Our lab studies basic principles of brain-wide operation, with special emphasis on the role of synaptic connectivity on local and global brain function. We apply two main approaches in our investigations. (1) We examine the foundations of basic brain functions using a simple system, the compact brain of the roundworm C. elegans. In this way we can simplify complex questions about the brain and potentially trace down the origins of elaborate brain operations. (2) We genetically synthesize new synaptic connections in C. elegans neural circuits, with the aim of ultimately engineering entire brain circuits. This synthetic biology approach, applied to a whole animal, provides deep insights into the causative links between neuronal connectivity and brain function.