The odor limonene feeding into a neural network to predict the odor.

Can we predict what a molecule smells like from its structure? A new exchange in @ChemSenses debates this question. 🧪 @kingfunk.bsky.social

Rapid temporal processing in the olfactory bulb underlies concentration-invariant odor identification and signal decorrelation - Nature Neuroscience This study shows that the brain’s smell center uses precise timing and inhibition to read out early odor signals, enabling reliable odor identity across concentrations while rapidly separating (decorr...

We are excited to share that this work has now been published in Nature Neuroscience. The study was co-supervised by @shyshoham.bsky.social and involved a fantastic team of postdocs: Mursel Karadas, @jonvgill.bsky.social and Sebastian Ceballo.

www.nature.com/articles/s41...

Using a novel all-optical approach in awake mice, we found that the olfactory bulb acts as a rapid temporal filter. It opens a brief window for early signals before inhibition kicks in, which creates a concentration-invariant representation and decorrelates the patterns from different odors.

When it comes to sensory processing, cortex should not get all the credit... In olfaction, a key challenge is identifying odors regardless of concentration. Our new paper in @natneuro.nature.com shows how the olfactory bulb performs this crucial computation before signals even reach the cortex.

New preprint from our group (collaboration with @sueyeonchung.bsky.social) showing that discriminating odor components within a complex mixture is constrained by neural sensitivity rather than background interference - likely due to sparse representations at the front end.

We then modeled how these temporal sequences can train downstream cortex to generalize to new odors via unsupervised learning.
Relevant if you study neural manifolds, sensory invariance, temporal codes, or biologically inspired ML.

Using fast two-photon imaging of jGCaMP8f in mitral and tufted cells, we found that odor evoked activity sequences were structured like waves traveling across neurons positioned in an ‘odor-tuning space’.

How do past sensory experiences prepare us for new ones? Our new paper tackles this long-standing question, revealing a role for activity sequences in the olfactory bulb. Excited to share our work led by @jonvgill.bsky.social with Mursel Karadas & Shy Shoham
www.biorxiv.org/content/10.6...

🚨 Preprint alert! 🚨
Can mice estimate the distance to an odour source?
New work led by Cristina Marin and colleagues, jointly supervised by @andreas-t-schaefer.bsky.social at the @crick.ac.uk and myself.

Spoiler alert: Yes, they can!

Read the paper here: bit.ly/43A9tF9
Short 🧵 below

Linking function and structure at scale with X-rays - and several times over. Massive congratulations to the team ‪@yuxinzhang.bsky.social‬, @carlesbosch.bsky.social, @apacureanu.bsky.social @esrf.fr, @crick.ac.uk and all our collaborators.

Due to a coincidence of timing, several PIs at NIMH had a term appointment that ended in Feb.
But renewals were blocked.

Several members of the NIMH external review board, led by chair @jmgrohneuro.bsky.social, wrote a letter to the Senate. It's worth a read.

2/

Axially decoupled photo-stimulation and two photon readout (ADePT) for mapping functional connectivity of neural circuits All optical physiology in vivo provides a conduit for investigating the function of neural circuits in 3-D. Here, we report a new strategy for flexible, axially-decoupled photo-stimulation and two pho...

New preprint: a simple method (ADePT) for optical control and recording of activity by axially-decoupling the focal planes for widefield patterned photo-stimulation and two photon imaging. Proof-of-principle analysis of functional connectivity in the olfactory bulb. 1/7 #neuroscience

Here it is finally: Our mathematical methods book for life scientists! Aimed at advanced undergrads and beginning grad students, plus all those who want a deeper look at the math behind quantitative biology. @portugueslab.bsky.social.
1/3

Perception and neural representation of intermittent odor stimuli in mice Odor cues in nature are sparse and highly fluctuating due to turbulent transport. To investigate how animals perceive these intermittent cues, we developed a behavioral task in which head-restrained m...

Yes, many worrying things happening in science that should take priority in grabbing our attention - but we are worried precisely because scientific knowledge is worth creating. In that spirit, I am proud to highlight our latest @biorxivpreprint.bsky.social preprint! #neuroscience 🧪

Dmitri Chklovskii outlines how single neurons may act as their own optimal feedback controllers From logical gates to grandmother cells, neuroscientists have employed many metaphors to explain single neuron function. Chklovskii makes the case that neurons are actually trying to control how their...

From logical gates to grandmother cells, neuroscientists have employed many metaphors to explain single neuron function. Dmitri Chklovskii makes the case that neurons are actually trying to control how their outputs affect the rest of the brain.

By Paul Middlebrooks

bit.ly/4hPYk7w

#neuroskyence

Fast updating feedback from piriform cortex to the olfactory bulb relays multimodal identity and reward contingency signals during rule-reversal - Nature Communications Hernandez-Trejo, Ciuparu, and Garcia da Silva et al. report that the piriform-to-olfactory bulb feedback in the mouse carries multimodal identity and reward contingency signals, which are re-formatted...

New paper from the lab: feedback from piriform cortex to the olfactory bulb carries identity and reward contingency signals in a multimodal (odor and sound) rule-reversal task. Feedback is re-formatted within seconds and reflects changes in the perceived rules of engagement.
doi.org/10.1038/s414...

Design Principles From Natural Olfaction for Electronic Noses Unlocking “universal smell” requires integrating key principles of natural olfactory systems: modulation of gas transport, utilization of non-selective sensing elements, chemical filters akin to the ...

Our perspective on designing electronic noses inspired by natural olfaction! #neuroscience #ChemSky 🧪

My talk at NAISys 2024 conference at CSHL. YouTube video by Alexei Koulakov

my talk about deep learning in olfaction at NAISys 2024 is posted on yoitube: www.youtube.com/watch?v=RRo5...

DeepNose: An Equivariant Convolutional Neural Network Predictive Of Human Olfactory Percepts The olfactory system employs responses of an ensemble of odorant receptors (ORs) to sense molecules and to generate olfactory percepts. Here we hypothesized that ORs can be viewed as 3D spatial filter...

Our DeepNose paper is in arxiv. In it, we present an equivariant CNN which can predict human olfactory perception based on molecular shapes, including mixtures. Comments/suggestions are very welcome.
arxiv.org/abs/2412.08747

Thank you, Gonzalo. The respect is mutual. Next time u in NYC, coffee on me

One nose but two nostrils: Learning to align with sparse connections between two olfactory cortices Sparse connectivity between brain hemispheres is sufficient to learn and achieve bilateral alignment based on a realistic local learning rule.

Glad to share this theory paper on learning to align neural representations with sparse connectivity. Work led by graduate student @leo-bo-liu.bsky.social, in a wonderful collaboration with Yuhai Tu from IBM Research and @shanq.bsky.social from Flatiron Institute. #neuroscience 🧪

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