Fig. 4

OPL connectivity of horizontal cells. A–F surface renderings from FIB scan 5, G–I segmentations from FIB scan 5, J + K STEM images. A H1 cell dendrites (yellow) contacting both, ribbons of short cone pedicles (green) and long cone pedicles (blue). B H2 cell dendrites (turquoise) contacting the ribbons of short cone pedicles (green) only. C H3 cell dendrites (red, pink) contacting the ribbons of rod spherules (#). D H1 dendrites (yellow) at the level of long cone ribbons (blue) and a bipolar dendrite. E H1 dendrites (yellow, with some artificial swellings *) and H2 dendrites (turquoise) at the level of short cone ribbons (green). F H3 dendrites (red, blue) at the level of rod spherules. G Selected EM plane showing the synaptic triad from D. H EM plane from E. I EM plane from F. J H cell dendrites with synaptic spinules invaginating a long cone pedicle (horizontal plane). K Radial plane showing two bunches of synaptic invaginations of a long cone pedicle. Arrows: spinules with postsynaptic densities, arrowheads: ribbons. Scale bars: A 5 µm (also B, C); D, E, G–J 1 µm; F, K 2 µm