催产素对社会决策行为的影响

大量的研究已经证明催产素对人类社会决策起着重要的调节作用。以往研究者采用多种实验范式用于探讨催产素对社会决策的影响, 研究内容主要包括合作与保护行为、道德行为、信任行为和慷慨行为。研究者已提出三种关于催产素的可能的作用机制用来解释观察到的实验结果, 三种理论各有侧重。未来的研究中应关注鼻喷催产素和受体基因多态性等生理机制、并考虑催产素影响社会决策行为的性别差异、建立更完善并可供检验的理论模型。     

The role of anabolic steroids on baseline and stress heart rate in cynomolgus monkeys

This investigation examined the role of anabolic steroids on baseline heart rate (HR) and HR responses to the threat of capture in Macaca fascicularis. Ten cynomolgus monkeys were randomly assigned either to a steroid or to a sham control group. Steroid-treated animals were given testosterone injections biweekly for 10 weeks, whereas sham controls received injections of sesame oil on an identical schedule. Pretreatment and posttreatment HRs were evaluated to establish both baseline and acute-stress responses. Results revealed that animals given testosterone experienced a statistically significant increase in baseline HR when contrasted with the sham controls. No difference between the groups was detected in response to the threat of capture.     

抗心肌缺血损伤潜在治疗新靶点——线粒体

缺血预处理可减轻缺血对心肌造成的损伤,提高病人的生存能力.近年来的研究发现,缺血预处理最终通过位于心肌线粒体内膜上的几种蛋白通道发挥作用.因此,研究可调控这些重要通道功能的特异药物,对于预防和治疗缺血性心肌病具有重要的临床意义.线粒体将会成为一个有潜力的重要的治疗缺血性心脏病的新的药物作用靶点.     

The effects of acute stress and pubertal development on metabolic hormones in the rat

A dramatic change in stress responsiveness occurs during pubertal development such that stress-induced corticosterone secretion in prepubertal animals takes 45-60 min longer to return to baseline compared to adults. Though corticosterone is known to influence energy mobilization, it is presently unknown whether stressors affect other hormones important in energy utilization and metabolism differentially in animals before and after pubertal development. Therefore, we exposed prepubertal (28 days of age) and adult (77 days of age) male rats to a single 30 min session of restraint stress in either the light or dark phase of the animals' light-dark (LD) cycle and measured plasma glucose, insulin and thyroid hormones (thyroxine (T4) and triiodothyronine (T3)). We found similar stress-induced increases in plasma glucose levels in prepubertal and adult animals in the LD phase of the LD cycle. We also found that prepubertal animals have lower circulating insulin and total and free T4 levels, but higher total and free T3 levels compared to adults in both the light and dark phases (LD). Interestingly, insulin and thyroid hormone levels were unaffected by acute stress at either age or time of day. These data indicate that, despite prepubertal animals showing an extended glucocorticoid stress response after a single acute exposure to stress, glucose levels are similarly affected by acute stress in prepubertal and adult animals. Furthermore, though stage of development significantly affects the levels of peripheral metabolic hormones such as insulin, T4 and T3, acute stress does not appreciably influence their secretion before or after puberty.     

The discrepant effect of acute stress on cognitive inhibition and response inhibition

This study aimed to investigate how acute stress impinges on individual’s cognitive inhibition and response inhibition abilities. Electroencephalography was adopted when 35 healthy adult females performing the No Go Flanker task before and after the Trier Social Stress Test. Both inhibition processes evoked N2 and P3 components, but only the response inhibition evoked the late positive potential (LPP), indicating the response inhibition needed continuous cognitive effort to inhibit the prepotent response. The N2 and the P3 amplitudes were decreased, while the LPP amplitudes were increased under acute stress. These results suggested that acute stress caused the detrimental effect by occupying cognitive resources. Contrastingly, individuals actively regulated and made more efforts to counteract the detrimental effect of acute stress on response inhibition. Thus, acute stress impaired cognitive inhibition but did not affect response inhibition.     

Effects of exposure to community violence on school functioning: The mediating role of posttraumatic stress symptoms

This study investigated the association between exposure to community violence (ECV) and school functioning, as well as posttraumatic stress (PTS) symptoms as a potential mediator of the relationship. PTS symptoms are commonly associated with ECV, and are characterized by difficulty regulating emotions and behaviors. Thus, PTS symptomatology may be one mechanism through which community violence impacts school functioning. The community-based sample included 47 low-income African American children (aged 10-13). Results revealed that ECV was inversely related to academic performance and attendance. Symptoms of posttraumatic stress emerged as a mediator of the relation between ECV and academic performance. Results have implications for urban students who face violence in their communities, and emphasize the need for school-based mental health services.     

