The laminar organization of the Drosophila ellipsoid body is semaphorin-dependent and prevents the formation of ectopic synaptic connections
Abstract
The ellipsoid body (EB) in the Drosophila brain is a central complex (CX) substructure that harbors circumferentially laminated ring (R) neuron axons and mediates multifaceted sensory integration and motor coordination functions. However, what regulates R axon lamination and how lamination affects R neuron function remain unknown. We show here that the EB is sequentially innervated by small-field and large-field neurons, and that early-developing EB neurons play an important regulatory role in EB laminae formation. The transmembrane proteins semaphorin-1a and plexin A function together to regulate R axon lamination. R neurons recruit both GABA and GABA-A receptors to their axon terminals in the EB, and optogenetic stimulation coupled with electrophysiological recordings show that Sema-1a-dependent R axon lamination is required for preventing the spread of synaptic inhibition between adjacent EB lamina. These results provide direct evidence that EB lamination is critical for local pre-synaptic inhibitory circuit organization.
Article and author information
Author details
Funding
Howard Hughes Medical Institute
- Xiaojun Xie
- Matthew P Brown
- Sarah P Mitchell
- Alex L Kolodkin
National Institutes of Health (1R01 NS079584)
- Masashi Tabuchi
- Mark N Wu
National Institutes of Health (1R21 NS088521)
- Masashi Tabuchi
- Mark N Wu
National Institutes of Health (P30 NS50274)
- Alex L Kolodkin
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Xie et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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