天麻制剂通过腺苷途径治疗偏头痛相关的分子机制研究

目的探讨天麻制剂各有效成分对偏头痛模型大鼠的降钙素基因相关肽(calcitonin gene-related peptide,CGRP)与腺苷A1受体(adenosine A1 receptor,A1R)表达的影响。方法将SPF级雄性SD大鼠84只随机分为7组(n=12):假手术组(A组/阴性对照组)、电刺激三叉神经节(electrical stimulation of the trigeminal ganglion,ESTG)模型组(B组)、舒马普坦干预组(C组/阳性对照组)、天麻素干预组(D组)、对羟基苯甲醇干预组(E组)、香英兰醇干预组(F组)、β-谷甾醇干预组(G组)。通过建立ESTG模型,采用酶联免疫吸附测定(enzyme-linked immuno sorbent assay,Elisa)、免疫荧光及Western-Blot技术检测天麻制剂各有效成分对CGRP与A1R表达的影响。结果与A组相比,B组大鼠三叉神经节(trigeminal ganglia,TG)、三叉神经脊束尾核(trigeminal nucleus caudalis,TNC)中的CGRP表达明显增高,A1R的表达明显降低,差异具有统计学意义(P 0. 01)。与B组相比,C、D组大鼠TG、TNC中的CGRP表达明显降低,A1R的表达明显增高,差异具有统计学意义(P 0. 01);而E、F、G组与B组之间差异无统计学意义(P0. 05)。与C组相比,D组大鼠TG、TNC中的CGRP、A1R的表达无明显差异(P 0. 05)。结论预防应用天麻素,与舒马普坦一样可对偏头痛发作起到一定保护作用,而香英兰醇、对羟基苯甲醇及β-谷甾醇对缓解偏头痛的作用疗效甚微,且天麻制剂有效成分中天麻素可通过激活A1R及抑制CGRP表达来抑制偏头痛的发生。     

腺苷A_1受体介导降钙素基因相关肽缓解偏头痛的相关机制研究进展

偏头痛发病机制至今尚未明确。目前三叉神经血管反射学说在偏头痛发病机制的相关学说中占主导地位,神经源性炎性反应及痛觉敏化是该学说的核心部分。降钙素基因相关肽(calcitonin gene-related peptide,CGRP)既是脑循环中最强有力的血管舒张肽,也是三叉神经微血管激活的标志物,其在偏头痛发病过程中发挥协同促进作用。腺苷A_1受体可通过介导腺苷抑制三叉神经血管系统内CGRP释放,进而缓解偏头痛的症状。本文对腺苷A_1受体介导CGRP缓解偏头痛的相关研究进展进行综述。     

异氟烷预处理对偏头痛大鼠行为学症状及三叉神经节相关蛋白表达的影响

目的探讨异氟烷(ISO)对硝酸甘油所致偏头痛大鼠行为学症状及三叉神经节内相关蛋白表达的影响。方法采用随机数字表法将SD大鼠分为对照组(S组)、模型组(M组)、ISO预处理组(包括低剂量和高剂量组,即L组和H组),每组10只,并采用皮下注射硝酸甘油法制备偏头痛模型。L组和H组于造模前30 min分别给予1%和2%ISO吸入麻醉30 min。观察并比较各组大鼠造模后耳红出现和消失的时间及每30 min时间(T_(1-7))段内的挠头、爬笼次数。采用Western blot测定三叉神经节内白介素-1β(IL-1β)、环氧合酶-2(COX2)、降钙素基因相关肽(CGRP)及核转录因子-κB p65(NF-κB p65)的蛋白表达水平。结果与S组相比,M组和ISO预处理组大鼠造模后均出现双耳发红及挠头、爬笼次数均增多等现象,三叉神经节内IL-1β、COX-2、CGRP及胞核NF-κB p65蛋白表达水平明显升高,胞浆NF-κB p65蛋白表达水平明显降低(P 0. 05);与M组相比,ISO预处理组大鼠耳红消失的时间明显缩短,T_(2-7)时挠头次数均明显减少,T_(2-6)时爬笼次数均明显减少,三叉神经节内IL-1β、COX-2、CGRP及胞核NF-κB p65蛋白表达水平明显降低,胞浆NF-κB p65蛋白表达水平明显升高(P 0. 05),且H组较L组更明显(除胞浆NF-κB p65蛋白外)。结论异氟烷能改善偏头痛大鼠的行为学症状,其机制可能与下调三叉神经节内IL-1β、COX-2、CGRP蛋白的表达水平及抑制NF-κB的激活有关。     

