Izumi Fukunaga

Buribushi Fellowship

Independent researcher fellowships (non-tenure track) at OIST, with a focus on broadly defined theory www.oist.jp/research/bur...

🧠 The Lipid #Brain Atlas is out now! If you think #lipids are boring and membranes are all the same, prepare to be surprised. Led by @lucafusarbassini.bsky.social with Giovanni D'Angelo's lab, we mapped membrane lipids in the mouse brain at high resolution.
www.biorxiv.org/cgi/content/...

📣If you are attending #SfN in San Diego this year, make sure to stay until the end.

Sonja Hofer @sonjahofer.bsky.social from @sainsburywellcome.bsky.social will give a ✨special lecture ✨on Wednesday 19th Nov, 10:30-11:30 🗓️

Not to be missed!!

www.sfn.org/meetings/neu...

Lots of exciting clinical PhD projects at Crick - including the opportunity for neurosurgeons to work with us and record electrical activity in patients with neuropixels probes. Please share widely!

Adaptive algorithms for shaping behavior Author summary Animals are commonly trained by ‘shaping’ their behavior using a sequence of simpler tasks towards a complex behavior. Numerous schools of thought have proposed heuristics for shaping b...

(edited repost) Thrilled to see our computational work on adaptive shaping of behavior (we call it outcome-based curriculum learning) in PLoS Comp Biol! @wl-tong.bsky.social, @gautamreddy.bsky.social & I formalize curricula in any RL task that can be framed as sequential simple-to-complex behavior.

Open faculty positions in Physics at OIST

We watched mice follow scent trails drawn on an “endless” treadmill. By manipulating trail geometry/statistics, perturbing mouse nose & brain, and modeling behavior with a Bayesian framework, we show that mice use predictive (rather than reactive) strategies.

One gene reveals clues to why humans thrived and Neanderthals didn’t Some mice were more adept at seeking water after the gene change, signaling a behavioral change and potential cognitive advantage.

Humans and Neanderthals are virtually identical at the genetic level.

Scientists are probing the differences to understand why we are here, and they aren’t.

Tracing brain chemistry across humanity’s family tree Small changes to an enzyme suggest how modern humans differ from Neanderthals and Denisovans in biochemistry and behavior.

Tiny changes in our brain chemistry sets us apart from Neanderthals and Denisovans – and when introduced into mice, seem to help females compete better for scarce resources 🧠 Read about how ADSL may have influenced our evolution www.oist.jp/news-center/...

Tracing brain chemistry across humanity’s family tree Small changes to an enzyme suggest how modern humans differ from Neanderthals and Denisovans in biochemistry and behavior.

You can read more about it in the press release

www.oist.jp/news-center/...

We don’t yet understand how our findings translate to human behavior and cognition, but hopefully they offer clues to our origins.

Grateful for the opportunity to take part in this fascinating collaborative work and to @oistedu.bsky.social for all the support.

What’s more, another mutation in the non coding region - also positively selected - reduces the ADSL expression in humans. So, reduction in the ADSL activity seems overall beneficial.

Turns out this mutation reduces the stability of the enzyme.

When the “humanised” ADSL was introduced into the mouse, the enzyme substrates increased particularly in the brain, and female mice became adept at accessing a scarce resource (in this case, water in the cage).

ADSL is an enzyme crucial for purine biosynthesis.

As the modern human lineage split from those of Neanderthals and Denisovans, a single amino acid mutation in this enzyme became fixed.

Talking of understanding the brain in the evolutionary context…

We have a new study out, led by Xiang-Chun Ju in Svante Pääbo’s lab at OIST:

The activity and expression of adenylosuccinate lyase were reduced during modern human evolution, affecting brain and behavior

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

Fantastic to see this collaborative work with Hopi Hoekstra out in Nature (tinyurl.com/3at3zvby). Lead by @felixbaier.bsky.social and @katjareinhard.bsky.social. Not possible without @bramnuttin.bsky.social , Chen Liu and @arnausd.bsky.social.

Excited to see where this work leads.

Barcoded Rabies In Situ Connectomics for high-throughput reconstruction of neural circuits Sequencing of oligonucleotide barcodes holds promise as a high-throughput approach for reconstructing synaptic connectivity at scale. Rabies viruses can act as a vehicle for barcode transmission, than...

Great technique from my @crick.ac.uk colleagues in @petrznam.bsky.social lab

Reconstructing neural circuits with barcoded Rabies virus & in situ sequencing

www.biorxiv.org/content/10.1...

Massive congratulations to everyone - predominantly of course @janice-bulk.bsky.social and @sophiesteculorum.bsky.social

Thank you Andreas and also for your very helpful feedback!

P.s., some colleagues in the field consider this study controversial :) We have tried our best to respond to the comments in the limited time we had. We would very much like to hear if others get a different result. An open discourse like that might help move the field forward.

Of course, we have not exhausted all possible ways of activating the olfactory bulb output. The encoding format may well depend on the downstream regions involved. There’s plenty more to do!

Congratulations to Xiaochen Fu and all authors!

What does this mean?

Sniff rhythms may not provide clock-like reference signals in downstream areas.

Rather, with progressive stages of olfactory processing, the system may rely more on firing rates and synchrony, with the sniff rhythm serving a more nuanced, modulatory role.

We found that, when the activity bypasses the olfactory bulb, mice can discriminate between:

✅ spike counts
✅ synchrony
❌ timing relative to respiratory cycle

This result is surprising because sniff-locking is prevalent in the output of the olfactory bulb.

Decoding olfactory bulb output: A behavioral assessment of rate, synchrony, and respiratory phase coding Neurogenetics; Behavioral neuroscience; Sensory neuroscience

Animals’ sniffing drives rhythmic input to the olfactory system.

How does this timing contribute to perception, especially beyond first steps of olfactory processing?

We tested this using simple closed-loop optogenetics in our new paper: www.cell.com/iscience/ful...

How do brain circuits evolve? We started looking for some answers by using synapse-resolution cross-species comparative connectomics on an entire olfactory circuit 👇

bit.ly/44aVm9E

Multi-timescale reinforcement learning in the brain - Nature Individual dopaminergic neurons encode future rewards over distinct temporal horizons.

Our work with Pablo Tano, @hyunggoo-kim.bsky.social Athar Malik, Alexandre Pouget and @naoshigeuchida.bsky.social exploring how dopamine neurons could enable multi-timescale reinforcement learning in the brain is out in @nature.com
www.nature.com/articles/s41...

Hyperdisordered Cell Packing on a Growing Surface In rapidly growing oval squid, skin pigment cells form a ``hyperdisordered'' pattern where density fluctuations grow with scale, revealing a novel link between growth and patterning that may apply bro...

Read the full research article in Physical Review X: doi.org/10.1103/Phys...

Special Application Deadline for Students Accepted or Studying in the United States

For students in USA who are affected by the current situation:

OIST Graduate School is accepting special applications right now.

Deadline June 15, 2025

www.oist.jp/admissions/s...

GitHub - oist/Physics-of-Behavior-Tutorials Contribute to oist/Physics-of-Behavior-Tutorials development by creating an account on GitHub.

A vital and very enjoyable component of my academic work is teaching students at all levels how to extend the frontiers of knowledge. So I’m pleased to announce a set of Jupyter notebooks organized around our ideas for “physics of behavior”. You can find them here: github.com/oist/Physics...

I really enjoyed this episode. Thank you.