Forced swim test for mice and rats

Background of forsed swim test

• Automatically scores active rat (and mouse) escapes and eliminates the subjectivity of immobility measurements. The number of wheel rotations count as escape attempts. Automated scoring of wheel rotations eliminates the subjectivity of immobility measurement.
• A modification of the classic Porsolt Forced Swim Test used to test for antidepressant activity, particularly in rats. S. Nomura et al introduced an objective measurement, the number of rotations of the water wheel in a 1982 paper, “... this water wheel test is more appropriate as a screening test for antidepressants than Porsolt’s test with regard to both objectivity and specificity.” (Nomura et al.)
• In the habituation phase, the rodent is left for 5 minutes to explore the tank, and will identify the wheel as a possible way to escape. The wheel rotates freely. During the test proper: rodents turn the wheel vigorously and when they give up attempts to escape from the water, the wheel stops revolving and the number of rotations are recorded.

Automatic detection, high throughput 

• Waterwheel rotations are automatically detected via a precision rotating encoder.
• Continuous water temperature feedback from temperature sensor (included).
• Optimized for use with ANY-maze or any other software able to receive video input. ANY-maze software automatically scores number of rotations, performs statistical analysis, and collects additional information from electronics using Forced Swim Module – available with full software license.
• Automate up to 40 tests simultaneously for high throughput. Up to 40 units can be connected to a single PC.
• Connection to PC via USB (or USB hub). 
• High quality, easy to assemble. All materials are selected for reliability and durability.

Application of ofrced swim test

“A depressed state can be induced in mice by forcing them to swim in a narrow cylinder from which they cannot escape. After a brief period of vigorous activity the mice adopt a characteristic immobile posture which is readily identifiable” (Porsolt et al.).
In other words, mice forced to swim in a restricted space rapidly cease moving and become lethargic. Porsolt et al. named this phenomenon ‘behavioral despair’, and demonstrated that antidepressants selectively reduced the immobility.
The modification suggested by S. Nomura et alia in their paper of 1982 involves a small water wheel set in a water tank, to provide an objective measurement (number of rotations) and overcome the bias intrinsic to Porsolt’s method.