神经病理性痛状态下腹外侧眶皮层内α_1肾上腺素受体的表达变化

目的:通过保留性神经损伤(SNI)模型,探索在神经病理性痛状态下,腹外侧眶皮层(VLO)中α_1肾上腺素受体的表达变化情况,为其在皮层水平参与神经病理性痛的调控提供证据。方法:成年雄性SD大鼠随机分为SNI组和假手术组(sham组),2周后通过机械痛行为学检测神经病理性痛模型成功,采用免疫组织化学染色方法检测大鼠VLO内α_1肾上腺素受体的分布变化,通过Western Blot方法检测VLO中α_1肾上腺素受体的表达变化。结果:SNI术后2周,SD大鼠的机械性痛痛阈明显下降,稳定在4 g以下,提示模型制备成功。免疫组织化学染色结果显示:与假手术组相比,SNI组大鼠在术后2周对侧VLO内α_1肾上腺素受体免疫阳性神经元表达显著增加(P 0. 001),而同侧无明显变化(P 0. 05)。Western Blot结果显示:SNI组对侧VLO内α_1肾上腺素受体表达水平相比假手术组亦显著增高(P 0. 01),而同侧无显著变化(P 0. 05)。结论:SNI大鼠对侧VLO中α_1肾上腺素受体表达出现显著上调,结合以往行为学结果提示其适应性升高可能参与内源性抗神经病理性痛效应。     

约束应激对大鼠5-HT1A和5-HT2A受体表达的影响

慢性应激如长期压抑 ,环境不适等易导致身心健康损害 ,出现学习记忆、情绪行为等多方面的改变[1,2 ] ,目前对其发生机制的研究多集中在下丘脑 -垂体 -肾上腺 (HPA)轴、自主神经系统和免疫系统等 ,而对 5 -羟色胺 (5 -HT)的研究较少。 5 -HT是一种重要的中枢神经递质 ,参与多种行为、情绪活动的调节 ,迄今已发现了 5 -HT受体的 7种类型 13个亚型。近来的研究报道认为 5 -HT1A 和 5 -HT2A 可能与精神机能和学习记忆有关[3 ,4] 。为探讨慢性应激与 5 -HT1A、5 -HT2A 受体的关系 ,我们采用PCR观察大鼠经 30天慢性约束应激后不同脑区 5…     

慢性应激抑郁模型大鼠脑内5-HT1A和5-HT2A受体的变化

为了在5-羟色胺受体水平研究抑郁症的机制和三环类抗抑郁药物(TCAs)阿米替林的药理学机理,将24只SD雄性大鼠随机均分为三组,即对照组、抑郁组、阿米替林治疗组.应用[3H]8-OH-DPAT、[3H]Ketanserin作为标记配基,采用放射性配体受体结合法,分别测定大鼠海马5-HT1A受体、大脑皮层5-HT2A受体结合.结果显示抑郁大鼠海马 [3H]8-OH-DPAT 特异性结合(18.78±5.62 fmol/mg prot),较正常对照组(26.12±5.52fmol/mg prot )明显下降(P＜0.05).抑郁大鼠大脑皮层[3H]Ketanserin特异性结合(112.58±4.21fmol/mg prot),较正常对照组(86.28±4.24fmol/mg prot)明显增加( P＜0.05).阿米替林治疗3周后,可使抑郁大鼠海马5-HT1A受体与大脑皮层5-HT2A受体结合恢复正常.提示 海马5-HT1A受体结合下降、大脑皮层5-HT2A受体结合增加可能与抑郁症病因有关;海马5-HT1A受体、大脑皮层5-HT2A受体是阿米替林发挥抗抑郁作用的环节.     