Predicting depression, anxiety and self-harm in adolescents: The role of perfectionism and acute life stress

Despite the growing evidence that perfectionism is associated with adolescent psychological distress, few studies have investigated this relationship prospectively with measures designed for use in adolescent populations. In the present study, within a diathesis-stress framework, we investigated the extent to which perfectionism and acute life stress predict depression, anxiety and self-harm among adolescent school children (n = 515) over a 6 month period (Time 1-Time 2). Socially prescribed perfectionism (SPP), self-oriented perfectionism-critical (SOP-critical) and the associated interactions with acute life stress differentially predicted anxiety, depression and self-harm. Acute life stress was an independent predictor of depression, anxiety and self-harm. SPP predicted depression and interacted with acute life stress to predict self-harm. SOP-critical and the SOP-critical by acute life stress interaction predicted anxiety. Self-oriented perfectionism-striving (SOP-striving) did not predict any of the Time 2 measures of distress. The dimensions of perfectionism are differentially associated with psychological distress. Tailored clinical interventions focused on adolescent perfectionism should offer promise in tackling psychological morbidity in adolescence.     

重复性急性应激对攻击行为的影响及调控机制

关于急性应激对攻击行为的影响, 现有研究多集中于单次急性应激情境下。然而, 相比单次急性应激, 对重复暴露于同一应激源的研究更能反映人们在现实生活中经历的应激事件。与单次应激不同, 重复性急性应激与应激适应有关, 能够节省资源, 具有很强的进化和适应意义, 但目前关于重复性急性应激对攻击行为的影响却知之甚少。鉴于此, 研究运用事件电位相关技术、鼻喷催产素和催产素受体基因型分析方法, 探讨重复性急性应激对攻击行为的影响及内部机制, 并进一步探讨通过内部和外部调控重复性急性应激反应后攻击行为的变化。     

急性应激与风险倾向：兴奋易感性的调节作用

为探索应激对决策的作用机理及其个体差异,减少工程作业中因应激导致的决策失误,本研究采用特里尔社会应激测试和气球模拟风险任务考察应激反应与应激下风险倾向的关系,并探索兴奋易感性在其中的调节作用。研究结果表明,应激下个体的皮质醇反应越大,行为越冒险。且这一作用受到兴奋易感性的调节：兴奋易感性较高的个体,应激下皮质醇反应越大,行为越冒险;而兴奋易感性较低的个体,其皮质醇变化不能预测风险倾向。该发现提示了兴奋易感性在应激影响中的重要作用,也为高压岗位的人员选拔提供了科学启示。     

The role of oxytocin in early mother-infant interactions: Variations in maternal affect attunement

The aim of the present research was to investigate the relationship between oxytocin and maternal affect attunement, as well as the role of affect attunement in the relationship between oxytocin and infant social engagement during early mother-infant interactions. Forty-three mother-infant dyads participated in the present study when infants were 4 months. They were observed during (1) a situation where no communication took place and (2) a natural interaction between mother and infant. During this procedure, three saliva samples from mothers and their infants were collected to determine their levels of oxytocin at different time points. Maternal affect attunement (maintaining attention, warm sensitivity) and infant interactive behaviors (gaze, positive, and negative affect) were coded during the natural interaction. Results indicated that overall maternal oxytocin functioning was negatively related to her warm sensitivity, while infant oxytocin reactivity together with maternal affect attunement were associated with infant positive social engagement with their mothers. Specifically, infant oxytocin reactivity was significantly related to their gazes at mother, but only for infants of highly attuned mothers. These results point to the complex role oxytocin plays in parent-infant interactions while emphasizing the need to analyze both overall oxytocin functioning as well as reactivity as different indices of human affiliative behavior.     

The adaptive response of adult rat Leydig cells to repeated immobilization stress: the role of protein kinase A and steroidogenic acute regulatory protein

The ability of immobilization stress (IMO) to decrease Leydig cell steroidogenesis and serum androgen concentration has been previously observed, but the possible mechanism(s) involved in the adaptation to prolonged or repeated stress have not been identified. In this study, we investigated whether the Leydig cells obtained from adult rats subjected to acute (15 min, 30 min or 2 h) and repeated (2 or 10 days, 2 h daily) IMO show adaptive mechanism(s) in response to stress-impaired steroidogenesis. The results showed that basal and human chorionic gonadotropin-stimulated cAMP production by Leydig cells isolated from rats exposed to both acute and repeated IMO was significantly reduced. Despite the reduced cAMP production, immunoblot analysis revealed increased immunoreactivity for both protein kinase A (PKA) and steroidogenic acute regulatory (StAR) protein in Leydig cells obtained from rats repeatedly exposed to IMO. Also, the phosphorylation and production of mature StAR protein was evident during exposure of rats to repeated IMO treatment. Treatment with cholesterol, the steroid substrate transported into mitochondria by StAR, significantly increased androgen and progesterone production by Leydig cells isolated from rats exposed to repeated IMO. In contrast, when other steroid substrates (22(R)-OH-cholesterol, pregnenolone, progesterone, Delta4-androstenedione) were present in the culture media, Leydig cell steroidogenesis was still reduced by IMO. Thus, PKA-mediated phosphorylation of StAR protein is an important mechanism in the adaptive response of Leydig cells to repeated IMO.     

