This course will explore how billions of neurons in our body are generated from a few specialized cells during embryonic development. Topics that will be covered in this class will include signals that regulate how cells are instructed to acquire a neural identity, how cells switch over from a progenitor to a fully differentiated neuron and the impact this may have on regulation of brain size with a special emphasis on exploring the mechanistic basis of human neocortex expansion, how neurons form functional neuronal circuits for proper function and regulation of behavior, and reorganization of these neuronal circuits during post-natal development. The importance of these fundamental processes in neuronal development will be highlighted through discussions of neurodevelopmental disorders such as neural tube defects that affect 3000 pregnancies each year in the US, lissencephaly, polymicrogyria among others. There will also be a brief section on use of stem cells and three-dimensional stem cell organoid approaches that are being used to answer previously unexplored questions of human nervous system development. Laboratory experiments will involve the use of vertebrate embryos in a humane manner to illustrate many of the fundamental concepts taught during lectures. Specific skills students can hope to acquire in the laboratory will be fine dissection skills, immunofluorescence, and microscopy, gross morphological analysis of embryos upon drug treatments known to affect neuronal development and finally, quantitative approaches for assessment of experimental manipulations that affect neuronal fate determination and neural circuit formation.