From perception to behavior: The neural circuits underlying prey hunting in larval zebrafish

Abstract

A key challenge for neural systems is to extract relevant information from the environment and make appropriate behavioral responses. The larval zebrafish offers an exciting opportunity for studying these sensing processes and sensory-motor transformations. Prey hunting is an instinctual behavior of zebrafish that requires the brain to extract and combine different attributes of the sensory input and form appropriate motor outputs. Due to its small size and transparency the larval zebrafish brain allows optical recording of whole-brain activity to reveal the neural mechanisms involved in prey hunting and capture. In this review we discuss how the larval zebrafish brain processes visual information to identify and locate prey, the neural circuits governing the generation of motor commands in response to prey, how hunting behavior can be modulated by internal states and experience, and some outstanding questions for the field.

Whole-brain imaging of freely-moving zebrafish

“…These naturally-occurring behaviors provide an attractive model system for understanding the neural circuits involved in sensory processing and sensory-motor transformations (e.g. Barker and Baier, 2015 ; Förster et al, 2020 ; Zhu and Goodhill, 2023 ). Larval zebrafish move in a series of discrete bouts, lasting 100-200 ms at a frequency averaging about 1 Hz (Johnson et al, 2020 ; Mearns et al, 2020 ).…”

“…Using the head-fixed assays described above, impressive progress has been made in deciphering the neural circuits underlying behavior in zebrafish larvae (Lin et al, 2020 ; Zhu and Goodhill, 2023 ). However in these paradigms the fish does not receive the visual, proprioceptive, vestibular or gustatory feedback that it would experience during unconstrained movements and prey hunting.…”

“…They are in widespread use as an animal model for a range of human neurological disorders, including schizophrenia (Thyme et al, 2019 ) and autism spectrum disorders (Stewart et al, 2014 ; Meshalkina et al, 2018 ), where changes can already be seen at larval stages (Thyme et al, 2019 ; Constantin et al, 2020 ; Marquez-Legorreta et al, 2022 ; Zhu et al, 2023 ). Larval zebrafish engage in visually-driven hunting behaviors which involve complex sensorimotor transformations (Bianco and Engert, 2015 ; Bollmann, 2019 ; Zhu and Goodhill, 2023 ). Considerable insight has been gained into the neural circuits underlying hunting from restrained preparations.…”

Diverse prey capture strategies in teleost larvae

“…For vertebrates, the zebrafish larva has become a dominant model for understanding the neuronal circuits and pathways controlling innate behavior (Baier & Scott, 2009; Friedrich et al, 2010; Gahtan & Baier, 2004; Orger & de Polavieja, 2017; Portugues & Engert, 2011). While many aspects of the visuomotor transformations and underlying neural circuitry for prey capture have been revealed in this species (reviewed by Zhu & Goodhill, 2023), it is not known if this is the general solution for larval teleosts or a derived adaptation to the zebrafish’s specific ecological niche.…”

“…For vertebrates, the zebrafish larva has become a dominant model for understanding the neuronal circuits and pathways controlling innate behavior (Baier & Scott, 2009; Friedrich et al, 2010; Gahtan & Baier, 2004; Orger & de Polavieja, 2017; Portugues & Engert, 2011). While many aspects of the visuomotor transformations serving hunting behavior (i. e., search, pursuit, and capture of prey) have been revealed in this species (reviewed by Zhu & Goodhill, 2023), it is not known if strategies employed by zebrafish are representative of those across larval teleosts or if they constitute a derived adaptation to the zebrafish’s specific ecological niche. Such knowledge would allow a search for conservation, or divergence, of neural circuit implementations across species.…”