Brain Circuits of Migraine Pain

摘要 偏头痛是一种流行的神经疾病，影响着全球数百万人。潜在的 偏头痛的病理生理学可能涉及三叉神经疼痛通路和疼痛的不同机制。 大脑中的相关结构。最近推出的针对CGRP机制的药物包括 抗体和小分子CGRP受体拮抗剂似乎作用于血脑屏障之外。这些 药物是有效的预防性治疗的一些患者涉及脑膜降钙素基因相关肽在 偏头痛病理学。然而，许多患者对这些疗法没有反应，甚至是那些经常有效的。 “突破性偏头痛”提示存在非降钙素基因相关肽外周偏头痛机制。 偏头痛的大脑回路仍未得到充分的研究。头部伤害性感受通路涉及 三叉神经传入神经的激活与伤害性信号的传递 三叉神经颈复合体(TCC)到多个脑区。偏头痛发作期间的人类神经成像研究 已显示杏仁核和背侧桥激活，包括臂旁核(PBN)。 PBN既接受外部感觉也接受内部感觉输入，并投射到多个部位，包括 杏仁核中央核(CEA)，这是一个调节疼痛情绪方面的区域。我们的临床前研究 利用硬脑膜传入的药理学和光遗传激活，神经元追踪和行为表明 从硬脑膜到TCC、PBN和CEA的功能通路可能促进偏头痛样疼痛。 在这项提案中，我们将使用光/化学遗传学方法、免疫染色显微镜和RNAScope， CRISPR-Cas9(即CRISPR)基因操作、电生理学、钙成像和疼痛行为 研究PBN→CEA通路是否以及如何促进由激活硬脑膜引起的偏头痛样疼痛 在雄性和雌性小鼠身上使用几种不同的方法进行传入。目标1将测量对标记的影响 大脑网络中的神经激活(显微镜)和对疼痛行为的后果；Aim 2将使用大脑 具有药理学、CRISPR或光/化学遗传学的切片电生理和钙成像 PBN输出的操作以评估CEA细胞类型的可塑性；目标3将使用化学发生抑制 在CEA中的PBN输出或CRISPR缺失，以评估对偏头痛疼痛行为的可能抑制。 我们的研究旨在解决我们对偏头痛中枢通路的认识上的重大差距。我们会 确定中央PBN→CEA环路作为偏头痛的共同通路的潜在相关性 可通过CGRP依赖和CGRP非依赖的外周机制参与。

Summary Migraine is a prevalent neurological disorder affecting millions of people worldwide. The underlying pathophysiology of migraine likely involves diverse mechanisms within the trigeminal pain pathways and pain- related structures in the brain. Recently introduced medications targeting CGRP mechanisms including antibodies and small molecule CGRP receptor antagonists appear to act outside of the blood brain barrier. These medications are effective as preventive treatment in some patients implicating the role of meningeal CGRP in migraine pathology. However, many patients do not respond to these therapies and even those that do often experience “breakthrough migraines” suggesting the existence of non-CGRP peripheral migraine mechanisms. The brain circuits mediating migraine pain remain understudied. Cephalic nociceptive pathways involve activation of trigeminal afferents and transmission of the nociceptive signal through the second order cells in the trigeminocervical complex (TCC) to multiple brain regions. Human neuroimaging studies during a migraine attack have demonstrated activations in the amygdala and dorsal pons, encompassing the parabrachial nucleus (PBN). The PBN receives both exteroceptive and interoceptive sensory inputs and projects to multiple sites including the central nucleus of the amygdala (CeA), an area mediating emotional aspects of pain. Our preclinical studies using pharmacological and optogenetic activation of dural afferents, neuronal tracing and behavior suggest a functional pathway from the dura mater to TCC, PBN and CeA that may promote migraine-like pain. In this proposal, we will use opto/chemo-genetic methods, microscopy with immunostaining and RNAscope, CRISPR-Cas9 (i.e., CRISPR) genetic manipulations, electrophysiology, calcium imaging and pain behavior to investigate if, and how, the PBN→CeA pathway may promote migraine-like pain elicited by activation of dural afferents using several different approaches in male and female mice. Aim 1 will measure the effects on markers of neural activation in brain networks (microscopy) and consequences on pain behavior; Aim 2 will use brain slice electrophysiology and calcium imaging with pharmacological, CRISPR or opto/chemo-genetic manipulations of PBN outputs to evaluate plasticity of CeA cell types; Aim 3 will use chemogenetic inhibition of PBN outputs or CRISPR deletions in the CeA to evaluate possible inhibition of migraine pain behaviors. Our studies aim to address significant gaps in our knowledge of central pathways of migraine pain. We will determine the potential relevance of the central PBN→CeA circuit as a common pathway of migraine pain that can be engaged by CGRP-dependent and CGRP-independent peripheral mechanisms.