瞬时感受电位香草酸亚家族蛋白1受体在慢性偏头痛大鼠模型中的作用研究

目的本研究通过炎性汤(IS)反复刺激SD大鼠上矢状窦区硬脑膜建立慢性偏头痛(CM)大鼠模型,探讨瞬时感受电位香草酸亚家族蛋白1(TRPV1)受体在CM发病过程中的作用,为研究CM发病机制和治疗药物提供理论依据。方法 72只SD大鼠随机数字表法分为空白对照组(A组)、假手术组(B组)、CM模型组(C组)及TRPV1受体拮抗剂Capsazepine组(D组),采用免疫组织化学染色、Western-Blot、Real-time PCR技术检测大鼠硬脑膜、三叉神经节(TG)、三叉神经脊束尾侧核(TNC)中的TRPV1受体、降钙素基因相关肽(CGRP)表达量变化。结果 TRPV1受体和CGRP在CM大鼠硬脑膜、TG及TNC上的表达量均增加(P0.05),通过侧脑室注射Capsazepine药物后明显缓解大鼠疼痛,且TRPV1受体、CGRP表达量均明显下降(P0.05)。结论 TRPV1受体通过影响CGRP释放参与CM神经源性炎症反应及痛觉传导,提示TRPV1可能通过TRPV1-CGRP信号通路参与CM病理生理过程。     

罗格列酮对硝酸甘油诱导偏头痛大鼠的保护作用

目的观察罗格列酮对硝酸甘油诱导大鼠偏头痛模型的保护作用。方法 48只雄性SD大鼠随机分为模型组、罗格列酮组和对照组。模型组(按Tassorelli法皮下注射硝酸甘油复制大鼠偏头痛模型),罗格列酮组(于造模后30 min腹腔注射罗格列酮),对照组(不造模,皮下注射生理盐水)。观察大鼠行为学变化,采用免疫组化和Western blot法观察三叉神经颈复合体过氧化物酶体增殖物激活受体γ(PPARγ)及白介素-6(IL-6)、细胞间黏附分子-1(ICAM-1)、基质金属蛋白酶-9(MMP-9)表达。结果对照组三叉神经颈复合体中PPARγ为弱阳性表达,模型组为阳性表达,罗格列酮组为强阳性表达。模型组IL-6、ICAM-1和MMP-9表达高于对照组(P0.05)。罗格列酮组大鼠耳发红、肢频繁挠头、爬笼次数增多、烦躁不安等症状减轻,IL-6、ICAM-1、MMP-9表达较模型组明显下降(P0.05)。结论偏头痛时PPARγ表达增强;罗格列酮可通过活化PPARγ,下调IL-6、ICAM-1、MMP-9对偏头痛具有一定的保护作用。     

神经调节蛋白/表皮生长因子受体通路在偏头痛大鼠模型中的作用

目的 探讨神经调节蛋白(neuregulin,NRG)/表皮生长因子受体(epidermal growth factor receptor,ErbB)通路在偏头痛大鼠模型中的作用。方法 将Wistar大鼠随机分为对照组、模型组、空载(空慢病毒载体)组、NRG沉默(含NRG基因干扰片段的慢病毒载体)组、NRG1(0.01 mg/kg)组,每组各12只; 除对照组外,其余各组制备偏头痛大鼠模型,观察大鼠行为学表现,记录一段时间内大鼠挠头次数、爬笼次数; 测定各组大鼠机械性刺激及温度痛阈; 用酶联免疫吸附实验(Enzyme linked immunosorbent assay,ELISA)检测各组大鼠血清肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α),白介素-6(Interleukin-6,IL-6)水平; 免疫印迹实验检测各组大鼠脑组织NRG/ErbB通路相关蛋白表达水平。结果 与对照组比较,模型组、空载组大鼠挠头次数、爬笼次数、血清TNF-α及IL-6水平明显增高,机械性刺激痛阈值、热刺激潜伏期、脑组织NRG/ErbB通路相关蛋白NRG表达水平及ErbB/磷酸化表皮生长因子受体(phospho-epidermal growth factor receptor,p-ErbB)明显降低(P<0.05)。与模型组比较,空载组大鼠各指标水平无明显变化(P>0.05); NRG沉默组大鼠挠头次数、爬笼次数、血清TNF-α及IL-6水平增高,机械性刺激痛阈值、热刺激潜伏期、脑组织NRG/ErbB通路相关蛋白NRG表达水平及ErbB/p-ErbB降低(P<0.05); NRG1组大鼠挠头次数、爬笼次数、血清TNF-α及IL-6水平降低,机械性刺激痛阈值、热刺激潜伏期、脑组织NRG/ErbB通路相关蛋白ErbB/p-ErbB增高(P<0.05),NRG表达水平无明显变化(P>0.05)。结论 NRG/ErbB通路可调控大鼠偏头痛,上调该通路可减轻其头痛。     

