Application for the Drosophila Ventral Nerve Cord Standard in Neuronal Circuit Reconstruction and In-Depth Analysis of Mutant Morphology

Abstract

The Drosophila standard brain has been a useful tool that provides information about position and size of different brain structures within a wild-type brain and allows the comparison of imaging data that were collected from individual preparations. Therefore the standard can be used to reveal and visualize differences of brain regions between wild-type and mutant brains and can provide spatial description of single neurons within the nervous system. Recently the standard brain was complemented by the generation of a ventral nerve cord (VNC) standard. Here the authors have registered the major components of a simple neuronal circuit, the Giant Fiber System (GFS), into this standard. The authors show that they can also virtually reconstruct the well-characterized synaptic contact of the Giant Fiber with its motorneuronal target when they register the individual neurons from different preparations into the VNC standard. In addition to the potential application for the standard thorax in neuronal circuit reconstruction, the authors show that it is a useful tool for in-depth analysis of mutant morphology of single neurons. The authors find quantitative and qualitative differences when they compared the Giant Fibers of two different neuroglian alleles, nrg⁸⁴⁹ and nrg^G00305, using the averaged wild-type GFS in the standard VNC as a reference.

Keywords::

• Drosophila
• Giant Fiber
• neuronal circuit
• Neuroglian
• standard brain
• ventral nerve cord

ACKNOWLEDGMENTS

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health and Human Development or the National Institutes of Health. We are grateful to the C. Duch and M. Heisenberg labs and to the Bloomington Stock Center for providing fly stocks and other resources. We also thank C. Trivigno and R. K. Murphey for their comments on the manuscript.

Declaration of interest: The project described was supported by grant number R01HD050725 from the National Institute of Child Health and Human Development to T.A.G.