This book, the seventh in the series 'Research and Perspectives in Neuroscience', contains the procedings of a meeting that was held in Paris on October14, 1996. The conference consisted of invited papers and poster presentations. The invited papers, included in this volume, were on cell proliferation prior to neuronal migration, on cellular and molecular factors characteristic of neuronal migration, and on postmigrational neuronal and axonal plasticity. There was a section devoted to disorders of neuronal migration and plasticity and the genetics of some developmental disorders. Great strides have been made in this relatively young branch of modern neuroscience.