杏仁核在疼痛及疼痛引起的情感和认知障碍中的作用

疼痛是一种不愉快的感觉和情绪体验, 伴随有强烈的负性情绪(如厌恶、恐惧、焦虑等)。 杏仁核作为边缘系统的皮质下中枢,在情绪反应中具有重要作用。我们的研究表明杏仁核在疼痛调制,特别是疼痛情绪反应中起关键作用。本文综述了杏仁核在疼痛及疼痛引起的焦虑行为和认知功能障碍中的作用。     

疼痛的意识与意识中的疼痛

 疼痛是长期困扰人类的临床、心理与社会问题。近年来,随着疼痛的神经机制研究的进展,相关研究日益指向疼痛相关的心理学过程。疼痛或对伤害的感受可能较早就出现在进化过程中,并且很久以前就具备了心理和社会属性。大脑从海量的神经冲动中,把伤害性信息以痛觉的方式呈现给意识,并伴随着情绪信息以反映其可能的伤害程度。意识还用类似的方式呈现和处理社会关系方面的伤害。由于生活经历的不同,每个人对痛觉的认知也可能有极大的差异。从心理学和神经科学的角度进一步了解疼痛,可能可以为了解疼痛本质提供依据。     

Mechanism for chronic pain generation

Neuropathic pain and the other abnormalities of sensation induced by axon injury or by peripheral nerve inflammation should result from functional compensations of the injured neurons during their regeneration. Ectopic distribution of proteins related to Na⁺, K⁺ and Ca²⁺ channels as well as of receptors on both membranes of injured axon and its cell body becomes a main pacemaker from which spontaneous ectopic afferent of primary sensatory neurons and crosstalk between neurons occur. Abnormal ectopic afferent activities lead to disorders of the sensation, such as hyperalgesia, allodynia, spontaneous pain and paraesthesia. Administration of some ion channel agents and/or α2-adrenergic blockers has shown efficiency in preventing neuropathic pain development and in relieving neuropathic pain.     

Spider toxins activate the capsaicin receptor to produce inflammatory pain

Bites and stings from venomous creatures can produce pain and inflammation as part of their defensive strategy to ward off predators or competitors. Molecules accounting for lethal effects of venoms have been extensively characterized, but less is known about the mechanisms by which they produce pain. Venoms from spiders, snakes, cone snails or scorpions contain a pharmacopoeia of peptide toxins that block receptor or channel activation as a means of producing shock, paralysis or death. We examined whether these venoms also contain toxins that activate (rather than inhibit) excitatory channels on somatosensory neurons to produce a noxious sensation in mammals. Here we show that venom from a tarantula that is native to the West Indies contains three inhibitor cysteine knot (ICK) peptides that target the capsaicin receptor (TRPV1), an excitatory channel expressed by sensory neurons of the pain pathway. In contrast with the predominant role of ICK toxins as channel inhibitors, these previously unknown 'vanillotoxins' function as TRPV1 agonists, providing new tools for understanding mechanisms of TRP channel gating. Some vanillotoxins also inhibit voltage-gated potassium channels, supporting potential similarities between TRP and voltage-gated channel structures. TRP channels can now be included among the targets of peptide toxins, showing that animals, like plants (for example, chilli peppers), avert predators by activating TRP channels on sensory nerve fibres to elicit pain and inflammation.     

Molecular mechanisms of nociception

The sensation of pain alerts us to real or impending injury and triggers appropriate protective responses. Unfortunately, pain often outlives its usefulness as a warning system and instead becomes chronic and debilitating. This transition to a chronic phase involves changes within the spinal cord and brain, but there is also remarkable modulation where pain messages are initiated - at the level of the primary sensory neuron. Efforts to determine how these neurons detect pain-producing stimuli of a thermal, mechanical or chemical nature have revealed new signalling mechanisms and brought us closer to understanding the molecular events that facilitate transitions from acute to persistent pain.     

