IMPORTANCE OF β-PHENYLETHYLAMINE (PEA) NEURONAL SYSTEM, EQUIVALENT TO D-NEURON SYSTEM AND TAAR1 LIGAND NEURON SYSTEM

Abstract Background β-phenylethylamine (PEA) is a trace amine, recently regarded as a neurotransmitter, rather than a neuromodulator, of which chemical structure is similar to amphetamine, mescaline or catecholamines. The PEA neuron may have aromatic L-amino acid decarboxylase (AADC) as a synthesizing enzyme, TAAR1 as a receptor, and MAOB as a degrading enzyme [1, 2, 3]. Aims & Objectives PEA affects on animal behaviours and human mental states. TAAR1 medicinal chemistry is prospective psychopharmacological field. The present study highlights PEA neuronal system. Methods Brains of mice, rats, monkeys and MAOA KO mice, and human post-mortem brains were used. AADC immunohistochemistry and MAO enzyme histochemistry was applied. Results Distribution of mouse D-neurons was overall overlapped with MAOB-positive neurons shown by applying MAO enzyme histochemistry to MAOA KO mice. In humans, D-neuron system was developped in the thalamus, striatum and nucleus accumbens, compared to rodents and monkeys. D-neuron system had distinct species differences. Discussion & Conclusion There are accumulating evidences showing that PEA neuronal system is equivalent to D-neuron system and TAAR1 ligand neuron system. Understanding of this neuronal system would serve to develop treatment of neuropsychiatric disaeses and TAAR1 medicinal chemistry. References 1Grimsby J et al. Nat Genet 17: 206-210, 1997 2Ikemoto K et al. Brain Res 771: 121-132, 1997 3Ikemoto K et al. In: Trace Amine and Neurological Disorders, Eds Tahira Farooqui &Akhlaq A Farooqui, pp.295-307, 2016