Brain and Substances

Question 1

With the aid of a diagram explain how drugs of abuse influence the reward system in the brain (3)

Answer 1

Drugs of abuse stimulate release of dopamine from terminals of the mesolimbic dopamine neurons in the ventral striatum (nucleus accumbens). Diagram showing mesolimbic dopaminergic neurons projecting from the VTA in the midbrain to the ventral striatum (nucleus accumbens).

Question 2

Explain how a person can become addicted to alcohol. With the aid of a diagram, describe the neurotransmitter pathway that is activated by alcohol to cause addiction (1 for the diagram +4 = 5)

Answer 2

Repeated binge drinking causes release of dopamine in the “reward” pathway which causes irreversible changes in the neural networks that control motivation and reward-related behaviour (modulated by dopamine release).

Drugs of abuse stimulate release of dopamine from terminals of the mesolimbic dopamine neurons in the ventral striatum (nucleus accumbens). Diagram showing mesolimbic dopaminergic neurons projecting from the VTA in the midbrain to the ventral striatum (nucleus accumbens)