Morphological properties of nociceptive and non-nociceptive neurons in primary somatic cerebral cortex (SI) of cat

With the techniques of intracellular recording and labelling, we investigated pain sensation and modulation of the somatic cortical cortex at the neuron’s level. After observing the evoked potentials from stimulating the saphenous nerves (SN) of 654 neurons in SI area of the cats, we labelled 30 of the neurons with Neurobiotin to preserve the distribution and the morphologic characteristics of the neurons in the cortex. Based on the tridimensional reconstruction in addition to the eletrophysiological functions, we found clear morphological distinctions between nociceptive and non-nociceptive neurons (P＜0.01). This result provided new experimental material to illustrate the function of nociceptive neurons in somatosensory cortex (SI) and presented further evidence to support the “specificity theory” of pain sensation in terms of morphology.     

Induction of vanilloid receptor channel activity by protein kinase C

Capsaicin or vanilloid receptors (VRs) participate in the sensation of thermal and inflammatory pain. The cloned (VR1) and native VRs are non-selective cation channels directly activated by harmful heat, extracellular protons and vanilloid compounds. However, considerable attention has been focused on identifying other signalling pathways in VR activation; it is known that VR1 is also expressed in non-sensory tissue and may mediate inflammatory rather than acute thermal pain. Here we show that activation of protein kinase C (PKC) induces VR1 channel activity at room temperature in the absence of any other agonist. We also observed this effect in native VRs from sensory neurons, and phorbol esters induced a vanilloid-sensitive Ca2+ rise in these cells. Moreover, the pro-inflammatory peptide, bradykinin, and the putative endogenous ligand, anandamide, respectively induced and enhanced VR activity, in a PKC-dependent manner. These results suggest that PKC may link a range of stimuli to the activation of VRs.     

促代谢型谷氨酸受体mGluR5参与膀胱的生理与伤害性感受

促代谢型谷氨酸受体(mGluRs)是一类G蛋白偶联受体,参与中枢神经系统的突触可塑性和学习记忆等过程。一些研究资料表明,mGluRs还在躯体痛的外周信号转导和信号传递中起重要作用,但其在内脏感受中的作用尚不清楚。本研究的目的在于考察Ⅰ组促代谢型谷氨酸受体(mGluR5)是否参与膀胱的生理与伤害性感受。在用戊巴比妥钠(50mg/kg,ip)麻醉的大鼠,mGluR5拮抗剂MPEP(3.0mg/kgiv)能明显提高排尿反射的容积阈值,并能减弱快速充胀膀胱引起的腹肌收缩反应,提示mGluR5参与膀胱的生理和伤害性感受过程。在取自正常小鼠的膀胱/盆神经模型,MPEP(0.1￣100μM)对充胀膀胱引起的传入神经活动没有明显影响,而在环磷酰胺(125mg/kgip)致间质性膀胱炎(IC)的小鼠,MPEP(0.3μm)能抑制高阈值膀胱传入神经放电。在清醒、自由活动的IC小鼠,MPEP(1μmol/kg,ip)还明显抑制其后肢对机械刺激的反应。上述结果表明,mGluR5可能并不参与正常膀胱的外周机械性感受的信号转导,但可能参与膀胱生理和伤害性感受信息向脊髓和在中枢内的传递过程;外周和中枢mGluR5在实验性间质性膀胱炎时有上调现象,故可能是治疗内脏感觉过敏的一个潜在药物作用靶点。     

Loss-of-function mutations in sodium channel Nav1.7 cause anosmia

Loss of function of the gene SCN9A, encoding the voltage-gated sodium channel Na(v)1.7, causes a congenital inability to experience pain in humans. Here we show that Na(v)1.7 is not only necessary for pain sensation but is also an essential requirement for odour perception in both mice and humans. We examined human patients with loss-of-function mutations in SCN9A and show that they are unable to sense odours. To establish the essential role of Na(v)1.7 in odour perception, we generated conditional null mice in which Na(v)1.7 was removed from all olfactory sensory neurons. In the absence of Na(v)1.7, these neurons still produce odour-evoked action potentials but fail to initiate synaptic signalling from their axon terminals at the first synapse in the olfactory system. The mutant mice no longer display vital, odour-guided behaviours such as innate odour recognition and avoidance, short-term odour learning, and maternal pup retrieval. Our study creates a mouse model of congenital general anosmia and provides new strategies to explore the genetic basis of the human sense of smell.     

风险规避、社会网络对农地转出契约期限的影响

[目的]探究风险规避、社会网络对农地转出契约期限的影响,以此了解农户地转出契约期限决策以及促成更多的农地长期流转.[方法]提出研究假设并利用中国家庭金融调查(CHFS)2015数据进行实证检验,实证研究中利用Logit模型进行基准回归,并采用Probit模型、OLS模型和异质性检验等方法进行稳健性检验.[结果]风险规避...     

Inhibiting pain with pain— A basic neuromechanism of acupuncture analgesia

(i) The structure and function of the meridian (channel and collateral) described by ancient medical doctors may correspond to the blood circulation, nerve control and neurohumoral modulation of modern medicine. (ii) The needling, which can injure the tissue, is a noxious stimulation inducing pain. Acupuncture manipulation, such as lifting and thrusting, twisting and twirling, or electroacupuncture (EA) with the sufferable biggest intensity for patients should be a stronger pain stimulation. The needling sensation of soreness, numbness, distension and heaviness is a deep pain. (iii) There is an intrinsic analgesic system in brain, which centers around the periventricular and periaqueductal grey matter, contains endorphins as possible mediators, goes through the descending inhibition system in medulla oblon-gata, and acts on the gating mechanism in spinal cord. Itcould be producing analgesia while the system is activated. (iv) NRM might be a supraspinal center modulating pain, and the R-S neurons could form a basic circuit of negative feedback modulating pain. The discovery of excitatory-inhibitory reversible R-S neurons may give a neuro-physiological explanation for the double direction modulation of acupuncture at acupoint. (v) Non-noxious stimulation such as massage or stroking could excite type I and n afferent fibers, producing a weaker and transient analgesia through the spinal mechanism. When the acupoint is near the pain area, the afferent information from them could be converged on the same and neighboring spinal segments, the light acupuncture or low intensity of EA also has analgesic effects, showing acupoint specificity. But the acupoint specificity is not limited in a specially designated channel line, and it is closely related to the segment of innervation. (vi) While acupuncture manipulation of lifting and thrusting, twisting and twirling or a high intensity of EA is used, because the intensities of these stimulations exceed the threshold of afferent C fibers, they could fully excite Ⅲ(Aδ) and Ⅳ (C) afferent fibers, producing a strong and lasting analgesia, mainly through the supraspinal negative feedback mechanism modulating pain, it has curative effects. Therefore, the essence of acupuncture analgesia may chiefly be inhibiting pain with pain.     

Can we be aware of both visceral and somatic sensations via a single neuronal pathway?

Sensory information arising from somatic and visceral area is thought to be respectively transmitted to the brain by two distinct sensory neuronal systems, the somatic and visceral sensory pathway. A novel and unique spinal sensory system, the spinosolitary tract-dorsal column postsynaptic neuronal system (SST-DCPS), was physiologically and anatomically identified. The spinal neurons project to both visceral (the solitary tract nucleus) and somatic sensory (the dorsal column nuclei) nuclei via their branched axons and receive both visceral and somatic sensory information ascending from periphery through dichotomized primary afferents and descending from their targets via their branched axons. The brain might thus be aware of both visceral and somatic sensation via a single SST-DCPS neuronal channel. The finding of SST-DCPS system, as an example, might be considered as an intersection or fuzzy set of the SST and DCPS system and the concept of dichotomy in classification of neurons and neuronal pathways might thus be challenged.     

基于混合指数型损失厌恶函数的投资组合模型

结合前景理论的核心思想,该文从期望效用最大化的角度研究不同风险资产的配置问题.在线性损失厌恶函数的基础上,该文结合指数效用函数的性质,提出了一个新的效用函数——混合指数型损失厌恶函数,建立了混合指数型损失厌恶投资组合(MELA)模型,并对中国股票市场数据进行实证研究,得出MELA模型优于均值-方差模型的结论.     

