Abraham Zelalem Vollan

1/N: Dear cognitive map fans, I’d like to share a model I’ve been working on for a while (clearing backlog :). I show how a vector navigation architecture (VNA) and a “positional inference network” (PIN) can build Universal Cognitive Maps (UCMs) for abstract spaces.

www.biorxiv.org/content/10.6...

Fantastic opportunity to do pioneering single-unit recordings from the HUMAN hippocampus and other parts of the brain, with @jorgen-sugar.bsky.social at @uio.no, Norway.

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Do neighboring #PlaceCells in #Hippocampus CA1 map neighboring locations in space? 🧠🗺️
Is there micro-scale spatial topography in the hippocampus?
See our latest paper from @kavlintnu now out in @pnas.org www.pnas.org/doi/10.1073/...

My first first-author paper is on bioRxiv! Here we ask whether the same subset of neurons in ACC always display object correlates during extensive familiarisation to 2 objects. A short 🧵1/10

Happy belated publication of some of my PhD work!

Building on our findings that grid field firing rate changes can cause hippocampal remapping and memory impairment, here we show that this effect has a fixed input-output relationship, and we can even predict how place cells will remap!

We are #hiring 2 PhD students at the University of Oslo! 🇳🇴
1️⃣ Systems Neuro: Spatial memory & addiction
2️⃣ Neuro/Cancer: Glioblastoma invasion.

Details: vervaeke-lab.org/Hiring
Please RT! 🔄 @UiO_LifeSci #Neuroscience #PhD #SystemsNeuro #Glioblastoma

Have you ever wondered how the brain should represent the sensory world in order to generate behavior? Read our new preprint: work by Shuhong Huang shuhonghuang.bsky.social with our long-standing collaborator James Fitzgerald at Northwestern.

New paper alert! 🚨

We found that the brain's compass is remarkably stable at two scales

1️⃣ the system maintains its internal organization for weeks
2️⃣ It "remembers" its orientation for weeks, even after a single visit

This may be key to how the brain aligns its other maps.

Paper: rdcu.be/e3waP

A Passage of Time Signal in the Human Brain In a dense-sampling resting–state functional magnetic resonance imaging study, Wang et al. (2025) recorded two individuals’ functional connectivity patterns over 30 consecutive days to find a marker o...

Check out our commentary on a recent paper arguing that neural activity in the (lateral) entorhinal cortex intrinsically drifts over a month-long period in humans.

With @virginievanw.bsky.social @vigano.bsky.social and Raphaël Bordas.

www.eneuro.org/content/13/1...

Thanks! Our hunch is that parasubiculum converts these egocentric vectors to allocentric ones by adding allo HD and ego "attention" signals, perhaps similar to how flies do it (eg Hulse 2021, Lyu 2022, Lu 2022).

By adjusting the direction, width and frequency sweeps, the sweep system may provide a mechanism for allocating spatial attention in allocentric hippocampal maps. Check out the preprint for more findings and videos!

www.biorxiv.org/content/10.6...

We had a lot of fun doing these experiments! Theta sweeps in MEC and internal direction signals in parasubiculum track moving objects during pursuit and reverse during backward movement. Simultaneously recorded HD cells in other areas remain locked to head direction across behaviors:

Such an elegant study, congratulations to all of you!

I’m excited to share my first PhD preprint!🎉
We studied how interactions between medial entorhinal cortex (MEC) and hippocampus shape theta sequences during navigation, and asked whether some “planning-like” patterns in hippocampus could arise from upstream MEC dynamics. (1/8)

Wow, congrats Flavio!!

Congrats, Adrian!

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How can the brain create countless unique memories using a single, universal metric of space? We’ve been waiting for the answer to this for two decades!
Read it here:
www.biorxiv.org/content/10.1...

Congrats, Thomas and team!!

