Prefrontal cortex, reward pathways

Initiation of behaviour Mesolimbic pathway to nucleus accumbens from VTA (AIO) Mesocortical pathways to prefrontal cortex from VTA (AIO) Animals Increases locomotor activity and intracranial self-stimulation Humans Hallucinations, psychoses (reward, reinforcement) Animals Decreases activity and self-stimulation Humans Reduces positive symptoms of schizophrenia D2 ... 

O Virtually all abused substances appear to activate the same brain reward pathway. Key components of the reward pathway are the dopamine (DA) mesocorticolimbic system that projects from the ventral tegmental area (VTA) and the nucleus accumbens (NA) to the prefrontal cortex, the amygdala, and the olfactory tubercle (Figs. 33-3 and 33-4).5 Animal studies... 

There is a reward pathway, or circuit, in the brain that positively reinforces pleasurable behavior (Figure 4.3). The reward circuit includes three areas of the brain that are interconnected with one another the ventral tegmental area (or VTA), the nucleus accumbens, and the prefrontal cortex. Axons from neurons in the VTA communicate with neurons in the other two areas via the reward pathway. 

When the brain receives a rewarding stimulus, a chemical messenger called dopamine is released by VTA neurons. Dopamine affects neurons of the nucleus accumbens and the prefrontal cortex, and its release is associated with a feeling of pleasure and reward. Scientists can measure an increased release of dopamine in the reward pathway after a rat receives a reward. ... 

Figure 4.3 The reward pathway is the pathway in the brain that positively reinforces pleasurable behavior. When the brain receives a rewarding stimulus, the neurons in the ventral tegmental area release dopamine. The dopamine, in turn, affects neurons in the nucleus accumbens and the prefrontal cortex.

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