头痛宁胶囊对偏头痛大鼠BDNF/TrkB信号通路表达的影响

目的观察头痛宁胶囊对偏头痛大鼠模型中脑源性神经营养因子(BDNF)及其信号通路上酪氨酸激酶(TrkB)受体、下游信号分子细胞外调节蛋白激酶(ERK)、磷酸化cAMP反应结合蛋白(p-CREB)表达的影响。方法将60只SD大鼠随机分为正常对照组、模型组、头痛宁干预组,依照Tassorelli法建立硝酸甘油实验性偏头痛SD大鼠模型,观察各组大鼠的行为学变化,第五次建模后用ELISA法检测血清BDNF水平及免疫组化法检测三叉神经组织中BDNF、TrkB受体、下游信号分子ERK和p-CREB的蛋白表达变化及其定位。结果行为学观察结果显示:模型组及干预组大鼠造模后出现挠头增多、双耳发红、爬笼活动频繁,但干预组大鼠的持续时间及挠头爬笼次数较模型组减少,差异具有统计学意义(P<0.05);对照组未出现上述行为学改变。ELISA结果显示:模型组大鼠发作期及间歇期血清BDNF水平高于干预组发作期及间歇期和对照组(P<0.05),无性别差异(P>0.05)。免疫组化结果显示:模型组大鼠发作期三叉神经节细胞内BDNF、TrkB、p-ERK、p-CREB的蛋白水平高于干预组发作期及间歇期和对照组(P<0.05),无性别差异(P>0.05)。结论头痛宁胶囊可能通过下调BDNF、TrkB、p-ERK、p-CREB蛋白的表达水平来达到防治偏头痛的作用。     

瞬时受体电位离子通道A1对慢性偏头痛大鼠模型的作用及氟桂利嗪对其影响

目的本实验通过炎性汤(IS)反复刺激大鼠上矢状窦区硬脑膜疼痛感受器建立慢性偏头痛(CM)大鼠模型,研究瞬时受体电位离子通道A1(TRPA1)及降钙素基因相关肽(CGRP)在CM大鼠模型中的作用,探讨TRPA1在CM发生发展中的可能作用及氟桂利嗪对其影响。方法清洁级SD雄性大鼠48只,体重250~300 g,按随机数字法分为4组(n=12):正常对照组(A组)、假手术组(B组)、CM模型组(C组)及药物干预组(D组)。注射试剂1 h后安静环境中进行大鼠行为学观察及机械刺激缩足反应阈值(PWMT)测定。采用Elisa、Real-Time PCR及Western-Blot技术检测大鼠硬脑膜、三叉神经节(TG)及三叉神经脊束核尾核(TNC)组织部位TRPA1及CGRP表达情况。结果与A组、B组相比较,C组大鼠行为学评分明显升高,PWMT测定值降低,大鼠硬脑膜、TG及TNC组织部位中CGRP及TRPA1表达量均明显上调,差异有统计学意义(P0.05);与C组相比较,D组大鼠行为学评分降低,PWMT测定值升高,硬脑膜、TG及TNC组织部位CGRP及TRPA1表达量均下调,差异有统计学意义(P0.05)。结论 I TRPA1受体可能参与CM发作的病理生理过程;氟桂利嗪可能通过影响TRPA1受体表达,引起CGRP表达下调,从而缓解CM症状。     

