TY - JOUR T1 - A complete electron microscopy volume of the brain of adult Drosophila melanogaster JF - bioRxiv DO - 10.1101/140905 SP - 140905 AU - Zhihao Zheng AU - J. Scott Lauritzen AU - Eric Perlman AU - Camenzind G. Robinson AU - Matthew Nichols AU - Daniel Milkie AU - Omar Torrens AU - John Price AU - Corey B. Fisher AU - Nadiya Sharifi AU - Steven A. Calle-Schuler AU - Lucia Kmecova AU - Iqbal J. Ali AU - Bill Karsh AU - Eric T. Trautman AU - John Bogovic AU - Philipp Hanslovsky AU - Gregory S. X. E. Jefferis AU - Michael Kazhdan AU - Khaled Khairy AU - Stephan Saalfeld AU - Richard D. Fetter AU - Davi D. Bock Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/05/22/140905.abstract N2 - Drosophila melanogaster has a rich repertoire of innate and learned behaviors. Its 100,000–neuron brain is a large but tractable target for comprehensive neural circuit mapping. Only electron microscopy (EM) enables complete, unbiased mapping of synaptic connectivity; however, the fly brain is too large for conventional EM. We developed a custom high-throughput EM platform and imaged the entire brain of an adult female fly. We validated the dataset by tracing brain-spanning circuitry involving the mushroom body (MB), intensively studied for its role in learning. Here we describe the complete set of olfactory inputs to the MB; find a new cell type providing driving input to Kenyon cells (the intrinsic MB neurons); identify neurons postsynaptic to Kenyon cell dendrites; and find that axonal arbors providing input to the MB calyx are more tightly clustered than previously indicated by light-level data. This freely available EM dataset will significantly accelerate Drosophila neuroscience.HIGHLIGHTS- A complete adult fruit fly brain was imaged, using electron microscopy (EM)- The EM volume enables brain-spanning mapping of neuronal circuits at the synaptic level- Olfactory projection neurons cluster more tightly in mushroom body calyx than expected from light-level data- The primary postsynaptic targets of Kenyon cells (KCs) in the MB are other KCs, as well as the anterior paired lateral (APL) neuron- A newly discovered cell type, MB-CP2, integrates input from several sensory modalities and provides microglomerular input to KCs in MB calyx- A software pipeline was created in which EM-traced skeletons can be searched for within existing large-scale light microscopy (LM) databases of neuronal morphology, facilitating cell type identification and discovery of relevant genetic driver lines ER -