A simple automated system for appetitive conditioning of zebrafish in their home tanks and studying underlying neural activation

Abstract

Zebrafish are emerging as a novel model for studying learning and memory. However, the number of behavioural paradigms which minimize handling stress and are suited to their social nature is limited. We developed an automated learning paradigm to condition groups of adult and juvenile zebrafish in their home tanks. Fish consistently learned to associate an auditory stimulus with the presentation of food and showed robust conditioned responses as early as the 5th trial. Memory of the association persisted for at least 2 days after training, when fish were tested either as groups or as individuals. This retention in juveniles was associated with increased immunoreactivity to phosphorylated ERK, a marker of neural activity, in the dorsolateral telencephalon. This simple paradigm permits scalable conditioning of zebrafish with minimal intervention, reducing variability and labour-intensiveness. In addition, these results support the use of phosphorylated ERK to examine the neural correlates of learning and memory.