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Reposted by Ryszard Wimmer

bioRxiv Neuroscience @biorxiv-neursci.bsky.social · 14/04/2026

A defined 2D system for generating and expanding human basal radial glia from iPSCs www.biorxiv.org/content/10.64898/20…

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Ryszard Wimmer @ryszardwimmer.bsky.social · 16/03/2026

Big news!I’m thrilled to share that my PhD research has officially been published in Neuron (Cell Press)! 🧠 🙃 @cellpress.bsky.social We show how bRG cells translocate in the developing human neocortex - bRG cells do not only translocate via MST ! Link : www.sciencedirect.com/science/arti...

sciencedirect.com

Two translocation mechanisms drive neural stem cell dissemination into the human fetal cortex

The strong increase in the size of the human neocortex is supported by a neural stem cell population, the basal radial glial (bRG) cells. Using live i…

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Ryszard Wimmer @ryszardwimmer.bsky.social · 09/08/2025

✨ #FluorescentFriday ✨ SOX2-positive cells forming the heart of the developing human cerebellum 🧡, framed by a glowing outline of PAX6-positive neighbors 💙. A tiny but breathtaking glimpse into brain development under the microscope. 🧠💡

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Ryszard Wimmer @ryszardwimmer.bsky.social · 26/05/2025

There is no better place to talk about Radial Glia Cells than on the beaches right under the Etna in Gardini Naxos @corticodevelopment.bsky.social !

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Reposted by Ryszard Wimmer

bioRxiv Neuroscience @biorxiv-neursci.bsky.social · 15/05/2025

DCHS1 Modulates Forebrain Proportions in Modern Humans via a Glycosylation Change www.biorxiv.org/content/10.1101/202…

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Ryszard Wimmer @ryszardwimmer.bsky.social · 11/04/2025

sciencebank.com/development-... A cool and smooth blog post on stem cell use, validation, quality control and on how to share Your precious stem cells with others! #stemcells I hope You enjoy!

sciencebank.com

Our community is thrilled to have Dr. Ekin Ucuncu join the ReplicApril conversation with a guest post on how shared standards in stem cell research can help drive reproducibility forward.

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Ryszard Wimmer @ryszardwimmer.bsky.social · 28/02/2025

In the neon glow of the cortex, a Radial Glia stretched its long, guiding arm. Suddenly, a rogue cell snatched a piece of its scaffold, disrupting the neural highway. "Hey!" it pulsed, but the thief vanished into the synaptic shadows. The network flickered—order shaken. #fluorescentfriday

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Reposted by Ryszard Wimmer

Awais Javed @itsmeawais.bsky.social · 20/02/2025

Delighted to have this out as a preprint! Thanks to all authors, especially @estherkli.bsky.social and @djabaudon.bsky.social for leading the work. If you are interested in how conserved genes played a part in evolving human brains, give it a read!

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Reposted by Ryszard Wimmer

Denis Jabaudon @djabaudon.bsky.social · 20/02/2025

New preprint out from the lab, check out thread below!

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Ryszard Wimmer @ryszardwimmer.bsky.social · 30/01/2025

While waiting on my paper to get rejected or accepted 🤗 I discovered that playing with clay is just a beautiful disconnection from everyday problems. Here is my first take at a flower-shaped candle ! #pottery #nature #flowers #qualitytime #science

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Ryszard Wimmer @ryszardwimmer.bsky.social · 17/01/2025

Images and all scientific data needs a voice. @clarissebrunet.bsky.social is running a beautiful podcast in spannish called Ciencia en Voz Alta „Science Out Loud”. It’s a beautiful series of podcasts with scientists on spotify talking about their research! cienciaenvozalta.com Enjoy! 🎧

cienciaenvozalta.com

Ciencia en Voz Alta (Website)

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Ryszard Wimmer @ryszardwimmer.bsky.social · 09/01/2025

Hello! My PhD pre-print is out on biorxiv, where in the Lab of @alexbaffet.bsky.social we managed to unravel how bRG (oRG) cells translocate and colonise the developing human brain. Interestingly features of these translocations are conserved in glioblastoma! Link : www.biorxiv.org/content/10.1...

biorxiv.org

Two independent translocation modes drive neural stem cell dissemination into the human fetal cortex

The strong size increase of the human neocortex is supported by the amplification and the basal translocation of a neural stem cell population, the basal radial glial cells (or bRG cells). Here, using...

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

I want to thank everyone involved in this work on top of Ryszard who did an amazing job. Laure Coquand, Amandine Di Cicco, Christophe Chehade, @clarissebrunet.bsky.social @pauline-lestienne.bsky.social, Julia Ladewig, Karin Forsberg-Nilsson, Fabien Guimiot and our fantastic imaging facility!

