Toviah Moldwin
@tmoldwin.bsky.social
Computational neuroscience: Plasticity, learning, connectomics.
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....
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 ...
pnas.org
Ariel Krakowski interviews me on his podcast about brains, AI, plasticity, connectomics, consciousness, and everything in between. open.spotify.com/episode/4m33...
Computational Neuroscience, Connectomics, and Consciousness
Zappable · Episode
open.spotify.com
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. 🪲 🧪
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...
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
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.
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...
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
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/?)
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.
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.
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
[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
...
astralcodexten.com
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...
cell.com
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...
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, ...
nature.com
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.
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!
bioRxiv Neuroscience@biorxiv-neursci.bsky.social · 2y agoDistinct roles of cortical layer 5 subtypes in associative learning https://www.biorxiv.org/content/10.1101/2025.01.07.631500v1
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?)
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 🥮!
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.
thetransmitter.org
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
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
What's a good review of information flow in the cortex that discusses cell types, layers, circuits, and inhibition?
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...
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
Son hormigas resolviendo un problema geométrico y es para flipar en colores.
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....
Aitor Morales-Gregorio@aitormg.bsky.social · 2y agoDAY 21: Advent of Comp Neuro 🎄🤖🧠🧪 Aligning stimuli to spontaneous activity creates more robust responses, both in a model and in ferrets! “The nature-nurture transform underlying the emergence of reliable cortical representations” By @traegenap.bsky.social et al www.biorxiv.org/content/10.1...
People climb the career ladder to get a management position (PI) and then once they get there they find that they have less time for non management-related things <surprised Pikachu face>.
🚨 New Paper! Can neuroscience localizers uncover brain-like functional specializations in LLMs? 🧠🤖 Yes! We analyzed 18 LLMs and found units mirroring the brain's language, theory of mind, and multiple demand networks! w/ @gretatuckute.bsky.social, @abosselut.bsky.social, @mschrimpf.bsky.social 🧵👇
Every cog neuro talk: “Here’s a picture of downtown Tokyo. How do humans navigate this rich visual environment? Let’s find out. In experiment 1, three rats looked at triangles while I measured one neuron from each…”
Neuronal dynamics can be #balanced without the need of strong external currents, as usually done, here with A. Politi we explain how (open access article 2024) #complexity #neuroscience #neuroskyence #compneurosky pubs.aip.org/aip/cha/arti...
A robust balancing mechanism for spiking neural networks
Dynamical balance of excitation and inhibition is usually invoked to explain the irregular low firing activity observed in the cortex. We propose a robust nonli
pubs.aip.org
DAY 15: Advent of Comp Neuro 🎄🤖🧠🧪 Heterogeneity of neural properties can improve some computational functions, but homogeneity also has its advantages! It's complicated 😅 “Neural heterogeneity controls computations in spiking neural networks” @rgast.bsky.social et al www.pnas.org/doi/epub/10....
Aitor Morales-Gregorio@aitormg.bsky.social · 2y agoDAY 14: Advent of Comp Neuro 🎄🤖🧠🧪 Neurotransmitter expression is very different throughout the cortex, and those differences are aligned with the hierarchy! “Gradients of neurotransmitter receptor expression in the macaque cortex” By @seanfw.bsky.social et al www.nature.com/articles/s41...
