Nervous systems are comprised of complex webs of synaptically interconnected neurons, which process sensory information and produce behaviors advantageous to an animal’s survival. In order to understand how neuronal circuits generate behaviors, a deep understanding of the brain’s architecture is required.

I am leading an effort to comprehensively reconstruct and analyze the brain of the Drosophila larva with synaptic resolution using electron microscopy. We have currently reconstructed all 2,500 differentiated neurons in the brain and mapped over 400,000 synaptic connections. Using graph theoretical techniques and spectral clustering, we have identified the primary functional units of the brain, including: seven sensory modalities and their respective processing centers, the memory and learning center, and brain output centers, which putatively generate behavior and modulate sensory input. We have also performed signal flow analyses to better understand how different sensory information flows through the brain and these neuron clusters.

Using this information, I will address the following questions:

1. How and where does multisensory integration occur?

2. How does this multisensory processing allow an animal to choose a single action and reject all other possible actions?

3. How are signals integrated across the two brain hemispheres and how is asymmetrical information interpreted by the animal?

Answering such questions will provide new conceptual understanding for circuit mechanisms in both invertebrates and vertebrates.