Selecting an appropriate stress model of depression in rodents

Figure 2 Learned helplessness model/social defeat stress model. A: Learned helplessness model. This model involves subjecting experimental animals to prolonged periods of social isolation, where they are deprived of social interactions. This isolation can lead to intense frustration and induce a phenomenon called behavioral despair in the animals; B: Social defeat stress model. The resident-intruder test involves placing a male rodent into an environment where it encounters a dominant or older male rodent, leading to aggressive interactions. The invading rodent is typically attacked by the resident animal, creating a model that is commonly referred to as the resident-intruder test. This experimental setup can induce intense frustration and evoke a phenomenon known as behavioral despair in the intruder animal.