Co-induction of long-term potentiation and long-term depression at a central synapse in the leech

Most studies of long-term potentiation (LTP) have focused on potentiation induced by the activation of postsynaptic NMDA receptors (NMDARs). However, it is now apparent that NMDAR-dependent signaling processes are not the only form of LTP operating in the brain [Malenka, R. C., & Bear, M. F. (2004). LTP and LTD: An embarrassment of riches. Neuron, 44, 5–21]. Previously, we have observed that LTP in leech central synapses made by the touch mechanosensory neurons onto the S interneuron was NMDAR-independent [Burrell, B. D., & Sahley, C. L. (2004). Multiple forms of long-term potentiation and long-term depression converge on a single interneuron in the leech CNS. Journal of Neuroscience, 24, 4011–4019]. Here we examine the cellular mechanisms mediating T-to-S (T → S) LTP and find that its induction requires activation of metabotropic glutamate receptors (mGluRs), voltage-dependent Ca²⁺ channels (VDCCs) and protein kinase C (PKC). Surprisingly, whenever LTP was pharmacologically inhibited, long-term depression (LTD) was observed at the tetanized synapse, indicating that LTP and LTD were activated at the same time in the same synaptic pathway. This co-induction of LTP and LTD likely plays an important role in activity-dependent regulation of synaptic transmission.     

Neuroimaging and Depression: Current Status and Unresolved Issues

ABSTRACT— Major depression is among the most debilitating, prevalent, and recurrent of all psychiatric disorders. Over the past decade, investigators have examined the neural mechanisms associated with this disorder. In this article we present an overview of neuroimaging research that has assessed the structure and functioning of the amygdala, subgenual anterior cingulate cortex, and dorsolateral prefrontal cortex in major depression. We then describe results of studies that have attempted to elucidate the nature of the relations among these brain structures. The picture that emerges from these investigations is one in which heightened activity in limbic structures that underlie the experience and expression of emotion dampens activation in dorsal cortical structures that are involved in affect regulation, reducing their ability to influence limbic activation. We conclude by highlighting unresolved issues concerning the roles of these structures in depression and their relation to specific symptoms of this disorder.     

留守青少年的社会支持网络与其抑郁、孤独之间的关系——基于变量中心和个体中心的视角

以来自河南省农村的400名双亲外出、单亲外出和非留守青少年为被试,考察了他们的社会支持网络状况,及其与青少年抑郁、孤独的关系.变量中心和个体中心的分析均表明,青少年所知觉的来自父亲、母亲、同学和老师的支持具有一致性,同一环境中各类社会支持的一致性更高.变量中心的分析发现,总体上,老师支持和父亲支持能够显著地预测青少年的抑郁水平,母亲支持和同学支持能够显著地预测青少年的孤独.但是,不同社会支持源的预测作用因青少年留守状况的不同而不同.个体中心的分析发现,处于高母亲/高父亲/高同学/高老师支持网络下青少年的抑郁和孤独水平低于其他支持网络中的青少年.     

表观遗传修饰在应激诱发抑郁症中的作用

应激可以对个体的生理和行为产生负面影响, 甚至导致抑郁症, 但病因机制尚不清楚。近年来许多研究发现应激导致的表观遗传修饰变化影响抑郁症的发生。表观遗传是指DNA序列不发生变化, 但基因表达却发生了可遗传的改变。应激引起的HPA轴、单胺类递质、BDNF三个方面的表观遗传修饰的变化, 在抑郁症发生中发挥重要作用。最后提出了目前表观遗传机制研究的局限性和未来研究热点。     

班级朋友对抑郁的影响:一项社会网络分析

采用朋友提名和Beck抑郁问卷,以73个班级3034名大学生为被试,考察班级朋友网络中不同连接步数朋友的抑郁水平对个体抑郁的影响。结果发现:(1)互选朋友数量对抑郁存在显著的负向影响;(2)在控制了互选朋友数量的影响后,互选朋友中是否存在抑郁者,对个体自身的抑郁不具有显著的预测作用;(3)提名与被提名的直接朋友和两度距离朋友中,抑郁朋友数量对个体的抑郁具有显著的正向预测作用;(4)同性抑郁朋友的数量对个体的抑郁具有显著的正向预测作用,而异性抑郁朋友的数量对个体的抑郁则不具有显著的预测作用。综合上述结果可以得出以下结论:抑郁朋友在班级朋友网络中的影响范围仅限两度距离以内(包括两度),且这种影响不受朋友关系方向的限制。随着抑郁朋友的数量增多,个体抑郁的风险也显著增加,然而抑郁朋友对个体抑郁的影响,可能更多的是受到同性抑郁朋友的影响。     