Media exposure to terrorism and people's risk perception: The role of environmental sensitivity and psychophysiological response to stress

Terrorist attacks have a destabilizing impact on the general population, causing distress and fear. However, not all individuals are equally susceptible to the effects of terror threat. This study aimed to examine whether exposure to terrorism-related pictures interacted with individual differences in environmental sensitivity and psychophysiological response to stress to explain people's risk perception, operationalized as perceived likelihood of a terrorist attack and willingness to trade off one's privacy to increase national security. Ninety-five university students were randomly assigned to one of two conditions (terrorism-related vs. neutral pictures). After watching the pictures, they answered questions concerning risk perception and completed questionnaires. Stress was induced by the Mannheim Multicomponent Stress Test, during which heart rate was recorded. Results showed that the perceived likelihood of future attacks was affected by the interaction between exposure to terrorism pictures and psychophysiological reactivity to stress, whereas willingness to trade off one's privacy to improve national security was influenced by the interaction between exposure to terrorism pictures and environmental sensitivity. The study suggests that individuals high in sensitivity and psychophysiological stress reactivity are particularly affected by terrorism-related pictures. Psychologists should direct their efforts to raise general awareness of the negative effects, especially for some people, of such media coverage.     

The effect of job stress on self-reported safety behaviour in container terminal operations: The moderating role of emotional intelligence

This study empirically examined the moderating effects of emotional intelligence on job stress and self-reported safety behaviour in the context of container terminal operations using survey data collected from 430 respondents who worked in the container terminals in Taiwan. A hierarchical regression analysis was used for data analysis. The research findings indicate that job stress negatively affects safety behaviour in terms of safety compliance, as well as emotional intelligence positively affects safety behaviour in terms of safety participation and safety compliance. Results also indicated that emotional intelligence plays a moderating role on the relationships between job stress and safety compliance. The theoretical and practical implications from the research findings are discussed.     

The effect of unilateral stellectomy on the regulation of heart rate during behavioral stress

Changes in heart rate were examined during classical aversive conditioning before and after either left (n=10) or right stellectomy (n=8). Heart rate (HR) significantly (p<0.01) increased in response to the conditional stimulus with a further increase noted during the unconditional stimulus. After right stellectomy (RSGx) the aversive stress elicited a significantly (p<0.01) smaller increase in heart rate (peak HR change: control 66.8 +/- 6.0; RSGx 36.1 +/- 6.8 beats/min). In contrast left stellectomy did not significantly alter the heart rate conditional response. Cardioselective beta-adrenergic receptor blockade, metoprolol HCl (BB, 1.0 mg/kg, n=8), significantly (p<0.01) reduced the heart-rate conditional response (peak HR change: control 66.8 +/- 6; BB 25.1 +/- 3.8 beats/min) to the same extent as noted during RSGx. These data suggest that the heart-rate increases elicited by aversive stress are mediated in part by sympathetic nerves that originate or pass through the right stellate ganglion. The residual HR increase noted after RSGx or BB probably results from the withdrawal of cardiac parasympathetic activity.     

Predictors of posttraumatic stress in children following injury: The influence of appraisals, heart rate, and morphine use

Prospective studies of posttraumatic stress disorder (PTSD) in children that investigate simultaneously both cognitive and biological or psychophysiological predictors are rare. The present research reports on the impact of cognitive factors (trauma-related appraisals) and biological indicators (heart rate, morphine use) in predicting PTSD and depression symptoms following single-incident trauma. Children and adolescents (N = 48) were assessed within 4 weeks of an injury that led to hospital treatment and followed up 6-months later. While morphine did not predict initial PTSD severity, it was associated with lower levels of PTSD at follow-up. Reductions in PTSD symptoms (change scores) between assessments were similarly associated with morphine dosage. Trauma-related appraisals also contributed to PTSD and depression symptom severity. While slightly different patterns of results were obtained depending on whether static or change scores were examined, as a whole the study adds to a growing literature that morphine has the potential to reduce PTSD symptoms severity. Likewise the relationship between unhelpful trauma appraisals and posttrauma psychopathology was replicated.     

