Aditya Krishna

New preprint out 🎉

What happens to the hippocampal “place code” when an animal is actively engaged in a task?

The answer surprised us (and might surprise you too!).

Let's dive in ⬇️

Link:
"Hippocampal trace coding dominates and disrupts place coding" www.biorxiv.org/content/10.6...

Place cells in CA1 lack topographical organization of firing locations | PNAS Topography is a well-described and well-known concept for cortical organization in primary sensory and motor cortices of mammalian brains. Similar ...

A half-century old question may have its final answer. Using high-resolution #Mini2P microscopes, we find no evidence of local topography in #PlaceCells. Place fields of neighbouring cells are no more similar than those of randomly selected cells. 🧠🗺️ Out now in @pnas.org www.pnas.org/doi/10.1073/...

Thrilled to finally share this work! 🧠🔊

Using a new reinforcement-free task we show mice (like humans) extract abstract structure from sound (unsupervised) & dCA1 is causally required by building factorised, orthogonal subspaces of abstract rules.

Led by Dammy Onih!
www.biorxiv.org/content/10.6...

New paper alert! 🚨

We found that the brain's compass is remarkably stable at two scales

1️⃣ the system maintains its internal organization for weeks
2️⃣ It "remembers" its orientation for weeks, even after a single visit

This may be key to how the brain aligns its other maps.

Paper: rdcu.be/e3waP

Bluesky Map Interactive map of 3.4 million Bluesky users, visualised by their follower pattern.

I made a map of 3.4 million Bluesky users - see if you can find yourself!

bluesky-map.theo.io

I've seen some similar projects, but IMO this seems to better capture some of the fine-grained detail

YouTube video by Johns Hopkins University Apes Share Human Ability to Imagine

Imagination in bonobos!

I am thrilled to share a new paper w/ Amalia Bastos, out now in @science.org

We provide the first experimental evidence that a nonhuman animal can follow along a pretend scenario & track imaginary objects. Work w/ Kanzi, the bonobo, at Ape Initiative

youtu.be/NUSHcQQz2Ko

The hippocampal map has its own attentional control signal!
Our new study reveals that theta #sweeps can be instantly biased towards behaviourally relevant locations. See 📹 in post 4/6 and preprint here 👉
www.biorxiv.org/content/10.6...
🧵(1/6)

Where does learning through imitation happen in the brain?

In juvenile zebra finches, we pinpoint a synaptic locus of song learning in a cortico-basal ganglia circuit and leverage this localization to measure the timescale of consolidation and make birds learn faster! #neuroskyence (1/14)

Cow Tools!

We have lived alongside cows for nearly 10,000 years.
We breed them and exploit them

It is now, only now, that we have discovered THEY CAN USE TOOLS

Here I describe our study

(paper) www.sciencedirect.com/science/arti... in @currentbiology.bsky.social
with @auersperga.bsky.social

So cool to see this one out! Congrats @markbrandonlab.bsky.social and the gang!!!!

Environmental representations in mouse hippocampal CA1 reflect the predictive structure of navigation Predictive theories of cognitive mapping propose that these representations encode the predictive relationships among contents as experienced by the n…

Another new paper from the lab: Predictive theories like the SR imply that navigators who navigate differently should have cognitive maps which differ in predictable ways. Here we show that this holds in mouse hippocampal CA1.

www.sciencedirect.com/science/arti...

0/10 Thanks for the interest in our preprint. Some takes say it negates or fully supports the “manifold hypothesis”, neither quite right. Our results show that if you only focus on the manifold capturing most of task-related variance, you could miss important dynamics that actually drive behavior.

Visual motion and landmark position align with heading direction in the zebrafish interpeduncular nucleus - Nature Communications How are various visual signals integrated in the vertebrate brain for navigation? Here authors show that different spatial signals are topographically organized and align to one another in the zebrafi...

(1/n) We are excited to share our new paper in Nature Communications, by Hagar Lavian (@hlavian.bsky.social) and team, revealing how the zebrafish brain integrates visual navigation signals! www.nature.com/articles/s41...

As a longtime fan of cool papers in @currentbiology.bsky.social, I am really thrilled to see this out!

This study sets the stage for understanding the origins of novel (vocal) behaviors.

Big shout out to the main architects of this work @xmikezheng20.bsky.social and @cliffscience.bsky.social

Zebrafish use spectral information to suppress the visual background Vertebrate eyes first evolved in water, where spectral content rapidly fades with distance. Zebrafish exploit this loss by antagonizing cone signals to suppress the background, pointing to distance es...

Excited to share our paper now published in Cell!
'Zebrafish use spectral information to suppress the visual background'

Huge thanks to @neurofishh.bsky.social & @teuler.bsky.social

@cellpress.bsky.social @cp-cell.bsky.social

👇🏻
www.cell.com/cell/fulltex...

