Blake Porter

Deconstruction of a memory engram reveals distinct ensembles recruited at learning - Nature Neuroscience Pouget et al. identified distinct CA1 neuron ensembles active during specific moments of fear learning and uncovered the core engram essential for memory formation.

How does the brain build a memory?
A common assumption is that the neurons activated during an experience collectively form the memory engram.
In our new Nature Neuroscience paper (finally out!), we show that this is not the case.
www.nature.com/articles/s41...

1/7 🧠 My journey into development begins with this work and question: how does the brain's spatial navigation system develop? We found that the neural networks for spatial navigation (tori and rings) are preconfigured and only later anchor gradually to the world with experience! 🧵

New review from our group out in Nature Reviews Psychology:

Determinants of individual navigation ability

with my excellent co-author: @emre-yavuz-21.bsky.social

Now out in Hippocampus. Fei Wang‘s model of Trace Vector Cells and intra-subiculum processing, consistent with know effects in CA1.

onlinelibrary.wiley.com/share/CPZPYM...

𝗪𝗵𝗮𝘁'𝘀 𝘁𝗵𝗲 𝗿𝗲𝗹𝗮𝘁𝗶𝗼𝗻𝘀𝗵𝗶𝗽 𝗯𝗲𝘁𝘄𝗲𝗲𝗻 𝗺𝗮𝗻𝗶𝗳𝗼𝗹𝗱𝘀 𝗮𝗻𝗱 𝗿𝗲𝗰𝘂𝗿𝗿𝗲𝗻𝘁 𝗻𝗲𝘁𝘄𝗼𝗿𝗸𝘀 𝗶𝗻 𝘁𝗵𝗲 𝗯𝗿𝗮𝗶𝗻?
This looks like a must read (suppl material bursting with goodies).
#neuroskeyence
doi.org/10.1016/j.ne...

Graph of award probability of R35 and R01 from NIH factbook as a function of review rank percentile. As is apparent, 2025 is a significant departure, with lower award probabilities at all scores <40 and significant departures from norm, where even being in the top 10% is no longer a nearly certain indicator of success. Data source: https://report.nih.gov/nihdatabook/report/302

The data is in: the NIH goalposts have shifted.

What were once almost certain fundable scores have become coin flips and what used to be likely grants have become aspirational, leading to fewer awards.

Another manifestation of how HHS policies have led to fewer awards and less science.

With this war on Iran costing $1B per day, we are now at 4$B, an amount that would fund 3,200 five year NIH biomedical research grants.

Research Technician Research Technician position available in the Grienberger lab at Brandeis University. We are a new neuroscience group studying the cellular basis of learning and memory in the mammalian brain. This is...

We’re looking for a new Research Tech! Our research tech is heading to graduate school (very exciting!), which means we’re recruiting someone new to join our team. The position involves hands-on neuroscience research in a collaborative environment.
brandeis.wd5.myworkdayjobs.com/Jobs/job/Bra...

$300 Million in jet planes lost to a fuckup.

That’s 83 five year NIH R01 grants burned in minutes due to error, aka poor execution of this unnecessary war which serves only to make the world more dangerous.

Human hippocampal theta–gamma coupling coordinates sequential planning during navigation

Impressive study from Dan Bush's Lab at UCL:

www.pnas.org/doi/10.1073/...

Neurons around a recording ephys electrode

Diagram of monkey looking at a screen in a neuroscience experiment

Spike rasters for two units in response to a checkerboard shown in the screen. One is an ON neuron, the other is an OFF neuron

Waveforms of single neurons within a single ephys electrode sorted using K-means clustering.

Just uploaded some of my *hand-crafted* comp-neuro teaching materials, thought they might be useful to someone out there.

It's just some exercise notebooks for data analysis github.com/morales-greg...

Sleep spindles promote hippocampal network downregulation during sleep Sleep is thought to globally downregulate neuronal network activity and synaptic connections enhanced during prior wakefulness and, in parallel, to up…

Sleep spindles promote hippocampal network downregulation during sleep

www.sciencedirect.com/science/arti...

I’m building a foundational reading list for our lab (systems & circuit neuroscience, compneuro, modeling, neuromodulators, population coding etc.).

I’d like to crowdsource recommendations.

Which review(s) would you consider mandatory reading for the next generation of researchers?

The inferred value of unchosen options spreads to related items in memory Counterfactual thinking — considering what could have come of choosing the other path — can facilitate inference. Previous studies have demonstrated t…

📢New paper out today in @cognitionjournal.bsky.social!

Does the value of an unchosen option — inferred through counterfactual reasoning — spread to related items in memory, similar to how the value of a chosen option — acquired through direct experience — does?

In short, yes!

BOSTON NATIONAL DAY OF ACTION LOCATJON PARKMAN BANDSTAND 139 TREMONT ST 02108

BOSTON!!! Visit this link:
fight2win.standupforscience.net/Boston-March/
to learn more about your local SATURDAY MARCH 7TH RALLY
to TAKE BACK OUR SCIENCE!

See map for location! Rally starts at 12PM and goes till 3!!

#March7Boston
#standupforscience
#science
#savescience!

Brain lessons from neuroscience | Dr. James M. Hyman, Ph.D. | TEDxTorrey Pines YouTube video by TEDx Talks

It's live! My talk at #tedxtorreypines is now available on Youtube. Go give it a watch and let me know what you think.

www.youtube.com/watch?v=T0jM...

