Topic: Colour vision

The retina is probably the most accessible part of the vertebrate central nervous system. Its computational logic can be interrogated in a dish, from patterns of lights as the natural input, to spike trains on the optic nerve as the natural output. Consequently, retinal circuits include some of the best understood computational networks in neuroscience. The retina is also ancient, and central to the emergence of neurally complex life on our planet. Alongside new locomotor strategies, the parallel evolution of image forming vision in vertebrate and invertebrate lineages is thought to have drive

In many butterflies, the ancestral trichromatic insect colour vision, based on UV-, blue- and green-sensitive photoreceptors, is extended with red-sensitive cells. Physiological evidence for red receptors has been missing in nymphalid butterflies, although some species can discriminate red hues well. In eight species from genera Archaeoprepona, Argynnis, Charaxes, Danaus, Melitaea, Morpho, Heliconius and Speyeria, we found a novel class of green-sensitive photoreceptors that have hyperpolarizing responses to stimulation with red light. These green-positive, red-negative (G+R–) cells are alloca

My research interests are centered on animal ecology, and more specifically include the following areas: visual ecology, behavioral ecology, and conservation biology, as well as the interactions between them. My research is question-driven. I answer my questions in a comprehensive manner, using a combination of empirical, theoretical, and comparative approaches. My model species are usually birds, but I have also worked with fish, mammals, amphibians, and insects. ​I was fortunate to enrich my education by attending Universities in different parts of the world. I did my undergraduate, speci

Colour vision plays important roles in regulating animal behaviour, yet understanding of how such information is processed in the brain is still incomplete. Here I discuss our work addressing this issue in mice where, despite aspects of retinal organisation that might suggest limited capacity for colour vision, we find evidence of extensive cone-dependent spectral opponency across subcortical visual centres. In particular, our data both reveals important contributions of such colour signals to non-image-forming functions (regulation of the circadian system) but also indicate surprisingly sophi

Colour vision is based on circuit-level comparison of the signals from spectral distinct types of photoreceptors. In our own eyes, the presence of three types of cones enable trichromatic colour vision. However, many phylogenetically ‘older’ vertebrates have four or more cone types, and in almost all their cases the circuits that enable tetra- or possibly even pentachromatic colour vision are not known. This includes the majority of birds, reptiles, amphibians, and bony fish. In the lab we study neuronal circuits for colour vision in non-mammalian vertebrates, with a focus on zebrafish, a tetr

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 co