Montirosso Rosario, Provenzi Livio, Tavian Daniela, Missaglia Sara, Raggi Maria Elisabetta, Borgatti Renato
0-3 Centre for the at-Risk Infant, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
0-3 Centre for the at-Risk Infant, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
Infant Behav Dev. 2016 Nov;45(Pt A):71-82. doi: 10.1016/j.infbeh.2016.09.006. Epub 2016 Oct 13.
Individual variability exists in infants' socio-emotional stress regulation, in terms of behavioral response (i.e., negative emotionality) as well as magnitude and direction (i.e., increase or decrease) of hypothalamic-pituitary-adrenal (HPA) axis reactivity (i.e., salivary cortisol post-stress concentration). The catechol-O-methyltransferase polymorphism at codon 158 (COMT) associates with stress regulation, but no evidence exists for infants. This study aimed to assess the association between COMT and both negative emotionality and salivary cortisol reactivity to socio-emotional stress in 4-month-old infants. Sixty-nine infants were exposed to the Face-to-Face Still-Face (FFSF) paradigm. During the FFSF paradigm, socio-emotional stress is elicited by experimental manipulation of maternal responsiveness (i.e., Still-Face episode). A double-exposure FFSF with two Still-Face episodes was used to evaluate both behavioral response and HPA axis reactivity. Negative emotionality was 1-s microanalytically coded. Magnitude (i.e., area under the curve, AUC) and Direction (increase vs. decrease) of salivary cortisol post-stress concentration were assessed. COMT genotype was categorized as val-homozygotes and met-carriers. Compared to val-homozygotes, met-carriers showed higher negative emotionality during the second Still-Face episode. AUC was greater in increaser met-carriers compared to val-homozygous infants. In addition, in the presence of an increasing HPA response, the met allele emerged as a specific risk condition in the face of repeated stress exposures. The present findings further extend previous studies conducted with children and adults suggesting that the COMT met allele might be involved in stress regulation during early infancy, especially in response to repeated socio-emotional stress exposure.
婴儿的社会情感应激调节存在个体差异，体现在行为反应（即消极情绪）以及下丘脑-垂体-肾上腺（HPA）轴反应性的程度和方向（即增加或减少）上（即应激后唾液皮质醇浓度）。第158位密码子的儿茶酚-O-甲基转移酶多态性（COMT）与应激调节有关，但尚无针对婴儿的相关证据。本研究旨在评估4个月大婴儿中COMT与消极情绪以及唾液皮质醇对社会情感应激反应性之间的关联。69名婴儿接受了面对面静止脸（FFSF）范式。在FFSF范式中，通过对母亲反应性的实验性操作（即静止脸阶段）引发社会情感应激。采用包含两个静止脸阶段的双暴露FFSF来评估行为反应和HPA轴反应性。消极情绪通过1秒微观分析编码。评估应激后唾液皮质醇浓度的幅度（即曲线下面积，AUC）和方向（增加与减少）。COMT基因型分为缬氨酸纯合子和甲硫氨酸携带者。与缬氨酸纯合子相比，甲硫氨酸携带者在第二个静止脸阶段表现出更高的消极情绪。与缬氨酸纯合子婴儿相比，增加型甲硫氨酸携带者的AUC更大。此外，在HPA反应增加的情况下，面对反复的应激暴露，甲硫氨酸等位基因成为一种特定的风险因素。本研究结果进一步扩展了先前对儿童和成人进行的研究，表明COMT甲硫氨酸等位基因可能在婴儿早期的应激调节中起作用，特别是在应对反复的社会情感应激暴露时。
