Søren Grubb

Double PI act @sorengrubb.bsky.social @amreenmughal.bsky.social continuing in brains with #cilia & #centrosome diversity across microvascular system, with striking species differences on cilia metrics & directionality of spaces sampled. Deep read: www.biorxiv.org/content/10.1... #UKCilia 5/8

Want to know about our latest research on #primarycilia and #centrosomes in #brain #microvasculature? Join this e-symposium tomorrow! 🧪

Thanks for a great 2025!🎆🥳🎉

We’re proud to share highlights from this year at Neuroscience Academy Denmark (NAD) – showcasing the incredible work of our PhD students. 👩‍🎓👨‍🎓

A big thank you to @lundbeckfonden.bsky.social for supporting our mission. 🙏

#Neuroscience #PhD #Research #Collaboration 🧪

Also thanks to @helenelab.bsky.social for access to the CA1 dataset!

a man in a suit and tie is giving a thank you sign . ALT: a man in a suit and tie is giving a thank you sign .

We would like to acknowledge the amazing #OpenScience #ElectronMicroscopy datasets by @alleninstitute.org ‬, @hhmijanelia.bsky.social and other sources!
This work is a collaboration between me at @ucph.bsky.social, @amreenmughal.bsky.social and Vanshika at #NIH, and Carolyn and Jennifer at #Janelia

🧩 Summary:
✅ #Pericytes have #PrimaryCilia with an arterio-venular gradient🏳️‍🌈
✅ 🚶‍♀️🧠 ECs have primary #cilia, 🐁🧠 ECs don’t
✅ EC polarity aligns opposite to #BloodFlow 🧭
❔Lots of open questions about cilia’s role in #NeurovascularCoupling!
Read the full preprint: 🔗 www.biorxiv.org/content/10.1...
🧪🧵8/8

🧭 #EndothelialCells are polarized against #BloodFlow direction ⤴️. #Centrioles are consistently upstream of the #nucleus. This polarity persists even in fixed tissue and could serve as a structural marker for flow direction. 📌
🧪🧵7/8

😮Surprise: 🚶‍♀️🧠 #EndothelialCells (EC) have #PrimaryCilia facing the vessel lumen, but 🐁🧠 ECs don’t. ~18% of 🚶‍♀️🧠 ECs are ciliated, mostly in arteriolar-end capillaries. What do these #cilia sense in the 🩸?
🧪🧵6/8

In 🐁, some #pericyte #PrimaryCilia penetrate #astrocytic #endfeet and reach the #neuropil - sometimes near #synapses! Could these #cilia act as sensory “antennae” 📡for #NeurovascularCoupling?
🧪🧵5/8

In 🐁🧠, #ultrastructure shows that #pericyte #cilia are often ensheathed by #astrocytic #endfeet. In 🚶‍♀️🧠, #astrocytes are swollen and cilia stay confined within the basal lamina. What are they sensing from the astrocytes?
🧪🧵4/8

🗺️We mapped #MuralCells — including #pericytes and #smoothmuscle — as vectors➡️ to visualize where #PrimaryCilia🌟 occur across the 🐁🧠 #microvasculature.
The result? A striking pattern: #cilia are abundant on #capillaries and #venules, but almost absent on #arterioles.
🧪🧵3/8

📊 #Pericytes are frequently ciliated in both 🐁 and 🚶‍♀️🧠—but mostly near #venules and venous-end #capillaries.
Venular mural cells: up to 90% ciliated in 🐁 datasets!
Arteriolar mural cells: almost none.
Why this gradient? Flow, pressure, permeability?
🧪🧵2/8

New on bioRxiv! 🚨
“Pericyte and Endothelial Primary Cilia and Centrioles have Disparate Organization Across the Brain Microvasculature”
This project studying #microvascular cells took an unexpected turn when we discovered that #pericytes have primary #cilia!
🔗 www.biorxiv.org/content/10.1...
🧪 🧵1/8

@martienkas.bsky.social @brittae.bsky.social @dresler.bsky.social

🎥 NAD 2025 Annual Meeting Highlights
From Oct 3–5, Neuroscience Academy Denmark hosted:
✅ 400+ participants
✅ 100 posters
✅ Keynotes on precision psychiatry, brain barriers, ultrasound treatments, brain stimulation, sleep & circadian rhythms

We look forward to next year!
#Neuroscience #NAD2025 🧪

That reminds me of Thor fighting “midgårdsormen” the world serpent 🤣

“Well I don’t like that study because it doesn't give me the result I want’

We are excited to report:
Cerebral blood flow is modulated by astrocytic cAMP elevation independently of IP3R2-mediated Ca2+ signaling in mice
Vittani et al. PNAS (2025)
pnas.org/doi/10.1073/...

The first Master’s student with me as main supervisor graduated today! I’m proud 🥹

Thanks Amreen! ❤️

Brain precapillary sphincters modulate myogenic tone in adult and aged mice - GeroScience Brain precapillary sphincters, which are surrounded by contractile pericytes and are located at the junction of penetrating arterioles and first-order capillaries, can increase their diameter by ~ 30%...

🔗 Full Open Access manuscript: link.springer.com/article/10.1...
👇 Curious to hear more about #PrecapillarySphincters?
Check out these threads about the subject:
Characterization: x.com/SorenGrubb/s...
Ultrastructure: x.com/SorenGrubb/s...

In older mice, where #MyogenicTone is weaker, #PrecapillarySphincters become even more critical barriers against #BloodPressure surges—compensating for #VascularStiffening and remodeling.

These changes suggest that #PrecapillarySphincters protect the capillaries 🛡️ by acting as a dynamic #resistance that regulates #capillary #BloodFlow and #BloodPressure.

Using #InVivo #VolumeImaging, we found #age related #vascular changes:
• ↑ #Tortuosity of #PenetratingArterioles
• ↓ #Arteriolar-capillary density
• ↑ #Capillaries at the venous end + #aneurysm-like bulbs downstream of #PrecapillarySphincters.

By recording #cortical #angiograms during i.v. injection of FITC-dextran 🟢 in #adult and #old #NG2DsRed mice, we time-colored the #arterioles 🔴 and #venules 🔵. We found that #OldMice have less #collaterals and more #tortuous #PenetratingArterioles.

After #LaserAblating pericytes around #PrecapillarySphincters, we observed impaired #MyogenicResponse and #NeurovascularCoupling—demonstrating #PrecapillarySphincter pericyte contractility is essential.

#OldMice also showed decreased pulsations of microvessel diameters measured by transverse line scans, likely due to #VascularStiffening.

In aged mice, the #MyogenicResponse was significantly blunted. This was shown by an increased #CorrelationCoefficient (CC) between #VascularDiameter and #BloodPressure

We challenged mice with acute #BloodPressure spikes (~70% increase via angiotensin II). Result: both adult and #old mice got their #MyogenicResponse and #NeurovascularCoupling disrupted

To visualize this, we used #InVivo #TwoPhotonMicroscopy in anesthetized adult and aged mice. Watch this video showing PS dilation in response to “SensoryStimulation! 🔬👇