Does Administering Abilify Decrease Depression in Rats?
Depression, for the purpose of this paper, is defined as the lethargy and immobility a rat experiences when put into a tank full of water during a forced swim test (Wee, Wang, Woolverton, Pulvirenti, & Koob, 2007). It is measured by the inability of the rat to swim, climb or keep their heads above the water over a short span of time (Arunrut, Alhandre, Chen, Cha, & Russo-Neustadt, 2009). Typically, in a forced swim test, the rat will swim hard for approximately 10 minutes, then give up and float until the experimenters take them out. On the next trial, they are put back in the water, whereupon they give up much faster, usually after 2 minutes. This illustrates the “learned helplessness” model of depression. The forced swim test is a common behavioral test for assessing depression in rodents. Animals are placed in acrylic glass or plastic tubs of water. The water level in the tub is high enough to prevent the rat from touching the bottom of the cylinder with his paws or tail, and low enough to avoid escape through the top opening of the cylinder. If the rat is non-depressed, it will try to swim out of the container. Depressed rats will stop trying and float showing behavioral despair (Gupta & Masand, 2004).
The floating or immobility time is an accurate indication of the effects of anti-psychotic drugs given to the rat prior to the start of the test. Studies carried out in recent years have shown that second-generation anti-psychotics seem to be the new option for the treatment of depressive symptoms. It has been shown that amisulpride, clozapine, olanzapine, and quetiapine are significantly better in reducing depressive symptoms in schizophrenia. Anti-depressant effects of some second-generation neuroleptics are significantly stronger than those of the traditional anti-psychotics (Arunrut et al., 2009). Such drugs include Abilify (aripiprazole). Abilify is used to treat schizophrenia and bi-polar disorder in adults and teenagers 13 years of age and older. When used for bi-polar disorder, it can be used alone or with other medications to treat episodes of mania, depression or mixed episodes which would include both depressive symptoms and manic outbursts. Abilify is also used with an anti-depressant to treat depression when symptoms cannot be controlled by the anti-depressant alone. Abilify has shown to be effective in treating irritable behavior such as aggression, temper tantrums, and frequent mood changes. It works by changing the activity of certain natural substances in the brain. When Abilify is administered to rats, it changes levels of DA D2 receptors (Wesolowska, Partyka, Jastrzebska-Wiesek, Kolarz, Mierzejewski, Bienkowski, & Kolaczkowski, 2011).
Wesolowska, Partyka, Jastrzebska-Wiesek, Kolarz, Mierzejewski, Bienkowski, and Kolaczkowski (2011) studied the effect of anti-depressant like properties using the tail suspension test. The subjects consisted of (15)...