During the first reporting period (August 2023 – Jan 2026), major progress has been achieved in developing behavioral paradigms, optical technologies, and analytical frameworks for dissecting individual and collective decision-making in zebrafish.
Behavioral Algorithms of Collective Interactions:
Four major behavioral projects have been initiated. We established virtual-reality tracking systems that allow real and virtual zebrafish to interact across arenas, enabling systematic dissection of distance-keeping, alignment, and leader-follower dynamics. These experiments revealed the sensory features that most strongly drive social attraction and alignment.
Phototactic Navigation in Juvenile Zebrafish:
We discovered that juveniles navigate light gradients using temporal rather than spatial luminance cues—a strategy distinct from that of larvae. This finding provides a new foundation for studying how sensory information is integrated within groups. A manuscript reporting this work is currently under review at iScience.
Collective Visual Motion Estimation:
We demonstrated that zebrafish improve their ability to estimate visual motion drift direction when swimming in larger groups, suggesting information sharing between individuals. We developed stimulation paradigms using naturalistic motion patterns, laying the groundwork for linking these behavioral benefits to neural circuit mechanisms.
Collective Threat Evasion:
By presenting looming stimuli to individual fish, we quantified how escape reactions propagate across group members. The resulting behavioral data have been incorporated into computational models that capture the transfer of information between individuals.
Technological and Methodological Developments:
We built large-scale tracking systems capable of following up to 30 animals simultaneously and designed frameworks for real-time virtual coupling between arenas. We also developed high-speed (100 Hz) imaging systems, advanced 3D projection methods that create mathematically correct virtual environments, and light-field microscopy for volumetric brain imaging at 100 Hz.
Neurobiological and Genetic Tools:
We established procedures for brain clearing, c-fos-based activity labeling, and single-cell optogenetic targeting, enabling causal manipulations of defined neurons.
Collectively, these achievements position the project at the frontier of behavioral and systems neuroscience, providing the first comprehensive toolkit for studying social decision-making in a vertebrate model.
