iiinova — where your digital self keeps evolving

Franck Polleux @franckp.bsky.social · 05/08/2026

I hope you enjoy reading the paper and the thread!

Franck Polleux @franckp.bsky.social · 05/08/2026

and finally a beautiful image of a single microglial cell in the cortex of a P30 mouse (failed attempt for a cover image at Neuron!! 😅):

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Franck Polleux @franckp.bsky.social · 05/08/2026

Microglia process dynamics in microglia-specific SRGAP2 deletion: www.cell.com/cms/10.1016/...

cell.com

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Franck Polleux @franckp.bsky.social · 05/08/2026

Microglia process dynamics in wild-type control: www.cell.com/cms/10.1016/...

cell.com

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Franck Polleux @franckp.bsky.social · 05/08/2026

with implications for understanding neurodevelopmental disorders where the timing of synaptic development is disrupted. As a bonus check out the dramatic effect of microglia-specific deletion of SRGAP2A on their process dynamics visualized by Carlos using in vivo 2-photon imaging:

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Franck Polleux @franckp.bsky.social · 05/08/2026

This work demonstrates that human-specific SRGAP2 paralogs synchronize neotenic microglia maturation and synaptic development. It reframes microglia as active drivers of the extended circuit development window characteristic of the human brain, 12/n

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Franck Polleux @franckp.bsky.social · 05/08/2026

Most strikingly, deleting SRGAP2A specifically in mouse microglia delays their morphological maturation and induces neotenic synaptic development in neighboring neurons, demonstrating that microglial maturation timing actively paces synaptic circuit formation rather than merely following it. 11/n

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Franck Polleux @franckp.bsky.social · 05/08/2026

and that its human-specific paralogs SRGAP2B/C, which arose during hominin evolution, by inhibiting SRGAP2A are necessary and sufficient to slow microglial morphological maturation. (10/n)

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Franck Polleux @franckp.bsky.social · 05/08/2026

(2) various genetically-modified mouse models allowing us to either conditionally remove one copy of SRGAP2A in microglia only or to induce expression of human-specific SRGAP2C in microglia only, we show that SRGAP2A promotes the timing of microglial morphological maturation during development (9/n)

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Franck Polleux @franckp.bsky.social · 05/08/2026

and that this delay is not incidental but causally linked to prolonged synapse formation. In the present study, we used (1) human iPSC-derived microglia xenotransplanted into neonatal mouse cortex, combined with (8/n)

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Franck Polleux @franckp.bsky.social · 05/08/2026

What could be the role of SRGAP2A and its human-specific paralogs in microglia? In this new publication, we first demonstrate that cortical microglia also mature far more slowly in humans than in mice both morphologically and transcriptionally, 7/n

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Franck Polleux @franckp.bsky.social · 05/08/2026

However, we knew that SRGAP2A and its human-specific SRGAP2B/C were not only expressed in all developing cortical neurons but are also highly expressed in microglia, the brain's resident immune cells, which among many other functions, play critical roles in synaptic development. 6/n

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Franck Polleux @franckp.bsky.social · 05/08/2026

and that the human-specific paralogs SRGAP2B/C express truncated proteins which inhibit all known functions of SRGAP2A, and are necessary and sufficient to induce synaptic neoteny in human cortical neurons (Charrier, Cell 2012; Fossatti, Neuron 2016; Libé-Philippot, Neuron 2024). 5/n

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Franck Polleux @franckp.bsky.social · 05/08/2026

which contains an ancestral gene SRGAP2A shared among all mammals and two human-specific gene duplicates SRGAP2B/C. We previously demonstrated that in cortical neurons, SRGAP2A promotes excitatory and inhibitory synaptic maturation. 4/n

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Franck Polleux @franckp.bsky.social · 05/08/2026

Over the past decade, our lab has initiated the study of human-specific gene duplication as a powerful genetic mechanism underlying the emergence of human-specific features of brain development. Among the ~30 human-specific gene families, we focused most of our attention on the SRGAP2 gene. 3/n

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Franck Polleux @franckp.bsky.social · 05/08/2026

One of the most striking features characterizing human brain development is the prolonged period of synaptic development and maturation compared to other mammals, taking weeks to months in rodents and non-human primates but nearly a decade in humans. 2/n

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Franck Polleux @franckp.bsky.social · 29/04/2026

very excited to speak at this meeting, join us! 👇

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Molly Schumer @mollyschumer.bsky.social · 23/04/2026

Please share widely! We will imminently be posting a technician position in our lab group since @rheasood.bsky.social is off to grad school 🙌! If you know of anyone excited about molecular biology, evolution, and functional genomics please have them reach out (schumer at stanford). Start date ~June

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Jeremy Berg @jeremymberg.bsky.social · 30/03/2026

Watch Director Bhattacharya's performance at CPAC really got to me. I chose to share some of my observations with him. Hold on... 1/11

media.tenor.com

Here We Go Sherman Bell GIF

ALT: Here We Go Sherman Bell GIF

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Awful Announcing @awfulannouncing.bsky.social · 29/03/2026

"The way some of these other immigrants are getting treated in our country right now is a travesty and a disgrace... I think what’s going on in our country — what we’re doing to some of these amazing immigrants, is really unfortunate and it’s really sad." - Charles Barkley on CBS

