Establishment Methods and Application Progress of Rodent Models for Drug Addiction

Drug addiction, also referred to as drug dependence or substance use disorder, is a chronic and recurrent brain disease. Its main characteristics are compulsive drug-seeking behavior, continued use of drugs, and a loss of control over intake. Prolonged use of addictive substances can result in both physiological and psychological dependence. When usage is ceased, individuals may experience intense discomfort, including anxiety, insomnia, nausea, vomiting, and a strong craving for the substances. Drug dependence is classified into two types: physical dependence and psychological dependence. Physical dependence describes a pathological state of adaptation that results from the repeated use of addictive substances, leading to severe withdrawal syndrome upon cessation. Psychological dependence involves a mental craving for addictive substances, which is needed to experience the specific euphoria that follows consumption. Regular or continuous use is required to sustain these euphoric effects. The mechanisms of addiction are complex and influenced by genetic, environmental, and various other factors. They involve higher-level neurological activities, such as memory, reward, and decision-making. Currently, effective treatment methods for drug addiction are insufficient. Due to the complexity of drug addiction, laboratory animal research is essential. Using animal behavioral models to simulate human drug addiction can enhance our understanding of the mechanisms of addiction. This research offers a comprehensive overview of various animal experimental models that explore both physical and psychological dependence. It includes detailed descriptions of the methods and procedures used to assess physical dependence, behavioral sensitization, conditioned place preference, drug discrimination, and self-administration experiments. Additionally, the characteristics of each experimental model are compared, and the relevance of these models is discussed, aiming to provide support for the research on addiction mechanisms and the development of therapeutic methods.