Foetal programming and cortisol secretion in early childhood: A meta-analysis of different programming variables

It is widely recognized that different events may take place in the intrauterine environment that may influence later developmental outcome. Scholars have long postulated that maternal prenatal stress, alcohol or drug use, and cigarette smoking may impact foetal formation of the hypothalamus–pituitary–adrenal (HPA) axis, which may later influence different aspects of early childhood socioemotional and cognitive development. However, results linking each of these factors with child cortisol secretion have been mixed. The current meta-analysis examined the relation between each of these programming variables and child cortisol secretion in studies conducted up to December 31st, 2012. Studies were included if they were conducted prior to child age 60 months, and if they reported an index of effect size linking either maternal prenatal stress, alcohol or drug use, or cigarette smoking with an index of child cortisol secretion. In total, 19 studies (N = 2260) revealed an average effect size of d = .36 (p < .001). Moderator analyses revealed that greater effect sizes could be traced to maternal alcohol use, to the use of retrospective research methodology, where mothers are questioned after childbirth regarding programming variables, and to the use of baseline measures of cortisol secretion, as opposed to recovery measures. Discussion focuses on processes that link the environment to foetal development and how both are linked to later adaptation.     

The cortisol awakening response and the big five personality dimensions

The present study investigated the association between the big five personality dimensions and the cortisol awakening response (CAR), a physiological parameter reflective of HPA axis activity. One hundred and seven participants completed the big five inventory (BFI; John, Donahue, & Kentle, 1991) and collected salivary cortisol samples at 0, 30, and 60 min after awakening on a weekday morning. The cortisol awakening response under the curve (CARauc) and the cortisol awakening response with respect to increase (CARi) were used as outcome variables in the statistical analyses. Hierarchical linear regression analyses were conducted using the data of 92 participants. Gender and age were included as covariates in block one of the regressions, followed by the personality dimensions in block two. Extraversion emerged as a significant predictor of CARauc. No other personality dimensions were significantly predictive of CARauc or CARi. Interestingly, gender emerged as the strongest predictor in the CARauc, with females exhibiting greater cortisol release across the awakening period than males. Our results suggest that extraversion and gender may be particularly important variables to consider in the regulation of the HPA axis.     

创伤后应激障碍患者的HPA轴功能变化的时间序列特征

已知创伤后应激障碍(posttraumatic stress disorder, PTSD)患者表现出HPA轴(hypothalamic-pituitary- adrenocortical axis)功能异常, 而皮质醇是反映PTSD患者HPA轴功能的重要生物标记。近期的研究结果提示, PTSD患者的皮质醇水平变化可能有明显的时间序列特征, 即应激事件发生后先升高, 后下降至正常水平之下。这一特征受到生物标记的时间特性, 患者病程, 应激源类型和强度, 伴生疾病等因素的干扰和掩蔽。未来研究应进一步采用长期追踪设计, 控制干扰因素的影响, 结合急性应激和慢性应激生物标记来综合验证PTSD患者皮质醇水平变化的时间序列特征|并利用该特征预测PTSD的发生、发展, 以便及时进行干预|考虑皮质醇的代谢、拮抗等机制, 结合多种生物标记综合评估、诊断PTSD患者的HPA轴功能活性。     

A psychology of the human brain–gut–microbiome axis

In recent years, we have seen increasing research within neuroscience and biopsychology on the interactions between the brain, the gastrointestinal tract, the bacteria within the gastrointestinal tract, and the bidirectional relationship between these systems: the brain–gut–microbiome axis. Although research has demonstrated that the gut microbiota can impact upon cognition and a variety of stress‐related behaviours, including those relevant to anxiety and depression, we still do not know how this occurs. A deeper understanding of how psychological development as well as social and cultural factors impact upon the brain–gut–microbiome axis will contextualise the role of the axis in humans and inform psychological interventions that improve health within the brain–gut–microbiome axis. Interventions ostensibly aimed at ameliorating disorders in one part of the brain–gut–microbiome axis (e.g., psychotherapy for depression) may nonetheless impact upon other parts of the axis (e.g., microbiome composition and function), and functional gastrointestinal disorders such as irritable bowel syndrome represent a disorder of the axis, rather than an isolated problem either of psychology or of gastrointestinal function. The discipline of psychology needs to be cognisant of these interactions and can help to inform the future research agenda in this emerging field of research. In this review, we outline the role psychology has to play in understanding the brain–gut–microbiome axis, with a focus on human psychology and the use of research in laboratory animals to model human psychology.     

