Platform Crossings in the Visual Water Maze: A Precision Metric for Zebrafish Spatial Memory
June 12, 2025
No Comments
The Elevated Plus Maze (EPM) remains one of the most extensively validated and widely used paradigms in behavioral neuroscience to assess anxiety-like behavior in rodents. It harnesses the natural conflict between the rodent’s innate curiosity to explore and its evolutionary aversion to exposed, elevated spaces.
At the center of this behavioral assay lies one of its most revealing variables: Time Spent in the Open Arms. This metric provides a direct, quantifiable window into an animal’s risk assessment, affective state, and behavioral inhibition—key constructs in anxiety research.
Unlike simple locomotor assays, the EPM offers contextual decision-making under stress, with the open arms posing a dilemma between fear and curiosity. The duration an animal willingly remains in this aversive but novel area is a sensitive readout of emotional regulation, particularly under pharmacological or genetic manipulation.
Conduct Science’s Elevated Plus Maze has been engineered with precision and reproducibility in mind, enabling consistent data generation across labs and studies. The standard EPM design consists of two open and two closed arms (each ~5 cm wide × 30 cm long), elevated ~50 cm above the floor, with a central platform (~5 × 5 cm).
Rodents are placed in the center zone facing an open or closed arm. As the session unfolds, tracking systems (such as ConductVision or ANY-maze) quantify:
Each of these contributes to a behavioral profile that speaks to the animal’s anxiety state, exploratory motivation, and neurobehavioral flexibility.
Rodents, especially nocturnal species like mice and rats, evolved to avoid exposed areas that increase vulnerability to predators. The open arms of the EPM mimic elevated, open environments, thus serving as anxiogenic stimuli.
Therefore, time spent in these zones is inversely related to anxiety-like behavior. Animals displaying anxiolysis (reduced anxiety) will explore open arms more frequently and for longer durations.
| Metric Profile | Interpretation |
|---|---|
|
High open-arm time, high entries |
Low anxiety, active exploration, increased risk-taking behavior |
|
Low open-arm time, high closed-arm entries |
Elevated anxiety, strong avoidance, exploration under restraint |
|
High open-arm time, low entries |
Slow, prolonged risk-taking or reduced vigilance (possibly sedated) |
|
No open-arm entries |
Severe anxiety, potential locomotor impairment or fear-induced freezing |
This contextual framework is essential in parsing true anxiolytic responses from confounding factors such as hyperactivity, sedation, or sensorimotor impairment.
Time in the open arms reflects the integrated output of multiple neural circuits:
Pharmacologically, benzodiazepines (e.g., diazepam), SSRIs, and endocannabinoid agonists have all been shown to increase open arm time, validating the EPM as a translational tool for anxiolytic drug screening.
Subjects: 24 adult male C57BL/6J mice
Conditions: 3 groups – Vehicle, Drug A (Low Dose), Drug A (High Dose)
Duration: 5-minute EPM exposure
Tracking: ConductVision at 30+ FPS, automated zone mapping
| Group | Time in Open Arms (s) | % of Total Duration | Open Arm Entries |
|---|---|---|---|
|
Vehicle |
52.3 ± 8.1 |
17.4% |
5.1 ± 1.3 |
|
Drug A – Low |
91.7 ± 10.5 |
30.6% |
8.9 ± 1.4 |
|
Drug A – High |
112.5 ± 11.7 |
37.5% |
10.2 ± 1.6 |
📊 Graphical Representation: Bar plot of time in open arms by treatment group.
Conclusion: Both treatment groups demonstrated increased open arm engagement, suggesting a dose-dependent anxiolytic effect of Drug A.
To ensure valid, reproducible results, researchers should adhere to:
For cross-paradigm studies, it’s best to run EPM alongside tests like the Light/Dark Box, Open Field, or Novelty-Suppressed Feeding to construct a comprehensive behavioral phenotype.
Our Elevated Plus Maze system offers:
Additionally, our platform supports multi-maze configurations, enabling simultaneous testing of multiple animals in high-throughput settings.
In the realm of rodent behavioral testing, Time in the Open Arms is more than just a number—it’s a reflection of adaptive flexibility, emotional conflict, and decision-making under stress. Whether you’re screening compounds for psychiatric disorders, investigating neural circuitry, or examining the behavioral consequences of genetic mutations, this metric offers high sensitivity and interpretability.
With the right maze design and software tools, your lab can generate data that is robust, reproducible, and meaningful.
Written by researchers, for researchers — powered by Conduct Science.
Dr Louise Corscadden acts as Conduct Science’s Director of Science and Development and Academic Technology Transfer. Her background is in genetics, microbiology, neuroscience, and climate chemistry.
Monday – Friday
9 AM – 5 PM EST
DISCLAIMER: ConductScience and affiliate products are NOT designed for human consumption, testing, or clinical utilization. They are designed for pre-clinical utilization only. Customers purchasing apparatus for the purposes of scientific research or veterinary care affirm adherence to applicable regulatory bodies for the country in which their research or care is conducted.
