His research aims to understand the structure and function of the brain. To do so, his lab takes a comparative approach and engineers molecular, viral, and sequencing technologies to measure neuronal connectivity networks and gene expression at scale in disease models and a wide range of vertebrates. He developed the first barcode sequencing-based approaches to map neuronal connectivity, increasing throughput of single-neuron mapping by orders of magnitude and opening the door to single-cell comparative connectomics. His lab complements these barcoding approaches by in situ sequencing of barcodes and genes. Leveraging these technologies, they ask questions including: How do new brain regions and connections evolve to support new computations? What are the organizing principles and fundamental circuit motifs of the vertebrate brain? And how do drugs of abuse and neurodevelopmental disorders break these principles? His work is highly interdisciplinary, residing at the interface of molecular engineering, neuroscience, synthetic and evolutionary biology, genomics, virology, and computational biology.