Selective activation of lower leg muscles during maximum voluntary isometric contractions

The pronators and supinators play a key role in the medio-lateral stability of the ankle joint complex (i.e. talo-crural and subtalar joints). We hypothesized that each shank muscle has a specific activation pattern determined by its anatomical course around the axes of the subtalar and talo-crural joints. A secondary objective was to examine the effect of foot posture on these activation patterns. Forty-nine young adults (25 normal-arched feet, 24 flat-arched feet) performed maximum voluntary isometric contractions against manual resistance in four movement directions: plantarflexion (PF), dorsiflexion (DF), pronation (PRO) and supination (SUP). Electromyographic activity was recorded from tibialis posterior (TP) and peroneus longus (PL) with intramuscular electrodes, and gastrocnemius medialis (GM) and tibialis anterior (TA) with surface electrodes. When compared to their agonist function, all muscles were co-activated at significantly lower levels in their synergistic function (GM: 23% during SUP, TA: 72% during SUP; TP: 42% during PF, PL: 52% during PF) (p < 0.001). A significant interaction between foot posture and contraction type was evident for TA. During isometric contractions, the electromyographic activity of the shank muscles is geared to their biomechanical advantage according to their position relative to the subtalar and talo-crural joint axes.     

细胞因子和抑郁症

在心理神经免疫学领域,越来越多的证据表明神经和免疫之间存在双向交流通路,免疫系统可能在一些心理精神障碍中具有重要作用。“抑郁症的细胞因子假说”认为细胞因子作为神经调质,可能在抑郁症的病因和病理过程中具有重要作用。这个假说得到了很多证据的支持。而在动物身上应用前炎性细胞因子也能够引起与人类抑郁症行为症状非常类似的“病态行为”。研究认为外周细胞因子通过信号传导进入脑内与中枢产生的细胞因子共同作用于下丘脑－垂体－肾上腺轴和5－羟色胺系统,从而导致抑郁症。细胞因子的中枢效应可以解释很多抑郁症状,“抑郁症的细胞因子假说”为探讨抑郁症状的机制和治疗抑郁症提供了一个新的视角     

急性应激影响工作记忆的生理心理机制

急性应激是机体面对外界环境变化所产生的一系列生理和心理反应, 对认知加工, 尤其是核心的工作记忆能力产生深远影响, 然而以往的研究存在大量不一致的结果。从应激诱发方式、工作记忆加工子成分、个体差异等三个方面系统阐释应激影响工作记忆的生理心理机制, 并结合认知神经机制的框架, 可以更好地理解以往的结果。未来研究应综合考虑应激诱发、认知任务和响应个体等方面的差异对应激带来的影响, 并关注急性应激负面影响的干预与调控。     

In the Wake of the Great Recession: Economic Uncertainty,Communication, and Biological Stress Responses in Families

The impact of spouses' communication about economic uncertainty on biological stress responses was examined. The sample included 82 Latino and Caucasian couples and one of their adolescents. Wives with low economic uncertainty experienced the greatest cortisol increase to a stressful discussion with their spouse, while wives with high economic uncertainty experienced a blunted cortisol response. Husbands with high economic uncertainty exhibited a low, unresponsive cortisol pattern. Wives who experienced elevated cortisol used more corumination and had low community support. The amount parents talked about their financial worries to their adolescent was not associated with the adolescent's mental health or biosocial markers, but the parents' economic uncertainty and corumination with each other were negatively associated with their own mental health.     

负性情绪对分泌型免疫球蛋白A的影响及其神经内分泌机制

本研究考察负性情绪条件下个体粘膜免疫功能与其交感神经系统、下丘脑-垂体-肾上腺皮质轴反应之间的关系。采用负性情绪图片为情绪应激材料,分析观看图片对个体心率、收缩压、舒张压、唾液皮质醇浓度和分泌型免疫球蛋白A(SIgA)浓度、分泌率的影响。结果发现:(1)负性情绪图片可以诱发被试明显的负性情绪,使其收缩压、舒张压、唾液皮质醇水平明显上升,SIgA水平下降;(2)相关分析表明,舒张压和心率变化趋势与被试的SIgA水平呈负相关;(3)实验说明由负性情绪图片诱发的情绪造成了SIgA下降,且与交感神经系统的变化有关。     

Stigma consciousness modulates cortisol reactivity to social stress in women

The aim of the current study was to examine whether stigma consciousness shapes cortisol responses to social stress among women in the laboratory. Undergraduate women (N = 45) completed background measures and then participated in a public speaking task, with assessments of cortisol prior to the stressor as well as 20 and 40 minutes post stressor onset. Results from multilevel models revealed that women higher in stigma consciousness evidenced blunted cortisol reactivity following social stress across the study session compared to women lower in stigma consciousness. This interaction was robust to adjustment for a number of covariates, including demographic (e.g., age), physiological (e.g., menstrual cycle), and psychological (e.g., depressive symptomatology) factors. Potential explanations for observed cortisol patterns are discussed, including hyporeactivity of the hypothalamic–pituitary–adrenal axis and elevated anticipatory stress. In conclusion, implications for health disparities research are considered.