A catecholamine, it is more selectively metabolized by the monoamine oxidase MOA-B than seratonin or norepinephrine, although it is a metabolic precursor to the latter.  For ten points, name this neurotransmitter synthesized from tyrosine and believed to play a role in schizophrenia, whose deficiency is a cause of Parkinson's disease.
A catecholamine, it is more selectively metabolized by the monoamine oxidase MOA-B than seratonin or norepinephrine, although it is a metabolic precursor to the latter.  For ten points, name this neurotransmitter synthesized from tyrosine and believed to play a role in schizophrenia, whose deficiency is a cause of Parkinson's disease.
A catecholamine, it is more selectively metabolized by the monoamine oxidase MOA-B than seratonin or norepinephrine, although it is a metabolic precursor to the latter.  
{dopamine} or {hydroxytyromine}