1/6: New publication from the lab: “Plastic landmark anchoring in zebrafish compass neurons” by Ryosuke Tanaka (@ryosuketanaka.bsky.social) and Ruben is available here:
rdcu.be/eX1L4
Also I am actively looking for a PI position! In principle I am hoping to stay in Japan, but please do reach out if you happen to know any opening for which I might be a fit, regardless of place!
Another major update: I am finally back in Tokyo after 8 years! Starting this January, I am a postdoc in the lab of @fumikubo.bsky.social at RIKEN CBS, with a continued support from HFSP. My plan is to dig deeper into the circuit surrounding the head direction neurons.
Thanks Lorena!
fish remaps 180º visual space onto the full neural compass
Instead, fish seemed to remap 180º of the visual space onto the 360º extent of their neural compass, effectively "considering" the two suns as an identical object. This shows the surprising capacity of the HD cells to rapidly pick up the correlation structure of the visual inputs.
The biggest update from the bioRxiv version is the reanalysis of the "double sun" experiment (heavily inspired by earlier fly works). Initially, we expected to see fish flip-flopping between (say) north- and south-facing interpretations in a scene with two-fold point symmetry.
My paper on the head direction neurons in the larval zebrafish is now published on Nature! Read it here:
www.nature.com/articles/s41...
Schematic of how ER-EPG plasticity enables the bump of activity in EPGs to accurately track visual cues. As a fly makes a counter-clockwise turn (top to bottom) it will view visual cues (e.g. the sun) from a new angle and the EPG activity bump (red) will swing clockwise around the network by integrating self motion signals with these visual inputs. When the fly faces a different angle, distinct visual ER neurons are active. Plasticity forms a trough of weak synapses (large circles - strong synapses, small circles - weak synapses) that allow ER neurons with distinct visual tuning to move the EPG bump via disinhibition.
*First preprint from our lab* !!!!!
How does the brain learn to anchor its internal sense of direction to the outside world? 🧭
led by Mark Plitt @markplitt.bsky.social & Dan Turner-Evans, w/ Vivek Jayaraman:
“Octopamine instructs head direction plasticity” www.biorxiv.org/content/10.6...
Thread ⬇️
A paper from my PhD lab is on Science! This is a really cool new way to utilize EM connectome datasets. Congrats to the team!
www.science.org/doi/10.1126/...
A study on distance estimation in flies from my PhD lab is now on @currentbiology.bsky.social !
www.cell.com/current-biol...
Our study on optic flow memory in fish is now on Current Biology:
www.cell.com/current-biol...
I'm back in Japan for the Japanese Neuroscience Society meeting last week in Niigata. It was a great opportunity to reconnect with old friends and meet new colleagues. Sushi was also excellent.
Bit late, but I was at the Lindau Nobel Laureate meeting at the beginning of the month. The topic was a bit out of my expertise, but I learned a lot about chemistry, met a lot of great people, and above all thoroughly enjoyed being at another corner of Freistaat Bayern.
I made up my mind to write this when I realized that not a single paper co-cites Meek & Schellart (1978) and Strausfeld (1970), which are classic Golgi studies on fish and fly visual systems with similar ambitions (at least according to Google Scholar).
As I transitioned from studying Drosophila to the larval zebrafish, I have been noticing a lot of interesting parallels between their visual systems (esp. tectum vs. lobula), which I feel are not talked about enough. We explored these analogies in depth in our latest review:
tinyurl.com/3hvkhsyk
As I am posting these, I am in Awaji island, Japan, for the Cold Spring Harbor Asia conference starting today. The last time I was here I was like 5. The landscape is incredible.
Imaging from the inferior olive, I found that IO cells integrate forward and backward optic flow separately (i.e., they lack opponency) with a long time constant. I built simple models that connect the IO physiology to the variable timescales of the behavior.
The key takeaways are: (1) The fish appear to remember only externally generated, but not self-generated optic flow, suggesting that they are tracking involuntary drifts (only), and (2) The fish become more forgetful when the stimulus changes its direction frequently.
Check out my new preprint: www.biorxiv.org/content/10.1...
Here I run a bunch of psychophysics experiments to better understand how the larval zebrafish🐟 remember the past optic flow in the context of stabilization behaviors.
1/3 How does visual input affect the heading direction (HD) network?
In our latest lab preprint, Ryosuke presents "visual landmarks" to larval zebrafish and shows that the HD network tethers to the visual environment. The experiments are again inspired by the beautiful recent work in Drosophila.