天舒胶囊对偏头痛动物模型血浆一氧化氮、一氧化氮合酶、降钙素基因相关肽含量及血流动力学的影响

目的 研究天舒胶囊对偏头痛动物模型血浆及脑组织血管活性物质及血流动力学的影响.方法 皮下注射硝酸甘油分别制作大鼠和兔偏头痛模型.给予天舒胶囊后用放免法和分光光度法测大鼠血浆一氧化氮(NO)和一氧化氮合酶(NOS)、降钙素基因相关肽(CGRP)含量;通过免疫组织化学染色观察三叉神经脊束核神经元型NOS(NOS1)和CGRP表达;用经颅多普勒检测兔颈内动脉血流速度改变.结果 模型组大鼠血浆NO、NOS和CGRP较对照组明显升高;经不同剂量天舒胶囊灌胃后大鼠血浆NO、NOS和CGRP的增加受到抑制,尤以中、高剂量组明显(P<0.05～0.01).模型组兔颈内动脉收缩期峰值流速明显下降,经中剂量天舒胶囊干预后流速下降也受到抑制 (P<0.05).免疫组织化学染色发现灌胃天舒胶囊后,偏头痛大鼠三叉神经脊束核NOS1和CGRP表达增加的程度减小(均P<0.05).结论 天舒胶囊可改善偏头痛发作时血管活性物质和神经递质水平失常,从而缓解偏头痛症状.     

偏头痛模型大鼠相关活性物质表达

目的研究磷酸化的细胞外信号调节激酶(the phosphorylated form of the extracellular signal-regulated kinase,p-ERK)、降钙素基因相关肽(calcitonin gene-related peptide,CGRP)及环氧化酶-2(cyclooxygenase-2,COX-2)在偏头痛模型大鼠硬脑膜、三叉神经节和三叉神经脊束尾核组织中的表达及其相关性,为探讨偏头痛发病机制提供依据。方法将60只雄性SD大鼠随机分为空白组、生理盐水组、硝酸甘油组和电刺激组;硝酸甘油组和生理盐水组根据注射后时间再分别分为30 min、1h和3h组;电刺激组再分为电刺激三叉神经节(ESTG)模型组、假手术组和尼美舒利干预组。采用免疫组化染色观察大鼠硬脑膜、三叉神经节和三叉神经脊束尾核p-ERK、CGRP、COX-2的表达。结果 (1)硝酸甘油组大鼠硬脑膜、三叉神经节和三叉神经脊束尾核的pERK、CGRP、COX-2表达均明显高于生理盐水组(均P0.01),ESTG大鼠不同部位组织的p-ERK、CGRP、COX-2表达均明显高于假手术组和空白组(均P0.01);(2)p-ERK表达在注射硝酸甘油后的30min组均高于1h组和3h组,后随时间增加其表达逐渐降低(均P0.01);(3)尼美舒利干预组大鼠不同组织中p-ERK、CGRP、COX-2的表达均低于ESTG模型组(P0.05)。结论 (1)p-ERK、CGRP、COX-2表达上调与偏头痛的炎性反应和疼痛敏化有关,其中p-ERK可能参与偏头痛早期过程;(2)偏头痛过程中,p-ERK、CGRP和COX-2蛋白之间有密切联系。     

New targets in the acute treatment of headache

PURPOSE OF REVIEW: The aim of this article is to review recently identified targets for the acute treatment of primary headache disorders. RECENT FINDINGS: Calcitonin gene-related peptide (CGRP) receptor blockade has been shown to be an effective acute anti-migraine strategy and is a non-vasoconstrictor in terms of the mechanism of action. It is likely that direct blockade of CGRP release by inhibition of trigeminal nerves would be similarly effective in both migraine and cluster headache. Options for acute treatment based on preclinical work and initial clinical studies include: serotonin 5HT1F and 5HT1D receptor agonists, glutamate excitatory amino acid receptor antagonists, nitric oxide synthase inhibitors and adenosine A1 receptor agonists. Proof of principle studies with octreotide, a somatostatin receptor agonist, demonstrated it to be better than placebo in the acute treatment of cluster headache but not in the acute management of migraine. SUMMARY: The prospect of a non-vasoconstrictor acute migraine therapy offers a real opportunity to patients, and perhaps more importantly, provides a therapeutic rationale to plant migraine and cluster headache firmly in the brain as neurological problems.     

Nitroglycerin facilitates calcitonin gene-related peptide-induced behavior

Nitric oxide and calcitonin gene-related peptide (CGRP) have been implicated in craniofacial pain including migraine headache, and CGRP induces face-grooming indicative of nocifensive behavior in animals. The aim of this study was to test whether systemic administration of nitroglycerin (NTG) influences the CGRP-induced behavior in awake rats and whether sumatriptan, a 5-HT1B/1D receptor agonist, can block the effects of NTG. CGRP was not significantly different from normal saline in inducing face-grooming behavior but NTG facilitated the effect of CGRP. Furthermore, sumatriptan was found to block the effect of NTG. These data suggest that facilitatory processes involving nitric oxide may be necessary for CGRP to play a role in some craniofacial pain conditions including possibly migraine headache.     

