Open field test

• Introduction
• Study design
• Workflow
• Equipment, software and supplies
• Reagents and solutions
• Procedure
• Measurements
• Experimental and technical parameters

Introduction

The open field test monitors the activity of mice in an open arena over a defined period of time in order to assess locomotor activity, anxiety, exploratory behavior, and habituation phenotypes.

Study design

Paradigm: Baseline study

Panel: Collaborative Cross

Number of strains: 18

Sex: Both

Age: 7-9 wks

Sample size: Seven mice per sex from at least two litters

Number of cohorts: 1

Workflow

Step	Description	Equipment	Data collected
1	Mice are acclimated to test room for at least 3 days	-	-
2	Each mouse is placed in the center of an arena	Open field arena	-
3	Behavior is recorded for 20 min	Open field arena	Locomotor activity, anxiety- and exploratory-related behaviors

Equipment, software and supplies

• Open field arena: Accuscan Versamax (VMX 1.4b) [See Experimental and technical parameters]
• Software: Accuscan Versamax 4.2

Reagents and solutions

• 1% Virkon S solution

 

Procedure

1. Mice are allowed to acclimate to the testing room for a minimum of 3 days.
2. Light levels within the room are set so that the light intensity in each arena is between 100-200 lux. Light metering is performed at the start of each test day.
3. Photobeam sensor check is performed at the start of each test day or in the event of drift in control parameters using the built-in diagnostic function.
4. The method of recording is:
   • Peripheral zone: 7.62 cm from the edge of the arena walls
   • Center zone: ~40% of the total surface area of the arena
   • Corner zones: 58.06 cm² each
5. Each mouse is placed in the center of each arena, nose facing to experimenter's left and released.
6. After all mice have been placed within an arena, behavior is recorded for 20 min.
7. At the end of the 20 min test, mice are removed from the arenas and returned to their homecages.
8. Arenas are cleaned with 1% Virkon solution to disinfect and remove scent cues from previously tested mice.
9. Analysis of the recording is done to measure the activity of each mouse in each of the three zones in 5-min bins.

Data collection: Data are reported as an activity summary in both seconds moving and cm per bin and zone. Versamax files are converted into text data files using the programs Versadat and Versamap. The resulting output is a .ACT file (containing general movement information) and Versamap (containing zone information).

Formulas and derivations: Local data processing is implemented to calculate derived measures from these data, and a table of the derived measures and raw time per bin per zone are reported per mouse in JaxLIMS.

 

Experimental and technical parameters

Light level	100-200 lux
Central zone surface area	Total area is 645.16 cm2 and 39.06% of whole arena
Peripheral zone surface area	7.62 cm from wall (total area is 1006.45 cm2 and 60.94% of whole arena)
Corner zone surface area	Total area is 232.26 cm2 and 14.06% of whole arena
Arena size	42 x 42
Equipment name	Open Field
Equipment manufacturer	Accuscan
Equipment model	Accuscan Versamax (VMX 1.4b)
Color of arena	Grey
Configuration file/software version	Versamax 4.2
Type of analysis	Wide beam break
Start time	0700 - 1700 EST
Disinfectant	1% Virkon Solution