A Simple and Effective Method to Condition Olfactory Behaviors in Groups of Zebrafish

We describe a simple assay for studying and conditioning olfactory behaviors of adult zebrafish. The apparatus consists of a circular flow-through tank into which odorants can be administered in a controlled fashion. Odorants (conditioned stimuli; CS) are repeatedly paired with food flakes (unconditioned stimuli; UCS) that are provided inside a tethered floating feeding ring. In response to conditioning, zebrafish develop an odorant-dependent place preference and restrict appetitive swimming behavior to the vicinity of the feeding ring. This robust assay can also be conducted with groups of zebrafish and thus provides a potentially important tool for large behavioral screens.