Behavioral and Pharmacological Aspects of Anxiety in the Light/Dark Preference Test

Abstract

Some teleost fish present scototaxis, a tendency to search for dark places and avoid brightly lit spaces. In zebrafish, it has been proposed that scototaxis (preference for dark environments) is a model of anxiety. In this chapter, we discuss some evidence regarding that proposal, and present a standardized protocol for assessing the effect of drugs on scototaxis and associated variables using a two-compartment, light–dark preference tank. This task represents a sensitive and reliable test of anxiolytic and anxiogenic drugs, being able to discriminate sedative or psychomotor effects, as well as panicolytic vs. anxiolytic effects.