Open Hardware efforts featured @Nature Magazine

We are delighted that several of our efforts to promote the use of Open Hardware in Research in Education were featured in a recent Nature Techology Feature by Sandeep Ravindran.

The article takes a sweeping cross-section across several people’s work, highlighting amongst others our work from the lab itself as well as the wider Sussex neuroscience community and our long-standing efforts to promote OH in Africa via TReND.


Access the full article here

New lab talk on Worldwide Neuro

On Tuesday 10th Nov 2021 Tom gave an online world-wide neuro seminar, hosted by IST Austra. The talk was recorded can be watched here: 

Go directly to video

In this talk I will summarize some of our recent unpublished work on spectral coding in the larval zebrafish retina. Combining 2p imaging, hyperspectral stimulation, computational modeling and connectomics, we take a renewed look at the spectral tuning of cone photoreceptors in the live eye. We find that already cones optimally rotate natural colour space in a PCA-like fashion to disambiguate greyscale from “colour” information. We then follow this signal through the retinal layers and ultimately into the brain to explore the major spectral computations performed by the visual system at its consecutive stages. We find that by and large, zebrafish colour vision can be broken into three major spectral zones: long wavelength grey-scale-like vision, short-wavelength prey capture circuits, and spectrally diverse mid-wavelength circuits which possibly support the bulk of “true colour vision” in this tetrachromate vertebrate.

New zebrafish colour vision paper on bioRxiv

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: direct link. pdf.

For colour vision, retinal circuits must separate information about intensity and wavelength. This requires circuit level comparison of at least two spectrally distinct photoreceptors. However, many vertebrates use four or more, and in those cases the nature and implementation of this computation remains poorly understood. Here, we establish the complete circuit architecture and function of outer retinal circuits underlying colour processing in the tetrachromatic larval zebrafish. Our findings reveal that the specific spectral tunings of the four cone types near optimally rotate the encoding of natural daylight in a principal component analysis (PCA)−like manner to yield one primary achromatic axis, two colour opponent axes as well as a secondary UV-achromatic axis for prey capture. We note that fruit flies − the only other tetrachromat species where comparable circuit-level information is available − use essentially the same strategy to extract spectral information from their relatively blue-shifted terrestrial visual world. Together, our results suggest that rotating colour space into achromatic and chromatic axes at the eye′s first synapse may be a fundamental principle of colour vision when using more than two spectrally well separated photoreceptor types.

Vertebrate Vision: Lessons from non-model species. Special Issue out now

The special review issue on “Vertebrate Vision: Lessons from non-model Species” is now out in Seminars in Cell and Developmental Biology. In this work we brought together experts on the visual systems of diverse groups of vertebrates, from lampreys to ground squirrels.

Access the full issue here

or download all pdfs here (44 MB Zip file)


0. Vertebrate vision: Lessons from non-model species. Tom Baden.



1. Lamprey vision: Photoreceptors and organization of the retina. Gordon L. Fain.

2. Vision in sharks and rays: Opsin diversity and colour vision. Nathan S. Hart.

3. The exceptional diversity of visual adaptations in deep-sea teleost fishes. Fanny de Busserolles, Lily Fogg, Fabio Cortesi, Justin Marshall.

4. Visual system diversity in coral reef fishes. Fabio Cortesi, Laurie J. Mitchell, Valerio Tettamanti, Lily G. Fogg, Fanny de Busserolles, Karen L. Cheney, N. Justin Marshall.

5. Axes of visual adaptation in the ecologically diverse family Cichlidae. Karen L. Carleton, Miranda R. Yourick.

6. Archerfish vision: Visual challenges faced by a predator with a unique hunting technique. Cait Newport, Stefan Schuster.

7. What the salamander eye has been telling the vision scientist’s brain. Fernando Rozenblit, Tim Gollisch.

8. A frog’s eye view: Foundational revelations and future promises. Kristian Donner, Carola A.M. Yovanovich.

9. Adaptations and evolutionary trajectories of the snake rod and cone photoreceptors. Einat Hauzman.

10. Vision in chameleons – A model for non-mammalian vertebrates. Hadas Ketter-Katzab, Tidhar Lev-Aric, Gadi Katzir.

11. The retinal basis of vision in chicken. M. Seifert, T. Baden, D. Osorio.

12. Visual adaptations of diurnal and nocturnal raptors. Simon Potier, Mindaugas Mitkus, Almut Kelber.

13. Ground squirrel – A cool model for a bright vision. Wei Li.



Two new “remote” lab additions

We are delighted to have two “remote” lab members join us this month:

Aisha Wamala joins us remotely from London as TReND General coordinator to cover for the maternity leave of Samyra Salek

Carola Yovanovich joins us remotely from São Paulo for a project on the evolution of retinal layering