabilities to control information flow and influence neural network dynamics through inhibitory and disinhibitory mechanisms. Interneuron diversity is largely conserved between rodents and primates, which indicates that the addition of new types of GABAergic neurons is not the most critical innovation of the primate cortex. In contrast, interneurons are much more abundant and seem more widely interconnected in the cerebral cortex of primates than in rodents, suggesting selective evolutionary pressure in the mechanisms regulating the generation, survival and maturation of cortical interneurons. Recent studies are beginning to shed light on the cellular and molecular mechanisms controlling the development of cortical interneurons in humans, from their generation in the embryonic telencephalon to their early integration in cortical networks. These studies identified many features in the development of human cortical interneurons that are shared with other mammals, along with distinctive features that seem characteristic of the primate brain, such as a previously unrecognised protracted period of neurogenesis and migration that extends the earliest stages of interneuron development into the first months of postnatal life in humans.