应激神经成像的研究述评

HPA轴(hypothalamic-pituitary-adrenal cortex axis)是人体的重要内分泌应激系统, 大脑通过控制HPA轴活动影响机体在应激情境中皮质醇(cortisol)的分泌, 同时皮质醇分泌对大脑也具有负反馈作用, 影响着大脑边缘系统的重塑; 海马、杏仁核、前额叶皮层和脑干都参与了应激反应中的皮质醇调节; 未来研究要进一步对应激源细化分类, 并且试图找到适合事件相关电位技术的社会心理性应激实验范式。     

Spatial term apprehension with a reference object’s rotation in three-dimensional space

It has been reported that the overall shapes of spatial categorical patterns of projective spatial terms such as above and below are not influenced by the rotation of a reference object on a two-dimensional (2D) upright plane. However, is this also true in three-dimensional (3D) space? This study shows the dynamic aspects of the apprehension of projective spatial terms in 3D space by detailing how the rotation of a reference object with an inherent front influences the apprehension of projective spatial terms on a level plane by mapping their spatial categorical patterns. The experiment was designed to examine how spatial categorical patterns on a level plane changed with the rotation of a reference object with an inherent front in 3D computer graphics space. We manipulated the rotation of a reference object with an inherent front at three levels (0°, 90°, and 180° rotations) and examined how such manipulation changed the overall spatial categorical patterns of four basic Japanese projective spatial terms: mae, ushiro, hidari, and migi (similar to in front of, behind, to the left of, and to the right of in English, respectively). The results show that spatial term apprehension was affected by the rotation of the reference object in 3D space. In particular, rotation influenced the mae–ushiro and hidari–migi systems differently. The results also imply that our understanding of projective spatial terms on a level plane in 3D space is affected dynamically by visual information from 3D cues.     

Investigations of HPA function and the enduring consequences of stressors in adolescence in animal models

Developmental differences in hypothalamic–pituitary–adrenal (HPA) axis responsiveness to stressors and ongoing development of glucocorticoid-sensitive brain regions in adolescence suggest that similar to the neonatal period of ontogeny, adolescence may also be a sensitive period for programming effects of stressors on the central nervous system. Although research on this period of life is scarce compared to early life and adulthood, the available research indicates that effects of stress exposure during adolescence differ from, and may be longer-lasting than, effects of the same stress exposure in adulthood. Research progress in animal models in this field is reviewed including HPA function and the enduring effects of stress exposures in adolescence on sensitivity to drugs of abuse, learning and memory, and emotional behaviour in adulthood. The effects of adolescent stress depend on a number of factors, including the age, gender, the duration of stress exposure, the type of stressor, and the time between stress exposure and testing.     

消化系统疾病与精神心理因素的辩证关系

消化系统疾病与精神心理因素相互影响,其相互作用呈现个体化差异,这与个体间的内环境以及外环境差别有关。主要病理生理学机制之一为"脑-肠轴"及"脑肠互动"学说。临床医生需要认识到二者之间辩证关系的普遍性和重要性,及时发现躯体症状背后潜藏的精神心理问题,综合运用各种心理干预和药物治疗手段。     

精神分裂症肠道微生物与脑影像和临床表征的关系

微生物-肠-脑轴假设在精神分裂症发病机制中的研究受到越来越多的关注。以往研究初步考察了肠道微生物的构成与精神分裂症患者脑影像和临床表征之间的联系,但具体的作用路径尚不明确。当前研究通过总结最新研究进展,并在此基础上提出肠道微生物影响精神分裂症患者大脑结构和功能的机制假设。相关内容对于进一步阐明精神分裂症的病理机制,为将肠道微生物纳入精神分裂症的评估与干预提供理论基础。     

创伤后应激障碍的动物模型及其神经生物学机制

创伤后应激障碍是指个体由于经历对生命具有威胁的事件或严重的创伤,导致症状长期持续的精神障碍。研究创伤后应激障碍的主要动物模型为条件性恐惧和应激敏感化模型。研究表明,创伤后应激障碍中长时程留存的恐惧性记忆、高唤醒等症状与大脑杏仁核、内侧前额叶皮层和海马三个脑区及下丘脑-垂体-肾上腺轴负反馈功能增强密切相关。其中杏仁核活动增强是条件性恐惧记忆获得、保持和表达的关键神经基础。内侧前额叶皮层对杏仁核的去抑制及海马向杏仁核传递的威胁性环境信息,促进创伤后应激障碍症状的出现。在经历创伤应激后糖皮质激素受体的上调及多巴胺活动的增强是创伤后应激障碍产生的主要神经基础。对创伤后应激障碍的药物治疗研究证明多巴胺D2受体在改善患者症状中的作用比较重要,但仍需作更深入的探索     