腹外侧眶皮层内给予谷氨酸抑制福尔马林诱发的大鼠脊髓背角Fos表达

目的:观察腹外侧眶皮层(ventrolateral orbital cortex,VLO)内微量注射谷氨酸对大鼠后爪注射福尔马林诱发的腰段脊髓背角Fos表达的抑制效应以及该效应是否通过中脑导水管周围灰质(PAG)下行抑制系统介导。方法:免疫组织化学染色技术。结果:(1)VLO内微量注射谷氨酸(100nmol/0.5μl)明显抑制大鼠后爪注射福尔马林诱发的脊髓背角Fos表达,与注射生理盐水相比,差异显著(P0.001),并且这种抑制效应可被VLO内预先注射非选择性谷氨酸受体拮抗剂kynurenic acid(2nmol/0.5μl)所翻转,与单独注射谷氨酸相比差异显著(P0.001),但与注射生理盐水相比无显著差异(P0.05);(2)双侧腹外侧PAG内微量注射局麻剂利多卡因(0.2nmol/0.5μl)可以明显阻断VLO内微量注射谷氨酸(100nmol/0.5μl)对大鼠脊髓背角Fos表达的抑制效应,与单独注射谷氨酸相比差异显著(P0.001),而双侧腹外侧PAG内微量注射生理盐水不影响VLO内微量注射谷氨酸对大鼠脊髓背角Fos表达的抑制效应(P0.05)。结论:VLO内谷氨酸可能通过其受体激活PAG脑干下行抑制系统在脊髓水平抗炎性持续性伤害感受效应。     

激活吻侧无颗粒岛叶皮层内5-HT_(1A)受体抑制福尔马林诱发的伤害性行为

目的:明确5-HT1A受体是否参与吻侧无颗粒岛叶皮层(rostral agranular insular cortex,RAIC)介导的抗炎性持续性痛效应。方法:采用行为药理学实验方法观察RAIC内微量注射选择性5-HT1A受体激动剂和拮抗剂对福尔马林诱发的伤害性行为(缩足反应)的影响。结果:RAIC内微量注射选择性5-HT1A受体的激动剂8-OH-DPAT(5.0μg/0.5μl)明显抑制福尔马林诱发的大鼠缩足反应;向RAIC内提前5min预先微量注射5-HT1A受体拮抗剂NAN-190(10μg/0.5μl)则可拮抗8-OH-DPAT(5.0μg/0.5μl)对缩足反应的抑制效应;RAIC内单独注射NAN-190对福尔马林诱发的大鼠缩足反应没有影响。结论:5-HT1A受体参与RAIC介导的抗炎性持续性痛效应。     

人淋巴组织中5-HT1A受体的表达

目的检测5-HT1A受体蛋白及其mRNA 在人淋巴组织中的表达情况,寻求神经免疫内分泌网络间功能双向调节的形态学依据.方法应用免疫组织化学Picture法及核酸分子原位杂交的方法,检测5-HT1A受体蛋白及其mRNA 在100例人淋巴结、脾脏及肠道淋巴组织中的表达.结果免疫表型显示5-HT1A受体蛋白在人各种淋巴组织中表达的阳性率为86.25%,与原位杂交(阳性率为75.0%)之间的差异无统计学意义(χ2=0.570, P》0.05).结论人的淋巴组织不但可以表达5-HT1A受体蛋白还可以合成其mRNA, 5-HT1A受体为神经免疫内分泌网络共有的生物学语言媒介;神经源性与免疫源性的5-HT都可以通过免疫细胞膜上的5-HT1A受体对免疫系统发挥调节作用.     

腹外侧眶皮层中miR-200对慢性应激所致大鼠抑郁行为调控作用研究

目的:观察慢性不可预知温和应激(CUMS)模型大鼠腹外侧眶皮层(VLO)内miR-200和双特异性磷酸酶1(DUSP1)表达变化,并探讨VLO内注射miR-200模拟物对抑郁行为的调控作用及机制。方法:大鼠建立CUMS抑郁模型后分为5组:CUMS+miR-200模拟物组(VLO内注射20 pmol miR-200 mimic);CUMS+阴性对照组(VLO内注射20 pmol阴性对照siRNA);无应激+阴性对照组;无应激+miR-200模拟物组;CUMS+氟西汀(10 mg/kg/d)组。依次进行蔗糖偏爱测试、旷场实验、高架十字迷宫实验。Western Blot检测VLO内DUSP1、细胞外调节蛋白激酶(ERK)、pERK蛋白表达。结果:与无应激组比较,CUMS组大鼠体重降低(P0.0001)、蔗糖偏爱下降(P=0.008),VLO中miR-200表达减少(P0.0001),DUSP1表达增高(P=0.0054);与CUMS+阴性对照组比较,CUMS+miR-200模拟物组大鼠蔗糖偏爱率(P=0.028),开放臂进入时间(P=0.031)和进入次数(P0.0001)均升高,总活动距离不受影响;与CUMS+阴性对照组比较,CUMS+miR-200模拟物组VLO中DUSP1(P=0.046)和pERK(P=0.042)蛋白水平显著升高。结论:慢性应激性环境所致抑郁样行为与VLO内pERK下调有关,miR-200可直接下调VLO内DUSP1表达,提高pERK表达并最终改善抑郁症状。     

