Hagar Lavian
@hlavian.bsky.social
Assistant professor at Tel-Aviv University. Likes to confuse tiny fish and watch their brains.
Textbook: tracking position during navigation is primarily the job of the hippocampus. Recent findings suggest a more complicated story. Recording >20k neurons brainwide, we indeed find spatial representations in every region! With @kenneth-harris.bsky.social and @carandinilab.net
bioRxiv Neuroscience@biorxiv-neursci.bsky.social · 3d agoBrainwide representation of navigation https://www.biorxiv.org/content/10.64898/2026.08.29.747979v1
Excited to share the first paper from my PhD work! Read it to find out how larval zebrafish don't let go of the past.
Bahl Lab @bahllab.bsky.social · 4w agoThe animal is the same. The stimulus is identical. Yet the behaviour varies. Why? In our new study, @ashritocyte.bsky.social explores the sources of this behavioural variability under fully controlled conditions in larval zebrafish doing optomotor response. (1/7) www.biorxiv.org/content/10.6...
Olfactory cues are undoubtedly relevant for fruitflies seeking for rotten 🍊🍒🍐🍌. The Ruta demonstrates the neural computations of olfactory-guided vector memories in the central complex and their relevance for plume tracking. www.nature.com/articles/s41...
A vector-based strategy for olfactory navigation in Drosophila - Nature
Using a virtual reality system, experiments in Drosophila show that flies use memory mechanisms to navigate along the boundary of an odour plume and track the source of a smell.
nature.com
New preprint! www.biorxiv.org/content/10.6... Nearly a decade after starting the project, the first major results from our comparative connectomics work is online! Comparing the head direction circuits of the central complex in bees, ants and flies, recapitulating >300million years of evolution.
Happy to say our head-direction-cell-in-3D is finally out! doi.org/10.1038/s420... Confirms that the brain's compass uses a dual-axis rule (like an iphone does) to maintain a constant estimate of horizontal heading even when the head is not horizontal. Blogpost explanation here: shorturl.at/9VdGM
How the brain adapts its 2D compass for a 3D world
The brain’s neural compass seems 2D, detecting only left and right head-turns. However, if the head is tilted in 3D, its rotation around the vertical axis also covertly changes its horizontal facing ...
communities.springernature.com
🧠 A new paper from our lab is out! In this study, we explore how dorsal raphe nucleus (DRN) circuits modulate forebrain activity and behavior. www.nature.com/articles/s41...
Topographically organized dorsal raphe activity modulates forebrain sensory-motor representations and contributes to defensive behaviors - Nature Communications
Functional heterogeneity of dorsal raphe nucleus is not fully understood. Here authors show topographically organized sensory and locomotor responses from the zebrafish dorsal raphe and its forebrain ...
nature.com
Functional Logic of a Cognitive Brain System for Navigation A fascinating review of the Drosophila head-direction system by Gaby Maimon and Larry Abbott #neuroskyence #compneuro
Functional Logic of a Cognitive Brain System for Navigation
It is unusual for cognitive neuroscientists to reach consensus around which computations a brain region implements, what algorithms are used to achieve those computations and how the algorithms are im...
annualreviews.org
🚨New paper out in @currentbiology.bsky.social "Stable neural coding of heading across locomotory modes by the insect compass system" by Christian Kraus et al @beetzjerome.bsky.social 🦋🧠☀️🧭 #CentralComplex #CompassOrientstion #Insects #Electrophysiology↘️ doi.org/10.1016/j.cu... ↙️
More #headdirection insights in @currentbiology.bsky.social "A multi-ring shifter network computes head direction in zebrafish" by Siyuan Mei et al. 🐟🪰🧠🧭 #Zebrafish #Drosophila #RingAttractor ↘️ doi.org/10.1016/j.cu... ↙️
International Society for Neuroethology@neuroethology.org · 2mo ago🚨New paper out in @currentbiology.bsky.social "Stable neural coding of heading across locomotory modes by the insect compass system" by Christian Kraus et al @beetzjerome.bsky.social 🦋🧠☀️🧭 #CentralComplex #CompassOrientstion #Insects #Electrophysiology↘️ doi.org/10.1016/j.cu... ↙️
🚨New in @cellpress.bsky.social We discovered that hippocampal replays in natural-scale environments are highly fragmented, not full-length. doi.org/10.1016/j.ce... 👇🧵
One of the world's leading brain research centers is shifting away from fruit flies and toward a tiny, transparent fish. The goal: to understand how brains control the behavior of an animal or human. n.pr/4vV8dYM
Is a transparent fish the future of brain science? This center is betting on it
One of the world's leading brain research centers is shifting away from fruit flies and toward a tiny, transparent fish. The goal: to understand how brains control the behavior of an animal or human.
n.pr
1/11 Excited to share my postdoc work from @schierlab.bsky.social and Rainer Friedrich! 🐟👃 How does the brain decide whether an odor is good or bad? In larval zebrafish, we find that odor preference is reflected in spatially cohesive neuronal domains of the olfactory bulb. 🧵
First whole-brain recording of social sound processing in a vertebrate. Surprises start in the hindbrain; thalamus gates conspecific calls; male and female brains diverge downstream. Work by @joerghenninger.bsky.social, @mh123.bsky.social sky.social and team. 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
Have you ever wondered how the brain should represent the sensory world in order to generate behavior? Read our new preprint: work by Shuhong Huang shuhonghuang.bsky.social with our long-standing collaborator James Fitzgerald at Northwestern.
bioRxiv Neuroscience@biorxiv-neursci.bsky.social · 7mo agoBehavioral alignment as an organizing principle in sensory coding https://www.biorxiv.org/content/10.64898/2026.02.04.703828v1
Excited to see this preprint out! Siyuan Mei did exceptional work leading this project, and it was a great experience working with the Herz lab. How do zebrafish update their internal compass? They use a multi ring shifter network, similar to flies despite 550M years of divergence. Full thread ⬇️
Portugues Lab@portugueslab.bsky.social · 8mo ago1/n: A new collaborative preprint from the lab to start the year: "A multi-ring shifter network computes head direction in zebrafish" together with Siyuan Mei, Martin Stemmler and Andreas Herz from the LMU, Munich.
