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1.
用急性佐剂性关节炎大鼠作为病理性疼痛的实验模型,以丘脑束旁核中对伤害性刺激发生兴奋反应的单位放电作为指标,观察电针的影响,并分析其机制,实验发现电针能明显抑制伤害性反应,脑室注射阿片受体阻断剂纳洛酮或M受体阻断剂阿托品均能翻转电针的这种抑制作用。实验还发现脑室注射纳洛酮或阿托品对关节炎大鼠束裤核神经元自发放电有增频作用。实验结果提示:电针对关节炎大鼠丘脑束旁核神经元伤害性反应的抑制,可能是通过脑内  相似文献   

2.
用急性佐剂性关节炎大鼠作为病理性疼痛的实验模型,以丘脑束旁核中对伤害性刺激发生兴奋反应的单位放电作为指标,观察电针的影响,并分析其机制。实验发现电针能明显抑制伤害性反应;脑室注射阿片受体阻断剂纳洛酮(4μg/10μl)或M受体阻断剂阿托品(5μg/10μl)均能翻转电针的这种抑制作用。实验还发现脑室注射纳洛酮或阿托品对关节炎大鼠束旁核神经元自发放电有增频作用。实验结果提示:电针对关节炎大鼠丘脑束旁核神经元伤害性反应的抑制,可能是通过脑内阿片系统和胆碱能系统而发挥作用的;这两个系统对关节炎大鼠丘脑束旁核神经元自发放电可能有紧张性抑制作用。  相似文献   

3.
刺激中缝背核(dorsalraphenucleus,DR)可以引起小脑间位核(interposednucleus,IN)神经元抑制,兴奋和双相(抑制-兴奋和兴奋-抑制)3种不同类型的反应,其中以抑制反应为主(76.0%),多数细胞的反应潜伏期〈30ms。IN细胞的自发放电频率为5-120Hz,自发放电频率高的神经元群体对DR刺激的反应率却比自发放电频率低的群体低。静脉注射5-HT2/1c受体阻断剂  相似文献   

4.
在清醒家兔中,双侧损毁导水管周围灰质(PAG)的腹侧部或在双侧PAG腹侧部微量注射阿片受体拮抗剂纳洛酮,可明显阻断电针对刺激下丘脑背内侧区引起的防御反应的抑制效应。双侧损毁PAG腹侧部或在双侧PAG腹侧部微量注射纳洛酮,也都能减低直接兴奋弓状核区对防御反应的抑制作用的程度,在PAG 腹侧部微量注射阿片受体激动剂吗啡则可抑制刺激下丘脑引起的防御反应。以上实验结果提示,PAG 腹侧部的阿片受体可能参与电针抑制防御反应的机制。本文讨论了电针可能激活弓状核的内啡肽神经元并激活PAG 腹侧部的阿片受体而对防御反应发生抑制作用的可能性。  相似文献   

5.
本文分析了大脑皮层体感Ⅰ区(SⅠ)的下行活动是否参与针刺对疼痛的调节过程。在清醒麻痹家猫观察到,电针穴区对丘脑中央中核(CM)多数神经元的伤害性反应有抑制作用。当用2%利多卡因局部阻滞 SⅠ后,多数神经元的伤害性反应不为电针所抑制。而盐水对照组的电针效应仍与单纯电针组相同,是以抑制为主。在一组神经元同体比较两次电针效应可见,SⅠ局部阻滞的结果是使得电针对伤害性反应的抑制明显减弱甚至消失、抑制时程可被缩短。这表明,针刺镇痛效应与 SⅠ机能状态有关;SⅠ的下行活动参与了针刺效应的产生与维持。  相似文献   

6.
Zhu JX  Tang JS  Jia H 《生理学报》2004,56(6):697-702
本文旨在研究阿片受体是否参与丘脑中央下核(nucleus submedius,Sm)和顶盖前区前核(anterior pretectal nucleus,APtN)所介导的不同强度电针的镇痛作用。以辐射热诱发甩尾(tail flick,TF)反射潜伏期为伤害性反应的指标,观察了Sm和APtN微量注射阿片受体拮抗剂纳洛酮对不同强度电针“足三里”穴(St.36)抑制大鼠TF反射的效应。结果表明,Sm给予纳洛酮(1.0μg,0.5μl)阻断强电针(5mA)对TF反射的抑制效应,而对弱电针(0.5mA)的效应无明显影响;相反,APtN给予纳洛酮阻断弱电针对TF反射的抑制效应,而对强电针的效应无明显影响;纳洛酮供给到Sm或APtN邻近其它脑区对强、弱电针的效应均无影响。这些结果提示,Sm内的阿片受体参与介导强电针兴奋细传入纤维(A-δ和C类)产生的镇痛,而APtN内的阿片受体则介导弱电针兴奋粗传入纤维(A-β类)产生的镇痛。  相似文献   

