[{"from": "human", "value": "Could you provide a description of this molecule? [11CH3][C@][Branch1][#C][C][C][=C][N][C][=C][C][=C][C][=C][Ring1][=Branch1][Ring1][=Branch2][Branch1][=Branch1][C][=Branch1][C][=O][O][N]"}, {"from": "gpt", "value": "The molecule is a radiopharmaceutical containing an analogue of tryptophan, alpha-methyltryptophan (AMT), labeled with carbon 11 (11C), used to measure serotonin synthesis in the human brain using positron emission tomography (PET). Upon administration and once it crosses the blood-brain barrier and into the cytoplasm of serotonergic neurons, carbon C 11 alpha-methyltryptophan acts as a substrate for the enzyme tryptophan hydroxylase and undergoes conversion to carbon C 11 alpha-methyl-5-hydroxytryptophan, also known as C 11 alpha-methyl-serotonin (AMS). C 11 AMS accumulates in serotonergic nerve terminals in proportion to the synthesis rate of serotonin because C 11 AMS cannot be broken down by the enzyme monoamine oxidase, and thus the synthesis rate of serotonin can be imaged using PET. C 11 AMT is not incorporated into proteins, nor are metabolites released into the blood pool, making C 11 AMT an excellent tracer for serotonin synthesis in vivo."}]