大鼠前庭神经核复合体内5-HT能终末与表达5-HT1A受体的前庭-臂旁核投射神经元之间的联系

目的 观察大鼠前庭神经核复合体(VNC)内5-羟色胺(5-HT)样阳性终末与表达5-HT1A受体(5-HT1A R)的前庭-臂旁核投射神经元之间的联系.方法 运用逆行束路追踪和免疫荧光组织化学染色相结合的双重标记技术,在激光共焦显微镜下观察.结果 将四甲基罗达明(TMR)注入臂旁核后,在双侧VNC的各个核团内均可观察到许多TMR逆标神经元,但以同侧为主.免疫荧光组织化学染色结果显示,在前庭内侧核(MVe)、前庭下核(SpVe)、前庭上核(SuVe)、前庭外侧核(LVe)、X核以及Y核的一些区域内,许多神经元表达5-HT1A R样免疫阳性,并可观察到大量5-HT样阳性纤维和终末.激光共焦显微镜下可进一步观察到一些TMR逆标神经元同时呈5-HT1A R样免疫阳性,且有部分5-HT样阳性终末与TMR/5-HT1A R双标神经元的胞体或树突形成密切接触.结论 提示5-HT可能通过5-HT1A R对前庭神经核复合体-臂旁核间的信息传递发挥调控作用.     

大鼠神经系统内5-羟色胺_(1A)受体亚型的定位分布(英文)

应用免疫组织化学技术观察了大鼠神经系统内 5 -羟色胺 1A受体亚型 ( 5 -HT1 AR)免疫阳性结构的分布。结果显示 :5 -HT1 AR免疫阳性结构主要分布于梨状皮质、隔核、丘脑腹后核、丘脑网状核、杏仁基外侧核、Purkinje细胞层、红核、面神经核、斜方体核等 ;在海马、额叶皮质、丘脑背内侧核、脚间核、三叉神经中脑核、中缝背核、三叉神经脊束核、脊髓背角浅层、背根神经节和三叉神经等结构内有中等强度的分布 ;在嗅球、尾壳核、苍白球、斜角带核、终纹床核、缰核、黑质、上橄榄等部位有弱的分布。本文的结果提示 5 -HT1 AR阳性结构广泛地分布在大鼠神经系统 ,它们可能介导 5 -HT在神经系统中的多种生理功能     

大鼠海马内5-羟色胺及其受体5-HT2A的表达

目的:观察5-羟色胺(5-HT)纤维和5-HT2A受体在大鼠海马CA1、CA2和CA3三个区域的分布特点.方法:用5-HT递质和5-HT2A受体特异性抗体的免疫组织化学显色以及图像处理与分析.结果:在海马内,抗5-HT2A受体的免疫反应阳性产物主要位于锥体细胞的细胞膜和树突,树突染色较深;5-HT2A受体的阳性胞体在C...     

The role of 5-HT receptor subtypes in the ventrolateral orbital cortex of 5-HT-induced antinociception in the rat

The present study examined the involvement of 5-HT in the ventrolateral orbital cortex (VLO) on descending antinociception and determined which subtypes of 5-HT receptors mediated this effect. This study focused on the effects of 5-HT microinjection in the VLO of lightly anesthetized male rats on the radiant heat-evoked tail flick (TF) reflex, as well as the influence of 5-HT(1A), 5-HT(2), 5-HT(3), and 5-HT(4) receptor subtype antagonists on the effect of 5-HT. Results showed that 5-HT microinjection (2, 5, 10 microg, in 0.5 microl) into the VLO depressed the TF reflex in a dose-dependent manner. Pretreatment with 5-HT receptor antagonists (1-(2-methoxyphenyl)-4-[4-(2-phthalimido)butyl] piperazine hydrobromide (NAN-190), cyproheptadine hydrochloride (CPT) and 1-methyl-N-(8-methyl-8-azabicyclo[3.2.3]-oct-3-yl)-1H-indazole-3-carboxamide maleate salt (LY-278,584)), specific for 5-HT(1A), 5-HT(2) and 5-HT(3) receptors, respectively, partially reversed the 5-HT-evoked inhibition. In contrast, the 5-HT(4) receptor antagonist, 1-[2-[(methylsulfonyl)-amino]ethyl]-4-piperidinyl]methyl1-methyl-1H-indole-3-carboxylate (GR 113808), had no effect on the inhibition of 5-HT. Microinjections of NAN-190, CPT and LY-278,584 alone into the VLO had no effect on the TF reflex. These results suggest that 5-HT(1A), 5-HT(2) and 5-HT(3), but not 5-HT(4) receptors, are involved in mediating 5-HT-induced antinociception in the VLO. According to different properties and distribution patterns of the 5-HT receptor subtypes on neurons, the possible mechanism of 5-HT activation of the VLO-periaqueductal gray (PAG) descending antinociceptive pathway is discussed.     

