Organisation des lignées d'interneurones du cortex cérébral

The cerebral cortex plays a primordial role in the brain since it integrates multiple sensory information and controls complex functions. To process information properly, it requires the coordinated activity of two main classes of neurons: projection-stimulating pyramidal cells - which transmit information between cortical and extracortical regions - and inhibitory interneurons - that locally modulate cell responses Pyramidals. In a tangential plane, the cortex is subdivided into layers whereas in a radial plane the neurons are organized in columns. This structure is formed during development through a series of steps such as proliferation, cell migration and final integration. Understanding the mechanisms behind this complex maturation process is one of the main challenges in this area. Pyramidal cells and interneurons originate in distinct and remote germinal areas, and use different strategies to reach the cortex. More specifically, pyramidal cells are produced by the progenitor cells of the embryonic pallium, and migrate radially to their final position. Internalurons, meanwhile, originate in the embryonic subpallium from three main sources: ganglionic median eminence (MGE), caudal ganglion eminence (CGE) and preoptic area (POA). Each of these regions contains stem cell populations that give rise in different proportions to highly diverse populations of cortical interneurons in terms of morphology, physiological profile and neurochemical content. In addition, the interneurons reach the cortex via long tangential migration and acquire their final laminar position after complex intracortical migration(Figure 1). This type of migration makes it more difficult to study the impact of cell lines on cortical development