中脑导水管周围灰质对猫丘脑后核内脏大神经诱发放电的影响

本以强电流刺激猫内脏大神经传入纤维引起的丘脑后核单位放电为内脏痛的指标，观察电刺激中脑导水管周围灰质(PAG)对内脏痛的影响。     

电刺激中脑导水管周围灰质对大脑皮层和脊髓慢痛反应的影响

本文以体感皮层诱发电位(C-CEP)为指标，观察中脑导水管周围灰质(PAG)对慢痛反应的影响，为探讨慢痛的调制提供资料。     

中脑导水管周围灰质内催产素参与电针镇痛

以钾离子透入法引起大鼠甩尾反应的电流强度（ｍＡ）为痛反应指标，通过向中脑导水管周围灰质（ＰＡＧ）内注射催产素（ＯＴ），抗催产素血清（ＡＯＴＳ）和纳洛酮（Ｎｘ），观察了ＰＡＧ内ＯＴ对动物电针镇痛的影响。结果表明，ＰＡＧ内生理水平的ＯＴ参与电针镇痛的过程，并且其作用不依赖于内源性阿片肽系统。     

中脑导水管周围灰质在电针镇痛和痛觉调制中的作用

我们对中脑导水管周围灰质(PAG)在针刺镇痛和痛觉调制中的作用进行了系列的研究，结果如下：     

中脑导水管周围灰质内催产素在电针镇痛中的作用及机制的实验研究

我们以往的工作表明 ,侧脑室和脊髓蛛网膜下腔内注射催产素 (ＯＴ)能明显提高大鼠电针镇痛效应 ,注射抗催产素血清 (ＡＯＴＳ)则能显著降低电针镇痛效应。提示 ,中枢神经系统内的催产素在电针镇痛的复杂过程中发挥着一定作用。中脑导水管周围灰质 (ＰＡＧ)是电针镇痛的关键部位 ,其内含有丰富的ＯＴ、ＯＴ神经末梢及ＯＴ受体 ,但中枢ＯＴ在电针镇痛中的作用是否与之有关 ,作用机制怎样 ?是一个引人关注的问题。本工作以钾离子透入法 ,以甩尾法作为疼痛指标 ,测定大鼠痛阈 ,观察ＰＡＧ注射ＯＴ、ＡＯＴＳ、纳洛酮 (Ｎｘ)、抗 β 内啡肽血清 (…     

电刺激中脑导水管周围灰质对猫丘脑后核内脏大神经诱发放电的影响

<正> 国内外的工作表明中脑导水管周围灰质(Pariagueauctal grag,简称PAG)是与镇痛作用密切相关的神经结构,也是微量注射吗啡和电刺激可产生最有效镇痛作用的脑区。此部位阿片受体较为密集。朱丽霞等人认为PAG是针刺传入信号和伤害性刺     

大鼠楔状核内微量注射TRH、ACh对中脑导水管周围灰质痛放电的影响

实验在60只SD大鼠上进行。采用细胞外记录方法，记录中脑导水管周围灰质（PAG）内痛兴奋神经元（PEN）的自发放电和伤害性刺激的诱发放电。主要观察中脑楔状核（NCF）内微量注射促甲状腺激素释放激素（TRH）和乙酰胆碱（ACh）对PAG内PEN的痛放电影响，以及TRH与NCF内胆碱能神经的关系。结果表明：（1）NCF内分别注入TRH（0．5μg／0．5μl）和ACh（2．5μg／0．5μl）均能明显抑制PAG内PEN的痛放电频率。而将等剂量TRH注入NCF背侧的下丘内，对PAG的痛放电则无明显影响。（2）预先注入阿托品（2．5μg／0．5μl）再注入TRH或ACh，阿托品能阻断ACh对PAG痛放电的抑制效应；但不影响TRH的抑制作用。（3）单独注入阿托品（2．5μg／0．5μl）对PAG的抑制效应也无明显影响。结果提示：外源性TRH和ACh都参与NCF对伤害性信息的调制作用，ACh的抑制效应是经m-受体介导的；而TRH的作用似乎与m-受体无关。     