Roles of different subtypes of opioid receptors in mediating the ventrolateral orbital cortex opioid-induced inhibition of mirror-neuropathic pain in the rat

Previous studies have demonstrated that opioid receptors in the prefrontal ventrolateral orbital cortex (VLO) are involved in anti-nociception. The aim of this current study was to examine whether opioid receptors in the VLO have effects on the hypersensitivity induced by contralateral L5 and L6 spinal nerve ligation (SNL), termed as mirror neuropathic pain (MNP) in the male rat. Morphine (1.0, 2.5, 5.0 microg) microinjected into the VLO contralateral to the SNL depressed the mechanical paw withdrawal assessed by von Frey filaments and the cold plate (4 degrees C)-induced paw lifting in a dose-dependent manner on the side without SNL. These effects were antagonized by microinjection of the non-selective opioid receptor antagonist naloxone (1.0 mug) into the same VLO site. Microinjection of endomorphin-1 (5.0 microg), a highly selective mu-opioid receptor agonist, and [d-Ala(2), d-Leu(5)]-enkephalin (DADLE, 10 microg), a delta-/mu-receptor agonist, also depressed the MNP. The effects of both drugs were blocked by selective mu-receptor antagonist beta-funaltrexamine (beta-FNA, 3.75 microg), but the effect of the DADLE was not influenced by the selective delta-receptor antagonist naltrindole (5.0 microg). Microinjection of the kappa-opioid receptor agonist spiradoline mesylate salt (U-62066) (100 microg) had no effect on the MNP. These results suggest that the VLO is involved in opioid-induced inhibition of the MNP and the effect is mediated by mu- (but not delta- and kappa-) opioid receptors.     

The role of dopamine receptors in ventrolateral orbital cortex-evoked anti-nociception in a rat model of neuropathic pain

The present study examined the role of dopamine and D₁-and D₂-like dopamine receptors in ventrolateral orbital cortex (VLO)-evoked anti-hypersensitivity in a rat model of neuropathic pain, as well as the possible underlying mechanisms. Results showed that microinjection of apomorphine [(R(−)-apomorphine hydrochloride)], a non-selective dopamine receptor agonist, into the VLO attenuated spared nerve injury (SNI)-induced mechanical allodynia in a dose-dependent manner. This effect was completely blocked by the D₂-like dopamine receptor antagonist S(−)-raclopride(+)-tartrate salt (1.5 μg), but was enhanced by the D₁-like dopamine receptor antagonist SCH23390 (R(+)-SCH-23390 hydrochloride, 5.0 μg). The attenuating effect of apomorphine on mechanical allodynia was mimicked by application of the D₂-like dopamine receptor agonist quinpirole [((−)-quinpirole hydrochloride, 0.5, 1.0, and 2.0 μg)]. In addition, microinjection of larger doses (10 and 20 μg) of SCH23390 into the VLO significantly attenuated allodynia. Furthermore, microinjections of GABA_A receptor antagonists, bicuculline [(+)-bicuculline,(S), 9(R)] and picrotoxin (200 and 300 ng for both drugs), into the VLO attenuated mechanical allodynia. A small dose of bicuculline or picrotoxin (100 ng) resulted in increased quinpirole (0.5 μg)-induced anti-allodynia. In contrast, GABA_A receptor agonists, muscimol hydrochloride (250 ng) or THIP [(2,5,6,7-retrahydroisoxazolo(5,4-c)pyridine-3-ol hydrochloride, 1.0 μg)], blocked quinpirole (2.0 μg)-induced attenuation. These results suggest that the dopaminergic system is involved in mediating VLO-induced anti-hypersensitivity, activation of D₂-like dopamine receptors, and inhibition of D₁-like receptors resulting in anti-hypersensitivity. In addition, the mechanisms of GABAergic disinhibition might be involved in D₂-like receptor mediating effects in neuropathic pain.     