Mission: record hippocampal place cells in zero gravity
Crew: 3 rats with electrode arrays
Vehicle: Space Shuttle Columbia
Status: data now publicly available on DANDI, 28 years later

The ratstronauts' mission is finally complete. 🐀🚀 h/t NASA

about.dandiarchive.org/blog/2026/02...

I played around with building a bluesky labeler for neuroscience methods. subscribe to: neuromethods.bsky.social and like the corresponding post to have a shiny methods label appear in your profile.

Meet the neuroscientist running for Congress Sam Wang, a neuroscientist running for the U.S. House of Representatives, has been interested in “fixing bugs in democracy” for decades.

@samwang.bsky.social , an autism scientist who made headlines for his data-based analyses of congressional districts, is running for a House seat in New Jersey.

By Lauren Schenkman

www.thetransmitter.org/policy/is-th...

Thrilled to finally share this work! 🧠🔊

Using a new reinforcement-free task we show mice (like humans) extract abstract structure from sound (unsupervised) & dCA1 is causally required by building factorised, orthogonal subspaces of abstract rules.

Led by Dammy Onih!
www.biorxiv.org/content/10.6...

🚨🚨New Preprint Alert!🚨🚨

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

Animal learning is painfully slow (at least initially). Yet, well trained animals can learn very fast, sometimes displaying few-shot inference. How does this transition occur?

New preprint out 🎉

What happens to the hippocampal “place code” when an animal is actively engaged in a task?

The answer surprised us (and might surprise you too!).

Let's dive in ⬇️

Link:
"Hippocampal trace coding dominates and disrupts place coding" www.biorxiv.org/content/10.6...

Place cells in CA1 lack topographical organization of firing locations | PNAS Topography is a well-described and well-known concept for cortical organization in primary sensory and motor cortices of mammalian brains. Similar ...

A half-century old question may have its final answer. Using high-resolution #Mini2P microscopes, we find no evidence of local topography in #PlaceCells. Place fields of neighbouring cells are no more similar than those of randomly selected cells. 🧠🗺️ Out now in @pnas.org www.pnas.org/doi/10.1073/...

Do you work or study in the fields of psychology, neuroscience, computer science, artificial intelligence, or philosophy?

What does the term 'representation' mean to you?

We invite you to participate in a brief survey on key conceptual questions across fields.

eu.surveymonkey.com/r/VX9GNXM

Neuronal spiking in the mammalian forebrain is dominated by a heterogeneous ground state Neuronal firing patterns have significant spatiotemporal variability with no agreed-upon theoretical framework. Using a combined experimental and mode…

With this one in print, I think I finally earned that PhD... 😅
Presented for the first time at the cosyne when the world ended (March 2020). I'll bring over a summary thread from twitter when it was still twitter...

www.sciencedirect.com/science/arti...

🚀 New preprint from the lab! Our first foray into the subiculum uses in vivo whole-cell recordings to show that dendritic plateaus are a prominent, learning-dependent signaling mode of subicular neurons. Feedback is welcome!

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

The University of Pittsburgh signed an agreement with Anthropic.

www.pittwire.pitt.edu/features-art...

I learned about this the same day I received materials about the Anthropic lawsuit settlement regarding using my textbook and other copyrighted materials without permission.

Hierarchy in neuronal representations of multiple tasks in prefrontal cortex https://www.biorxiv.org/content/10.64898/2026.02.10.705211v1

Adaptive episodic memory: how multiple memory representations drive behavior in humans and nonhumans | Physiological Reviews | American Physiological Society Episodic memory is a declarative long-term memory of a specific past experience. As such, it is multifaceted, encompassing both the objective and subjective components of that experience. These components can be flexibly represented at different levels of granularity, from precise, context-specific details to generalized, gistlike representations. In this review, we suggest that 1) multiple representations of an episodic memory at different levels of granularity are simultaneously encoded into a memory trace and 2) the relative weighting of these representations determines the extent to which a memory is reconstructed or reproduced at retrieval. We propose that this representational flexibility drives adaptive behavior by prioritizing reconstruction or reproduction depending on the age of the memory, its relationship to prior knowledge, current attentional goals or task demands, and individual differences. Drawing on research in humans and nonhuman animals, we show a close correspondence between psychological and neural representations of a memory across encoding, consolidation, and retrieval. Specifically, we discuss how hippocampal activity in humans and engram formation and activation in rodents support the reproduction of detailed memory representations, whereas schema formation across species, mediated by the medial prefrontal cortex, facilitates reconstruction and generalization to guide behavior. Finally, we consider how species- and individual-level differences shape episodic memory representations. By integrating findings across species, we illustrate how the correspondence between neural and psychological representations enables multiple memory representations to balance stability and flexibility, ultimately driving adaptive behavior.

How do memories guide behaviour?

Multiple memory representations, from detailed to gist-like, let us flexibly reconstruct or reproduce past experiences to behave adaptively across species.

Now out in Physiological Reviews with Morris Moscovitch, Melanie Sekeres & @brianlevine.bsky.social!

Building compositional tasks with shared neural subspaces Nature - The brain can flexibly perform multiple tasks by compositionally combining task-relevant neural representations.

Thrilled that my paper is out in the @nature.com. We explored how the brain builds complex tasks by compositionally combining simpler sub-task representations. The brain flexibly performs multiple tasks by dynamically reusing neural subspaces for sensory inputs and motor actions

rdcu.be/eRVUk