avoiding potentially dangerous areas ( Cryan and Holmes, 2005 Cryan and Sweeney, 2011).
The EPM and the EZM (as well as other tests including the open field and light-dark box) are referred to as unconditioned, “approach-avoidance” tasks that rely on rodents’ innate conflict between approaching and exploring (foraging) vs. The EZM also eliminated the “boxed-in” regions of the closed arms of the EPM, allowing more continuous exploration of the apparatus. Interpretation of time spent in the central square of the EPM is often difficult, and was particularly a problem in mice as they can spend at least 20%–30% of the test session in this region ( Lee and Rodgers, 1990 Rodgers et al., 1992). (1994) modified the design into an elevated “zero-maze” (EZM) with alternating “open” and “closed” quadrants, which had the benefit of removing the central square region of the EPM, resulting in simpler analysis of closed and open quadrants only. The test was developed and pharmacologically validated in rats ( Pellow et al., 1985) and mice ( Lister, 1987), and is comprised of two enclosed arms and two exposed arms joined by a central square.
#Any maze stoelting plus
In conclusion, the design of the EZM encourages greater exploration of the anxiogenic regions of the apparatus, and may also be a more suitable test than the EPM for experimental designs in which assessment of anxiety-related behaviors is needed at more than one time point following experimental manipulations.įor decades, the elevated plus maze (EPM) has been the most popular test for the evaluation of anxiety-like states of rodents following experimental manipulations and for testing pharmacological agents ( Griebel and Holmes, 2013 Haller et al., 2013). Sex differences were limited to activity levels, with females being more active than males. In contrast, behavior in the EZM remained comparatively stable for several trials when the animals were tested weekly or daily.
#Any maze stoelting trial
After the first trial in the EPM, amounts of ambulation and percent time in the open arms decreased significantly (independent of inter-trial interval) which has been well-described in previous research as the one-trial tolerance phenomenon. However, mice tested in the EZM spent nearly twice the amount of time in the anxiogenic regions (open quadrants) as the mice tested in the EPM spent in the open arms of that apparatus. During the first trial, the mazes were explored equally as measured by the total distance traveled during the test session. Mice were tested either daily or weekly, exclusively in the EPM or EZM, for a total of five exposures. The goal of this research was to compare, under identical laboratory conditions, the behavior of male and female C57BL/6J mice in EZM and EPM during repeated trials.
Both tests are based on approach/avoidance conflict, with rodents perceived as “less anxious” being more willing to explore the brighter, open and elevated regions of the apparatus as opposed to remaining in the darkened and enclosed regions. The elevated plus maze (EPM) and elevated zero maze (EZM) are behavioral tests that are widely employed to assess anxiety-like behaviors in rats and mice following experimental manipulations, or to test the effects of pharmacological agents. Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA