Jan 31, 2024
Open field test for mice
- Csilla Novák1,
- Andrés Mauricio Jaramillo Flautero1,
- Matthias Prigge1
- 1Neuromodulatory Network Group, Leibniz Institute for Neurobiology, Magdeburg
Protocol Citation: Csilla Novák, Andrés Mauricio Jaramillo Flautero, Matthias Prigge 2024. Open field test for mice. protocols.io https://dx.doi.org/10.17504/protocols.io.q26g7pk29gwz/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: January 30, 2024
Last Modified: May 31, 2024
Protocol Integer ID: 94407
Keywords: Phenotyping, Behavior, anxiety-related behavior, ASAPCRN
Funders Acknowledgement:
ASAP
Grant ID: 020505
Abstract
The open field test is a classical test for the quantification of locomotor activity and anxiety-like behaviors in laboratory animals. This protocol is optimized for mice, and it includes the automatic analysis of their movement by Biobserve Viewer. Higher amount of time spent next to the walls of the arena is associated with higher levels of anxiety.
Materials
- A 50x50(x50) cm opaque arena.
- A webcam.
- White lights.
Biobserve Viewer
Biobserve Viewer
Open Biobserve Viewer.
30s
Make sure that the arena is well positioned in the middle of the view of the webcam.
1m
Go to Configuration and Experiment. Set “stop experiment after: “ to 20 minutes. If you are alone, it is best to tick “Delayed start”, so you can start the recording at the moment when the animal is put into the arena.
30s
At Camera, go to Capture settings and disable auto focus.
30s
At Filters and Objects, calibrate the camera. It is easiest if you highlight the whole arena and tell the software its dimensions (50x50 cm).
2m
If you click on the Area configuration button, you can select the tracking area. Make sure that the whole arena is within the tracking area. If you would like to measure the mouse’s average distance from the walls, then the tracking area should be equivalent to the floor of the arena.
2m
You can make a background filter. With this, you can mask the walls, so the tracking system will not confuse the mouse with dark areas.
3m
With a mouse which does not participate in your experiment, you can optimise the sensitivity of the background filter and the animal filter. Recommended values:
Background filter sensitivity: 20
Animal filter: 35
Min. animal size: 270 pixels
3m
Define the tracking zones in Zone Definition. I used the following zones:
50x50 cm is the whole arena
25x25 cm in the middle is the center
12.5x12.5 cm in the middle is the minimal center
5m
Reference point is the body.
1s
If you would like, you can define velocity classes.
3m
At Saving options, set the summary to 300 seconds (this will give you information about the mouse’s behaviour in 5-min bins).
30s
Tick “Record movie” and set the frame rate to 25 fps.
30s
Define your output folders. The initial data path is to the folder where you want to save the videos and the .vrf files, and the initial export data path is where you will save the csv files.
2m
Save your settings.
1s
Behaviour
Behaviour
1h 4m 30s
Transport the mice to the behaviour room and put the mice in individual cages.
5m
Leave them in the lobby in darkness or with red light for at least 30 minutes.
30m
Turn on the red lights in the room.
Place a 50x50 cm arena on the table.
Clean the arena and the table with 70% ethanol.
1m
Turn on the white lights above the arena. Set the light intensity in the bottom of the arena to 300 lux with the luxmeter.
2m
Bring a mouse to the behaviour room. Open the cage and gently get the animal out. Do not chase it around in the cage.
2m
Place the animal in the center of the arena. Depending on your handling protocol, you can put it in by the tail or in the palm of your hand.
30s
Make sure to start the recording at the moment when you place the mouse in the arena. You can either do it by setting a delayed start in Biobserve, or with the help of another person.
Make a recording of 20 min.
20m
Make sure to save the video file.
After the video file is saved, go to Data analysis and click on the second icon on the left to save the results in .csv.
Pick the mouse out of the arena and put it back in the cage.
2m
Count poop pellets and take a note of them.
1m
Clean the arena and the table with 70% ethanol. If you feel the necessity, you can rinse the area with distilled water.
1m
Data analysis
Data analysis
Deep lab cut