Toviah Moldwin
@tmoldwin.bsky.social
Computational neuroscience: Plasticity, learning, connectomics.
Reposted by Toviah Moldwin
Tool use in insects: Assassin bugs apply resin to their forelegs before a stingless bee hunt. This makes the bees attack the bug in just the right position to be caught!
Videos will worth watching
www.pnas.org/doi/full/10....
Videos will worth watching
www.pnas.org/doi/full/10....
Tool use aids prey-fishing in a specialist predator of stingless bees | PNAS
Tool use is widely reported across a broad range of the animal kingdom, yet comprehensive
empirical tests of its function and evolutionary drivers ...
www.pnas.org
May 17, 2025 at 3:54 AM
Tool use in insects: Assassin bugs apply resin to their forelegs before a stingless bee hunt. This makes the bees attack the bug in just the right position to be caught!
Videos will worth watching
www.pnas.org/doi/full/10....
Videos will worth watching
www.pnas.org/doi/full/10....
Ariel Krakowski interviews me on his podcast about brains, AI, plasticity, connectomics, consciousness, and everything in between.
open.spotify.com/episode/4m33...
open.spotify.com/episode/4m33...
Computational Neuroscience, Connectomics, and Consciousness
Zappable · Episode
open.spotify.com
April 28, 2025 at 12:25 PM
Ariel Krakowski interviews me on his podcast about brains, AI, plasticity, connectomics, consciousness, and everything in between.
open.spotify.com/episode/4m33...
open.spotify.com/episode/4m33...
Reposted by Toviah Moldwin
On today’s science headlines :
A newly discovered species of carnivorous caterpillar on the Hawaiian island of Oahu has earned the nickname “bone collector” for its eerie habit of adorning itself with the remains of its prey, such as ant heads and fly wings.
🪲 🧪
A newly discovered species of carnivorous caterpillar on the Hawaiian island of Oahu has earned the nickname “bone collector” for its eerie habit of adorning itself with the remains of its prey, such as ant heads and fly wings.
🪲 🧪
April 26, 2025 at 5:31 PM
On today’s science headlines :
A newly discovered species of carnivorous caterpillar on the Hawaiian island of Oahu has earned the nickname “bone collector” for its eerie habit of adorning itself with the remains of its prey, such as ant heads and fly wings.
🪲 🧪
A newly discovered species of carnivorous caterpillar on the Hawaiian island of Oahu has earned the nickname “bone collector” for its eerie habit of adorning itself with the remains of its prey, such as ant heads and fly wings.
🪲 🧪
Reposted by Toviah Moldwin
Emergence and maintenance of modularity in neural networks with Hebbian and anti-Hebbian inhibitory STDP
with @raphaelbergoin.bsky.social and @gzamora-lopez.bsky.social finnally published in @plos.org Computational Biology #neuroskyence #compneurosky
journals.plos.org/ploscompbiol...
with @raphaelbergoin.bsky.social and @gzamora-lopez.bsky.social finnally published in @plos.org Computational Biology #neuroskyence #compneurosky
journals.plos.org/ploscompbiol...
Emergence and maintenance of modularity in neural networks with Hebbian and anti-Hebbian inhibitory STDP
Author summary One of the most remarkable qualities of the brain is its capacity to learn and adapt. How the learning process imprints and maintains memories, by shaping the architecture of connectivi...
journals.plos.org
April 23, 2025 at 12:08 PM
Emergence and maintenance of modularity in neural networks with Hebbian and anti-Hebbian inhibitory STDP
with @raphaelbergoin.bsky.social and @gzamora-lopez.bsky.social finnally published in @plos.org Computational Biology #neuroskyence #compneurosky
journals.plos.org/ploscompbiol...
with @raphaelbergoin.bsky.social and @gzamora-lopez.bsky.social finnally published in @plos.org Computational Biology #neuroskyence #compneurosky
journals.plos.org/ploscompbiol...
Join us in Jerusalem for a great program!
April 22, 2025 at 3:12 PM
Join us in Jerusalem for a great program!
Reposted by Toviah Moldwin
High-Dimensional Dynamics in Low-Dimensional Networks.
New preprint with a former undergrad, Yue Wan.
I'm not totally sure how to talk about these results. They're counterintuitive on the surface, seem somewhat obvious in hindsight, but then there's more to them when you dig deeper.
New preprint with a former undergrad, Yue Wan.
I'm not totally sure how to talk about these results. They're counterintuitive on the surface, seem somewhat obvious in hindsight, but then there's more to them when you dig deeper.
April 21, 2025 at 5:00 PM
High-Dimensional Dynamics in Low-Dimensional Networks.