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Indivisible ❌👑 @indivisible.org · 28/03/2026

The regime had no idea what it was going up against when Trump decided to invade Minnesota. #NoKings

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Max Kozlov @maxkozlov.bsky.social · 27/02/2026

The impact is already hitting science agencies hard. The NIH—the world's largest public biomedical research funder—has had to rely on leftover stopgap funds. New grant awards have slowed to a trickle — exacerbating the effects of a record-long shutdown in October. (h/t @jeremymberg.bsky.social)

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Franck Polleux @franckp.bsky.social · 27/02/2026

A timely and insightful perspective written by our former postdoc @justinkohare.bsky.social in @thetransmitter.bsky.social on dendritic integration and the urgent need to develop better ways to bridge molecular/cellular neuroscience with circuit/systems neuroscience 👇

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The New Republic @newrepublic.com · 27/02/2026

DHS agents kidnapped Columbia neuroscience undergraduate student Ellie Aghayeva, lying to gain access to the building. trib.al/i0n38SC This comes less than a year after DHS agents abducted Columbia University student Mohsen Mahdawi and graduate Mahmoud Khalil.

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Denis Wirtz @deniswirtz.bsky.social · 26/02/2026

Federal funding for US biomedical research is moribund. Since October 1 2025, NIH is -80% in new grants and -70% in values (total dollars). Labs are closing down and researchers are leaving science. To what end?

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Angus Johnston @angus.bsky.social · 26/02/2026

Columbia says DHS entered a dorm at dawn today under false pretenses, detaining a student in violation of the law and university policy.

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Will Bunch @willbunch.bsky.social · 16/02/2026

MPLS was a great moral and practical victory for a new Trump-era resistance, but it was only the end of the beginning 15,000 new masked goons. 150 new ICE offices in every state, and a national network of warehouse concentration camps My column on the battle ahead www.inquirer.com/opinion/ice-...

inquirer.com

No, ICE isn’t ‘retreating.’ It’s loading up to invade your town. | Will Bunch

A much-hyped ICE pullback from Minneapolis is a blip in a looming nationwide surge of arrests, concentration camps.

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Boo!-per Lund @cooperlund.online · 10/02/2026

That's fucking right, go Team USA

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Governor JB Pritzker @govpritzker.illinois.gov · 09/02/2026

Unidos somos América.

Bad Bunny holds a football that says Together, we are America.

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Alexa Philippou @alexaphilippou.bsky.social · 25/01/2026

Unrivaled co-founder and WNBA MVP Breanna Stewart held up an “Abolish ICE” sign during player intros ahead of Mist’s game this afternoon. Photo via @unrivaledwbb.bsky.social

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Carl T. Bergstrom @carlbergstrom.com · 25/01/2026

It appears that this legend owns a little bookstore — and you can order books from him instead of Bezos. Link in next post.

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Fionna O’Leary @fascinatorfun.bsky.social · 25/01/2026

This is excellent, careful, ruthlessly calm effective reporting from @bbcrosatkins.bsky.social in stark contrast to the earlier both-siding bollox from other BBC colleagues.

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Joshua J. Friedman @joshuajfriedman.com · 22/01/2026

Do you appreciate @nws.noaa.gov's posts on Bluesky? Did you know that this account is a pilot program that may or may not be continued and even expanded to NWS field offices? NWS is soliciting comments here! www.surveymonkey.com/r/PrototypeN... Press release: www.weather.gov/media/notifi...

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Will Stancil @whstancil.bsky.social · 21/01/2026

They are targeting children because they are trying incite violence. I have talked to many journalists today, and they all made the same observation: Border Patrol and ICE have been rolling around with maximum aggression, lingering for ages as crowds, gather, seemingly trying to cause a riot.

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David Ho @davidho.bsky.social · 20/01/2026

This is the most astonishing graph of what the Trump regime has done to US science. They have destroyed the federal science workforce across the board. The negative impacts on Americans will be felt for generations, and the US might never be the same again. www.nature.com/immersive/d4...

This line graph illustrates the percentage change in agency staff levels from the previous year for nine major U.S. federal scientific and health organizations between the fiscal years 2016 and 2025. The agencies tracked include the CDC, Department of Energy, EPA, FDA, NASA, NIH, NIST, NOAA, and NSF. For the majority of the timeline between 2016 and 2023, the agencies show relatively stable fluctuations, generally staying within a range of +5% to -5% change per year. However, there is a dramatic and uniform plummet starting in the 2024–25 period. Every agency depicted shows a sharp downward trajectory, with staffing losses ranging from approximately -15% to over -25%. The Environmental Protection Agency (EPA) shows the most significant decline, dropping to roughly -26%, while the National Institute of Standards and Technology (NIST) shows the least severe but still substantial drop at approximately -15%.

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Chris Murphy @chrismurphyct.bsky.social · 20/01/2026

I flew down to south Texas today to do my job - investigate why people are dying in ICE detention centers. I was just illegally denied entry to Dilley Detention Center. Because they have something to hide.

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Franck Polleux @franckp.bsky.social · 19/01/2026

It’s never been so relevant…

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