Every brain is unique, yet individuals of the same species share a set of common behaviors. To study this conundrum, you will map the brain wiring diagram of many individuals and extract both the consensus cellular connectome across all of them and the set of each individual’s idiosyncrasies. Mapping the complete synaptic wiring diagram of a whole brain is feasible for relatively small animals, such as the Drosophila larva. In this genetic model organism, each neuron is uniquely identified, presenting a stereotyped morphology and connectivity--to a point--, being recognizable between the left and right brain hemispheres, and across individuals. By using an existing complete reconstruction of the larval brain, and building on prior work from the lab, you will devise supervised methods that exploit the priors--the structure of the neuronal arbors in one individual--to enable the fully automatic segmentation of neuronal arbors in additional individuals from volume electron microscopy. Then, with graph-theoretic methods you will extract the minimum common synaptic wiring diagram across all reconstructed brains, to then study how each brain differs from this consensus and from other individual brains. The identification of what makes each brain unique will not only reveal a potential neural circuit basis for inter-individual differences in behavioral responses, but also indicate which neural circuits are more robust to architectural perturbations and which ones are strongly conserved.

References

Schneider-Mizell CM, Gerhard S, Longair M, Kazimiers T, Li F, Zwart MF, Champion A, Midgley FM, Fetter RD, Saalfeld S, Cardona A. (2016)
Quantitative neuroanatomy for connectomics in Drosophila.
Elife. 5:e12059.

Eichler K, Li F, Litwin-Kumar A, Park Y, Andrade I, Schneider-Mizell CM, Saumweber T, Huser A, Eschbach C, Gerber B, Fetter RD. (2017)
The complete connectome of a learning and memory centre in an insect brain.
Nature. 548(7666):175-82.

Winding M et al. (2020)
The complete wiring diagram of the Drosophila larval brain.
In preparation.