The Forced Swim Test as a Model of Depressive-like Behavior

The overall goal of this procedure is to induce depressive like behavior in rodents and to test the effect of therapeutics for the study of depression. This is accomplished by first preparing transparent, cylindrical glass containers filled with water to a depth in which the mouse cannot touch the bottom with its hind legs. The second step is to place each animal in a water-filled cylindrical container and film the behavior of the mice for a total of six minutes.

The final step is to code the duration of time spent in mobile struggling and swimming using forced swim test analysis software. Ultimately, the forced swim test is used to show that when placing an animal in a container filled with water, it will eventually exhibit immobility. That may be a measure of behavioral despair.

Treatment with antidepressive and anti-anxiety medication can alter these behaviors. The main advantage of this technique over existing methods like sucrose preference test is that it is relatively and easy to perform and the results are easily and quickly analyzed. Duplication of this technique extend toward therapy or diagnosis of depression.

Its sensitivity toward a broad range of antidepressants. Make it a suitable screening test For the forced swim test. Used two adjacent rooms, one room as a waiting room for holding the animals prior to behavioral testing, and the other for carrying out the procedure.

Prepare transparent cylindrical glass containers measuring 50 centimeters in height with a diameter of 20 centimeters. Next, prepare video cameras in front of the containers so that every camera perceives one or more containers in a way that will allow the clear observation of the animal's behavior while viewing the footage. Also, prepare clean drying cages, heat lamps, and heat pads for the animals that have finished the procedure.

To avoid hypothermia, make sure the bottom of the cage has blotting paper and change it when it gets wet. To perform the training procedure on mice, there is one six minute long session divided into pretest for the first two minutes, and test for the last four minutes to get the mice acclimated to the testing environment. Transport the animals to the waiting room in their home cages at least 30 minutes prior to behavioral testing.

Fill the cylinders with tap water at 25 degrees Celsius and adjust the water depth according to the mouse's weight so that it cannot touch the bottom of the container with its hind legs. Mark the cylinder with the animal number for the purpose of the identification of the animal while viewing the footage proceed to turn on the video cameras then place each mouse in the water-filled cylinder container for six minutes. After six minutes have elapsed, turn the cameras off and remove the mouse from the container.

Place the mouse in the transient drying cage with the heat lamp above it, and the heat pad under it. Change the water after every session to avoid any influence on the next mouse. The performance of the behavioral coding can be done either by an experimenter blind to the mice's condition or by a forced swim test analysis software.

First code the duration of time spent as immobile. If the mouse is floating with the absence of any movement except for those necessary for keeping the nose above water, then code the duration of time spent as struggling climbing. If quick movements of the four limbs are observed such that the front paws break the surface of the water, finally code the duration of time spent as swimming.

If movements of for limbs or hind limbs in a paddling fashion is observed in this experiment. Adult ICR female mice were treated after three weeks of treatment with the selective serotonin reuptake inhibitor, a citalopram, or with the novel herbal antidepressive and anti-anxiety treatment NHT treatment with either a citalopram or the NHT reduced immobility and thus the depressive like behavior in the forced swim test. In addition, treatment with a citalopram resulted in higher levels of struggling behavior in the forced swim test.

Conversely, treatment with either a citalopram or the NHT had no effect on swimming behavior Following this procedure. Other methods like histological and biochemical analysis can be performed in order to answer additional questions like the nature of the neural mechanism underlying this depressive like behavior.