Abstract
Roundabout (Robo) is one of the axon guidance molecules which has been identified to be expressed in layers Ⅱ/Ⅲ, Ⅴ and Ⅵ in the developing neocortex. Studies have shown that reduced expression of Robo1 is associated with developmental disorders including autism and dyslexia, suggesting that the expression levels of Robo1 is crucial for neuronal differentiation and higher brain function. Over recent years, the roles of Robo1 in the developing neocortex has been examined using molecular and genetic approaches, highlighting its importance in the differentiation of cortical neurons and the formation of the cerebral cortical circuit. Suppression of Robo1 expression in the upper‐layer pyramidal neurons reveal migration delay and ectopic localization of these neurons, where Robo1‐suppressed neurons fail to establish the characteristic inside‐out neuronal distribution. Morphologically, Robo1‐suppressed neurons exhibit changes in their dendritic patterns, especially in the number of apical neurites. In this review, we will present an overview of the function of Robo1 in the developing neocortex and update our knowledge concerning the mechanisms by which a single receptor gene mediates pleiotropic roles in cortical circuit formation.
