Allgemein

The “Flywire package” is out. Several papers that describe and utilize the full fly brain connectome are now published in Nature /  Nature Neuroscience / Nature Communications. Many of us (Sebastian, Maria, Jonas, Annika, Lena, Rachita, Annalena, Chris, Marion) contributed to this work within the “Flywire Community” and we are especially happy to see our work on heterogeneity of synaptic connectivity in the fly visual system (Cornean, Molina-Obando et al. 2024) being part of the package.

Brains are complex structures. Even in the small brains of a fruit fly, hundreds of thousands of neurons are connected via millions of synapses. Neuroscience has entered the connectome era, where we try to map and understand with cell type and synapse resolution. We have contributed to a major effort, in which a full adult fly brain was reconstructed and annotated (flywire.ai).

In a big team effort of the lab, we focused on the fly visual system and mapped the presynaptic inputs of several cell types. This work showed that the visual system is by far not as homogenous as text books are trying to tell us. Instead, there is a lot of variability in synaptic connectivity, and even more in some cell types than in others. We’re not only excited by the finding, but also by its implications for future research: Could it be that this variability in wiring is not noise but is there for a reason? We next want to explore whether wiring variability is actually advantageous to encode visual information across the fly eye.

Read the full paper here.

Madhura teamed up with Shuai from the Gjorgjeva group to show that luminance gain control past photoreceptors is multi-faceted. Madhura and Shuai combined imaging and behavioral experiment with computational modeling to show that a single luminance-sensitive visual pathways (via L3 neurons) implements gain control at both fast and slow time scales. This computation is bidirectional in that it prevents underestimation of contrast in low luminance and overestimation of contrast in high luminance. It's remarkable how a single neuronal pathway can perform diverse computation to ensure stable processing of visual stimuli.

We are thrilled about having received funding by the ERC Consolidator Grant 2022 for our project “Adaptive functions of visual systems”, and already popped the Champagne bottles.

This will allow us to investigate common challenges that visual systems face in dynamically changing environments, and to also work out how diverse visual system are adapted to the animal’s specific environmental and behavioral constraints. Contact us if you’re as excited about this question as we are and are interested in being part of this.
Read more here

The last "Göttingen defence" is one to memorize: Burak Gür defended his PhD thesis "Molecular and circuit analysis of stable contrast processing in the visual system" with a well-deserved summa cum laude

Our work on stable contrast processing is now out in eLife! Our work shows that a luminance gain leads to stable behavior in the ON pathway. This luminance gain is mediated by distinct first-order luminance-sensitive lamina interneurons L1 and L3 of the fly visual system. Contrary to our previous understanding, all lamina neurons give input to both ON and OFF pathways, redefining the input architecture to the fly visual system. The three lamina neurons L1, L2 and L3 distribute distinct contrast and luminance information to enable downstream computations such as motion vision

We proudly present Dr. Sebastian Molina-Obando. Sebastian successfully defended his PhD on "Mechanisms of robust feature extraction in early visual processing” and the whole lab (successfully?) got to practice their dancing skills.

We are very excited to see our recent work on global motion processing in Drosophila  published in Science Advances. The population of local motion detectors, T4/T5, encodes six different optic flow patterns generated by self-motion. This work brings together  puzzle pieces about how local motion is encoded from a hexagonally arranged fly eye, and how global motion can be computed from many local motion detectors.

Time to pop the champagne!
Congratulations to Freya for obtaining a TransMed fellowship right at the start of her PhD!
And congratulations to Miriam who won the Bernstein SmartSteps Award for her work on global motion processing.
You can read more about it here, and if you haven't, you should definitely watch Miriam's talk here.

Check out our new preprint "First-order visual interneurons distribute distinct contrast and luminance information across ON and OFF pathways to achieve stable behavior". This collaborative work by Madhura, Burak and Sebastian explores luminance invariance in the Drosophila ON pathway and redefines the input architecture to fly visual circuitry: The first order interneurons L1, L2 and L3 are not pathway specific but all distribute distinct types of information to both ON and OFF pathways.