Sriram S

Happy #FluorescenceFriday from this pair of white-matter oligodendrocytes!

Thread coming soon, but be the first to read the latest from @franziau.bsky.social!

In the desert of tools to manipulate oligodendrocytes in the brain, we built an OASIS. 🌿 Pun intended. I’m still in awe every time I spot an amazing-looking cell. The beauty of OL and myelin never fails me!
Hope this tool helps more people see it too.

Congratulations Julien!

New cell-type for #FluorescenceFriday: astrocytes in the cerebral cortex

Which track do I choose: On #FluorescenceFriday, a pair of newly formed oligodendrocytes encounter a field of neuronal axons. Later in development, they will wrap around and insulate subset of these axons

(A) The canonical flow of information is outlined in gray, from the entorhinal cortex to DG granule cells (GCs), CA3, and then CA1 principal cells (PCs). PCs in noncanonical regions, which receive direct input from the hypothalamic supramammillary nucleus (SuM), are shown in green. (B) Large-amplitude events recorded from LFP in the DG hilus, known as dentate spikes, are associated with profound increases in brain-wide firing.

The hippocampus is one of the most studied brain areas because of its major role in fundamental brain functions including learning, memory, and spatial navigation.

In a new #ScienceReview, researchers focus on the role of overlooked areas and circuits within the hippocampus. https://scim.ag/3VKRbMM

Delighted to share this work on intracortical arbor development and selective synaptogenesis by corticothalamic neurons. This was a really fun collaboration with Alan and the Brown lab during my PhD.

The Wu Lab at @JohnsHopkins is looking for a new postdoc fellow to study sleep and/or circadian-related behaviors in mice. If you're interested in, please contact us.

www.markwulab.net

#JNeurosci: @srirams433.bsky.social‬ Guzman-Clavel et al. uncover roles for Mef2c in cortical development: regulation of laminar subtype specification during embryogenesis & axon targeting in postnatal callosal neurons. @oneneuroinitiative.bsky.social
https://doi.org/10.1523/JNEUROSCI.0201-25.2025

Mapping the projectional architecture of the mouse midbrain dopaminergic system using cell type-specific barcoding Brain-wide neural circuits are formed by the diverse axonal branching patterns of many individual neurons. Here we introduce POINTseq (projections of interest by sequencing), a high-throughput and use...

www.biorxiv.org/content/10.1...

A dark ring of myelin in a black and white image of a cell. Image courtesy of Michelle Monje.

Erin Gibson examines an electron microscope image of rings of myelin surrounding an axon.

Michelle Monje’s lab has used electron microscopy to study rings of myelin surrounding an axon.

Brad Zuchero (wearing a Ben Barres T-shirt) and Husniye Kantarci

Stanford research by Dr Barres changed our understanding of myelin—once seen as static insulation, now linked to learning & memory. Learn how @michellemonje.bsky.social, @erinmgibson.bsky.social, @bradzuchero.bsky.social & others continue to shape the field: neuroscience.stanford.edu/news/underst...

Thank you so much! Really nice to hear you enjoyed the paprr

Mef2c Controls Postnatal Callosal Axon Targeting by Regulating Sensitivity to Ephrin Repulsion Intracortical circuits, including long-range callosal projections, are crucial for information processing. The development of neuronal connectivity in the cerebral cortex is contingent on ordered emer...

If you're interested in how Mef2c tunes neuronal response to repulsive guidance cues in the cortex, here's a link to the paper: www.jneurosci.org/content/45/2...

Celebratory #FluorescenceFriday this week, with the JNeurosci cover featuring an image from our article on how Mef2c controls intracortical projection targeting

The winner of OneNeuro's April #FotoFriday #FluorescenceFriday
contest was submitted by Luis Guzman-Clavel at the Alex Kolodkin Lab.

For more information, see pubmed.ncbi.nlm.nih.gov/40228894/

View the complete gallery of OneNeuro BRAINART images here:
www.oneneurojhu.org/art/

Heterochronic transcription factor expression drives cone-dominant retina development in 13-lined ground squirrels. Evolutionary adaptation to diurnal vision in ground squirrels has led to the development of a cone-dominant retina, in stark contrast to the rod-dominant retinas of most mammals. The molecular mechani...

Our latest manuscript (7 years in the works) tackles the question of how diurnal ground squirrels evolved a cone-dominant retina, in contrast to the ancestral rod-dominant retina retained by virtually all other mammals./1
www.biorxiv.org/content/10.1...

Our colleague Prof. Benny (Ben Zion) Shilo passed away this morning @WeizmannScience . Benny worked at the forefront of world science in the study of molecular and developmental genetics. Among other things, he won the A.M.T. Prize in the field of genetics in 2013. He was also a great explainer of science, a kind teacher - and an artist photographer with a sharp eye and a sensitive soul. Benny, we will miss you very much. May his memory be blessed.

Our field has lost an amazing scientist, mentor, and old friend. Benny, along with Mike Hoffman, had a brilliant idea in the early 1980s. The first oncogenes were being cloned and they realized if we wanted to understand their roles in cancer, we needed to understand their normal function 1/n 🧪

FlyVISTA, an integrated machine learning platform for deep phenotyping of sleep in Drosophila A machine learning platform identifies and characterizes the dynamics of microbehaviors during fly sleep.

I am proud to share that our work of 4+ years has finally been published. We wondered if there are distinct behaviors that mark sleep in 🪰, where sleep has been defined as prolonged immobility.
🔗 www.science.org/doi/10.1126/...

Bittersweet #FluorescenceFriday saying goodbye to the Kolodkin lab with one last image, this time from the retinal side side of the lab. Here's a collection of retinorecipient targets in the mouse brain. How many of them can you name?

We're organizing the 4th iDISCO / TRISCO workshop at @rockefelleruniv.bsky.social in NYC!
April 14-19 - FREE - registration to kavlifellows@mail.rockefeller.edu. Deadline: March 1st.

We'll talk about brain mapping of cells, genes, axons, vasculature, light sheet microscopy, tissue clearing.

'From thought to action'... axons from the sensory cortex (green) arrive in the motor region to synapse with target neurons (yellow). Can't wait to get back to more imaging after weeks of thesis writing #FluorescenceFriday

Thanks a lot, Julien!

Very grateful to my advisor, Alex, for the support and freedom that made this study possible. And for Luis, first as a summer intern and now as a Kolodkin lab technician, for driving this forward.(12/n)

Mef2c loss and disrupted interhemispheric connectivity are both associated with neurodevelopmental and neuropsychiatric conditions. We find a functional link between Mef2c control of an axon guidance gene, EphA6, and the topography of interhemispheric connectivity (11/n)

Also, reducing the levels of repulsive ligand EfnA5 in the opposite (target) hemisphere restored targeting by Mef2c mutant neurons (10/n)

Overexpressing EphA6 in otherwise normal callosal neurons also reduces their contralateral targeting; disrupting EphA6 signaling partly restores targeting by Mef2c mutant neurons (9/n)

We reasoned that Mef2c mutants fail to project to the opposite somatosensory cortex because of this misregulation of EphA receptor expression (8/n).

Looking at transcriptional profiling from Christopher Cowan’s lab, we were struck by the upregulation of EphA repulsive guidance receptors upon Mef2c loss. The somatosensory cortex has high levels of repulsive ligand EphrinA5, compared to more medial regions. (7/n)

Curiously, initial axon growth into the corpus callosum and midline crossing are unaffected. The target innervation step is specifically compromised. (6/n)