Can be used to detect: benzodiazepines, serotonergic anxiolytic-like compounds and anxiolytic drugs acting on neuropeptide receptors, changed anxiety levels of in transgenic rodent models.

The elevated plus maze is perhaps the most employed animal model of anxiety in current practice. The apparatus is raised above floor level, and is composed of two enclosed arms opposed perpendicularly by two open arms. The test is based on the natural tendency of rodents to explore novel environments and their innate avoidance of unprotected, bright, and elevated places.

Administration of anxiolytic drugs at non-sedative doses promotes an increase in the open arm exploration without affecting enclosed arm exploration.

The basal activity of the animals in the EPM is affected by several factors, such as lighting levels, prior handling or stress exposure, and familiarity with the maze. Re-exposure to the EPM results in marked reductions in open arm exploratory behaviour and can totally abolish the anxiolytic effect of benzodiazepines.