Analyzing habituation responses to novelty in zebrafish (Danio rerio)

Analysis of habituation is widely used to characterize animal cognitive phenotypes and their modulation. Although zebrafish (Danio rerio) are increasingly utilized in neurobehavioral research, their habituation responses have not been extensively investigated. Utilizing the novel tank test, we examine intra- and inter-session habituation and demonstrate robust habituation responses in adult zebrafish. Analyzing the intra-session habituation to novelty further, we also show that selected anxiogenic drugs (caffeine, pentylenetetrazole), as well as stress-inducing alarm pheromone, attenuated zebrafish habituation. Some acute anxiolytic agents, such as morphine and ethanol, while predictably reducing zebrafish anxiety, had no effects on habituation. Chronic ethanol and fluoxetine treatments improved intra-session habituation in zebrafish. In general, our study parallels literature on rodent habituation responses to novelty, and reconfirms zebrafish as a promising model for cognitive neurobehavioral research. (C) 2009 Elsevier B.V. All rights reserved.