A commom protocol of the FST in mice involves testing for 6 minutes, but discarding the first 2 minutes. Does anyone know why this procedure takes place?
All the papers that I've found didin't discuss about this. So I would like to receive any suggestion. Thanks.
The mouse version of FST is typically, from start to finish, six minutes long. However, generally only the last four minutes of the test are analyzed. This is due to the fact that most mice are very active at the beginning of the FST, and the potential effects of the treatment can be obscured during the first two minutes.This article migth be helpful;
Adem Can, David T. Dao, Michal Arad, Chantelle E. Terrillion, Sean C. Piantadosi, and Todd D. Gould. The Mouse Forced Swim Test. J Vis Exp. 2012; (59): 3638.
The mouse version of FST is typically, from start to finish, six minutes long. However, generally only the last four minutes of the test are analyzed. This is due to the fact that most mice are very active at the beginning of the FST, and the potential effects of the treatment can be obscured during the first two minutes.This article migth be helpful;
Adem Can, David T. Dao, Michal Arad, Chantelle E. Terrillion, Sean C. Piantadosi, and Todd D. Gould. The Mouse Forced Swim Test. J Vis Exp. 2012; (59): 3638.
During the first two minutes of the FST most mice show high struggling and low floating. If you consider the first two minutes in the analysis, your experimental group and the controls could fail to show any differences due to a ceiling effect. If you consider instead the last 4 minutes, it will be more easy to detect differences between highly and lowly motivated animals.
I did not find why 4 min?,
However, forced swimming test is used to measure the reflex by experimental design, by observing mobility, swimming and climbing scores for the final 4 minutes of the swimming session.
I feel it could be to test endurance, when the study object is subjected to various factors,
I want to understand if it is better to calculate immobility time divided by total time or just use immobility time to draw the graph.
Dear Nashwa, for FST it is common to refer absolute time of immobility (in seconds), but you can as well report results as percentage of time spent immobile.