The ulcerogenic effect of a rest period after exposure to water-restraint stress in rats

Shock-induced gastric ulceration in rats is exacerbated by allowing animals to rest between the period of stress and sacrifice. Conflicting data have been reported for similar post-stress rest effects using restraint stress. In Experiment 1, rats restrained in water for 2 h and then allowed a 2-h rest period exhibited significantly greater gastric ulceration than rats sacrificed immediately after the 2-h restraint-in-water stress period. The strength of this phenomenon is confirmed by Experiment 2, in which rats challenged with restraint in water for 1.25 h and then allowed a 1.25-h rest period before sacrifice exhibited greater ulceration than animals maintained in the restraint-in-water stress for the full 2 1/2 h. Corticosterone levels for these two treatment groups were similar at the time of sacrifice. Post-stressor rest therefore actively contributes to the ulcerogenic processes initiated by this form of stress challenge.     

The effect of unilateral stellectomy on the regulation of heart rate during behavioral stress.

Changes in heart rate were examined during classical aversive conditioning before and after either left (n = 10) or right stellectomy (n = 8). Heart rate (HR) significantly (p less than 0.01) increased in response to the conditional stimulus with a further increase noted during the unconditional stimulus. After right stellectomy (RSGx) the aversive stress elicited a significantly (p less than 0.01) smaller increase in heart rate (peak HR change: control 66.8 +/- 6.0; RSGx 36.1 +/- 6.8 beats/min). In contrast left stellectomy did not significantly alter the heart rate conditional response. Cardioselective beta-adrenergic receptor blockade, metoprolol HC1 (BB, 1.0 mg/kg, n = 8), significantly (p less than 0.01) reduced the heart-rate conditional response (peak HR change: control 66.8 +/- 6; BB 25.1 +/- 3.8 beats/min) to the same extent as noted during RSGx. These data suggest that the heart-rate increases elicited by aversive stress are mediated in part by sympathetic nerves that originate or pass through the right stellate ganglion. The residual HR increase noted after RSGx or BB probably results from the withdrawal of cardiac parasympathetic activity.     

Effects of live exposure on symptoms of posttraumatic stress disorder: the role of reduced behavioral avoidance in improvement

Although the effectiveness of cognitive-behavioral treatment in posttraumatic stress disorder (PTSD) is well established, few studies examined its effects on individual PTSD symptoms and possible mechanisms of improvement in symptoms. In a previous randomized controlled study [Ba?og lu, M., Salciog lu, E., Livanou, M., Kalender, D., & Acar, G. (2005). Single-session behavioral treatment of earthquake-related posttraumatic stress disorder: A randomized waitlist controlled trial. Journal of Traumatic Stress, 18, 1-11] a single session of behavioral treatment involving self-exposure instructions was highly effective in reducing earthquake-related PTSD. In the present study we examined the effects of treatment on each PTSD symptom and which symptoms improved early in treatment. Because the intervention focused solely on behavioral avoidance, we hypothesized that avoidance would be the first symptom to change and that reduction in avoidance would generalize to all other symptoms. The results showed significant between-groups treatment effect on only behavioral avoidance early in treatment (week 6). At 6 months post-treatment recovery rates ranged from 60% to 89% for 15 PTSD symptoms, including the numbing symptoms. Lack of improvement in avoidance was associated with lack of improvement in 12 symptoms. The critical process in recovery thus appeared to be increased sense of control associated with reduction in avoidance. These findings imply that live exposure to fear cues designed to enhance sense of control might be sufficient for recovery from PTSD.     

Repeated acute stress alters heart morphometry in male and female rats differently

Stress exerts deleterious effects on the cardiovascular system. Left ventricular hypertrophy has been identified as a risk factor for heart disease. The effects of stress on other heart parameters, including heart size and heart shape, are not well-characterized. In addition, the extent to which males and females differ in stress effects on these measures has not been examined, but may help to further explain gender differences in heart disease morbidity and mortality. The present experiment examined effects of mild daily stress on heart morphology and blood volume (obtained by ex-sanguination at decapitation) in 39 male and 40 female rats of two strains. Following 14 days of stress exposure, rats were killed and blood volume was measured. Heart length, heart weight, left ventricle cavity width, right ventricle width, lateral wall thickness, anterior wall thickness, posterior wall thickness, and septal wall thickness were measured. In males, after controlling for body weight, stress decreased heart length and left ventricle cavity width and increased septal wall thickness. In females, after controlling for body weight, stress reduced total blood volume, but did not significantly affect other heart parameters. These findings suggest that stress exposure can alter heart morphology and blood volume and that there are sex differences in these effects.