Social interactions in medaka fish depend on discrete kinematic states of swimming behavior

Current Biology · 2026-02-17

we tested how medaka translate social information from neighbors into actions across these kinematic states. The models revealed distinct computations governing social information processing and movement responses in each state. Moreover, social responsiveness varied significantly between states: it was strongest during constant-speed epochs, intermediate during accelerations, and lowest during decelerations. These findings highlight discrete behavioral modes as key modulators of social interaction computations underlying collective behavior.

Divergent spatiotemporal integration of whole-field visual motion in medaka and zebrafish larvae

bioRxiv (Cold Spring Harbor Laboratory) · 2025-08-27 · 1 citations

Abstract Cross-species comparisons offer leverage for identifying conserved and divergent neural computations underlying innate behavior. Visual motion integration is a fundamental operation that stabilizes position relative to the moving environment and supports object tracking, yet how its underlying algorithms vary across closely related vertebrate brains remains poorly understood. We investigated how zebrafish ( Danio rerio ) and medaka ( Oryzias latipes ) larvae implement visual motion integration using distinct spatiotemporal filters that trade speed for persistence through separable control modules. Using controlled whole-field motion stimuli, we found that medaka pool motion signals over visual fields nearly twice as large as those of zebrafish and exhibit enhanced weighting of peripheral inputs, whereas zebrafish rely more strongly on motion signals directly beneath the body. Temporally, zebrafish respond robustly to motion signals with lifetimes as short as 100 ms, whereas medaka require stimulus durations exceeding one second and maintain motion-driven activity for several seconds after stimulus offset. Decomposition of turning behavior revealed separable control modules for large and small corrective maneuvers, with species differences arising primarily from prolonged temporal integration in medaka small-turn control. Together, these differences reveal species-specific tuning of spatial kernels and temporal filters underlying visuomotor control. Our results demonstrate how alterations in basic computational motifs, spatiotemporal pooling, gain, and persistence, can generate divergent visuomotor strategies across closely related vertebrate brains. Significance Statement Animals rely on visual motion to stabilize positions and interact with dynamic environments, yet how these computations vary across related species remains unclear. By comparing larval zebrafish and medaka, we show that visually similar vertebrates implement motion integration using distinct spatiotemporal strategies. Medaka integrate motion over larger visual fields and retain motion signals for seconds, whereas zebrafish favor rapid, spatially restricted integration. These differences arise from separable control modules governing fine and large motor adjustments. Our results reveal how small changes in core computational motifs—pooling, gain, and persistence—can generate divergent sensorimotor strategies across evolution.

Fishexplorer: A multimodal cellular atlas platform for neuronal circuit dissection in larval zebrafish

bioRxiv (Cold Spring Harbor Laboratory) · 2025-07-15 · 1 citations

Understanding how neural circuits give rise to behavior requires comprehensive knowledge of neuronal morphology, connectivity, and function. Atlas platforms play a critical role in enabling the visualization, exploration, and dissemination of such information. Here, we present FishExplorer, an interactive and expandable community platform designed to integrate and analyze multimodal brain data from larval zebrafish. FishExplorer supports datasets acquired through light microscopy (LM), electron microscopy (EM), and X-ray imaging, all co-registered within a unified spatial coordinate system which enables seamless comparison of neuronal morphologies and synaptic connections. To further assist circuit analysis, FishExplorer includes a suite of tools for querying and visualizing connectivity at the whole-brain scale. By integrating data from recent large-scale EM reconstructions (presented in companion studies), FishExplorer enables researchers to validate circuit models, explore wiring principles, and generate new hypotheses. As a continuously evolving resource, FishExplorer is designed to facilitate collaborative discovery and serve the growing needs of the teleost neuroscience community.

Collective Behavior in Medaka Fish Depends on Discrete Kinematic States of Swimming Behavior

bioRxiv (Cold Spring Harbor Laboratory) · 2025-07-31

Abstract Complex collective behaviors such as schooling are believed to emerge from simple, individual-level computations that translate incoming information from conspecifics into actions. Recently, it has been proposed that discrete behavioral modes, or internal states, may modulate these computations, affecting the resulting collective behaviors. Direct evidence for such hierarchical control remains limited due to challenges in inferring hidden perception-action computations and uncovering discrete behavioral modes from continuous behaviors. To address this, we analyzed swimming behaviors of Medaka fish ( Oryzias latipes ) throughout development. At the group level, Medaka exhibit synchronized swimming formations that develop early, emerging around two weeks of age and stabilizing within one month. Unlike many teleost species that use burst-and-coast swim patterns, Medaka exhibit continuous tail and body undulations. We show that this continuous behavior can be segmented into three distinct kinematic states: acceleration, deceleration, and prolonged constant speed swimming. Using state-dependent computational models, we tested how Medaka translate social information from neighbors into actions across these kinematic states. The models revealed distinct computations governing social information processing and decision making in each state. Moreover, social responsiveness varied significantly between states—it was strongest during constant-speed epochs, intermediate during accelerations, and lowest during decelerations. Compared to similarly-sized zebrafish that employ burst-and-coast kinematics, Medaka exhibited greater diversity in state-dependent social interaction computations, ultimately resulting in stronger coordinated swimming. These findings highlight discrete behavioral modes as key modulators of social interaction computations underlying collective behavior.

