Cognitive tests in zebrafish (Danio rerio): T-and Y-mazes

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 posi-tive (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.