Thrilled to share our new Adesnik lab paper! Using holography in excitatory & inhibitory neurons, we reveal how a single cortical circuit can both complete and cancel predictable sensory activity, sharpening representations 📄 https://t.co/x2wZ6hL86O 🧵

A pair of papers on using holographic optogenetics and compressed sensing for connectomics Rapid learning of neural circuitry from holographic ensemble stimulation enabled by model-based compressed sensing https://t.co/amA4i1BoGV

As an Argentinian neuroscientist, I wanted to show people back home what it means to write neural activity directly into the brain using lasers. So naturally, I chose the one word guaranteed to spark joy across the country: #Messi 🇦🇷 See our fantastic study led by @shinehyeyoung

What a joy to see this one OUT! Had an incredible time recreating illusory representations in cortex with holography, alongside the brilliant Prof. Shin. Also, BRAVO to this inspiring collaborative synergy with the OpenScope team!

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@LuRodForster @DanFeldmanPhD @amarinburgin @Kaeli_Vandemark Also, huge thanks to Ho Yin Chau, @APalmigiano and Ken Miller for the many MANY discussions over this complex data and the possible circuit computations! It's been a huge learning opportunity 💙

Also big thanks to @LuRodForster (x100), @DanFeldmanPhD @amarinburgin and @Kaeli_Vandemark for their super valuable feedback on the manuscript.

Huge thanks to all the authors!!, especially @LamiaeAdm who designed and built this ultra powerful all-optical system, and to the great Adesnik Team!!

We think feature-specific recurrent inhibition may be a general cortical strategy to minimize redundancy, suppress ambiguity, and sharpen internal models of the world. Read the full story: [ https://t.co/x2wZ6hLFWm]

Our results: 🔘Identify a feature-specific PC→SST→PC motif 🔘Show how it can switch from completion to cancellation (unifying previous findings) 🔘Demonstrate how feature-tuned recurrent inhibition sharpens cortical codes

So WHY is the brain wired with a like-to-like inhibitory loop? Stimulating co-tuned SSTs while showing their preferred visual input: -Reduces evidence for flanking orientations (consistent with explaining away) -Preserves evidence for correct orientation -Boosts discriminability

In fact, directly activating co-tuned SST ensembles alone is sufficient to remove input-matching representations in the absence of visual input.

Feature completion can be explained by the well-known like-to-like PC-PC connectivity in V1, but where does the feature-specific suppression come from? -PCs recruit co-tuned SSTs (but not PVs) -SSTs, in turn, suppress co-tuned PCs → a “like-to-like-to-like” inhibitory loop

Same microcircuit, opposite computations, depending on input sparsity. This partially reconciles previous contradictory findings using similar tools. But how does this happen?

Using all-optical physiology in awake mice we photostimulated orientation-tuned PC ensembles in V1 in the absence of visual input, and we found: Small PC ensembles → dominant feature suppression Large PC ensembles → dominant feature completion

This means that both excitatory AND inhibitory connections in the cortex are highly structured: They store information (statistical regularities → “an internal model”) that can be used during sensory processing.

We show that this dual capacity is present in the same circuit with two components: (1) Like-to-like connections between PCs (for pattern completion) (2) A newly discovered circuit motif: Reciprocal like-to-like connections between PCs and SSTs (for pattern cancelation)

Brain circuits can use learned statistical regularities to enable completion or cancelation of predictable signals, but how?

Check out this new paper from the amazing prof. Shin! On the tradeoffs between robustness and efficiency of sensory representations. Congrats!

NADIE se salva solo. Están destrozando a la ciencia, la universidad, la salud, la cultura… nos movilizamos el 28 de mayo a las 13 hs al polo científico. Muy fuerte esta intervención en la UNQ, musicalizada como la escena de la Iglesia en el Eternauta.