伤害性杏仁核在阿片诱导的痛觉过敏中的作用及其分子机制

Opioid induced hyperalgesia (OIH) hindle analgesia, the underlie mechanism is to be elucidated. OIH only partialy elucidated by sensitiztion of peripheral nociceptive afferant and primary and secnondary neurons and their releae of nocicpeptive monelculars.Several lines of evidence imply decending faciliation may contribute to OIH,but the superspinal central for OIH modulation has yet to be determined .Based on the fact that centrocapsular divison of central amygdala (CeLA), now named nociceptive amygdala,plays a key role in the modulation of both inflammatory and neuropathic hyperalgesia, we propose that CeLA may also plays a pivotal role in induction of OIH. To test this hypothesis, we have three specific aims: aim 1, neural plasty including sensitiztion of neurons in CeLA as well as long term potetiation (LTP)of synaptic trsmission in CeLA will be recorded in vivo and in vitro. Aim 2, microinjetion of specific antagnist or agonist to CeLA area to block or augmentaion the LTP may alliviate or deteriorate OIH. Aim 3,the modulation of CeLA on LTP of C fiber snynapses will be evaluated.Once we have confirmed these hypothesis, we'll furter expore the undelie molecular mechanism, specifically, the role of some hyperalgesia-related-factors, including N-methyl-D-aspartic acid receptor, metabolic glutamate recetpor group 3 and 5 ,protein kinase A (PKA),protein kinase C (PKC), extrocellular signaling regrulate kinase (ERK),and mammalin targeting of rapamycin (mTOR),in OIH will be tested. Main methods including but not limited patch clamp recoding on slice from CeLA in vitro,field potention recording in vivo, and steotaxic microinjection , molecular colon tecnology,and immuohistochemistry. The elucidation of the molecular mechanism of OIH will definitely faciliate cure OIH and benefit sufferer from it in clinic.

阿片诱导的痛觉过敏（OIH）是临床急需解决的难题，外周及脊髓研究不能完全阐释OIH的机制，研究脊髓上游中枢对OIH的调控才有可能最终阐明OIH的机制。业已证明，伤害性杏仁核（CeLC）对多种疾病痛觉过敏的形成至关重要，申请者推测CeLC可能是调制OIH的上游中枢，并提出如下具体假说：（1）OIH时CeLC神经元敏化，出现突触传递长时程增强（LTP）；（2）随CeLC神经元LTP发生或抑制，OIH被诱导或阻断；（3）C纤维突触投射的脊髓背角神经元的场电位LTP现象受CeLC调制。本研究将用CeLC脑片膜片钳记录、在体脊髓背角场电位记录、CeLC区立体定位药物干预、免疫组化、和分子生物学技术检验上述假设，同时对NMDA受体、代谢型谷胺酸受体、PKA、PKC、ERK、mTOR等调制痛觉过敏，因此也有可能调制OIH的潜在分子进行筛查，以便初步明确OIH发病的分子机制，为治疗OIH提供科学依据。

阿片诱导的痛觉过敏（OIH）是临床急待解决的难题，外周及脊髓机制无法完全解释OIH的机制,本课题提出伤害性杏仁核（CeLC）可能是脊髓上水平调节OIH的重要中枢，并提出OIH时CeLC区突触传递增强是调制OIH的重要机制的假说。为验证此假说，我们首先确认了芬太尼诱导的痛觉过敏的时效关系，然后利用Western blot检测到OIH大鼠杏仁核中央核（CeA）ERK和CaMKIIα表达上调，在CeA区立体定位注射相应的抑制剂可翻转OIH大鼠的痛敏行为；离体脑片箝记录到OIH大鼠CeA区自发的微小兴奋性突触后电流（mEPSCs）的频率和强度均增强，ERK和CaMKIIα抑制剂可逆转这种突触可塑性变化；在体实验观测到OIH大鼠脊髓场电位增强，在CeA区给予ERK抑制剂可调制这种脊髓水平突触传递的变化。由此我们的假说基本得到验证，而且发现了ERK和CaMKIIα是OIH调制的重要分子基础。为进一步探究OIH的下行调控机制，我们通过在CeLC-PAG-RVM-spinal cord通道上不同节点注射CaMKIIα抑制剂，观察其对OIH大鼠的疼痛行为，通道各节点的CaMKIIα的表达，以及mEPSCs的影响，最终证明CeA区CaMKIIα可能通过CeLC-PAG-RVM-spinal cord下行通路调控芬太尼诱发大鼠痛觉过敏。以上研究部分揭示了OIH脊髓上中枢机制，提示CeLC是研究OIH机制的重要靶区。