1/ Excited & proud to share the results of an exceptional collaboration with @ejrideout.bsky.social led by R. Manceau & D. Majeur @crchum.bsky.social & @umontreal-en.bsky.social, demonstrating the conserved role of lipid droplet function in hunger-activated neurons. www.nature.com/articles/s42...

Astrocytes in mouse amygdala encode emotional state The glial cells’ activity reliably tracks with freezing, hesitancy and other behaviors reminiscent of anxiety.

“Based on astrocytic activity alone, you can tell whether a mouse is in its comfort zone,” a new study suggests.

By Holly Barker

www.thetransmitter.org/spectrum/ast...

The major finding of this work reveals that BLA astrocyte calcium activity reliably encodes and drives anxiety states. This entire project started when Ossama showed me this video -

Basolateral amygdala astrocytes encode anxiety states Ghenissa et al. provide evidence that basolateral amygdala astrocytes reliably encode anxiety states. Using simultaneous in vivo calcium recordings across an array of behavioral tasks, combined with g...

Incredibly proud of this paper led by @ossamaghenissa.bsky.social and @mathiasgua.bsky.social titled Basolateral 'Amygdala Astrocytes Encode Anxiety States'.
www.cell.com/neuron/fullt...
🧵 below

Astrocytic opposition for this #FluorescenceFriday, Cytoskeleton vs. Cytoplasm.
⚪️GFAP 🟠eGFP 🔵DAPI

Imaging credit: undergrad Camila Cabarcas

Fluorescence image showing astrocytes labelled with eGFP (green), what appears to be primary blood vessels with GFAP (magenta), and cell nuclei stained with DAPI (cyan)

Couldn't wait for Friday to share this really incredible image from superstar undergraduate student Camila Cabarcas, iInvestigating astrocyte morphology

Fingers crossed for Camila as she's at U Cincinnati this week to interview for grad school!

Astrocytic Encoding of Threat in the Basolateral Amygdala The basolateral amygdala (BLA) has long been implicated in threat detection and the generation of anxiety states. While previous experiments have demonstrated the important role of BLA principal neuro...

Delighted to share our first preprint of the year!

A project that we're all really proud of in the lab led by @ossamaghenissa.bsky.social with @mathiasgua.bsky.social in which we set out to test the role of basolateral amygdala astrocytes in anxiety behaviour.
www.biorxiv.org/content/10.6...

Went fishing for this #FluorescenceFriday (GCaMP6s zebrafish larvae)

The views we are lucky to witness from the @crchum.bsky.social

Just out in Nature! “The astrocytic ensemble acts as a multiday trace to stabilize memory.” We identified astrocytic ensembles that link experiences across days to stabilize memory nature.com/articles/s41.... New astrocyte tools are openly available at Addgene: addgene.org/Jun_Nagai/. 1/8

Étude réalisée à Montréal | L’impact du stress sur le cerveau dépendrait du sexe Le cerveau des mâles et des femelles ne réagit pas de la même manière au stress, démontrent pour la première fois des travaux réalisés à Montréal.

L’impact du stress sur le cerveau dépendrait du sexe www.lapresse.ca/actualites/s...

Thrilled to share our new study showing microglia prune astrocyte processes in adult brain, to regulate synaptic transmission, hypothalamic neuron activity, and salt-induced hypertension in🐀. Huge team effort - congratulations to all🥂🍾🎉

Go Lewis 👏👏👏

Sleep loss is a metabolic disorder Sleep deprivation shifts metabolic resources and deprioritizes processes that support cognition.

Sleep loss is a metabolic disorder

"This review describes how sleep deprivation increases resting energy expenditure, leading to the development of a negative energy balance in highly active cells like neurons."

www.science.org/doi/10.1126/...

Overall, this heterogeneity shows astrocytic functional adaptations to synaptic circuits within CA1.

Thanks to everyone involved.

Despite this, both astrocyte populations rely on the eCB system to maintain iLTD at the postsynapse.
Possibly underlying a fundamental property of CA1 astrocytes to regulate pyramidal cells inhibition.
Finally, the 2 astrocyte populations are also reflected in their gene expression profiles

Combining chemo- and optogenetics with dual patch-clamp revealed heterogeneous synaptic regulation, mirroring the spatial segregation of astrocytes and interneurons. We found that SP astrocytes exclusively modulate PV related inhibition while SR astrocytes exclusively affect SOM related inhibition

Using GCaMP and dye-filling, we uncovered syncytial and calcium dynamics heterogeneity between SP and SR astrocytes. Ca2+ activities progressively shifted along the SP–SR axis, with a threshold at 20 μm from stratum pyramidale border.

Astrocytes detect and upregulate transmission at inhibitory synapses of somatostatin interneurons onto pyramidal cells - Nature Communications Astrocytes have been shown to regulate glutamatergic transmission in the brain. Here, the authors show that astrocytes also detect and modulate GABAergic transmission from somatostatin but not parvalb...

Following on the finding that stratum radiatum astrocytes upregulate SOM inhibition (but not PV inhibition) onto pyramidal cells(www.nature.com/articles/s41...), I wondered whether this could be tied to heterogeneous astrocyte populations within CA1. Meeting the needs of diverse synaptic environment

Happy to see that the 2nd part (2018 to 2021) of my postdoc work is now out as a preprint.

@lewisholt.bsky.social sharing some cool data about astrocytes driving stress-induced behaviour! #astroglia

Astrocytes This book gathers methods essential for investigating the multifaceted roles of astrocytes in both physiology and pathological conditions.

Very happy to share several common protocols used in our lab for the second edition of the book "Astrocytes: Methods and Protocols"
@lewisholt.bsky.social @astroantho.bsky.social

Thanks @dibenedetto-lab.bsky.social for being a very patient editor!

link.springer.com/book/10.1007...

Poster showing details for seminar from Dr Jun Nagai. Principal Investigator Team Leader at RIKEN Centre for Brain Science Tokyo, Japan Title: Behaviorally relevant astrocyte ensembles for systems stabilization Le conférence seront présentées en anglais Le mercredi 2 Avril 2025 - Wednesday 2nd April 2025 at 12pm Locale : R05.212B

Montréal glia people / neuroscience community - I'm hosting Jun Nagai (RIKEN) on April 2nd at the @crchum.bsky.social
If you're interested see details below, or reach out to me! Open to all.

Two-photon image showing astrocytes with stained with SR101 in magenta, membrane tethered-GCaMP in cyan

Not sure if our 'striking image' we submitted will get used but here it is. Super striking, if you ask me!

Credit - @mathiasgua.bsky.social

Very honoured to be named the researcher of the month by SENSUM - the mental health and neuroscience strategy at @umontreal.ca

www.sensum.umontreal.ca/en/2025/01/3...

A spatial threshold for astrocyte calcium surge In astrocytes, there exists an intrinsic spatial threshold of subcellular calcium levels that triggers an astrocyte calcium surge throughout the cell, demonstrating cellular astrocyte calcium integrat...

Astrocyte physiologists and computationalists!

Imaging astrocyte structure and function, we discovered and quantified a spatial threshold to astrocyte calcium surge ⭐

doi.org/10.7554/eLif...

Sped up*

Same here :)
Yes spontaneous activities in acute slice. It's been speed up for aesthetics here, initially it is a 7 min recording.

More folks will realize how beautiful astrocytes are 🤩

A touch of blue velvet LUT with this #FluorescenceFriday

GCaMP8 astrocytic activities at the 2p