Fig. 5: Axon topography is present in some, but not most, optic glomeruli.
From: Synaptic gradients transform object location to action
a, LC4 is a VPN cell type that retains axonal topography in optic glomerulus. Left, hemibrain connectome reconstructions of 15 anterior (red), 15 posterior (blue) and central LC4 cells (grey). Middle, EM reconstruction of axons in the LC4 glomerulus shows separation of anterior and posterior terminals. M, medial. Right, image of the LC4 glomerulus region with axon terminals of one anterior (red) and one posterior (green) cell labelled using MultiColor FlpOut and assessed using light microscopy (n = 9, all A–P pairs of individual clones from different brains exhibited reproducible axon terminal topography). Axonal projections form a topographic map in the glomerulus, corresponding to the location of their dendrites along the A–P axis of the lobula. Scale bars, 5 μm. b, LPLC2 is a VPN cell type without axonal topography. LPLC2 axon terminals do not form a topographic map along the D–V axis of the lobula as visualized from EM reconstruction (left and middle) and light microscopy (right, n = 6 pairs of clones). Scale bars, 5 μm. c, Relationship between synaptic gradients and topography of axon terminals for different VPN types (see Extended Data Fig. 8 for more examples). *LC6 retains coarse axonal retinotopy25. **LC10 was previously shown to have A–P axonal retinotopy6,13. A, anterior; P, posterior; D, dorsal; M, medial; L, lateral.