父母冲突对青少年攻击行为的影响:一个有调节的中介模型

采用青少年攻击行为量表、青少年攻击信念量表、亲子关系量表和儿童感知父母冲突量表对506名青少年进行测查,结果表明：（1）父母冲突对青少年攻击信念和攻击行为均有显著的正向预测作用;（2）青少年攻击信念在父母冲突与攻击行为之间起着中介作用;（3）青少年攻击信念与攻击行为的关系（中介效应的后半段路径）受到亲子关系的调节,即父母冲突对青少年攻击行为的影响是有调节的中介效应。     

Influence of executive functioning difficulties on verbal aggression in adolescents: Moderating effects of winning and losing and increasing and decreasing levels of provocation

We examined the extent to which executive functioning difficulties were related to verbal aggression under conditions of gradually increasing or decreasing provocation over both winning and losing trials. Sixty adolescent boys and girls completed a modified Taylor aggression paradigm in which verbally offensive remarks were sent and received. Results showed (a) that during increasing levels of provocation, verbal aggression increased on both winning and losing trials, (b) that verbal aggression decreased during decreasing levels of provocation but only on losing trials, and (c) that difficulties on two measures of executive functioning were related to verbal aggression, but only in the context of increasing verbal provocation. Individuals with executive functioning difficulties responded with more verbal aggression than did individuals with less severe executive functioning difficulties. Results have implications for the manner in which provocation is studied and for understanding the conditions in which executive functioning difficulties contribute to verbal aggression. Aggr. Behav. 29:475–488, 2003. © 2003 Wiley‐Liss, Inc.     

Dimensions of Perfectionism, Unconditional Self-Acceptance, and Depression

The current research investigated the associations among dimensions of perfectionism, unconditional self-acceptance, and self-reported depression. A sample of 94 students completed the Multidimensional Perfectionism Scale, the Unconditional Self-Acceptance Questionnaire, and a self-report depression measure. Correlational results indicated that all three trait dimensions of perfectionism (i.e., self-oriented, other-oriented, and socially prescribed perfectionism) were associated negatively with unconditional self-acceptance. Also, as expected, depression was associated with relatively low unconditional self-acceptance. Finally, a path analysis revealed that unconditional self-acceptance mediated the association between socially prescribed perfectionism and depression, and other-oriented perfectionism was found to affect depression only indirectly through its association with low levels of self-acceptance. The findings indicate that perfectionists evaluate themselves in terms of a contingent sense of self-worth, and as such, they are vulnerable to psychological distress when they experience negative events that do not affirm their self-worth.     

青少年学生自我价值感全国常模的制定

自我价值感是个体自我中对人的认知、情绪和行为具有弥漫性影响的一个重要方面 ,也是影响人的心理健康水平的重要方面。本文的目的是使用自编的青少年自我价值感量表建立青少年学生自我价值感(SW )全国常模。对在全国各省市分层随机抽取的 34715大中学生测量结果的方差分析表明 ,在大部分自我价值感维度上 ,存在显著的年级差异和性别×年级交互作用效应。据此给出了男女学生的自我价值感年级常模 ,并进行了常模等级分转换。文中还讨论了青少年学生自我价值感特点。     

Building bridges between body and mind: The analysis of an adolescent with paralyzing chronic pain

This paper describes the evaluation, initial psychotherapy and subsequent psychoanalysis of an adolescent who presented with a severe psychosomatic process involving total body pain and profound fatigue. The author details the complex and multifaceted nature of the psychosomatic process as it unfolded in the treatment. The psychosomatic problem was not a single entity, but rather was comprised of diverse interwoven elements such as somatization, conversion on pre-oedipal and oedipal levels, conflicts over aggression, sexuality, identity, masochism, secondary gain, anaclitic depression, internalized self-other interactions with a depressed mother and transgenerational transmission of trauma. The author uses the case material to discuss technical approaches to problems that often arise in the analytic treatment of patients with complicated chronic pain and fatigue as the primary complaints. Such approaches include respecting the mind-body split as a primary defense, speaking the language of the body along with the language of the mind and developing the verbal sphere around the non-verbal symptoms. The author emphasizes that complicated chronic pain problems are common and can be helped by psychoanalysis as long as the unique and complex features are understood and reflected in the technical approach.