Suppressing effect of the serotonin 5HT1B/D receptor agonist rizatriptan on calcitonin gene-related peptide (CGRP) concentration in migraine attacks

Calcitonin gene-related peptide (CGRP) is one of the neuropeptides most abundant in the nervous tissue. Recent studies indicate that local cranial release of CGRP from the trigeminal nerve perivascular endings within arachnoidea plays an important role in the pathophysiology of migraine attacks and cluster headaches. Elevated CGRP levels in cranial venous blood (in the jugular vein) during an acute spontaneous migraine attack have been reported in rather few studies so far. Sumatriptan--a selective serotonin 5HT1B/D receptor agonist, highly effective in terminating migraine attacks, decreases the elevated CGRP level back to normal. The aim of our study was to determine the effect of rizatriptan (a drug from a new generation of triptans) on CGRP release in migraine attacks. In 45 patients suffering from migraine attacks with and without aura, plasma CGRP levels were assessed during an attack twice: before treatment and two hours after rizatriptan administration. In the group under study the plasma CGRP level before treatment was significantly higher than that measured two hours after rizatriptan administration. The decrease in CGRP levels was associated with subsidence of the migraine attack. There was no difference between migraine patients with and without aura. These results suggest that triptans as serotonin 5HT1B/D receptor agonists decrease CGRP plasma concentration in migraine attacks.     

Inhibition of NR2A reduces calcitonin gene-related peptide gene expression induced by cortical spreading depression in rat amygdala

Despite robust evidence on the role of calcitonin gene-related peptide (CGRP) in migraine via both central and peripheral actions, relatively less is known about how CGRP in the limbic system is involved in migraine progression. This study investigated whether CGRP production machinery exists in the two key limbic regions including hippocampus and amygdala using cortical spreading depression (CSD) as a model of migraine and whether such alteration by CSD is sensitive to N-methyl-d-aspartate (NMDA) receptor regulation in rats. A single or repetitive CSD was induced by topical application of KCl and monitored using electrophysiological methods. The NR2A-containing NMDA receptor antagonist, NVP-AAM077, or its vehicle, was perfused into the contralateral cerebroventricular ventricle of rat. Quantitative PCR was used to measure CGRP mRNA levels in the ipsilateral and contralateral hippocampus and amygdala after CSD events and compared to respective sham treatments. The results showed that neither a single CSD nor repetitive CSD affected CGRP mRNA levels in both the contralateral and ipsilateral hippocampus at 24 h post CSD induction. Differently, significant elevation of CGRP gene expression was observed in the ipsilateral amygdala at 24 h post multiple CSD, but not contralateral side, and not post-single CSD. Further results showed that the CSD-induced CGRP gene expression in the amygdala was markedly reduced by NVP-AAM077 and this reduction corresponded to a reduced cortical susceptibility to CSD in rats. We conclude that repetitive CSD events induce CGRP gene expression in amygdala, which is sensitive to NR2A regulation.     

Localization of CGRP Receptor Components, CGRP, and Receptor Binding Sites in Human and Rhesus Cerebellar Cortex

The cerebellum is classically considered to be mainly involved in motor processing, but studies have suggested several other functions, including pain processing. Calcitonin-gene-related peptide (CGRP) is a neuropeptide involved in migraine pathology, where there is elevated release of CGRP during migraine attacks and CGRP receptor antagonists have antimigraine efficacy. In the present study, we examined CGRP and CGRP receptor binding sites and protein expression in primate cerebellar cortex. Additionally, mRNA expression of the CGRP receptor components, calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1 (RAMP1), was examined. In addition, expression of procalcitonin was studied. We observed high [³H]MK-3207 (CGRP receptor antagonist) binding densities in the molecular layer of rhesus cerebellar cortex; however, due to the limit of resolution of the autoradiographic image the exact cellular localization could not be determined. Similarly, [¹²⁵I]CGRP binding was observed in the molecular layer and Purkinje cell layer of human cerebellum. CLR and RAMP1 mRNA was expressed within the Purkinje cell layer and some expression was found in the molecular layer. Immunofluorescence revealed expression of CGRP, CLR, and RAMP1 in the Purkinje cells and in cells in the molecular layer. Procalcitonin was found in the same localization. Recent research in the biology of cerebellum indicates that it may have a role in nociception. For the first time we have identified CGRP and CGRP receptor binding sites together with CGRP receptor expression through protein and mRNA localization in primate cerebellar cortex. These results point toward a functional role of CGRP in cerebellum. Further efforts are needed to evaluate this.     

