Brain, acting as headquarter of an organism, performs meticulous functions to communicate and interpret information from all parts of the body. The power of human brain lies in a whole network of circuits consisting billions of neurons that are interconnected to form trillions of synapses. Similar to an electronic circuit, not only the properties of individual components, but also the connection diagram between all components is crucial to a neural circuit’s function. Neurons can be divided into many different subtypes with very specialized and distinct properties. While the properties of individual neurons are relatively well studied, how a neural circuit is formed by a cohort of neurons remains poorly understood. The Cai lab utilizes and develop multidisciplinary techniques, including multi-color genetic labeling, ultra-fast imaging modalities and image processing software to delineate neuronal lineages and neural circuits. By studying the processes of generating, patterning and wiring large numbers of neurons at the single cell resolution, we aim to understand the cellular and molecular mechanisms that control neural circuit formation in the developing mouse brain.