The relation between preparatory stance and trunk rotation movements

The influence of preparatory stance on rotation movement reaction time of the trunk by bending of the knee and hip joint(s) was examined in 12 subjects. Four preparatory stances were examined: straight knee and hip extension (STAND), slight flexion of knee joints and hip joint (LIGHT), deep flexion (DEEP), and free initial position, i.e. that felt to be the most comfortable and effective (FREE). There was no significant influence of the preparatory stance on hip latency, but there were significant differences between the preparatory stances on response time (RT) and movement time (MT). Furthermore, using a quadratic curve fitting technique, knee joint angles of 24.8 degrees and a hip joint angle of 23.3 degrees were shown to be the optimum flexion angles in the preparatory stance for the initiation of quick trunk rotation movements. It is proposed that mechanical factors have considerably more effects on trunk rotation movements than does the nervous system.     

神经质人格的神经生理基础

神经质作为一种人格特质, 核心特征是具有负性情绪体验的倾向。高神经质个体表现出更强的情绪反应、更差的情绪感知和应对, 因而体验到更多的负性情绪, 进而容易形成一系列精神障碍和身体疾病。因此, 神经质成为精神病理学中一个重要的风险因素。来自自主神经系统、神经内分泌系统和脑的证据发现, 高神经质个体心血管灵活性降低、HPA轴基线活动增强、EEG活动增大以及负性情绪引起的杏仁核活动增强, 其中杏仁核的自上而下和自下而上通路可能是整合多方面证据的关键。进一步研究应致力于将遗传学、电生理学、生物化学、脑成像技术等相结合, 构建神经质产生、形成的神经生理模型。     

Daily and trait rumination: diurnal cortisol patterns in adolescent girls

Rumination is a maladaptive form of emotion regulation associated with psychopathology. Research with adults suggests that rumination covaries with diurnal cortisol rhythms, yet this has not been examined among adolescents. Here, we examine the day-to-day covariation between rumination and cortisol, and explore whether trait rumination is associated with alterations in diurnal cortisol rhythms among adolescent girls. Participants (N?=?122) provided saliva samples 3 times per day over 3 days, along with daily reports of stress and rumination, questionnaires assessing trait rumination related to peer stress, and diagnostic interviews assessing depression and anxiety. Greater rumination than usual during the day was associated with lower cortisol awakening responses the following morning, but this effect was not significant after accounting for wake time and an objective measure of adherence to the saliva sampling protocol. Trait rumination was associated with lower average cortisol levels at waking and flatter diurnal slopes, accounting for wake time, protocol compliance, and other factors. These patterns may help to explain why rumination is related to the development of psychopathology.     

Variation in hypothalamic-pituitary-adrenal axis activity among bullied and non-bullied children

We examined the relationship between being bullied during childhood and activity of the hypothalamic-pituitary-adrenal (HPA) axis as assessed through repeated measures of salivary cortisol. A non-clinical sample of 154 (74 boys) predominantly Caucasian middle-class 12-year-olds each provided detailed information about their experiences with bullying and six saliva samples were standardized across time and day. Children with a history of child maltreatment, diagnosed psychiatric illness, foster care placement, medication use (psychotropic and oral contraception) and aggression directed toward peers and/or family members were excluded. Using multilevel regression and applying orthogonal polynomial contrasts to model the observed circadian pattern in the data, we found that occasional and frequent verbal peer victimization was associated with hyposecretion of cortisol when controlling for sex, pubertal status, age, depression and anxiety. This relation, however, was moderated by sex. For boys, occasional exposure was associated with higher cortisol levels, whereas for girls exposure was associated with lower cortisol levels. The present study highlights the need to consider the plight of peer-victimized children seriously, as it is associated with alterations to the HPA axis that affect males and females differently, and likely diminishes a person's ability to cope with stress, possibly placing them at risk for psychopathology and ill health.