Divergent Visuomotor Strategies in Teleosts: Neural Circuit Mechanisms in Zebrafish and .

UNLABELLED

Many animals respond to sensory cues with species-specific coordinated movements to successfully navigate their environment. However, the neural mechanisms that support diverse sensorimotor transformations across species with distinct navigational strategies remain largely unexplored. By comparing related teleost species, zebrafish ( ) and ( ), we investigated behavioral patterns and neural architectures during the visually guided optomotor response (OMR). Closed-loop behavioral tracking during visual stimulation revealed that larval employ burst-and-glide locomotion, while larval display continuous, smooth swimming punctuated with sharp directional turns. Although achieve higher average speeds, they lack the direction-dependent velocity modulation observed in . Whole-brain two-photon calcium imaging and tail tracking in head-fixed fish reveals that both species exhibit direction-selective motion encoding in homologous regions, including the retinorecipient pretectum, with exhibiting fewer binocular, direction-selective neurons overall. Kinematic analysis of head-fixed behavior reveals that sustain significantly longer directed swim events across all stimuli than , highlighting the divergent visuomotor strategies, with reducing tail movement duration in response to oblique, turn-inducing stimuli. Lateralized motor-associated neural activity in the medial and anterior hindbrain of both species suggests a shared circuit motif, with distinct neural circuits that independently control movement vigor and direction. These findings highlight the diversity in visuomotor strategies among teleost species, underscored by shared sensorimotor neural circuit motifs, and establish a robust framework for unraveling the neural mechanisms driving continuous and discrete visually guided locomotion, paving the way for deeper insights into vertebrate sensorimotor functions.

RESEARCH HIGHLIGHTS

exhibit faster swimming than , matching the direction of visual motion. execute OMR in smooth, curved swimming patterns, interspersed with sharp directional turns. and share similar visuomotor neural architecture, recruiting pretectal and hindbrain regions. and demonstrate lateralized encoding of turns, particularly in medial hindbrain neurons.

IN BRIEF

Larval respond to global visual motion cues in smooth, low-angle swimming patterns, interspersed with sharp directional turns, swimming consistently faster than zebrafish. Fouke et al. use behavioral tracking of freely moving and head fixed fish to reveal an evolutionarily conserved visuomotor neural architecture transforming visual motion cues into species-specific locomotor behaviors.