PT - JOURNAL ARTICLE AU - Casey M. Schneider-Mizell AU - Stephan Gerhard AU - Mark Longair AU - Tom Kazimiers AU - Feng Li AU - Maarten F. Zwart AU - Andrew Champion AU - Frank Midgley AU - Richard Fetter AU - Stephan Saalfeld AU - Albert Cardona TI - Quantitative neuroanatomy for connectomics in <em>Drosophila</em> AID - 10.1101/026617 DP - 2016 Jan 01 TA - bioRxiv PG - 026617 4099 - http://biorxiv.org/content/early/2016/02/17/026617.short 4100 - http://biorxiv.org/content/early/2016/02/17/026617.full AB - Neuronal circuit mapping using electron microscopy demands laborious proofreading or reconciliation of multiple independent reconstructions. Here, we describe new methods to apply quantitative arbor and network context to iteratively proofread and reconstruct circuits and create anatomically-enriched wiring diagrams. We measured the morphological underpinnings of connectivity in new and existing reconstructions of Drosophila sensorimotor (larva) and visual (adult) systems. Synaptic inputs were preferentially located on numerous small, microtubule-free “twigs” which branch off a single microtubule-containing “backbone”. Omission of individual twigs accounted for 96% of errors. However, the synapses of highly connected neurons were distributed across multiple twigs. Thus the robustness of a strong connection to detailed twig anatomy was associated with robustness to reconstruction error. By comparing iterative reconstruction to the consensus of multiple reconstructions, we show that our method overcomes the need for redundant effort through the discovery and application of relationships between cellular neuroanatomy and synaptic connectivity.