In this project, I studied the evolution of brain anatomy and connectivity using multiple neuroimaging methods across a large number of species and across scales, with a focus on folding and mechanical morphogenesis – the emergence of complex shapes from physical instabilities triggered by growth – and phylogenetic comparative methods.
I studied different evolutionary models and their application to understanding the evolution of vertebrate neuroanatomy, and investigated patterns of brain variability across species. I created a large dataset of comapartive MRI and histological data of vertebrate brains within a framework for distributed collaboration.
We have developed several Web applications for real-time, distributed scientific collaboration on open data, including tools for the collaborative annotation of neuroimaging data (BrainBox), of high resolution histology data (MicroDraw), for an online intuitive tissue segmentation of MRI data (Thresholdmann). Furthermore, we have developed a framework for building and maintaining a community, providing a permanent space for distributed research teams to discover each other's project, find people with similar or complementary skills to build teams, and to meet (BrainWeb).
Diversity and evolution of cerebellar folding in mammals
We have been diving into the mesmerising anatomical diversity and evolution of folding across 56 mammalian species with Roberto Toro, Nicolas Traut, Alexandra de Sousa, Sofie Valk, Julien Clavel. |
I collected and analysed histological data from 56 species, and created tools to study the geometry of cerebellar folia and to estimate the thickness of the molecular layer. Cerebellar size and folding correlate strongly with cerebral size and folding. Ancestral character state estimations showed that size and folding of the cerebrum and cerebellum increase and decrease concertedly through evolution. |
Our results confirm the strong correlation between cerebral and cerebellar volumes across species, and we extended these results to show that the same strong relationship holds for cerebellar folding: larger cerebella are disproportionately more folded than smaller ones. |
Evolution of brain anatomy
I expanded our MRI data collection to include 70 primate species across a large range of the phylogenetic tree, spanning a 1500 fold differece in cerebral volume. Together with Roberto Toro, Nicolas Traut, Leandro Aristide, S. Faezeh Alavi, Marc Herbin, Rogier Mars, Rajeev Mylapalli, Shaghayegh Najafipashaki, Tomoko Sakai, Mathieu Santin, Víctor Borrell. |
Using ancestral estimations of primate neuroanatomy, I observed diverse patterns, with some branches, like that leading to humans, showing only increase in brain volume from the common ancestor of all primates, while others, like that leading to the galago, exhibited only decreases. In some other branches we observe a mix of increases and decreases. |
We have continued developing several Web applications for real-time, distributed scientific collaboration on open data.
BrainBox is a tool for the collaborative curation and real-time interactive annotation and segmentation of any neuroimaging dataset available on the Web.
Check out our 3-minute video.
MicroDraw is an online tool for visualising and collaboratively annotating high resolution histology data. It allows users to segment regions and annotate them based on a common ontology.
Thresholdmann is an open source Web tool for the interactive application of space-varying thresholds to Nifti volumes. No download or installation is required and all processing is done in the user’s computer.
The BrainWeb is a permanent virtual space for online collaboration on projects related to neuroscience, and a framework to organise distributed communities and an interactive space for virtual poster sessions.
During the project, I have organised and co-organised several meetings. In 2022, I co-organised the QBio Symposium on Mechanics, morphogenesis, development & evolution at Institut Pasteur. In 2023, I organised the International Comparative Brain Meeting together with colleagues from Institut Pasteur, University of Oxford and Tel Aviv University which aimed at stimulating exchange about our projects and progress on comparative brain analyses. I have also organised the BrainWeb series.
The BrainWeb Series. A series of talks around various topics.
Comparative Brain Meeting. Stimulating exchanges on brain evolution and comparative analyses. At Institut Pasteur.
QBio Symposium MeMoDEvo. Mechanics, morphogenesis, development & evolution. At Institut Pasteur.
I have authored and co-authored 6 peer-reviewed publications; 1 manuscript submitted; 8 talks and presentations as invited speaker. All papers are openly accessible.
| Heuer, K., Traut, N., de Sousa, A. A., Valk, S., Clavel, J., & Toro, R. (2023). Diversity and evolution of cerebellar folding in mammals. eLife. https://doi.org/10.7554/eLife.85907 |
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| Heuer, K., Traut, N., & Toro, R. (2024). Thresholdmann: A Web tool for interactively creating adaptive thresholds to segment MRI data. Journal of Open Science Software. https://joss.theoj.org/papers/10.21105/joss.06336 |
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| Magielse, N., Toro, R., Steigauf, V., Abbaspour, M., Eickhoff, S. B., Heuer, K.❖, & Valk, S. L.❖ (2023) Phylogenetic comparative analysis of the cerebello-cerebral system in 34 species highlights primate-general expansion of cerebellar crura I-II. Communications Biology. https://doi.org/10.1038/s42003-023-05553-z [❖shared co-last author] |
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| de Sousa, A. A.*, Beaudet, A.*, Calvey, T., Bardo, A., Benoit, J., Charvet, C. J., Dehay, C., Gómez-Robles, A., Gunz, P., Heuer, K.*, van den Heuvel, M. P., Hurst, S., Lauters, P., Reed, D., Salagnon, M., Sherwood, C. C., Ströckens, F., Tawane, M., Todorov, O. S., Toro, R., & Wei, Y. (2023). From fossils to mind. Communications Biology. https://doi.org/10.1038/s42003-023-04803-4 |
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| Magielse, N., Heuer, K., Toro, R., Schutter, D. J. L. G., & Valk, S. L. (2022). A Comparative Perspective on the Cerebello-Cerebral System and Its Link to Cognition. The Cerebellum. https://doi.org/10.1007/s12311-022-01495-0 |
This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No101033485 (Individual Fellowship Katja Heuer).
I thank Roberto Toro for integrating me in his lab for Applied and Theoretical Neuroanatomy and his great support of all my efforts. I thank Institut Pasteur for hosting me with this project.
Please contact me if you have any questions or would like to work together with us.
katjaQheuer(at)gmail.com