The central goal of this study was to try and infer the total effective cone-integration logic of bipolar cells in larval zebrafish by way of linking highly resolved spectral tuning functions across these two populations of neurons.
We previously showed that the four zebrafish cones exhibit distinct but highly stereoypical tunings at the level of their output (Yoshimatsu et al. bioRxiv 2020). Accordingly, we used the same recording conditions to also obtain spectral tuning functions of the downstream neurons, the retinal bipolar cells (right).
We find that this works very well, allowing us to explain ~95% of the variance in bipolar cell responses based on linear cone-combinations. Based on this, we chart an overview of the total cone-integration logic in larval zebrafish, and relate these insights to spectral processing in mammalians.