Abstract
The central complex is a highly conserved insect brain region composed of morphologically stereotyped neurons that arborize in distinctively shaped substructures. The region is implicated in a wide range of behaviors and several modeling studies have explored its circuit computations. Most studies have relied on assumptions about connectivity between neurons based on their overlap in light microscopy images. Here, we present an extensive functional connectome of Drosophila melanogaster's central complex at cell-type resolution. Using simultaneous optogenetic stimulation, calcium imaging and pharmacology, we tested the connectivity between 70 presynaptic-to-postsynaptic cell-type pairs. We identified numerous inputs to the central complex, but only a small number of output channels. Additionally, the connectivity of this highly recurrent circuit appears to be sparser than anticipated from light microscopy images. Finally, the connectivity matrix highlights the potentially critical role of a class of bottleneck interneurons. All data are provided for interactive exploration on a <ext-link ext-link-type="uri" xlink:href="https://romainfr.github.io/CX-Functional-Website/">website</ext-link>.
Highlights
Positioned in the middle of the insect brain, the central complex provides a unique opportunity to obtain mechanistic insights into the way brains build and use abstract representations (TurnerEvans and Jayaraman, 2016)
Detailed anatomy at the light microscopy level (Hanesch et al, 1989; Wolff et al, 2015; Lin et al, 2013) of a significant fraction of the cell types, along with the availability of tools to genetically target these neurons by type (Wolff et al, 2015), have fueled the first mechanistic investigations of how the circuit constructs a stable heading representation (Kim et al, 2017), and how this representation updates as the animal turns in darkness (Turner-Evans et al, 2017; Green et al, 2017)
We chose to apply this combination of Neuroscience optogenetics and calcium imaging on a large scale by systematically testing genetically defined pairs of central complex cell types in an ex vivo preparation, building a large and extensible map of functional connections in the structure at cell-type resolution
Summary
Positioned in the middle of the insect brain, the central complex provides a unique opportunity to obtain mechanistic insights into the way brains build and use abstract representations (TurnerEvans and Jayaraman, 2016). Detailed anatomy at the light microscopy level (Hanesch et al, 1989; Wolff et al, 2015; Lin et al, 2013) of a significant fraction of the cell types, along with the availability of tools to genetically target these neurons by type (Wolff et al, 2015), have fueled the first mechanistic investigations of how the circuit constructs a stable heading representation (Kim et al, 2017), and how this representation updates as the animal turns in darkness (Turner-Evans et al, 2017; Green et al, 2017) Such results and related findings from other insects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
