Drawing a Circuit Diagram of the Fruit Fly Drosophila Brain

Abstract

With less than 10⁵ neurones, and subject to powerful genetic techniques, the fruit fly Drosophila melanogaster is a good model system for drawing a circuit diagram or the whole brain. The GAL4 enhancer-trap strains label specific subsets of brain cells according to their gene expression pattern. The FRT-GAL4 system labels neurones according to their cell lineage. The three dimensional fibre structures of the cells labelled with these techniques can be visualised using various reporters such as Tau and GFP A comprehensive catalogue of neurones, and the neural circuits they form, are being compiled by the large-scale screening of the labelled cells.