CGRP and migraine: Could PACAP play a role too?

Migraine is a debilitating neurological disorder that affects about 12% of the population. In the past decade, the role of the neuropeptide calcitonin gene-related peptide (CGRP) in migraine has been firmly established by clinical studies. CGRP administration can trigger migraines, and CGRP receptor antagonists ameliorate migraine. In this review, we will describe multifunctional activities of CGRP that could potentially contribute to migraine. These include roles in light aversion, neurogenic inflammation, peripheral and central sensitization of nociceptive pathways, cortical spreading depression, and regulation of nitric oxide production. Yet clearly there will be many other contributing genes that could act in concert with CGRP. One candidate is pituitary adenylate cyclase-activating peptide (PACAP), which shares some of the same actions as CGRP, including the ability to induce migraine in migraineurs and light aversive behavior in rodents. Interestingly, both CGRP and PACAP act on receptors that share an accessory subunit called receptor activity modifying protein-1 (RAMP1). Thus, comparisons between the actions of these two migraine-inducing neuropeptides, CGRP and PACAP, may provide new insights into migraine pathophysiology.     

Decrease of adenosine A1 receptor density and of adenosine neuromodulation in the hippocampus of kindled rats

Adenosine is a neuromodulator that has been proposed to be a major endogenous anticonvulsant acting via A1 receptors. We tested if implementation of kindling through stimulation of the amygdala affected A1 receptor-mediated neuromodulation in hippocampal slices taken from rats 4 weeks after the last stage 5 seizure. The A1 receptor agonist, N6-cyclopentyladenosine (CPA) (6-100 nm), inhibited field excitatory postsynaptic potential (fEPSP) slope with an EC50 of 19.1-19.5 nm in control and sham-operated rats, but was less potent in kindled rats (EC50 = 42.7 nm). This might result from a decreased number of A1 receptors in hippocampal nerve terminal membranes, because A1 receptor immunoreactivity decreased by 28 +/- 3% and the binding density of the A1 receptor agonist [3H]R-PIA decreased from 1702 +/- 64 to 962 +/- 78 fmol/mg protein in kindled compared with control rats. The tonic inhibition of hippocampal synaptic transmission by endogenous adenosine was also lower in kindled rats, because A1 receptor blockade with 50 nm 1,3-dipropyl-8-cyclopentyladenosine (DPCPX) enhanced fEPSP slope by 23 +/- 3% and theta-burst-induced long-term potentiation by 94 +/- 4% in control rats but was virtually devoid of effects in kindled rats. The evoked release of adenosine from hippocampal slices or nerve terminals was 56-71% lower in kindled rats probably due to the combined decrease in the capacity of adenosine transporters and decreased release of adenosine 5'-triphosphate (ATP), which was partially compensated by a higher extracellular catabolism of ATP into adenosine in kindled rats. These results indicate that, although adenosine might inhibit the onset of epileptogenesis, once kindling is installed, the efficiency of the adenosine inhibitory system is impaired.     

Migraine: a research field matured for the basic neurosciences.

Progress in migraine research has been rapid in recent years, from both the basic science and the clinical perspectives. A new internationally accepted headache classification with operational diagnostic criteria was published in 1988, eliminating much diagnostic uncertainty. More than a decade of study of regional cerebral blood flow (rCBF) has gradually shown a pathognomonic pattern of abnormalities, probably reflecting spreading cortical depression. Recently it has been shown that pain probably arises from excitation of perivascular pial arterial nociceptors. The innervation and receptor mechanisms of pial and extracranial arteries have been worked out in detail both in animal and humans. Involvement of calcitonin gene-related peptide (CGRP) and 5-hydroxytryptamine (5-HT) during migraine attacks has been demonstrated. A new and specific 5-HT1D receptor agonist has proved to be highly effective in treating migraine. Therefore, major research efforts recently have been concentrated on discovering the location and function of 5-HT1D receptors, extra- and intracranially. Thus, it is now possible to formulate useful neuroscientific research strategies aimed at clarifying migraine mechanisms.