Experimental study of human development and disease formation is inherently challenging. However, recent studies have demonstrated that it is possible to model aspects of this process through the directed differentiation of embryonic and induced pluripotent stem cells.  Our research employs this approach to investigate the development of the human brain and spinal cord, with the goal of using this tissue to understand the basis of neurodevelopmental and neuropsychiatric disorders, as well as the root causes of neurodegenerative diseases such as spinal muscular atrophy and amyotrophic lateral sclerosis.  We further seek to use this experimental platform for drug discovery and the development of cellular therapies to repair the injured or diseased nervous system.