New preprint with a former undergrad, Yue Wan.
I'm not totally sure how to talk about these results. They're counterintuitive on the surface, seem somewhat obvious in hindsight, but then there's more to them when you dig deeper.
New preprint with a former undergrad, Yue Wan.
I'm not totally sure how to talk about these results. They're counterintuitive on the surface, seem somewhat obvious in hindsight, but then there's more to them when you dig deeper.
Our work elaborating on, simplifying, and extending earlier formulations of the dynamics of calcium-based plasticity has been published in JOCN. Bottom line is: 'calcium tells the synaptic weight where it's going and how fast it gets there.'
link.springer.com/article/10.1...
link.springer.com/article/10.1...
A generalized mathematical framework for the calcium control hypothesis describes weight-dependent synaptic plasticity - Journal of Computational Neuroscience
The brain modifies synaptic strengths to store new information via long-term potentiation (LTP) and long-term depression (LTD). Evidence has mounted that long-term synaptic plasticity is controlled vi...
link.springer.com
April 10, 2025 at 8:41 PM
Our work elaborating on, simplifying, and extending earlier formulations of the dynamics of calcium-based plasticity has been published in JOCN. Bottom line is: 'calcium tells the synaptic weight where it's going and how fast it gets there.'
link.springer.com/article/10.1...
link.springer.com/article/10.1...
Reposted by Toviah Moldwin
How does a neuron get its activity? 👀
Check out our latest preprint, where we tracked the activity of the same neurons throughout early postnatal development: www.biorxiv.org/content/10.1...
see 🧵 (1/?)
Check out our latest preprint, where we tracked the activity of the same neurons throughout early postnatal development: www.biorxiv.org/content/10.1...
see 🧵 (1/?)
March 3, 2025 at 11:23 AM
How does a neuron get its activity? 👀
Check out our latest preprint, where we tracked the activity of the same neurons throughout early postnatal development: www.biorxiv.org/content/10.1...
see 🧵 (1/?)
Check out our latest preprint, where we tracked the activity of the same neurons throughout early postnatal development: www.biorxiv.org/content/10.1...
see 🧵 (1/?)
Anyone here do EM/connectomics? Any pointers to why I don't really see differences in luminance symmetry between E and I syns (defined acc. to presynaptic cell type?)
February 27, 2025 at 2:45 PM
Anyone here do EM/connectomics? Any pointers to why I don't really see differences in luminance symmetry between E and I syns (defined acc. to presynaptic cell type?)
Adventures in proofreading:
Journal has online system to edit proofs. Work for an hour, am auto-logged out. Log back in, all edits are gone.
Try editing on PDF instead. For a substantial number of edits, it's impossible to highlight the relevant text because UNCORRECTED PROOF gets in the way.
Journal has online system to edit proofs. Work for an hour, am auto-logged out. Log back in, all edits are gone.
Try editing on PDF instead. For a substantial number of edits, it's impossible to highlight the relevant text because UNCORRECTED PROOF gets in the way.
February 20, 2025 at 6:38 PM
Adventures in proofreading:
Journal has online system to edit proofs. Work for an hour, am auto-logged out. Log back in, all edits are gone.
Try editing on PDF instead. For a substantial number of edits, it's impossible to highlight the relevant text because UNCORRECTED PROOF gets in the way.
Journal has online system to edit proofs. Work for an hour, am auto-logged out. Log back in, all edits are gone.
Try editing on PDF instead. For a substantial number of edits, it's impossible to highlight the relevant text because UNCORRECTED PROOF gets in the way.
Now out in PLOS CB!
We propose a simple, perceptron-like neuron model, the calcitron, that has four sources of [Ca2+]...We demonstrate that by modulating the plasticity thresholds and calcium influx from each calcium source, we can reproduce a wide range of learning and plasticity protocols.
We propose a simple, perceptron-like neuron model, the calcitron, that has four sources of [Ca2+]...We demonstrate that by modulating the plasticity thresholds and calcium influx from each calcium source, we can reproduce a wide range of learning and plasticity protocols.
The calcitron: A simple neuron model that implements many learning rules via the calcium control hypothesis
Author summary Researchers have developed various learning rules for artificial neural networks, but it is unclear how these rules relate to the brain’s natural processes. This study focuses on the ca...
journals.plos.org
February 19, 2025 at 4:46 PM
Now out in PLOS CB!
We propose a simple, perceptron-like neuron model, the calcitron, that has four sources of [Ca2+]...We demonstrate that by modulating the plasticity thresholds and calcium influx from each calcium source, we can reproduce a wide range of learning and plasticity protocols.
