Classical fear conditioning in zebrafish (Danio rerio) using an upgraded version of the goldfish conditioned withdrawal preparation (2019)


Barela, P. B. (2020) Classical fear conditioning in zebrafish (Danio rerio) using an upgraded version of the goldfish conditioned withdrawal preparation. Journal of Neuroscience Methods, doi: 10.1016/j.jneumeth.2019.108503

Abstract

Zebrafish are a popular animal model for investigations into the neurobiological mechanisms of learning. However, there remains a need for a standardized set of behavioral methods for use with this species.

The goldfish conditioned withdrawal preparation was upgraded and its efficacy for use with zebrafish tested. The upgrades consisted of, 1) automating the presentation of stimulus events, 2) adding a third conditioned stimulus (CS) to the previous two, 3) using a larger conditioning chamber to make it easier to track the subject's position, and 4) using a non-reflective chamber floor to prevent the occurrence of defensive shoaling behavior, directed towards the subject's reflection, which can interfere with testing performance.

Conditioning was demonstrated with all three CSs, but it could only be detected if the requirements for scoring a conditioned withdrawal response were made more stringent than those previously used with goldfish. This was necessary to accommodate their comparatively high rates of locomotor activity. Comparison with existing methods. Several classical conditioning preparations are available for use with zebrafish. However, most seem difficult to reproduce, due to one or more of the following: insufficient construction information, the high level of technical expertise needed, and prohibitively high costs. In contrast, the preparation tested in this report can be easily and inexpensively constructed by virtually any student or professional researcher.

The goldfish conditioned withdrawal preparation is a highly effective, efficient, and easily obtainable tool for the study of classical fear conditioning in zebrafish.

Keywords

classical conditioning; fear; learning; zebrafish; goldfish; animal models