电针对偏头痛大鼠中脑导水管周围灰质5-羟色胺7受体和血浆降钙素基因相关肽表达的影响

目的:探讨电针是否能通过调控中脑导水管周围灰质(PAG)5-羟色胺7(5-HT7)受体和外周血降钙素基因相关肽(CGRP)介导抗偏头痛。方法:雄性SD大鼠随机分为对照组、模型组和电针组,每组14只。反复电刺激大鼠上矢状窦区硬脑膜诱发神经源性偏头痛模型。对照组仅予颅内电极安置,电针组于硬脑膜电刺激后电针"风池"穴,每日1次,治疗6次。采用免疫荧光标记法和Western blot法检测PAG区5-HT7受体的表达,放射免疫法检测外周血CGRP含量。结果:与对照组比较,反复硬脑膜电刺激造模后PAG区5-HT7受体阳性神经元数目和蛋白相对表达量及外周血CGRP含量显著增高(均P0.001);与模型组比较,电针组5-HT7阳性神经元数目和蛋白相对表达量显著降低(P0.01),外周血CGRP含量降低(P0.05)。结论:电针"风池"穴可下调偏头痛大鼠PAG区5-HT7受体表达,降低其外周血CGRP含量。     

慢性坐骨神经损伤大鼠中脑导水管周围灰质MC4R的表达及HS014对热痛觉过敏的影响

目的观察大鼠慢性坐骨神经损伤(CCI)后不同时间点中脑导水管周围灰质(PAG)4型黑皮质素受体(MC4R)mRNA表达变化及给予选择性MC4R拮抗剂HS014对CCI大鼠疼痛行为学的影响。方法 1将42只健康成年雄性Wistar大鼠随机分为对照组6只、假手术组18只和CCI组18只,检测各组大鼠术前和术后3,7,14 d热缩足潜伏期(TWL),假手术组和CCI组分别于术后3,7,14 d,对照组于术后14 d TWL检测完成后处死大鼠,取PAG脑组织,用半定量RT-PCR法检测PAG脑区MC4R mRNA表达情况。2将30只健康成年雄性Wistar大鼠随机分为对照组6只、假手术组6只和CCI组18只,均先进行PAG置管。置管后7 d,CCI组随机分成CCI+NS组、CCI+HS014 5μg组和CCI+HS014 10μg组,每组6只。假手术组和CCI各组手术造模。术后7 d,CCI+NS组经导管注射生理盐水0.5μL,CCI+HS014 5μg组注射HS014 5μg/0.5μL,CCI+HS014 10μg组注射HS014 10μg/0.5μL。检测各组大鼠置管后7 d、术后7 d和干预后(注射后10~30 min完成检测)TWL。结果 CCI组大鼠术后3 d开始出现TWL缩短(P0.05),术后7 d和14 d TWL缩短更加明显(P均0.05),与对照组和假手术组比较差异均有统计学意义(P均0.05)。CCI组术后各时间点MC4RmRNA表达量均明显高于对照组和假手术组(P均0.05),并且随着CCI术后时间的推移,MC4RmRNA的表达量逐渐增高(P均0.05)。CCI各组大鼠术后7 d TWL明显低于置管后7 d(P均0.05);CCI+NS组干预后TWL与术后7 d比较差异无统计学意义(P0.05),而CCI+HS014 5μg组和CCI+HS014 10μg组干预后TWL均明显长于术后7 d和CCI+NS组(P均0.05),CCI+HS014 10μg组干预后TWL明显长于CCI+HS014 5μg组(P0.05)。结论 CCI可引起PAG中MC4RmRNA的表达增加,其选择性拮抗剂HS014可剂量依赖性减轻CCI大鼠的热痛觉过敏,提示PAG中MC4R的表达增加可能参与神经病理性疼痛的形成和维持。     

