In order to truly understand what makes the human brain unique, as well as what can go wrong in disease states, we need to develop methods for studying human neurons and neuronal progenitors in vitro. This will provide us with an invaluable tool by which we can recapitulate development, recreate circuits, and engineer models designed to illuminate the role played by each brain cell type. The brain is composed of a dazzling array of cell types, which interact with each other in a variety of ways. In recent years, the loss or malfunction of inhibitory interneurons has been shown to be involved in a number of disorders, including epilepsy, schizophrenia, and autism spectrum disorders. My ultimate goals are: 1) to provide a reliable source of inhibitory interneurons of all subtypes for systems biology experiments; 2) to further our understanding of the differentiation and functional role of interneurons through in vitro molecular characterization and 3) to recapitulate human cortical circuits in vitro for use in molecular, imaging and electrophysiological experiments. Building on my previous work in neuronal specification and differentiation, my role at the Allen Institute is to generate brain cell types found in the human brain from progenitor cells such as induced pluripotent stem cells (IPSCs). Once the protocols for generating the most important cell types in the brain are established, the molecular networks team will use these cells to assay the molecular events that characterize the differentiation of specific human neuronal populations. This information will be invaluable for comparison with neurons generated from IPSCs derived from individuals with neuropsychiatric disorders, yielding clues to the mechanisms and potential treatments for these disorders.