Final answer:
Stress has been found to increase the self-administration of cocaine in rats, indicating that stress can amplify drug-seeking behavior and contribute to addiction. Studies suggest that stress affects the brain's reward system, which, in combination with cocaine's effect on dopamine levels, can result in heightened drug intake.
Step-by-step explanation:
Research indicates that the experience of stress can alter various behavioral responses to drugs, including cocaine. Stress tends to enhance drug-taking behavior, which can be demonstrated in animal models. For instance, in studies involving rats, it has been found that stress can increase the amount of cocaine self-administered by the animals. In a stressed state, the animals are more likely to take higher doses of cocaine, suggesting that stress could exacerbate drug use and addiction in humans as well.
Cocaine's ability to prevent the reuptake of dopamine results in heightened levels of this neurotransmitter, which stimulates the pleasure centers in the brain, resulting in a 'high'. However, after the effects wear off, dopamine is depleted, leaving the user in a state lacking pleasure and often craving more cocaine. Stress can compound these effects by further influencing the brain's reward system and exacerbating cravings and consumption behavior.
Therefore, the correct answer to the question is that the experience of stress has been found to increase the amount of cocaine self-administered by rats. This aligns with the body of evidence suggesting that stress can amplify drug-seeking behavior and potentially contribute to the cycle of addiction.