Description:This special issue highlights the development of the mammalian forebrain, particularly the cerebral cortex. A special focus lies on the many factors that influence the development of neurons and glia in forebrain structures. All articles have been written by leading scientists, well known in the area of neuronal and glial development. Topics include recent findings about the factors influencing the fate of stem cells in the cortex and hippocampus; the origin, mapping and development of cortical layers; the role of growth factors, neurotransmitters and their receptors in neuronal and glial development; the regulation of cortical and thalamic axonal growth; the expression of genes during forebrain development; and the control of neuronal and glial migration in the cortex. This publication will be of interest to anyone studying brain development, neuronal and glial differentiation, cell migration and process extension in the nervous system.