PT  - JOURNAL ARTICLE
AU  - Katharina Eichler
AU  - Feng Li
AU  - Ashok Litwin-Kumar
AU  - Youngser Park
AU  - Ingrid Andrade
AU  - Casey M. Schneider-Mizell
AU  - Timo Saumweber
AU  - Annina Huser
AU  - Claire Eschbach
AU  - Bertram Gerber
AU  - Richard D. Fetter
AU  - James W. Truman
AU  - Carey E. Priebe
AU  - L. F. Abbott
AU  - Andreas S. Thum
AU  - Marta Zlatic
AU  - Albert Cardona
TI  - The complete connectome of a learning and memory center in an insect brain
AID  - 10.1101/141762
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 141762
4099  - http://biorxiv.org/content/early/2017/05/24/141762.short
4100  - http://biorxiv.org/content/early/2017/05/24/141762.full
AB  - Associating stimuli with positive or negative reinforcement is essential for survival, but a complete wiring diagram of a higherorder circuit supporting associative memory has not been previously available. We reconstructed one such circuit at synaptic resolution, the Drosophila larval mushroom body, and found that most Kenyon cells integrate random combinations of inputs but a subset receives stereotyped inputs from single projection neurons. This organization maximizes performance of a model output neuron on a stimulus discrimination task. We also report a novel canonical circuit in each mushroom body compartment with previously unidentified connections: reciprocal Kenyon cell to modulatory neuron connections, modulatory neuron to output neuron connections, and a surprisingly high number of recurrent connections between Kenyon cells. Stereotyped connections between output neurons could enhance the selection of learned responses. The complete circuit map of the mushroom body should guide future functional studies of this learning and memory center.