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🚨 New preprint! 🚨

Excited and proud (& a little nervous 😅) to share our latest work on the importance of #theta-timescale spiking during #locomotion in #learning. If you care about how organisms learn, buckle up. 🧵👇

📄 www.biorxiv.org/content/10.1...
💻 code + data 🔗 below 🤩

#neuroskyence

Congrats to you all! Looks great in its final form🤩

Direct entorhinal control of CA1 temporal coding Nature Communications - Temporal coding in the hippocampus is thought to be key for memory and predictions. Here, the authors show that blocking one entorhinal input affects two aspects of...

Our collaboration - from PhD work - examining input-specific (EC L3) contributions to rate and temporal coding in CA1 place cells is now out in @natcomms.nature.com 🔬🧠

rdcu.be/evWtz

Our study is out in Nature!
Using wireless Neuropixels we recorded hippocampal activity in freely flying bats and uncovered replay and theta(less) sweeps, revealing striking differences from classic rodent models.

👉 www.nature.com/articles/s41...

Our work with Maxim Bazhenov's group showing interleaved replay of new and old memories within individual Up states using a combination of biophysical modeling and electrophysiology experiments.

Event structure sculpts neural population dynamics in the lateral entorhinal cortex Our experience of the world is a continuous stream of events that must be segmented and organized at multiple timescales. The neural mechanisms underlying this process remain unknown. In this work, we...

Your brain doesn’t just passively track time ⏳ - it structures it.
In @Science.org we show that activity in 🧠 memory circuits (LEC) drifts constantly, but makes sharp jumps at key moments, segmenting life into meaningful events. (1/2)

👉 www.science.org/doi/10.1126/...

Our new paper out now in Science explores how neural activity in the lateral entorhinal cortex (LEC) *drifts* over time - and *jumps* at key boundaries - to help organize events in memory.

🔗 www.science.org/doi/10.1126/...

Here's a quick summary of what we found 🧵👇

A hypothalamus–brainstem circuit governs the prioritization of safety over essential needs - Nature Neuroscience Animals need to adapt behavior to balance survival with fulfillment of essential needs. Krauth et al. identify neurons in the lateral hypothalamus that, when activated, prioritize survival over other ...

Honored to share that our paper is out today in Nature Neuroscience:

www.nature.com/articles/s41...

We identify a hypothalamic-brainstem circuit linking internal states to locomotion: These projections drive safety-focused movement over competing behavior.

#Neuroscience #Hypothalamus #Locomotion

Dynamic basal ganglia output signals license and suppress forelimb movements - Nature Basal ganglia output neurons fire dynamically in bidirectional and movement-specific patterns to license forelimb movements. 

Forelimb movement control at the basal ganglia - brainstem interface!

Happy to finally share this work from me and @harsh-kanodia.bsky.social with Silvia Arber!

@biozentrum.unibas.ch @fmiscience.bsky.social

www.nature.com/articles/s41...

Are you interested in visual systems? How are they similar or different across species? Read the review by Ryosuke @ryosuketanaka.bsky.social and Ruben published today in @natrevneuro.nature.com. It is available here: rdcu.be/enlpC

The Hippocampus Book Abstract. The Hippocampus Book investigates the structure, function and pathology of the hippocampus and related cortical areas. It highlights the importan

As I transition over to Bluesky I have to plug our new #book. If you haven't already, check out the 2nd edition of The #Hippocampus Book!

academic.oup.com/book/59509?s...

Stereo olfaction underlies stable coding of head direction in blind mice - Nature Communications Stereo olfaction involves comparing odor differences between the two nostrils. Here, using neuronal recordings and a behavioral test, the authors demonstrate that blind mice use stereo olfaction to fo...

Excited to share the sequel to our 2022 paper! In this follow-up, we show that the stable head direction (HD) signals we reported in blind mice rely on stereo olfaction—that is, the comparison of odor info. between the two nostrils.

Link: www.nature.com/articles/s41...

🧵highlights below