We propose a simple, perceptron-like neuron model, the calcitron, that has four sources of [Ca2+]...We demonstrate that by modulating the plasticity thresholds and calcium influx from each calcium source, we can reproduce a wide range of learning and plasticity protocols.
[T]he priesthoods are a perfect environment for memetic plagues...Those plagues that successfully capture them have found some way to thread this balance, basing themselves in overarching social theories outside the specialties’ competence to assess.
On Priesthoods
...
www.astralcodexten.com
January 28, 2025 at 3:20 PM
[T]he priesthoods are a perfect environment for memetic plagues...Those plagues that successfully capture them have found some way to thread this balance, basing themselves in overarching social theories outside the specialties’ competence to assess.
Reposted by Toviah Moldwin
Sharing our most recent paper, in which we find that electrical synapses in C. elegans drive action selection by "filtering" sensory information. C. elegans can learn temp, move across the temp. gradient and then track that temp. How? Configuration electrical synapses www.cell.com/cell/fulltex... 1/
Configuration of electrical synapses filters sensory information to drive behavioral choices
Sensory information can be differentially processed, enabling similar sensory stimuli
to elicit different, context-specific behavioral strategies. This study uncovers a
conserved configuration of elec...
www.cell.com
January 19, 2025 at 5:24 PM
Sharing our most recent paper, in which we find that electrical synapses in C. elegans drive action selection by "filtering" sensory information. C. elegans can learn temp, move across the temp. gradient and then track that temp. How? Configuration electrical synapses www.cell.com/cell/fulltex... 1/
Reposted by Toviah Moldwin
Is our brain infinitely flexible or constrained? Oby & colleagues cleverly uses BCIs to test what cortical activity can/can't be generated quickly. Highly recommend!
www.nature.com/articles/s41...
And you can get a tl;dr + my takes on why this is exciting here: www.nature.com/articles/s41...
www.nature.com/articles/s41...
And you can get a tl;dr + my takes on why this is exciting here: www.nature.com/articles/s41...
Dynamical constraints on neural population activity - Nature Neuroscience
Oby, Degenhart, Grigsby and colleagues used a brain–computer interface to challenge monkeys to override their natural time courses of neural activity. They found the time courses to be highly robust, ...
www.nature.com
January 17, 2025 at 2:18 PM
Is our brain infinitely flexible or constrained? Oby & colleagues cleverly uses BCIs to test what cortical activity can/can't be generated quickly. Highly recommend!
www.nature.com/articles/s41...
And you can get a tl;dr + my takes on why this is exciting here: www.nature.com/articles/s41...
www.nature.com/articles/s41...
And you can get a tl;dr + my takes on why this is exciting here: www.nature.com/articles/s41...
More people should leave academia to start companies. There's a lot of overlap in the skill sets. If you can turn an idea into a published paper, there's a decent chance you can also turn an idea into a product. Probably more impactful in the long run than writing papers that 5 people will read.
January 15, 2025 at 5:21 PM
More people should leave academia to start companies. There's a lot of overlap in the skill sets. If you can turn an idea into a published paper, there's a decent chance you can also turn an idea into a product. Probably more impactful in the long run than writing papers that 5 people will read.
Reposted by Toviah Moldwin
Ever wondered what different layer-5 PC types do for learning?
Our work suggests that one (IT PCs) does representational learning whereas the other (ET PCs) encodes representational value!
A great exp-theory collaboration with the Larkum and Takahashi's labs!
Our work suggests that one (IT PCs) does representational learning whereas the other (ET PCs) encodes representational value!
A great exp-theory collaboration with the Larkum and Takahashi's labs!
January 13, 2025 at 2:58 PM
Ever wondered what different layer-5 PC types do for learning?
Our work suggests that one (IT PCs) does representational learning whereas the other (ET PCs) encodes representational value!
A great exp-theory collaboration with the Larkum and Takahashi's labs!
Our work suggests that one (IT PCs) does representational learning whereas the other (ET PCs) encodes representational value!
A great exp-theory collaboration with the Larkum and Takahashi's labs!
Long shot, but does anyone have a version of the Allen Microns connectomics dataset with *all* synapses labeled as E or I (based on synapse morphology, not presynaptic neuron identity?)
January 9, 2025 at 12:29 PM
Long shot, but does anyone have a version of the Allen Microns connectomics dataset with *all* synapses labeled as E or I (based on synapse morphology, not presynaptic neuron identity?)
Reposted by Toviah Moldwin
Excited to see @thetransmitter.bsky.social feature our preprint on how the neural code changes across the cortical hierarchy! A multi-region perspective on categorical selectivity 🧱 and geometric dimensionality 📐
Blueprint thread coming soon— after I am done with panettone digestion 🥮!
