Fig. 1.

Number of axonal ribbons of distinct ON BC types across development. a Schematics showing the key neurons of this study and their ribbon synapses. Ph photoreceptors, BC bipolar cell, IPL inner plexiform layer, GC ganglion cell, PSD postsynaptic density. b Confocal images showing individual axon terminals and ribbons of three different types of ON BCs across development. Ribbons were labelled by anti-CtBP2 and those outside the axon terminals were excluded digitally (see Methods for details). c Axonal arbor volume of the three BC types. d Developmental increase in the total number of ribbons per axon, and e the fraction of ribbons (CtBP2 positive puncta) normalized to the average total ribbon number per axon at P21, for each BC type studied. Data were collected from 6–10 cells from 4–8 retinas for each age-group. Data are presented as mean ± sem