Figure 1

(a) Example of a full UV-cone reconstruction, taken from the acute zone. Dark purple: nucleus; light purple: mitochondria; purple: outer segment; yellow: ribbon. (b) Zoom-ins of UV-cone terminals from different regions, which are illustrated on the rightmost panels. Ribbons are highlighted in yellow. Each terminal is shown from the side (top) and from below (bottom). (c) Example electron microscopy images from each zone, with arrowheads indicating ribbons. (d–f) Violin plots of the ribbon geometry and number for the three different regions (two-sided shuffling test with Bonferroni correction, nAZ, nN, nD = 6, 6, 6, *p<0.05, **p<0.01). (g) Two-dimensional schema of the vesicle pools at a ribbon synapse. (h) Mean and 95% confidence intervals for vesicle densities as a function of distance to the ribbon. Predictions are made from a generalised additive model (GAM, Materials and methods; see Figure 1—figure supplement 1 for statistical comparisons). (i) Summary schema of observed Electron microscopic-level differences between UV-cones at the level of ribbon geometry, number, and vesicle distributions. Asterisks indicate significant differences compared to acute zone (AZ). The stacked ribbons (gold) indicate the ribbon number per cone, whereas the vesicles (small circles) are exemplified in a two-dimensional plane for a single ribbon.