Multi-species community platform for comparative neuroscience in teleost fish

bioRxiv (Cold Spring Harbor Laboratory) · 2024-02-15 · 3 citations

Abstract Studying neural mechanisms in complementary model organisms from different ecological niches in the same animal class can leverage the comparative brain analysis at the cellular level. To advance such a direction, we developed a unified brain atlas platform and specialized tools that allowed us to quantitatively compare neural structures in two teleost larvae, medaka ( Oryzias latipes ) and zebrafish ( Danio rerio ). Leveraging this quantitative approach we found that most brain regions are similar but some subpopulations are unique in each species. Specifically, we confirmed the existence of a clear dorsal pallial region in the telencephalon in medaka lacking in zebrafish. Further, our approach allows for extraction of differentially expressed genes in both species, and for quantitative comparison of neural activity at cellular resolution. The web-based and interactive nature of this atlas platform will facilitate the teleost community’s research and its easy extensibility will encourage contributions to its continuous expansion.

Epigenetically distinct synaptic architecture in clonal compartments in the teleostean dorsal pallium

eLife · 2023-06-29 · 4 citations

The dorsal telencephalon (i.e. the pallium) exhibits high anatomical diversity across vertebrate classes. The non-mammalian dorsal pallium accommodates various compartmentalized structures among species. The developmental, functional, and evolutional diversity of the dorsal pallium remain unillustrated. Here, we analyzed the structure and epigenetic landscapes of cell lineages in the telencephalon of medaka fish ( Oryzias latipes ) that possesses a clearly delineated dorsal pallium (Dd2). We found that pallial anatomical regions, including Dd2, are formed by mutually exclusive clonal units, and that each pallium compartment exhibits a distinct epigenetic landscape. In particular, Dd2 possesses a unique open chromatin pattern that preferentially targets synaptic genes. Indeed, Dd2 shows a high density of synapses. Finally, we identified several transcription factors as candidate regulators. Taken together, we suggest that cell lineages are the basic components for the functional regionalization in the pallial anatomical compartments and that their changes have been the driving force for evolutionary diversity.

Author response: Epigenetically distinct synaptic architecture in clonal compartments in the teleostean dorsal pallium

2023-05-25

The dorsal telencephalon (pallium) in medaka fish accommodates an epigenetically distinct brain area that selectively regulates unique set of synaptic genes compared to the surrounding pallial region, providing insights into the evolution of the pallium in vertebrate.

A Visual Interface for Exploring Hypotheses About Neural Circuits

IEEE Transactions on Visualization and Computer Graphics · 2023-02-09 · 8 citations

One of the fundamental problems in neurobiological research is to understand how neural circuits generate behaviors in response to sensory stimuli. Elucidating such neural circuits requires anatomical and functional information about the neurons that are active during the processing of the sensory information and generation of the respective response, as well as an identification of the connections between these neurons. With modern imaging techniques, both morphological properties of individual neurons as well as functional information related to sensory processing, information integration and behavior can be obtained. Given the resulting information, neurobiologists are faced with the task of identifying the anatomical structures down to individual neurons that are linked to the studied behavior and the processing of the respective sensory stimuli. Here, we present a novel interactive tool that assists neurobiologists in the aforementioned tasks by allowing them to extract hypothetical neural circuits constrained by anatomical and functional data. Our approach is based on two types of structural data: brain regions that are anatomically or functionally defined, and morphologies of individual neurons. Both types of structural data are interlinked and augmented with additional information. The presented tool allows the expert user to identify neurons using Boolean queries. The interactive formulation of these queries is supported by linked views, using, among other things, two novel 2D abstractions of neural circuits. The approach was validated in two case studies investigating the neural basis of vision-based behavioral responses in zebrafish larvae. Despite this particular application, we believe that the presented tool will be of general interest for exploring hypotheses about neural circuits in other species, genera and taxa.

Epigenetically distinct synaptic architecture in clonal compartments in the teleostean dorsal pallium

bioRxiv (Cold Spring Harbor Laboratory) · 2022-10-04 · 1 citations

Summary The dorsal telencephalon (i.e. the pallium) exhibits high anatomical diversity across vertebrate classes. The mammalian dorsal pallium accommodates a six layered-structure, the neocortex, whereas the teleostean dorsal pallium possesses various compartmentalized structures among species. The development, function and evolution of the fish dorsal pallium remain unillustrated. Here, we analyzed the structure and epigenetic landscapes of cell lineages in the telencephalon of medaka fish ( Oryzias latipes ) which possesses a clearly delineated dorsal pallium (the Dd2 region). We found that different pallial regions, including Dd2, are formed by mutually exclusive clonal units, and that each pallium compartment exhibits a distinct epigenetic landscape. In particular, Dd2 possesses a unique open chromatin pattern that preferentially targets synapse-related genes. Indeed, Dd2 shows a high density of synapses, which might reflect strong plasticity. Finally, we identified several transcription factors as candidate regulators for the Dd2, which are partially shared with the human neocortex and hippocampus.

Quantifying Social Interactions in Medaka Fish

Neuromethods · 2022-01-01 · 3 citations