The elevated plus maze (EPM) is a rodent model

Animal testing on rodents

Rodents are commonly used in animal testing, particularly guinea pigs, hamsters, gerbils, rats, and mice.-The statistics:In the UK in 2004, 1,910,110 mice, 464,727 rats and 37,475 other rodents were used...

 of anxiety

Anxiety

Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...

 that is used as a screening test for putative anxiolytic

Anxiolytic

An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...

 or anxiogenic

Anxiogenic

An anxiogenic substance is one that causes anxiety. Anxiogenic effects can be measured by, for example, the hole-board test in rats and mice. A number of agents are used to provoke anxiety or panic in experimental models...

 compounds and as a general research tool in neurobiological anxiety research.

Method

The test setting consists of a plus-shaped apparatus with two open and two enclosed arms, each with an open roof, elevated 40–70 cm from the floor. The model is based on rodents' aversion of open spaces. This aversion leads to the behavior termed thigmotaxis, which involves avoidance of open areas by confining movements to enclosed spaces or to the edges of a bounded space. In EPM this translates into a restriction of movement to the enclosed arms.

Anxiety reduction in the plus-maze is indicated by an increase in the proportion of time spent in the open arms (time in open arms/total time in open or closed arms), and an increase in the proportion of entries into the open arms (entries into open arms/total entries into open or closed arms). Total number of arm entries and number of closed-arm entries are usually employed as measures of general activity (see). The relation between the EPM and other tests of exploratory activity (open-field

Open Field (animal test)

The Open Field Test is an experiment used to assay general locomotor activity levels and anxiety in rodents in scientific research.- Experimental Design :...

 and emergence) have been analyzed in two mouse strains.

Validity

While EPM is the most commonly employed behavioral animal anxiety model, there are several issues concerning the validity of the model. Classical clinical anxiolytics, such as benzodiazepines (e.g., Valium), do reduce measures of anxiety in EPM. However, more novel compounds, such as 5-HT_1A agonists (e.g., Buspar) give mixed results. Selective serotonin reuptake inhibitors and tricyclic antidepressants, which are commonly employed in clinical settings to treat anxiety disorders, also do not lead to a stable anxiolytic effect on EPM. This raises the possibility that EPM is a suitable model for testing GABA

Gabâ

Gabâ or gabaa, for the people in many parts of the Philippines), is the concept of a non-human and non-divine, imminent retribution. A sort of negative karma, it is generally seen as an evil effect on a person because of their wrongdoings or transgressions...

-related compounds, such as benzodiazepines or direct GABA_A agonists, but not for other drugs. Despite this, the model is commonly employed for screening putative anxiolytics and for general research into the brain mechanisms of anxiety, because of the ease of employment and the vast number of studies already in the literature. An alternative explanation to the lack of correlation between this model and treatments for the purportedly related DSM-IV conditions is that the psychopharmacological

Psychopharmacology

Psychopharmacology is the scientific study of the actions of drugs and their effects on mood, sensation, thinking, and behavior...

paradigm relating to these conditions is flawed.