Larval zebrafish display dynamic learning of aversive stimuli in a constant visual surrounding

Abstract

Balancing exploration and anti-predation are fundamental to the fitness and survival of all animal species from early life stages. How these basic survival instincts drive learning remains poorly understood. Here, using a light/dark preference paradigm with well-controlled luminance history and constant visual surrounding in larval zebrafish, we analyzed intra- and intertrial dynamics for two behavioral components, dark avoidance and center avoidance. We uncover that larval zebrafish display short-term learning of dark avoidance with initial sensitization followed by habituation; they also exhibit long-term learning that is sensitive to trial interval length. We further show that such stereotyped learning patterns is stimulus-specific, as they are not observed for center avoidance. Finally, we demonstrate at individual levels that long-term learning is under homeostatic control. Together, our work has established a novel paradigm to understand learning, uncovered sequential sensitization and habituation, and demonstrated stimulus specificity, individuality, as well as dynamicity in learning.

Causal Genetic Loci for a Motivated Behavior Spectrum Harbor Psychiatric Risk Genes

“…We hypothesized that variation of dark avoidance in larval zebrafish reflected an individualized strategy for resolving a motivational conflict between approach versus avoidance. We tested 6-7 dpf larval zebrafish from an outbred EKW (EKkwill Wildtype) line using a multi-trial light-dark preference behavioral paradigm 27-29 . The light-dark choice index (LDCI), which computes % time in dark - % time in light, provides a quantitative measure of the behavior.…”

“…The light-dark preference behavior was performed as previously described 29 . Fish were raised as a group of 40 in a petri dish on a blue pad at 28.5 0 C with 14-10 hours light/dark cycle and those with normal morphology were individualized in 12-well plates at 5 dpf.…”

“…Light-dark preference is a behavior that is observable across species 19-23 and considered an anxiety-like trait in mammals 24 . Larval zebrafish generally avoid dark that mimics a predator shadow, and this dark avoidance behavior, enhanced by stressors and alleviated by commonly used anxiolytics 25,26 , is naturally variable in the population and such variability is heritable 27-29 .…”

Learning and memory formation in zebrafish: Protein dynamics and molecular tools

“…Habituation has been commonly used in zebrafish paradigms based on a rapid startle response that decreases over time upon repeated exposure to a sensory stimulus (auditory, visual, or tactile) ( Eaton et al, 1977 ; Best et al, 2007 ; Wolman et al, 2011 ). The light preference of larval zebrafish has been used to show dynamic learning including sensitization and habituation during a dark-avoidance task ( Xu et al, 2021 ). The use of virtual reality paradigms with larval zebrafish embedded in agarose combined with light sheet microscopy allows for whole brain imaging during short-term motor learning ( Kawashima et al, 2016 ).…”

Behavioural responses of zebrafish with sound stimuli in microfluidics

“…[23][24][25][26][27][28][29] Studies on learning and memory in a laboratory setting require an experimental platform to incorporate the control stimuli. 30 Such stimuli are difficult to manoeuvre in a threedimensional environment of conventional platforms such as plates and dishes. 23 As an alternative, several microfluidic devices 31,32 have been proposed to incorporate the zone of stimuli for manoeuvring the learning processes.…”