动物造模 z-bio 2021-12-31 451

　　Researchers report that elevated serotonin levels can prevent mice from compulsive seeking and addiction to cocaine. These findings help address the biological markers of addiction risk. Like other addictive drugs, cocaine works by blocking the reuptake of key neurotransmitters such as dopamine and serotonin, resulting in euphoric effects. However, not all drug users are addicted-only about 20% of cocaine users will lose control and continue to use drugs compulsively, despite the negative consequences.

　　What makes some users addictive is still unknown. Although previous studies have shown that the different functions of the brain's serotonin system may play a role in the formation of cocaine addiction, the related brain circuits and processes are still elusive behind the transition from casual use to forced use. In this study, Yue Li and his colleagues report that they have discovered a mechanism that reveals the regulatory effect of serotonin in preventing compulsive cocaine seeking and addiction in mice. In a series of experiments using wild-type and transgenic mice, Li et al. showed how cocaine binds to a serotonin transporter to prevent reuptake, leading to increased levels of extracellular serotonin. This accumulation activates the serotonin receptor 5-HT1B, leading to presynaptic depression, inhibiting the synaptic transmission between the orbitofrontal cortex and the dorsal striatum, and preventing wild-type mice from becoming addicted. However, in transgenic mice where the serotonin transporter did not bind to cocaine to prevent extracellular serotonin accumulation, compulsive cocaine seeking behavior increased. The researchers said that the results of the study show that serotonin plays a vital role in regulating the risk of addiction. "Further research should clarify the neural mechanisms by which serotonin regulates the transition to drug addiction, which serotonin receptor-specific drugs can be used, and when these drugs can be used to potentially treat drug addiction."