FTP, name this neurotransmitter which has been used as a treatment for Parkinson's patients, the precursor to dopamine.
The activity of the enzyme aromatic amino acid decarboxylase is so high that this compound is essentially unmeasurable in the central nervous system, since it is almost immediately metabolized.  Another enzyme that metabolizes this compound is catechol O-methyltransferase.  Tyrosine is the precursor to this catecholamine, which is readily able to cross the blood-brain barrier, while its metabolite is not.  FTP, name this neurotransmitter which has been used as a treatment for Parkinson's patients, the precursor to dopamine.
The activity of the enzyme aromatic amino acid decarboxylase is so high that this compound is essentially unmeasurable in the central nervous system, since it is almost immediately metabolized.  
L-dopa or levorotatory-dopa