Dopamine Neurons in the VTA Synapse onto Neurons in the Nucleus

Essay

Dopamine neurons in the VTA synapse onto neurons in the nucleus accumbens. Neurons in the VTA are dopaminergic and is has been hypothesized that dopaminergic neurons signal reward prediction error. In this hypothesis the actual reward is compared with the predicted reward. If these two things are not equal dopaminergic signals change the predicted reward so that it matches the actual reward. Figure Q10-42
A. Figure Q10-42 shows a recording from a VTA dopaminergic neuron in a monkey. What happened when only the juice was presented to the animal prior to training? Was the predicted reward similar to the actual value? Explain your answer.
B. After training of a light to predict the amount of juice, what happened to the response to juice and why?
C. The juice was then NOT given to the monkey after it was predicted by the light. What happened and what is the reason for this response based on the abstract circuit model?