Howell Brittany R, Grand Alison P, McCormack Kai M, Shi Yundi, LaPrarie Jamie L, Maestripieri Dario, Styner Martin A, Sanchez Mar M
Yerkes National Primate Research Center, Emory University, Atlanta, GA; Department of Psychiatry & Behavioral Sciences, Emory University, Atlanta, GA.
Dev Psychobiol. 2014 Dec;56(8):1735-46. doi: 10.1002/dev.21237. Epub 2014 Sep 4.
This study investigated the impact of infant maltreatment on juvenile rhesus monkeys' behavioral reactivity to novel stimuli and its associations with amygdala volume. Behavioral reactivity to novel stimuli of varying threat intensity was measured using Approach/Avoidance (AA) and Human Intruder (HI) tasks. In vivo magnetic resonance imaging (MRI) was used to measure amygdala volume. Interestingly, group behavioral differences were context-dependent. When exposed to a human intruder, maltreated subjects displayed more anxious behaviors than controls; however, when presented with fear-evoking objects, maltreated animals exhibited increased aggression and a shorter latency to inspect the objects. Finally, under testing conditions with the lowest levels of threat (neutral novel objects) maltreated animals also showed shorter latencies to inspect objects, and reduced avoidance and increased exploration compared to controls. This suggests alterations in threat assessment and less behavioral inhibition in animals with early adverse experience compared to controls. Some of these behavioral responses were associated with amygdala volume, which was positively correlated with abuse rates received during infancy, particularly reflecting a relationship with exploration, consistent with previous studies.
本研究调查了婴儿期受虐待对幼年恒河猴对新刺激的行为反应性的影响及其与杏仁核体积的关联。使用接近/回避（AA）任务和人类入侵者（HI）任务测量了对不同威胁强度的新刺激的行为反应性。采用活体磁共振成像（MRI）测量杏仁核体积。有趣的是，组间行为差异取决于情境。当暴露于人类入侵者时, 受虐待的受试者比对照组表现出更多的焦虑行为；然而，当面对引发恐惧的物体时，受虐待的动物表现出更强的攻击性，并且检查物体的潜伏期更短。最后，在威胁水平最低的测试条件下（中性新物体），与对照组相比，受虐待的动物检查物体的潜伏期也更短，回避行为减少，探索行为增加。这表明与对照组相比，有早期不良经历的动物在威胁评估方面存在改变，行为抑制减少。其中一些行为反应与杏仁核体积有关，杏仁核体积与婴儿期遭受虐待的比率呈正相关，尤其反映出与探索行为的关系，这与之前的研究一致。