Blueprint thread coming soon— after I am done with panettone digestion 🥮!
Most neurons in mouse cortex defy functional categories
The majority of cells in the cerebral cortex are unspecialized, according to an unpublished analysis—and scientists need to take care in naming neurons, the researchers warn.
www.thetransmitter.org
January 7, 2025 at 2:03 PM
Excited to see @thetransmitter.bsky.social feature our preprint on how the neural code changes across the cortical hierarchy! A multi-region perspective on categorical selectivity 🧱 and geometric dimensionality 📐
Blueprint thread coming soon— after I am done with panettone digestion 🥮!
Blueprint thread coming soon— after I am done with panettone digestion 🥮!
Reposted by Toviah Moldwin
Key-value memory is an important concept in modern machine learning (e.g., transformers). Ila Fiete, Kazuki Irie, and I have written a paper showing how key-value memory provides a way of thinking about memory organization in the brain:
arxiv.org/abs/2501.02950
arxiv.org/abs/2501.02950
Key-value memory in the brain
Classical models of memory in psychology and neuroscience rely on similarity-based retrieval of stored patterns, where similarity is a function of retrieval cues and the stored patterns. While parsimo...
arxiv.org
January 7, 2025 at 9:21 AM
Key-value memory is an important concept in modern machine learning (e.g., transformers). Ila Fiete, Kazuki Irie, and I have written a paper showing how key-value memory provides a way of thinking about memory organization in the brain:
arxiv.org/abs/2501.02950
arxiv.org/abs/2501.02950
What's a good review of information flow in the cortex that discusses cell types, layers, circuits, and inhibition?
January 6, 2025 at 8:07 AM
What's a good review of information flow in the cortex that discusses cell types, layers, circuits, and inhibition?
Reposted by Toviah Moldwin
Dissecting origins of wiring specificity in dense cortical connectomes
Looks hot! Generative modeling for neural networks -- trying to get insight into the wiring rules of dense connectomes.
www.biorxiv.org/content/10.1...
Looks hot! Generative modeling for neural networks -- trying to get insight into the wiring rules of dense connectomes.
www.biorxiv.org/content/10.1...
December 30, 2024 at 3:02 PM
Dissecting origins of wiring specificity in dense cortical connectomes
Looks hot! Generative modeling for neural networks -- trying to get insight into the wiring rules of dense connectomes.
www.biorxiv.org/content/10.1...
Looks hot! Generative modeling for neural networks -- trying to get insight into the wiring rules of dense connectomes.
www.biorxiv.org/content/10.1...
Reposted by Toviah Moldwin
Excited to announce the publication of our team's work suggesting a new framework for understanding hashtag#synapse hashtag#development and diversity in the mammalian hashtag#brain in Nature Neuroscience rdcu.be/d2100 🧵
Stepwise molecular specification of excitatory synapse diversity onto cerebellar Purkinje cells
Nature Neuroscience - Brain function requires the formation of diverse and specific synapses. The authors show that the molecular code specifying excitatory connectivity on Purkinje cells evolves...
rdcu.be
December 10, 2024 at 1:44 PM
Excited to announce the publication of our team's work suggesting a new framework for understanding hashtag#synapse hashtag#development and diversity in the mammalian hashtag#brain in Nature Neuroscience rdcu.be/d2100 🧵
Reposted by Toviah Moldwin
Son hormigas resolviendo un problema geométrico y es para flipar en colores.
December 25, 2024 at 5:34 PM
Son hormigas resolviendo un problema geométrico y es para flipar en colores.
Reposted by Toviah Moldwin
DAY 22: Advent of Comp Neuro 🎄🤖🧠🧪
Memories in a network can drift at the single neuron level, but persist at the population level! 🍎🍏
“Drifting assemblies for persistent memory: Neuron transitions and unsupervised compensation”
www.pnas.org/doi/full/10....
Memories in a network can drift at the single neuron level, but persist at the population level! 🍎🍏
“Drifting assemblies for persistent memory: Neuron transitions and unsupervised compensation”
www.pnas.org/doi/full/10....
December 22, 2024 at 3:07 PM
DAY 22: Advent of Comp Neuro 🎄🤖🧠🧪
Memories in a network can drift at the single neuron level, but persist at the population level! 🍎🍏
“Drifting assemblies for persistent memory: Neuron transitions and unsupervised compensation”
www.pnas.org/doi/full/10....
Memories in a network can drift at the single neuron level, but persist at the population level! 🍎🍏
“Drifting assemblies for persistent memory: Neuron transitions and unsupervised compensation”
www.pnas.org/doi/full/10....