Figure 1

Architecture of the adult Drosophila olfactory circuit and local interneurons marked by GAL4-LN1 and GAL4-LN2. (A) Adult brain stained with mAbnc82, which recognizes presynaptic terminals. The antennal lobes are demarcated with blue dotted lines. (B) Schematic representation of olfactory interneurons. Note the three clusters of projection neurons (PNs; red) in anterodorsal (adPN), lateral (lPN) and ventral (vPN) locations and the single cluster of local interneurons (LNs; green) in the dorsolateral location. LNs ramify multiple glomeruli and PNs project from the antennal lobe to the calyx of the mushroom bodies and the lateral horn (LH). mACT, medial antennocerebral tract; iACT, inner antennocerebral tract. (C, D) Cell bodies of GAL4-LN1 (C) and GAL4-LN2 (D) are clustered lateral (encircled by red dots) to the lobe (encircled by blue dots). Scale bars, 20 μm. (E-F) Neurotransmitter identity of the LNs. Cell bodies of GAL4-LN1, UAS-mcD8::GFP (E1) and GAL4-LN2, UAS-mcD8::GFP (F1) were immunolabelled by antibodies to GABA (blue asterisks). A few cells expressing Cha-dsRed were detected (E2, F2; cyan arrowheads). Genotype in (F): GAL4-LN2, UAS-mCD8::GFP/Cha-dsRed and Cha-dsRed/+; GAL4-LN1, UAS-mCD8::GFP/+.