Karere Genesio M, Kinnally Erin L, Sanchez Jessica N, Famula Thomas R, Lyons Leslie A, Capitanio John P
Department of Population Health and Reproduction, University of California, Davis, CA, USA.
Biol Psychiatry. 2009 May 1;65(9):770-7. doi: 10.1016/j.biopsych.2008.11.004. Epub 2008 Dec 21.
Studies have been inconsistent in demonstrating that early adversity and specific genotype can be joint risk factors for poor behavioral outcomes. Using a rhesus monkey model, we examined how social context and different forms of early adversity influence whether a specific genotype (polymorphism in the promoter region of monoamine oxidase A [MAOA]) affects display of aggressive, fearful, and anxious behaviors.
Rhesus monkey infants (n = 473) were exposed to brief social challenge at age 3-4 months. Infants were reared 1) with mothers and up to 150 other animals in large cages; 2) with mothers in smaller social groups; 3) with mother and access to, at most, one other mother-infant pair; and 4) without mother but with access to a same-age peer in a nursery.
No effects of genotype were found for infants reared by mothers in large social cages, although several genotype by rearing environment interactions were evident. Animals reared in smaller social groups were more likely to display aggression, which was especially true of animals possessing the low-activity MAOA genotype. In addition, animals with low-activity genotypes that had experienced restricted mother rearing showed more anxious behavior (scratch, yawn).
Among mother-reared animals, broader contextual features, associated with the social environment and experience of the mother, can affect the extent to which genotype contributes to behavioral expression under conditions of challenge. Results also suggest that different forms of early adverse experience can affect the types of responses displayed by animals of different genotypes.
关于早期逆境和特定基因型是否为不良行为结果的联合风险因素，各项研究结果并不一致。我们使用恒河猴模型，研究了社会环境和不同形式的早期逆境如何影响特定基因型（单胺氧化酶A [MAOA] 启动子区域的多态性）对攻击、恐惧和焦虑行为表现的影响。
473只恒河猴幼崽在3 - 4个月大时接受短暂的社会挑战。幼崽的饲养方式如下：1）与母亲及最多150只其他动物一起饲养在大笼子里；2）与母亲在较小的社会群体中饲养；3）与母亲一起，最多能接触到另一对母婴；4）没有母亲，但在保育室里能接触到同龄同伴。
在大社会笼子里由母亲饲养的幼崽未发现基因型的影响，不过有几个基因型与饲养环境的相互作用很明显。在较小社会群体中饲养的动物更有可能表现出攻击性，低活性MAOA基因型的动物尤其如此。此外，经历过受限母亲养育的低活性基因型动物表现出更多焦虑行为（抓挠、打哈欠）。
在由母亲养育的动物中，与社会环境和母亲经历相关的更广泛背景特征，会影响基因型在挑战条件下对行为表达的作用程度。结果还表明，不同形式的早期不良经历会影响不同基因型动物表现出的反应类型。