Vanilloid receptor-1 is essential for inflammatory thermal hyperalgesia

The vanilloid receptor-1 (VR1) is a ligand-gated, non-selective cation channel expressed predominantly by sensory neurons. VR1 responds to noxious stimuli including capsaicin, the pungent component of chilli peppers, heat and extracellular acidification, and it is able to integrate simultaneous exposure to these stimuli. These findings and research linking capsaicin with nociceptive behaviours (that is, responses to painful stimuli in animals have led to VR1 being considered as important for pain sensation. Here we have disrupted the mouse VR1 gene using standard gene targeting techniques. Small diameter dorsal root ganglion neurons isolated from VR1-null mice lacked many of the capsaicin-, acid- and heat-gated responses that have been previously well characterized in small diameter dorsal root ganglion neurons from various species. Furthermore, although the VR1-null mice appeared normal in a wide range of behavioural tests, including responses to acute noxious thermal stimuli, their ability to develop carrageenan-induced thermal hyperalgesia was completely absent. We conclude that VR1 is required for inflammatory sensitization to noxious thermal stimuli but also that alternative mechanisms are sufficient for normal sensation of noxious heat.     

肌内效贴的研究现状及展望

归纳、概述了近40年来国内外对肌内效贴的应用现状和研究进展。近年来,肌内效贴在运动损伤防治和康复方面起到的作用已得到证实。对肌内效贴提高痛点、改善肌力、增加关节稳定性、促进循环代谢和促进感觉输入五方面相关研究进行了概括与总结。拟就未来肌内效贴作用机制、组织的即刻和延迟效果以及辅助其它康复治疗手段综合治疗运动损伤等方面进行研究。     

食品安全事件心理表征初探

探讨了公众对食品安全事件的心理表征结构。通过在网上收集数据(598) , 对食品安全事件的心理表征结构进行了探索性和验证性因素分析。结果发现, 公众对食品安全事件的心理表征可分为认知维度和情绪维度, 认知维度包括行业信任、风险估计、负面影响和责任归因4个子维度, 而情绪维度则为单一的负性情绪。对食品安全事件心理表征结构进行了分析, 并讨论了研究的理论和实践意义。     

回避还是模仿？同事亲家庭非伦理行为对员工亲家庭非伦理行为的影响

基于情感事件理论，以事件-情感-态度-行为为线索，研究构建了同事亲家庭非伦理行为双重人际影响模型.基于两个时点的529份有效样本数据，运用结构方程模型进行了实证检验.结果表明:同事亲家庭非伦理行为会通过羡慕情感和间接学习正向影响员工亲家庭非伦理行为；同事亲家庭非伦理行为会通过厌恶情感和互动回避负向影响员工亲家庭非伦理行为.这不仅丰富了现有亲家庭非伦理行为的相关研究，揭开了亲家庭非伦理行为双重人际影响效应的黑箱，同时也为组织有效地预防亲家庭非伦理行为的产生，为促进组织的良性发展提供了有益指导.     

浅析双负材料的原理及应用

双负材料(又称左手材料)是指介电常数和磁导率均为负的材料,双负材料具有与普通材料不同的电磁特性.双负材料在实验上取得了突破性的进展,各种特性逐渐被实现,文章对双负材料的原理和应用进行了研究.     

利用情感因素提高英语听力学习效果

文章在克拉申(Krashen)的情感过滤假设理论的基础上,阐述了怎样调动学生的积极情感,减少学生的情感焦虑,帮助学生提高英语听力学习效果,进而改变目前大部分学生听力水平差的听力学习现状。     

“疼痛”持守诗意的根性——简论龙克“疼痛”诗歌及“疼痛诗学”

针对达州诗人龙克诗歌创作的“疼痛”现象和倡导的“疼痛诗学”，指出龙克以“疼痛”为词根或关键词，不仅由此出发去理解、拷问诗歌，雄心勃勃地建构他的“疼痛诗学”；而且，疼痛也像一道血迹斑斑、永难愈合的伤口。无休止地到处撕咬着他的诗歌。阐述了在经历、穷尽了现代主义、后现代主义等花样繁多的革命性语言方式和文本样态之后，诗歌创作和诗学理论的标举“疼痛”既是龙克个人新的写作生长点的突破口，也是当下中国诗歌新的写作生长，最。