Connectomes are brain wiring diagrams at the synapse level. They are crucial for reverse engineering circuit function but are extremely scarce. Connectome reconstruction is challenging because it requires imaging and identifying axons and dendrites over tens of microns at nanometer resolution.
Currently, the only imaging technology that can bridge this range of scales is serial electron microscopy. The bottleneck in connectome reconstruction lies in the tracing of axons and dendrites, through millions of serial electron micrographs.
When done manually, a connectome reconstruction takes many years, even for a relatively small circuit such as that of C. elegans.
We have automated high-throughput connectome reconstruction and assembled the largest connectome to date (based on synapse count). Because humans are still superior to computers in reconstructing connectomes, we are now developing biologically inspired reconstruction algorithms. In parallel, we are developing methods to infer circuit function from connectomes.