Muramyl dipeptide (MDP) and 5-HT receptors. Neuroimmunomodulatory effects of MDP are probably not mediated through 5-HT4 or 5-HT1A receptors

A possible interaction of immunomodulator muramyl dipeptide (MDP) with 5-HT₄ and 5-HT_1A receptors was investigated. The activation of 5-HT₄ receptors releases acetylcholine from nerve terminals, thereby contracting the guinea-pig distal ileum. The whole ileum segments were therefore cut and placed into the bath. The preparations were contracted by 5-HT (10 nM-3.2 µM); these contractions were totally abolished in the presence of atropine (1 µM) and significantly attenuated in the presence of SDZ-205,557 (320 nM). The 5-HT evoked contractions remained unchanged in the presence of MDP (5, 50 or 500 nM). MDP (10 nM-3.2 µM) could not directly contract the preparations. In further experiments, the possible interaction of MDP with 5-HT_1A receptors was investigated. The activation of 5-HT_1A receptors inhibits the release of acetylcholine from nerve terminals, thereby decreasing the height of electrically evoked neurogenic twitches of guinea-pig ileum. The whole ileum segments were cut, placed into the bath and stimulated electrically. Selective 5-HT_1A agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) decreased the height of twitches and this effect was significantly attenuated in the presence of 5-HT antagonist metergoline (1 µM). The effect of 8-OH-DPAT remained unchanged in the presence of MDP (5, 50 or 500 nM). MDP (10 nM-3.2 µM) did not exert any direct effect on the preparations. These results suggest that MDP interacts with neither 5-HT₄ nor 5-HT_1A receptors.     

PTSD样行为异常大鼠中缝背核5-HT1A受体的改变

目的观察创伤后应激障碍(PTSD)样行为异常大鼠中缝背核(DRN)神经元5-HT1A受体表达变化,为探讨PTSD的发病机制提供资料。方法成年健康雄性Wistar大鼠60只,随机分为连续单一刺激(SPS)模型1d、4d、7d组及正常对照组,采用免疫组化、Western blot方法检测PTSD样行为异常大鼠中缝背核神经元5-HT1A受体表达变化。结果 SPS刺激后1d大鼠中缝背核神经元5-HT1A受体表达水平开始逐渐升高,第4天高于第1天,第7天高于第4天。结论 PTSD样大鼠中缝背核神经元5-HT1A受体呈规律性过表达。     

The effects of antipsychotic drugs administration on 5-HT1A receptor expression in the limbic system of the rat brain

Increasing evidence suggests that 5-HT1A receptors are involved in the pathophysiology and treatment of schizophrenia. This paper investigated 5-HT1A receptor mRNA expression and binding density in female rats treated with aripiprazole (2.25 mg/kg/day), olanzapine (1.5 mg/kg/day), haloperidol (0.3 mg/kg/day) or vehicle (control) orally three times/day for 1 or 12 weeks. Animals were sacrificed 48 h after the last administration. Aripiprazole significantly increased 5-HT1A receptor binding density by 33% in the CA1 region of the hippocampus and by 21% in the medial posterodorsal nuclei of posterior amygdala (MeP) compared to the control group after 1 week of treatment. Olanzapine significantly decreased 5-HT1A receptor binding density by 17–22% in Layers I–IV of the cingulate cortex after 1 week of treatment. Neither of these antipsychotic drugs affected 5-HT1A receptor binding density after 12 weeks drug treatment. As expected, haloperidol treatment did not have any significant effect on 5-HT1A binding density after 1 or 12 weeks of treatment. 5-HT1A receptor mRNA expression was not altered by antipsychotic treatment in any brain region. The results indicate that aripiprazole and olanzapine have differential effects on 5-HT1A receptor expression, which may contribute to their distinct profiles in improving negative symptoms and cognitive deficits in schizophrenia. Aripiprazole and olanzapine may produce adaptation and desensitization of 5-HT1A receptor expression after long term treatment.