Knowledge Base

Introduction

The Porsolt Forced Swim Test

The Porsolt Forced Swim Test (Porsolt et al., 1977; Hédou et al., 2001; Juszczak et al., 2008) is the most commonly used test for assessment of depression in animal models. In the Porsolt test, a state of depression is induced by forcing a rodent to swim in a narrow cylinder or water tank from which it cannot escape.

The procedure is generally divided into a pre-test session lasting 15 minutes, followed 24 hours later by a 5-minute test session. After a period of vigorous activity in the pre-test session, the animal adopts a characteristic immobile posture. Twenty-four hours later, after administration of antidepressants, the effect on immobility can be investigated by measuring the time of being immobile in the test session and comparing this with control animals.

The Sample Experiment

To see how a Porsolt forced swim test is carried out in EthoVision XT, see the sample experiment Porsolt Forced Swim test XT180 on the downloads section of the Noldus website (see my.noldus.com).

Download this file and save it on your computer. Next, in EthoVision XT, select File, Restore Backup and select this file. See also the document Description of sample experiments of EthoVision XT.pdf for more information.

References

• Castagné, V., Moser, P., Roux, S., and Porsolt, R.D. (2011) Rodent Models of Depression: Forced Swim and Tail Suspension Behavioral Despair Tests in Rats and Mice. Current Protocols in Neuroscience 8.10A.1-8.10A.14.
• Juszczak, G.R., Lisowski, P., Sliwa, A.T., and Swiergiel, A.H. (2008). Computer assisted video analysis of swimming performance in a forced swim test: Simultaneous assessment of duration of immobility and swimming style in mice selected for high and low swim-stress induced analgesia. Physiology and Behavior: 400-407.
• Hédou, G., Pryce, C., Di Iorio, L., Heidbreder, C.A., and Feldon, J. (2001). An automated analysis of rat behavior in the forced swim test. Pharmacology, Biochemistry and Behavior: 65-76.
• Porsolt, R.D., Bertin, A., and Jalfre, M. (1977). Behavioral despair in mice: a primary screening test for antidepressants. Archives Internationales de Pharmacodynamie et de Therapie: 327-36.

Physical Setup

The following suggestions are meant to optimize the quality of tracking.

Camera View

The camera should have a good, frontal view of the entire region the animals can be in. The complete body of the animal should be visible.

Number of Animals

You can test two or more animals simultaneously, when the Porsolt cylinder fits in the same camera view. For tracking multiple animals you need the Multiple Arenas add-on module.

Contrast

Try to create as much contrast as possible between the animal and the background. This can be done by placing the cylinder or tank against a contrasting, non-reflecting background (so, a matt black background for white animals and vice versa).

You can also use back-lighting to create maximum contrast. In this case, make sure you place a screen or curtain between the lights and the cylinders to avoid reflections.

Water Surface

You can reduce the contrast due to the water surface by placing the cylinders in a bigger tank with the water surface of the tank above those of the cylinders.

Source: EthoVision XT 18 - Application Manual, Noldus Information Technology