Anxiety is a complex and multifaceted neurobehavioral disorder that includes various forms of chronic pathological anxiety and fears, and is also the cause for various comorbid pathologies, such as depression or cardiovascular diseases. Behavioral testing of various model organisms, including the zebrafish (Danio rerio), is widely used to study neurobiological mechanisms of anxiety. Here, we discuss the novel tank test, the open field test, light-dark box and shoaling test that are widely used in translational biological psychiatry to characterize anxiety-related behavioral phenotypes in zebrafish.

T- and Y-shaped mazes are traditionally used to assess spatial learning and memory of zebrafish. In the installation of the T-shaped maze, the fish are taught to swim into the desired sleeve and not swim into the wrong one using both positive (for example, food reinforcement) and negative (for example, electric current) stimuli to form more persistent reflexes. The Y-shaped maze is based on the principle of spontaneous choice. Spontaneous choice behavior describes the tendency of animals to change their direction of rotation in a series of successive turns. Each choice statistically depends on the previous one, which indicates its mnestic origin. Unlike other types of memory tasks, testing in the Y-shaped maze does not require prior training or reinforcement (as in the T-shaped maze). Both aquatic mazes are becoming useful tools for assessing zebrafish cognitive phenotypes.