Response dynamics of midbrain dopamine neurons and serotonin neurons to heroin, nicotine, cocaine, and MDMA
Cell Discovery October 5, 2018 Chao Wei, Xiao Han, Danwei Weng et al. 83 citations
Four widely abused drugs—heroin, nicotine, cocaine, and MDMA—modulate the activity of midbrain dopamine and serotonin neurons in mice with distinct potency and timing. Heroin strongly activates dopamine neurons but excites serotonin neurons only at higher doses. Nicotine activates dopamine neurons within seconds and has minimal effect on serotonin neurons. Cocaine and MDMA cause long-lasting suppression of both neuron types, with MDMA more profoundly inhibiting serotonin neurons. These inhibitory effects depend on dopamine and serotonin autoreceptors. The findings suggest that dopamine neuron activity relates more to a drug's reinforcing property, while serotonin neuron activity relates more to its euphorigenic property.