侧脑室微量注射血管紧张素Ⅱ对大鼠中脑导水管周围灰质伤害性神经元电活动的影响

本实验用玻璃微电极记录技术,在５５只雄性ＳＤ大鼠ＰＡＧ区记录到６５个伤害性神经元,观察了 ＡＩＩ对 ＰＡＧ伤害性神经元电活动以及吗啡镇痛效应的影响。结果显示：①ＡＩＩ（５０ｎｇ、１μｇ、２μｇ／５μｌ,ｉ．ｃ．ｖ．）对ＰＡＧ区痛兴奋神经元（ＰＥＮ）电活动产生显著的兴奋效应;②９个ＰＡＧ痛抑制神经元（ＰＩＮ）在给 ＡＩＩ后 ８个产生抑制效应,一个无反应;③ＡＩＩ（５０ｎｇ、２μｇ／５μｇ,ｉ． ｃ． ｖ）部分翻转吗啡（ｉ．ｐ,２．５ｍｇ／ｋｇ体重）的抑制作用,两组间ＡＩＩ的作用有显著性差异。以上结果提示：ＡＩＩ可能通过易化ＰＡＧ区 ＰＥＮ、抑制 ＰＩＮ的电活动,从而调制伤害性信息的传递,拮抗吗啡镇痛。     

吗啡和电针对伤害性刺激诱发体感皮层单位放电的时锁和非时锁反应的影响

<正> 过去研究电针对痛敏单位放电的影响时,大多数报道都以非时锁反应(单位时时内放电数量或平均放电率的变化)为指标,也有用时锁反应(对刺激有效固定的时间关系的短暂反应)为指标。我们对这两种反应进行了对比,两者反映角度不完全相同。本文以伤害性刺激猫的腓浅神经(PN)诱发     

Effects of radix Salviae Miltiorrhizae on visceral pain discharges in the posterior nucleus of the thalamus in cats

Extracellular microelectrode method and stereotaxic technique of brain were used to investigate the effects of Radix Salviae Miltiorrhizae on the discharges of visceral pain in the posterior nucleus of thalamus(po)in cats. Experiments showed that Radix Salvia Miltiorrhizae inhibited the discharges of visceral pain in po, Radix Salviae Miltiorrhizae acts directly on the peripheral nerve trunk and cannot block its exciting conduction. This suggests that the analgesic effect of Radix Salviae Miltiorrhizae is exerted via central nervous system.     

Relationship between neurons in the nucleus raphe magnus and motor reflex evoked by noxious stimulation

The article reviews the main results of recent years study on the relationship between neurons in nucleus raphe magnus (NRM) and moving reflex evoked by noxious stimulation, including: 1. Relative phasic discharge frequency change of on-cell and off-cell in NRM occurred when tail-flick reflex (TF) evoked by noxious stimulation. The relative phasic activity of on-cell and off-cell in NRM was decreased or lost when TF was inhibited by brain stimulation and morphine analgesia. The data suggested that on-cell and off-cell in NRM participated in descending inhibition on spinal cord. 2. The initial EPSPS on neurons of NRM always occurs after the initial digastric EMG elicited by tooth pulp shock. 3. There is a positive feedback loop of reciprocal excitation between descending pathway from NRM and ventral horn neurons projecting to NRM of spinal cord. It was suggested that motor neuron pool in spinal cord possible involved in the mechanism of descending inhibition from the NRM.     

Electron microscopic observation on the effect of electroacupuncture (EA) on the ultrastructure of periaqueductal gray (PAG) and nucleus raphe magnus (NRM) in rats

12 Wistar rats (220-250g) were divided into control and experimental groups. Pain threshold was determined by WQ-9E Pain Threshold Measuring Apparatus. EA was applied at bilateral "Zusanli" points. The animals showing EA analgesia and the control animals were sacrificed and the ventrolateral part of PAG and the NRM were taken out for electron microscopic observation. The peripheral region of ventrolateral PAG (PAG-PR) and the NRM contained a wide variety of cell types and synaptic relationships. The neurons and axo-dendritic synapses of the PAG-PR and NRM were analysed in EA and control groups. In EA analgesia group, the clear round vesicle-containing presynaptic boutons and the presynaptic bouton with clear round vesicles and granular vesicles showed a significant decrease of their vesicle content. Part of the mitochondria and endoplasmic reticulum in the neurons appeared the expanded profiles. These ultrastructural changes of the PAG and the NRM during EA analgesia may indicate an increased release of acetylcholine, biogenic amines and/or peptide neurotransmitters and that the neurons were in active functional state.