Harro Jaanus, Oreland Lars
Division of Neuropsychopharmacology, Department of Psychology, Estonian Centre of Behavioural and Health Sciences, University of Tartu, Estonia; Psychiatry Clinic, North Estonia Medical Centre, Tallinn, Estonia.
Department of Neuroscience, Pharmacology, University of Uppsala, Biomedical Centre, Uppsala, Sweden.
Prog Neuropsychopharmacol Biol Psychiatry. 2016 Aug 1;69:101-11. doi: 10.1016/j.pnpbp.2016.02.013. Epub 2016 Mar 7.
Monoamine oxidases, both MAO-A and MAO-B, have been implicated in personality traits and complex behaviour, including drug use. Findings supporting the involvement of MAO-A and MAO-B in shaping personality and in the development of strategies of making behavioural choices come from a variety of studies that have examined either prevalence of gene variants in clinical groups or population-derived samples, estimates of enzyme activity in blood or, by positron emission tomography, in the brain and, most recently, measurement of methylation of the gene. Most of the studies converge in associating MAO-A and MAO-B with impulsive, aggressive or antisocial personality traits or behaviours, including alcohol-related problems, and for MAO-A available evidence strongly supports interaction with adverse environmental exposures in childhood. What is known about genotype effects, and on expression and activity of the enzyme in the brain and in blood has not yet been possible to unite into a mechanistic model of the role of monoamine systems, but the reason for this low degree of generalization is likely caused by the cross-sectional nature of investigation that has not incorporated the developmental effects of MAO-s in critical time windows, including the foetal period. The "risk variants" of both MAO-s appear to increase behavioural plasticity, as supportive environments may particularly well enhance the hidden potential of their carriers. Importantly, male and female brain and behaviours have been found very different with regard to MAO×life events interaction. Future studies need to take into consideration these developmental aspects and sex/gender, as well as to specify the role of different types of environmental factors.
单胺氧化酶，即MAO-A和MAO-B，均与人格特质及复杂行为（包括药物使用）有关。支持MAO-A和MAO-B参与塑造人格以及影响行为选择策略形成的研究结果来自于各类研究，这些研究或是检测临床群体或人群样本中基因变体的流行情况，或是评估血液中或通过正电子发射断层扫描测量大脑中的酶活性，以及最近对该基因甲基化的测量。大多数研究都认为MAO-A和MAO-B与冲动、攻击性或反社会人格特质或行为有关，包括与酒精相关的问题，而且就MAO-A而言，现有证据有力地支持其与儿童期不良环境暴露的相互作用。关于基因型效应以及该酶在大脑和血液中的表达与活性的已知信息，尚未能统一纳入单胺系统作用的机制模型，但这种普遍程度较低的原因可能是研究的横断面性质，未纳入MAO在关键时间窗口（包括胎儿期）的发育影响。两种MAO的“风险变体”似乎都会增加行为可塑性，因为支持性环境可能特别有助于增强其携带者的潜在能力。重要的是，已发现男性和女性在MAO与生活事件相互作用方面，大脑和行为存在很大差异。未来的研究需要考虑这些发育方面以及性别因素，并明确不同类型环境因素的作用。