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

Using 9 different glioblastoma lines we show that IST and MST both occur, although not in all cells, reflecting the heterogeneity of these tumors. Strikingly, glioblastoma undergoing IST and MST did so using the same molecular mechanism as the ones identified here in bRG cells.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

Finally, because past work form @bhadurilab.bsky.social and others had shown a facilitating similarity between bRG cells and glioblastoma cells (including the presence of MST), we tested the conservation of our mechanisms in these cells.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

Therefore, microtubule related genes are more likely to affect human oSVZ expansion than actin-related ones.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

So MST and IST are totally different mechanisms, but what is their relative contribution to bRG dissemination in the human fetal cortex? After extensive recording in fetal explants, Ryszard could show that IST contributes to 85% of the total basal movement, while MST contributes to 15%.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

Mechanistically, we demonstrate that MST is dependent on the mitotic cell rounding pathway, that enables most adherent cells to round up for proper chromosome segregation through an increase of the cell cortex stiffness. Knocking down ERM proteins (Ezrin-Radixin-Moesin) or Vimentin all alter MST.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

We next focused our attention on MST and, using Sir-tubulin dyes, first showed that it occurred after nuclear envelope breakdown, and is therefore a mitotic spindle translocation event!!! I find this crazy, and to our knowledge quite unique in biology (so far...).

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

Together, this microtubule-dynein-LIS1-LINC pathway generates pulling force and the nucleus, for translocation. Interestingly, this mechanisms is different from INM in aRG cells, but similar to nucleokinesis in neurons. Neuronal migration disorders may therefore also result from bRG cell defects.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

We demonstrate that IST is dependent on the dynein motor and its activator LIS1. Accordingly, IST is severely affected in LIS1-patient derived organoids (Lissencephalic). We also show that the dynein-LIS1 complex is recruited to the nuclear enveloppe (and underlying Lamins) via the LINC complex.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

On top of identifying the mechanism for MST, we realised that bRG cells also translocate during interphase, a process we call Interphasic Somal Translocation (IST). We show that IST is microtubule dependent and actomyosin independent, while MST is actomyosin-dependent and microtubule independant.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

bRG cells were known to translocate rapidly during mitosis, a process called Mitotic Somal Translocation (MST). This translocation relies on acto-myosin contractility and was identified by the Kriegstein lab.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

Great work from @ryszardwimmer.bsky.social, who live imaged and manually tracked over 11,000 human bRG cells, for 48-96 hours 😱. (I feel bad) What he realised is that bRG cells have two, totally independent modes of migration, for which he managed to identify the molecular mechanisms.

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Reposted by Ryszard Wimmer

Alexandre Baffet @alexbaffet.bsky.social · 09/01/2025

Our new paper is out in BioRxiv. Using human fetal tissue and cortical organoids, we figured out how human bRG cells colonize the developing neocortex to expand the oSVZ stem cell niche. Turns out, it's a more complex process than we had anticipated! www.biorxiv.org/content/10.1...

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Ryszard Wimmer @ryszardwimmer.bsky.social · 03/01/2025

There is something profoundly beautiful about using lineage tracing methods to live-image human neural stem cells in the developing human brain, observing in real time as they divide and give rise to their progeny. #fluorescentfriday #imaging #microscopy #stemcells #live #biology #neuroscience #cell

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Ryszard Wimmer @ryszardwimmer.bsky.social · 23/12/2024

The Polish Tatra Mountains have never looked more stunning than they do this Christmas season! Stepping away from the microscope and gazing at nature’s beauty is a powerful reminder of just how breathtaking the world around us can be 🎄🎁🥹 #mountains #mountainlovers #travel #poland #christmas

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Ryszard Wimmer @ryszardwimmer.bsky.social · 06/12/2024

Happy #FluorescentFriday ✨💡 Witness the dazzling magic of human neural stem cells forming their intricate, mind-blowing connections! 🧠💫 Science has never looked this amazing 😏🧪 #NeuroscienceGlow #CellularSizzle #BrainsAndBeauty #nanolive

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Ryszard Wimmer @ryszardwimmer.bsky.social · 03/12/2024

Hello Bluesky-sphere! It's my first post on this Twitter 2.0. I thought I'd start of my profile with this beautiful image, I acquired during my PHD, of a beautiful human cerebral organoid ventricular zone where we can see aRG (vRG) cells dividing at the ventricular surface. #neurogenesis #stemcells

Here we can see a ventricular zone of a human cerebral organoid. aRG (vRG) cells undergo interkinetic nuclear migration and divide at the ventricular surface. The centrosomes of aRG cells are localised in the apical endfoot of Radial Glia Cells. The soma, through a cell cycle cues is pulled via molecular motors to the ventricular surface where the cell will divide. It's interesting we can see different cleavage angles of Radial Glia cell divisions.

Stainings :
Yellow - DNA
Purple - Progenitors
Cyan - Centrosomes
Green - Vimentin

100x Nikon AXR Confocal microcope denoised with Nikon AI software

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