Open Field Behavior Test: A Method to Assess General Locomotion and Exploration Habits

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

NOTE: Murine behavioral studies are largely sex/age/strain-dependent, and therefore it is essential to collect the proper time points and to remain consistent across experimental groups. Environmental factors (e.g., scents, noise, temperature, humidity lighting, etc.) greatly affect behavior and anxiety in mice. Try to reduce these environmental factors as much as possible.

1. Open Field Test

NOTE: The frequency of behavioral testing can be weekly or monthly, or a combination of the two (i.e., weekly when one expects to see the biggest difference, and monthly elsewhere). Prior to behavioral testing, the animals should be habituated to the room where the testing is to take place for 10–15 min prior to the beginning of testing. Ensure that proper personal protective equipment and all local facility guidelines are followed for the behavioral testing protocols.

NOTE: No training prior to the test.

1. Ensure that the computer and OFT program are on, running, and properly connected to the camera or open field box. Click on the smartware program, the open field icon, and "OK." Chose the "digital analog converter" source from the camera options. Click on "detection" and make sure that the whole open field space is visualized and that the dimensions are 30 cm x 30 cm.
   NOTE: Equipment layout may vary depending on space constraints, but ensure that the computer and open field apparatus are near to each other in a well-lit room for proper video capture.
2. Click "calibration," "snapshot," and then "OK" to make sure that the mouse is being detected within the confines of the open field. Click "time" to pre-set an amount of time to test the mice; in this case, set 5 min.
3. Enter the subjects by clicking the "subjects" icon. Click "scheduler" and highlight all test subjects and then click the double green arrows and "phase one, session one;" this will bring in all of the subjects in order to begin collecting data.
4. Place a mouse in the center of the open field and click the "start" icon to prompt the program to begin recording. Test only one mouse at a time.
5. Once 5 min is complete, the program will automatically move to the next subject. In this case, remove the mouse that has completed the test and place the next subject into the open field. Click "start."
6. Wipe down the equipment. Repeat steps 1.3–1.4 for the remaining test subjects.
7. In order to analyze the data once all the subjects have gone through testing, click on the "analyze" icon at the top right of the screen. Click "analyze" again and then "summary report." Optionally, export the data onto a USB.