Rajat Saxena
@rajatsxn.bsky.social
110 followers 100 following 9 posts
Neural correlates of learning and memory. Postdoc @ Moser lab, NTNU PhD @ McNaughton lab, UCIrvine (Prev: IISc Bangalore, BITS Pilani)
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Reposted by Rajat Saxena
manfredic.bsky.social
I’m pleased to share our new paper, “Hippocampal ripple diversity organizes neuronal reactivation dynamics in the offline brain”, out in @cp-neuron.bsky.social !

With @vitorlds.bsky.social and David Dupret, we show that diversity in ripple current profiles shapes reactivation dynamics
rajatsxn.bsky.social
This is really exciting work! Congratulations!!
Reposted by Rajat Saxena
clykken.bsky.social
1/8
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...
Reposted by Rajat Saxena
rhythmicspikes.bsky.social
1/
🚨 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
Reposted by Rajat Saxena
apeyrache.bsky.social
🚨New preprint alert!

The thalamus has long been seen as a relay of sensory signals to cortex.
But could it also generate its own structured activity?
Our study explores this question in the head-direction (HD) system.

Some explanation 🧵👇 1/13

www.biorxiv.org/content/10.1...
Coherent dynamics of thalamic head-direction neurons irrespective of input
While the thalamus is known to relay and modulate sensory signals to the cortex, whether it also participates in active computation and intrinsic signal generation remains unresolved. The anterodorsal...
www.biorxiv.org
Reposted by Rajat Saxena
mace-lab.bsky.social
Thrilled to share that our work is now published in Science! ✨

We found a preference for visual objects in the mouse spatial navigation system where they dynamically refine head-direction coding. In short, objects boost our inner compass! 🧭

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

🧵1/
rajatsxn.bsky.social
Check our new preprint where we examine how enriched experiences alter synaptic connectivity and coding sparsity across the neocortex.
biorxiv-neursci.bsky.social
Enriched experience increases reciprocal synaptic connectivity and coding sparsity in higher-order cortex https://www.biorxiv.org/content/10.1101/2025.09.01.673156v1
rajatsxn.bsky.social
Congratulations Roxana! I hope you had a fun celebration
Reposted by Rajat Saxena
roxana-zeraati.bsky.social
This is a super interesting paper from Bruce McNaughton’s lab, showing why we should study behavior in the context of natural/ecological environments. They show that living in enriched complex environments, prior to task performance, affects both behavior and the underlying neural activity.
behavecolpapers.bsky.social
Environmental enrichment accelerates cortical memory consolidation bioRxivpreprint
Environmental enrichment accelerates cortical memory consolidation
Environmental enrichment is an established strategy to enhance learning and to build resilience against neurodegeneration. In humans, this is known as cognitive reserve. Though the beneficial effects of exposure to a complex environment in animal models have been well-documented by behavioural, immunohistological and morphological observations, its impact on the functional properties of neuronal populations remains poorly understood. This study aimed to compare the functional encoding and offline memory retrieval dynamics of cortical neurons in enriched and control mice performing a virtual spatial foraging task. Thy1-GCaMP6s mice aged 21 days were enriched for 9 weeks by running a complex obstacle course, during which they were gradually exposed to many different types of obstacles requiring climbing, jumping, and/or balancing elements. Control animals were exercise-matched by running a similar track containing only repeating ramps. At the age of 3 months, two-photon calcium imaging was conducted on populations of neurons from the secondary motor cortex in both groups before, during, and after repeated locomotion through a virtual environment with salient visual-tactile cues. We observed an increase in memory reactivation in the enriched group during the first day of exposure. With training, enriched animals exhibited a stronger anticipatory reduction in running speed near the reward location. Moreover, cortical neuron activity representing locations on the track became substantially more stable and precise over days in enriched but not control animals. Altogether, these results indicate that prior environmental enrichment accelerates the consolidation of stable and task-relevant memory representations in the cortex for a novel task, and enables faster and more robust acquisition of new sequence representations.
dlvr.it
Reposted by Rajat Saxena
carandinilab.net
A new study led by @timothysit.bsky.social reveals that different layers of mouse V1 integrate visual and non-visual signals differently.

Activity is dominated by vision (or spontaneous fluctuations) in L2/3 and by movement in L5. This leads to different geometries.
www.biorxiv.org/content/10.1...
Reposted by Rajat Saxena
I'm pleased to share our new work, “Spatio-temporal organization of network activity patterns in the hippocampus”, out in @cp-cellreports.bsky.social !
With Demi Brizee & David Dupret, we track how oscillations and spiking behaviour map onto hippocampal layers using an LFP-based embedding.

(1/13)
rajatsxn.bsky.social
Congratulations! 🎉
Reposted by Rajat Saxena
Reposted by Rajat Saxena
aforli89.bsky.social
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...
Replay and representation dynamics in the hippocampus of freely flying bats - Nature
Nature - Replay and representation dynamics in the hippocampus of freely flying bats
www.nature.com
Reposted by Rajat Saxena
rajatsxn.bsky.social
We observed that hippocampal SWRs arriving near the Down-to-Up or Up-to-Down transitions of the sleep slow oscillations (SO) can entrain novel memory replay in cortex, while the middle phase of the Up state tends to replay familiar cortical memories.
rajatsxn.bsky.social
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.
biorxiv-neursci.bsky.social
Interleaved Replay of Novel and Familiar Memory Traces During Slow-Wave Sleep Prevents Catastrophic Forgetting https://www.biorxiv.org/content/10.1101/2025.06.25.661579v1
Reposted by Rajat Saxena
Reposted by Rajat Saxena
beneuroscience.bsky.social
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 🧵👇
Reposted by Rajat Saxena
marius10p.bsky.social
Your brain learns for you even when you're not actively learning. Maybe. (in mice).
hhmijanelia.bsky.social
🚶Aimlessly wandering around a city or exploring the new mall may seem unproductive, but new research led by @zh0ng0.bsky.social @marius10p.bsky.social @computingnature.bsky.social suggests it could play an important role in how our brains learn.‬‬ 🧠
🔗 www.janelia.org/news/zoning-...