Introduction to Animal Models of Depression

Animal models of depression are classic research tools for simulating human depressive‑like behaviors and neurobiological alterations. Common modeling approaches include chronic unpredictable mild stress (CUMS), chronic social defeat stress (CSDS), and pharmacologically induced models. At their core, these methods employ prolonged or repeated stressors to elicit phenotypes such as anhedonia, reduced locomotor activity, changes in body weight, and anxiety‑like behaviors, accompanied by pathophysiological changes—including hypothalamic–pituitary–adrenal (HPA) axis dysregulation, neurotransmitter imbalances, and diminished hippocampal neuroplasticity—thereby closely mimicking the core symptoms and underlying mechanisms of human depression. These models are widely used for screening antidepressant agents and investigating the disease’s pathogenic pathways.

Advantages of Aniphe BioLab’s Animal Model Platform for Depression Research

The Aniphe BioLab animal model platform for depression centers on standardized modeling using multi-stressor paradigms and the ability to stably recapitulate depression‑like behavioral phenotypes, providing a robust in vivo evaluation system for antidepressant drug development and mechanistic research.

	Refinement of multiple classic model systems It encompasses mainstream depression models, including chronic unpredictable mild stress (CUMS), chronic social defeat stress (CSDS), and pharmacologically induced models, thereby meeting diverse research needs.
	Standardization of Stress Response Procedures Stimulus type, intensity, and duration are managed under a strictly standardized operating procedure (SOP), minimizing variability among experimenters and enhancing batch-to-batch consistency.
	Behavioral phenotypes are stable and reliable. It can reliably induce typical depression-like phenotypes, including anhedonia, reduced locomotor activity, anxiety‑like behaviors, and impaired cognitive function.
	Multi-time-window dynamic assessment Supports a phased research design encompassing the stress‑induction phase, the behavioral‑formation phase, and the intervention‑recovery phase.
	Multidimensional evaluation system Systematic pharmacological efficacy validation is achieved through a combination of behavioral assays, biochemical markers, and histopathological analysis of brain tissue.

Modeling cycle	2–8 weeks
Laboratory animals	C57BL/6 mice or SD rats
Positive drug	Commonly used classic antidepressants such as fluoxetine (an SSRI), sertraline, venlafaxine (an SNRI), the rapid‑acting antidepressant ketamine (an NMDA receptor antagonist), and tricyclic imipramine are employed to validate the predictive validity of the model.
Application areas	Research on the screening and mechanistic investigation of novel antidepressant agents, neuroplasticity (including hippocampal neurogenesis and the BDNF signaling pathway), the gut–brain axis, neuroinflammation, neuroendocrine dysregulation (particularly HPA-axis dysfunction), and comorbidities of depression, such as chronic pain and metabolic disturbances.

Construction of Animal Models of Depression

01 Chronic unpredictable mild stress (CUMS): By chronically and randomly exposing animals to a variety of mild stressors—such as circadian disruption, damp bedding, and restraint—this model induces hallmark depression‑like behaviors, including anhedonia and reduced locomotor activity, thereby more closely mimicking the pathogenesis of chronic depression.

02 Social defeat stress model: Aggressive “dominant mice” are used to repeatedly subordinate laboratory mice, inducing behavioral changes such as social avoidance, increased anxiety, and diminished interest, thereby highlighting the role of psychosocial stressors.

03 Forced Swim Test (FST): Animals are placed in an inescapable water environment, and their immobility time is recorded to assess the degree of behavioral despair; this is a classic model frequently used for the rapid screening of antidepressant drugs.

04 Tail Suspension Test (TST): This method induces a brief stress response in animals by suspending them from their tails, with immobility duration serving as an indicator of depression-like behavior. It is simple to perform, highly reproducible, and commonly used for preliminary drug efficacy screening.