Functional specialisation of multisensory temporal integration in the mouse superior colliculus - Nature Communications Whether and how anatomically distinct regions of the superior colliculus (SC) exhibit specialisation in multisensory temporal integration to facilitate different behavioural responses are not fully un...

Proud to have contributed to @gaiabianchini.bsky.social and @flor-iacaruso.bsky.social new paper on how the superior colliculus temporally integrates multisensory information

Sensory expectations shape neural population dynamics in motor circuits Nature - Experiments with human volunteers and macaques show that expectations produced by probabilistic cueing of future sensory inputs shape motor circuit dynamics in order to increase the...

Thrilled that our paper is out today in Nature!
www.nature.com/articles/s4...

Neurons in the bat auditory cortex encode class and complexity of future vocalizations Vocal production is a complex behavior across the animal kingdom that relies on coordinated motor and auditory networks. However, the contribution of sensory areas in vocal control remains poorly unde...

Our new paper is now in BioRxiv ☺️
See how the auditory cortex encodes vocalizations before the bat produces them 📣🦇🧠

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

with @talking-bat.bsky.social and Dennis Röhrig!

🧠🌟🐭 Excited to share some of my postdoc work on the evolution of dexterity!

We compared deer mice evolved in forest vs prairie habitats. We found that forest mice have:
(1) more corticospinal neurons (CSNs)
(2) better hand dexterity
(3) more dexterous climbing, which is linked to CSN number🧵

The work with bats on barren, 7-acre Latham Island was Nachum Ulanovsky’s most complex undertaking yet.

By @claudia-lopez.bsky.social

#neuroskyence

www.thetransmitter.org/neuroetholog...

YouTube video by Weizmann Institute of Science Bat Island: The New Era of Science

Neuroscience projects last several years, and you are usually a bit jaded by the time you wrap it up. Not this one– spending several months on an island in the middle of nowhere, away from all the craziness of the world reminds you how beautiful the world really is.

www.youtube.com/watch?v=46sv...

Our latest study on the neurobiology of collective behavior is now posted as a preprint, led by UCSD PhD student Jo-Hsien Yu @anitajhyu.bsky.social @ucsandiego.bsky.social @danionella.bsky.social

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

Insect spatial memory is thought to be based on panoramic snapshots that are modelled as retinotopic images. This idea won't allow a distinction of landmarks from the scene. Unexpectedly, our data suggest that 🐝 learn 3D-objects as individual landmarks. #neuroethology
www.biorxiv.org/content/10.1...

Functional independence of entorhinal grid cell modules enables remapping in hippocampal place cells A systems-level understanding of cortical computation requires insight into how neural codes are transformed across distinct brain circuits. In the mammalian cortex, one of the few systems where such ...

1/5 How does the brain turn the low-dimensional, universal grid cell metric into the rich, diverse codes needed for memory in hippocampal place cells? 🧵
Preprint link 👇

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

1/
🚨 New preprint! 🚨

Excited and proud (& a little nervous 😅) to share our latest work on the importance of #theta-timescale spiking during #locomotion in #learning. If you care about how organisms learn, buckle up. 🧵👇

📄 www.biorxiv.org/content/10.1...
💻 code + data 🔗 below 🤩

#neuroskyence

Thrilled to share that our work is now published in Science! ✨

We found a preference for visual objects in the mouse spatial navigation system where they dynamically refine head-direction coding. In short, objects boost our inner compass! 🧭

www.science.org/doi/10.1126/...

🧵1/

Special thanks to the Kavli JHU for funding my current work on how the bat hippocampus forms internal models of targets moving along naturalistic 2D trajectories.

A big shout to my co-authors, and to my mentor Cindy Moss, without whom none of this would have happened.

Auditory object representation in the bat hippocampus Krishna et al. identify two populations of CA1 neurons that encode allocentric object location or egocentric object distance but only when bats actively track a moving target using echolocation. These...

Super excited to share that the first work from my PhD is out in @currentbiology.bsky.social

www.cell.com/current-biol...

We tackle two fundamental questions:
1) How does the brain create a cognitive map solely using auditory information?
2)How does the hippocampus represent a moving object?

Differential kinematic coding in sensorimotor striatum across behavioral domains reflects different contributions to movement - Nature Neuroscience Hardcastle and Marshall et al. show that striatal function is domain specific, required for task-related but not spontaneously expressed movements. This functional distinction is reflected in starkly ...

Excited to announce that my first postdoc paper is now online!

Links:
www.nature.com/articles/s41...
rdcu.be/eAcN7

In it, we examine the perennial question: what changes in the brain when learning a new motor skill?

Read more below to find out 👇