title: [Localization of non-monoaminergic aromatic L-amino acid decarboxylase neurons (D-neurons) in the human striatum and their functional significance].
abstract: It has recently been reported that the human corpus striatum, especially its ventral part, named as the nucleus accumbens, contains numerous non-monoaminergic aromatic L-amino acid decarboxylase (AADC; the second-step monoamine synthesizing enzyme) neurons (D-neurons). D-neurons are the neurons immunoreactive for AADC but not immunoreactive for dopamine or serotonin. They lack the first-step monoamine synthesizing enzymes, tyrosine hydroxylase and tryptophan hydroxylase. AADC is also the rate-limiting enzyme of phenylethylamine (PEA) synthesis. D-neurons might participate in the manifestation of efficacy of pharmacotherapy for Parkinson's disease by uptaking monoamine precursors including L-dopa or droxidopa (L-threo-DOPS) and by converting them to dopamine or noradrenaline, respectively. As the nucleus accumbens is one of the brain regions that are involved in the pathogenesis of schizophrenia and drug dependence, D-neurons might be related to the etiology of these mental disorders. It has also been suggested that striatal D-neurons are the pluripotential cells that have compensating functions against aging or degeneration.
authors.affiliation: Clinical Research Institute, National Minami Hanamaki Hospital, 500 Suwa, Hanamaki, Iwate 025-0033, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Ikemoto
mesh_terms: D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000032:analysis*; D003342:Corpus Striatum / Q000166:cytology*; D006801:Humans; D001523:Mental Disorders / Q000473:pathology; D009474:Neurons / Q000201:enzymology / Q000502:physiology; D009714:Nucleus Accumbens / Q000166:cytology
chemical_list: D001142:Aromatic-L-Amino-Acid Decarboxylases