iiinova — where your digital self keeps evolving

Hugo Ladret @therehugolad.bsky.social · 28/07/2026

"Ah yes, VISal and AUDd, my favorite star systems in the Andromeda Galaxy." Allen Institute acronyms sound more like deep-space coordinates than brain regions to me. If your brain also refuses to index those name, I built a quick cheat-sheet: hugoladret.fr/tools/allen-...

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

Overall, ECT can alleviate a wide range of mental health conditions. By bridging circuit neuroscience and clinical psychiatry to characterize CSD, we aim to translate these results directly into better patient outcomes. Thank you for reading, and thanks to all the hardworking co-authors! 🧠

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

If CSD explains plasticity, then CSD should also explain the therapeutic outcomes of ECT. We computed EEG metrics that predict a positive treatment outcome in patients - on average, they predicted the occurence of CSD in mice. All details in the preprint: www.biorxiv.org/content/10.6... (12/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

Downstream of that massive calcium influx is a lot of secondary messengers. One of them is Fos, an immediate early gene involved in cortical plasticity. We found that CSD (but not ECS alone!) explained 100% of cortical Fos expression after ECS - even matching the laterality of the CSD. (11/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

What was very impressive (to me and to the PMT) was that, following CSD, almost every neuron across all cortical layers gets flooded with a huge amount of calcium (1500% df/f!). The time scale and the sheer magnitude of CSD can only cause massive neuronal circuit effects. (10/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

But is CSD a better explanation for the treatment effects of ECT than seizures? We looked closely at the neurons using 2-photon imaging. (Notice the blood vessel contracting on the top left—this is the type of hemodynamic signal we should be able to measure in patients). (9/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

Eventually after filtering, we saw that oscillations co-occur with CSD. We ended up combining EEG with widefield imaging and saw that the calcium signal held beautifully to the EEG. Most likely, AC-coupled patient EEG is simply blind to the CSD, and can only pick up the oscillatory response. (6/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

To the best of my knowledge, this is the 1st time mouse ECS is validated as a pre-clinical model of human ECS based on direct neuronal responses. However, during the very first ECS we recorded, I completely missed the oscillations, and had a proverbial tree (i.e. a CSD) hiding the forest: (5/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

We started by measuring these oscillations following a single electroconvulsive stimulation (ECS) in mice and patients. They look extremely similar - one could mistake the mouse response for the human one (that actually happened when I sent the first figures draft around🙃). (4/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

There is nearly a century of research on the effects of ECT, and it has become clear that the "seizure" it induces does not predict therapeutic effects. In patient EEG, the immediate response to ECT are beautifully synchronous oscillations stabilizing around 1-5 Hz before abrutply ending. (3/12)

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

We've come a long way since the 1st ECT by Ugo Cerletti and team in 1938 (the history of ECT is worth a read btw). To transform ECT from psychiatry’s most potent intervention into a targeted, reliable therapy, we need to fully characterize what it ECT "does" to the brain. (2/12)

https://pubmed.ncbi.nlm.nih.gov/11940941/

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Hugo Ladret @therehugolad.bsky.social · 16/04/2026

Thank you Georg! Very happy to have worked on this. Here is a short 🧵 on what ECT-triggered CSD looks like, and why we think it is going to help shape the future of ECT research. (1/12)

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