1/n: A new collaborative preprint from the lab to start the year: "A multi-ring shifter network computes head direction in zebrafish" together with Siyuan Mei, Martin Stemmler and Andreas Herz from the LMU, Munich.
Very proud to see our paper selected as one of Nature’s 2025 highlights! @johanneskappel.bsky.social @jlarsch.bsky.social @mpiforbi.bsky.social www.nature.com/articles/d41...
Asteroids, antibiotics and ants: a year of remarkable science
Highlights from News & Views published in 2025.
nature.com
*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 ⬇️
Very excited to share this thread on our recent paper! We show how Zebrafish integrate visual navigation signals in aligned topographic maps. Full thread below🧵
Portugues Lab@portugueslab.bsky.social · 10mo ago(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...
Like most animals, fish move less at night. Underwater, stable posture requires movement. Find out how fish don't fall down at night in: Lighting and circadian cues shape locomotor strategies for balance and navigation in larval zebrafish from @yunluzhu.bsky.social doi.org/10.1101/2025...
Lighting and circadian cues shape locomotor strategies for balance and navigation in larval zebrafish
Most fish are inherently unstable and must swim to stabilize posture. How diurnal fish reduce activity at night while maintaining postural control remains unclear. We defined distinct locomotor strate...
doi.org
New work from Baier Lab 🧠 🐟 🔗 to paper: www.sciencedirect.com/science/arti...
Molecular delineation of a retina-dependent photoneuroendocrine pathway in zebrafish
Many vertebrates, including fish, amphibians, and reptiles, dynamically adjust their body color to the perceived brightness of the ambient background.…
sciencedirect.com
MPI for Biological Intelligence@mpiforbi.bsky.social · 10mo agoHow does a fish know when to blend in? Scientists identified a key circuit controlling camouflage in zebrafish – from cells in the retina sensing light to nerve cells in the brain controlling the release of a hormone that pales the skin to match bright backgrounds. www.bi.mpg.de/news/2025-11...
Now online! Zebrafish use spectral information to suppress the visual background
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 estimation—rather than color—as an ancestral cone function.
dlvr.it
Out now in @currentbiology.bsky.social led by Kaarthik A Balakrishnan: We identify medullary circuits that represent the valence of thermal stimuli and control both long-term strategies of cold-avoidance and short term hot avoidance behaviors to enable thermoregulation. www.cell.com/current-biol...
Behavioral and circuit principles of temperature gradient navigation
Behavioral thermoregulation is critical for survival across animals. Balakrishnan and Haesemeyer discover that thermoregulatory behavior in larval zebrafish is organized into longer-term swim modes. T...
cell.com
I am excited to share my PhD work on head-direction cells recorded in the wild, now published in @science.org, where we recorded neurons in bats flying outdoors on an island. doi.org/10.1126/sci... With @ray-neuro.bsky.social, Shir Maimon, Liora Las, Nachum Ulanovsky and many others
Zebrafish Study Reveals Hidden Dimensions of Attention🧠 🧪🧬 #AcademicSky #higherEd www.mcb.harvard.edu/department/n... @sterrett-sc.bsky.social @hannazwaka.bsky.social @zwitscherarmin.bsky.social @rachellegaudet.bsky.social @dulaclab.bsky.social @harvardbrainsci.bsky.social @neurovenki.bsky.social
Zebrafish Study Reveals Hidden Dimensions of Attention - Harvard University - Department of Molecular & Cellular Biology
Why do we sometimes falter at even the simplest of tasks? A new study from the lab of MCB Professor Florian Engert suggests that lapses in focus, rather […]
mcb.harvard.edu
Ever wonder if there are spatial maps in the brain outside the hippocampal-entorhinal regions? In this preprint, we describe a novel spatial map in the orbitofrontal cortex (OFC) that preserves the topological arrangements and distance between locations. However, ... www.biorxiv.org/cgi/content/...
The orbitofrontal cortex forms a context-generalized spatial schema that preserves topology and distance
Flexible and efficient navigation requires the brain to construct maps that are both topological, preserving the relationships between locations, and schematic, enabling generalization across environm...
biorxiv.org
*New preprint from the lab* – “Granularity of thalamic head direction cells” doi.org/10.1101/2025... 🧠📈 🧪 1/11
Granularity of thalamic head direction cells
Head direction signaling is fundamental for spatial orientation and navigation. The anterodorsal nucleus of the thalamus (ADn) contains a high density of head direction (HD) cells that process sensori...
doi.org
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/
Preprint - Excited to present WHOLISTIC, which extends the concept of whole-brain functional imaging to the entire body. Pioneering work by incredibly talented Virginia Ruetten @vmsruetten.bsky.social, this platform reveals whole-organism cellular dynamics in vivo. www.biorxiv.org/content/10.1...