Studying spatial directional memory in larval zebrafish

Spatial navigation relies on short and long-term memory, requiring animals to continuously process positional and directional cues. Larval zebrafish are ideal for studying spatial cognition, combining well-characterized behavior with whole-brain imaging and reported head direction and place cells. We design and adapt an experimental arena to study directional memory in head-embedded, tail-free zebrafish larvae. Taking advantage of optomotor responses, our setup combines optic flow visual stimulation via moving oriented bars with direction-specific water jets acting as aversive stimulus. First, we determine the bar rotation angle required to induce directional swimming turns, measured as asymmetric tail bouts. Next, we characterize behavioral and heart rhythms responses to lateral water jets . Finally, we test the larvae's capacity to learn and discriminate associations between optic flow orientation and the location of the aversive stimulus. Tail kinematics are tracked using DeepLabCut. In parallel, we monitor heart rate as a complementary physiological readout, providing a more sensitive measure of state changes that may reveal subtle signatures of associative memory. The system is compatible with light-sheet microscopy for whole-brain imaging, providing a simple and robust framework for studying directional spatial memory. We will present early preliminary results and invite discussion with the community on the ideas, goals, and future directions of this new project.