Fig. 2: Amacrine cell inputs onto an ON DSGC.

a Electron-microscopic reconstruction of the distribution and sources of all detected amacrine-cell synaptic contacts onto an ON DSGC. Dendrites of the ganglion cell are shown in black except for the sparse branches in the OFF sublayer (red). Synaptic contacts are plotted as dots, color coded by amacrine-cell source (see key), as determined by reconstruction of presynaptic cells. Numbers of synapses are in parentheses. ‘Other’ synapses: H18 AC (2), medium field unidentified AC (2), and A17 AC (1). ‘Unidentified’: fragments of dendritic arbors too small to identify. The plexus of ON SAC dendrites is shown in gray. Boundaries of the SBEM volume appear as a fine rectangle. b–e side (vertical) views of depth of these inputs within the IPL. Gray bands mark the ON and OFF SAC plexuses. Color scheme as in (a). g–i Example SBEM images of amacrine-cell synapses onto the ON DSGC. ON-DSGC dendritic profiles are tinted yellow. The presynaptic cells are color coded as in (a–e): VGluT3 cells (f, g), an ON SAC (h) and a WF amacrine cell (i).