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Abstract
The long axons of these neurons extend to other parts of the brain, including the nucleus accumbens, the dorsal striatum and the prefrontal cortex. Yet dopamine release in the target regions is more complicated than its textbook description. [...]studies in animals of the activity of dopamine neurons using an imaging approach to monitor the activity of dopamine neurons or a microelectrode method to assess dopamine release indicate that an unexpected reward can cause the predicted increase in the activity of the axonal arbor, and dopamine release in the nucleus accumbens6,7. Mohebi et al. observed that, when the rate of reward increased, there was also an increase in the animals' response rate, with a decrease in the time taken by the animal to start the task by making a nose poke into the central port after receiving the light cue. The authors found that neuronal activity in the VTA of rats was unaffected by an increase in the reward rate, however, suggesting that the motivation-related dopamine release is dissociated from the activation of dopamine neurons.