Chunk #13 — THE GENETIC BASIS OF VULNERABILITY TO ALCOHOLISM — The Neurobiology of Addiction: Dopamine Reward Circuitry and Interacting Stress Response Systems
The mesolimbic dopamine (DA) system is implicated in the development of all addictions and is also stimulated by stress [33]. This “reward” pathway originates in the ventral tegmental area of the midbrain and projects to the nucleus accumbens, the limbic system and the orbitofrontal cortex. The amygdala, hippocampus and medial prefrontal cortex send excitatory projections to the nucleus accumbens [34]. The feeling of euphoria experienced by humans subsequent to alcohol ingestion is associated with increased synaptic DA in the reward pathway that is entwined with complex changes in signal transduction pathways and numerous neurotransmitters including GABA, glutamate, serotonin (5-HT), opioid peptides and cannabinoids.
