Cerebral Cortex Connectomics

The mapping of neuronal connectivity is one of the main challenges in neuroscience. Only with the knowledge of wiring diagrams is it possible to understand the computational capacities of neuronal networks, both in the sensory periphery and especially in the mammalian cerebral cortex. Our methods for dense circuit mapping are based on 3-dimensional electron microscopy (EM) imaging of tissue, which allows imaging of nerve tissue at nanometer-scale resolution across substantial volumes, extending to more than one millimeter on the side, followed by AI-based image analysis to obtain dense connectivity maps, or connectomes. With these, we have mapped local circuitry in the mouse and human cortex, determining learning-related synaptic traces and inhibitory axonal development, and discovered an expanded interneuron-to-interneuron network in the human cortex. Most recently we completed the connectomic reconstruction of a cortical column. We are screening cortical connectomes across age, disease states, and experience to better understand their relevance to individual behavioral performance and brain pathology.