DOI: 10.5061/dryad.wstqjq2n5
title: Data from: Spectral inference reveals principal cone-integration rules of the zebrafish inner retina

description: In the vertebrate retina, bipolar cells integrate the signals from
 different cone types at two main sites: directly, via dendritic inputs in
 the outer retina, and indirectly, via axonal inputs in the inner retina.
 Of these, the functional wiring of the indirect route, involving diverse
 amacrine cell circuits, remains largely uncharted. However, because
 cone-photoreceptor types differ in their spectral sensitivities, insights
 into the total functional cone-integration logic of bipolar cell might be
 gained by linking spectral responses across these two populations of
 neurons. To explore the feasibility of such a “spectral-circuit-mapping”
 approach, we here recorded in vivo responses of bipolar cell presynaptic
 terminals in larval zebrafish to widefield but spectrally resolved flashes
 of light. We then mapped the results onto the previously established
 spectral sensitivity functions of the four cones. We find that this
 approach could explain ∼95% of the spectral and temporal variance of
 bipolar cell responses by way of a simple linear model that combined
 weighted inputs from the cones with four stereotyped temporal components.
 This in turn revealed several notable integration rules of the inner
 retina. Overall, bipolar cells were dominated by red-cone inputs, often
 alongside equal sign inputs from blue- and green-cones. In contrast,
 UV-cone inputs were uncorrelated with those of the remaining cones. This
 led to a new axis of spectral opponency which was mainly set-up by
 red-/green-/blue-cone “Off” circuits connecting to “natively-On” UV-cone
 circuits in the outermost fraction of the inner plexiform layer – much as
 how key colour opponent circuits are established in mammals. Beyond this,
 and despite substantial temporal diversity that was not present in the
 cones, bipolar cell spectral tunings were surprisingly simple. They either
 approximately resembled both opponent and non-opponent spectral motifs
 already present in the cones or exhibited a stereotyped non-opponent
 broadband response. In this way, bipolar cells not only preserved the
 efficient spectral representations in the cones, but also diversified them
 to set up a total of six dominant spectral motifs which included three
 axes of spectral opponency. More generally, our results contribute to an
 emerging understanding of how retinal circuits for colour vision in
 ancestral cone-tetrachromats such as zebrafish may be linked to those
 found in mammals.
description: 2P imaging of retinal bipolar cells in larval zebrafish,
 stimulated with widefield but spectrally narrow flashes of light. For full
 details, please see the methods in the associate manuscript.
 https://www.biorxiv.org/content/10.1101/2021.08.10.455697v1
description: All preprocessed data is contained in the two csv
 files. In addition, we provide all key processed data
 panels as shown in the paper as IgorPro format. There are contaoined in
 the big zip folder. To read these, go to
 Wavemetrics.com and download a free trial version of Igor (valid 1 month).
 Opening each file will then bring up the relevant data panel as plotted in
 the MS. The data therein can be looked at via the "Data Browser"
 option. From here, the data can also be exported into any common format
 (delimited text, hd5 etc. as needed).