Appetitive Learning Paradigm for Zebrafish (Danio rerio) in their Home Tanks Utilising Visual or Olfactory Cues

Abstract

A visual or olfactory stimulus (green light or phenylethyl alcohol) was presented to groups of adult zebrafish in their home tanks. An automatic feeder dispensed food immediately after the conditioned stimuli (CS), or at variable delays for controls. Fish showed anticipatory movement towards the food dispensing area after as few as 7-10 trials, learning that the CS was a predictor of food presentation at the water surface. Memories of the conditioned association persisted at least 2 days after training when fish were again presented with the CS. Control fish, for which the visual or olfactory stimuli were unpaired with food, showed no response when exposed to the CS. This simple, low-cost, automated system permits scalable conditioning of zebrafish with minimal human intervention, greatly reducing both variability and labour-intensiveness. It will be useful for studies of the neural basis of learning and memory, and for high-throughput screening of compounds modifying those processes.