With EM, 2p-imaging and computational modelling we show that on the synaptic level of single neuron types in the retina there exist highly specialized mechanisms which are advantageous for the encoding of different visual features.
Already in EM we see different geometries of the ribbon depending on the location of the UV-cones.
We confirm these differences by “dual-color” 2-photon imaging of pre-synaptic calcium and glutamate release of the synapse.
We use these recordings to build a computational model of the ribbon synapse, which reproduces region-specific response properties. An interactive model tool can be found on #github and you can run it on #googlecolab here: http://www.tinyurl.com/h3avl1ga
By using simulation-based inference we get full posterior estimations of the parameter distributions and can compare these between different retinal regions.
Finally, the computational model allows us to extrapolate to new stimuli and predict response behaviours of different synapse configurations. Hereby we identify principles which are advantageous for the encoding of different visual features, which may be more relevant in different locations of the visual field.
This work builds on previous findings, where we showed fovea-like photoreceptor specializations in UV Cones in zebrafish, which drives prey-capture behavior: https://www.cell.com/neuron/pdf/S0896-6273(20)30313-5.pdf
We are most delighted that Maxime Zimmermann has just passed his PhD viva!
For his thesis, maxime looked at the retinal basis of colour vision in zebrafish, with a key focus on bipolar cells. He also spent much energy building a wide range of open source lab tools, including visual stimulators.
Thank you to Isaac Bianco and Andy Penn for serving as examiners, and Guy Richardson for chairing.
Max’s papers so far:
Zimmermann MJY*, Nevala NE*, Yoshimatsu T*, Osorio D, Nilsson DE, Berens P, Baden T
Zimmermann MJYbioRxiv version). d, Chagas AM, Bartel P, Pop S, Prieto Godino LL, Baden T . LED Zappelin’: An open source LED controller for arbitrary spectrum visual stimulation and optogenetics during 2-photon imaging. HardwareX e00127 (
We are most delighted that Philipp Bartel has just passed his PhD viva!
For his thesis, Philipp looked at spectral processing in zebrafish, from cones to brain circuits. Some of his work is already published, with much more to come!
Thank you to Andrew Stockman and Tom Collett for serving as examiners, and Daniel Osorio for chairing.
Phil’s papers so far:
Bartel P$, Janiak FK, Osorio D, Baden T$. Colourfulness as a possible measure of object proximity in the larval zebrafish brain. bioRxiv doi: https://doi.org/10.1101/2020.12.03.410241. direct link. pdf.
Yoshimatsu T, Bartel P, Schroeder C, Janiak FK, St-Pierre F, Berens P, Baden T$. Near-optimal rotation of colour space by zebrafish cones in vivo. bioRxiv doi: https://doi.org/10.1101/2020.10.26.356089. direct link. pdf.
Janiak FK, Bartel P, Bale M, Yoshimatsu T, Komulainen EH, Zhou M, Staras K, Prieto Godino LL, Euler T, Maravall M, Baden