Fig. 10

The TJ⁺ MNB neurons are Ladder neurons. a 3D reconstruction of a first instar larva VNC stained for Gad1 (magenta) and showing the morphology of a single GABAergic TJ⁺ MNB progeny neuron (arrowhead, expressing Venus under the combined expression of TJ-Flp and R47G08-lexA) in dorsal view (a), lateral view (a1), and posterior view (a2). For all three views (a, a1, a2), the magenta channel (Gad1 staining) was omitted to allow a better observation of the MNB progeny neuron morphology. Close-up in a confirms that the TJ⁺ MNB progeny neuron shown is indeed GABAergic. b, c Dorsal projection of first instar larva single MNB progeny neurons. d–g 3D reconstruction of a first instar larva VNC showing the morphology of Ladder-d neurons visualized using the split Gal4 line JRC-SS00863 driving 20XUAS-6XGFP and stained for FasII and TJ. f, g Single confocal sections through the soma showing that Ladder-d neurons express TJ (arrows). h Proposed circuit for TJ⁺/Gad1⁺ MNB progeny-dependent modulation of the speed of locomotion. Mechanosensory input, relayed by chordotonal neurons, activates TJ⁺/Gad1⁺ MNB progeny (Ladder-d) neurons, which through inhibition of Basin neurons (Basins) can modify motor output either through projections into the brain or directly through connections with premotor circuitry. Scale bars: 5 µm