7.
Zhang RH  Tang GX 《生理学报》1999,51(1):101-105
本文采用细胞内记录技术,研究了猫皮层第一躯体感觉区(primarysomatosensorycortexarea,SⅠ区)躯体伤害感受神经元膜的电学特性和对刺激腹后外侧核(ventralposteriorlateralnucleus,VPL核)的反应。极化电流绝对值小于或等于10nA时,伤害感受神经元IV极相关(r=096),整流作用不明显;极化电流绝对值大于10nA时,在两个方向上发生整流,IV曲线表现为S型,其中伤害感受神经元的整流作用较非伤害感受神经元明显。伤害性感受神经元Rm、τ、Cm明显大于非伤害感受神经元(P<001或P<005)。刺激VPL与刺激隐神经在SⅠ区伤害感受神经元的诱发反应中存有相似与不同两种形式。用细胞内电位记录方法证明了单一神经元有会聚现象。结果提示,SⅠ区伤害感受神经元与非伤害感受神经元可能在细胞膜形态结构、细胞体积大小等方面存在有意义的差别,从而反映其不同的生理功能。  相似文献   

8.
脚内核在电针镇痛及兴奋尾壳核镇痛中的作用   总被引:2,自引:0,他引:2  
Wu GJ  Chen ZQ  Shi H 《生理学报》2002,54(1):55-59
用行为学和电生理学的方法 ,探讨脚内核在电针镇痛及兴奋尾壳核镇痛中的作用。脚内核微量注射红藻氨酸 7d后 ,电针对辐射热引起的大鼠缩腿潜伏期无明显影响 ,电针或兴奋尾壳核对丘脑束旁核神经元的伤害性反应亦无明显影响。与正常对照组电针或兴奋尾壳核产生的抑制作用相比有显著性差异 (P <0 .0 5 ) ;与脚内核微量注射生理盐水 7d后 ,电针可提高大鼠缩腿潜伏期 ,及电针或兴奋尾壳核对束旁核神经元伤害性反应的抑制作用相比 ,有显著性差异 (P <0 0 5 )。上述结果提示 ,脚内核在电针及兴奋尾壳核镇痛中发挥重要作用  相似文献   

9.
目的 :阐明下丘脑背内侧核 (DMH)在缰核 (Hb)兴奋诱发的心血管反应中的作用及DMH在腓深神经 (DPN)传入冲动调节Hb兴奋诱发的心血管活动中的作用及机制。方法 :脲酯和氯醛糖混合静脉麻醉的家兔 ,电刺激Hb、腓深神经 ,记录股动脉血压及心外膜电图 ,DMH内微量注射受体拮抗剂。结果 :同侧DMH微量注射谷氨酸受体阻断剂Kynurenicacid ,部分取消了电刺激Hb兴奋诱发的升压反应及缺血性心电变化反应。同侧DMH微量注射纳洛酮对腓深神经传入冲动抑制Hb兴奋诱发的上述反应有削弱作用。结论 :DMH及其中的谷氨酸受体参与电刺激缰核兴奋诱发的心血管反应 ,DMH及其中的阿片受体参与了DPN传入冲动对上述心血管反应的抑制作用  相似文献   

10.
本研究旨在了解弓状核内的阿片受体在体温调节中的作用。研究使用细胞介素IL1β做致热源。以自动推进器向SD雄性大鼠弓状核微量注射1μ1IL1β。在给药前30min分别向弓状核微量注射通常阿片受体拮抗剂纳洛酮(Nal)、阿片受体μ、δ和κ各自特异性拮抗剂CTAP、NTI和norBNI做预处理,用生理盐水(Sal)做对照。结果表明:IL1β所致的升体温效应能被Nal和CTAP阻断,提示弓状核中的阿片受体(主要是μ受体)参与或介导了IL1β的致热效应;δ和κ受体特异性拮抗剂阻断IL1β所致的体温升高效应不明显。提示δ和κ阿片受体参与体温调节的可能性较小。对照ARH和POAH中阿片受体在IL1β所致发热中的作用可发现:二者作用极为相似,这一结果有力地支持了弓状核是体温调节中枢重要组成部分的观点。  相似文献   

11.
Droperidol causes the blockage of the dopamine receptors in the central nervous system that are involved in pain transmission. However, the mechanism of action of droperidol in pain-related neurons is not clear, and it is still unknown whether opioids are involved in the modulation of this processing. The present study examines the effect of droperidol on the pain-evoked response of pain-excitation neurons (PENs) and pain-inhibition neurons (PINs) in the caudate nucleus (Cd) of rats. The trains of electric impulses applied to the sciatic nerve were used as noxious stimulation. Our results revealed that droperidol decreased the frequency of PEN discharge, and increased the frequency PIN discharge evoked by the noxious stimulation in the Cd of normal rats, while administration of droperidol to morphine-dependent rats produced the opposite response. Those demonstrated that droperidol is involved in the modulation of nociceptive information transmission in Cd, and there were completely opposite responses to painful stimulation between normal and morphine-dependent rats after administration of droperidol.  相似文献   

12.
阻断大鼠杏仁中央核AMPA受体对臂旁核味觉反应的影响   总被引:1,自引:0,他引:1  
Kang Y  Yan JQ  Huang T 《生理学报》2004,56(6):671-677
以往的研究表明,电刺激或损毁杏仁中央核明显改变臂旁核味觉神经元的活动。为了研究杏仁中央核内的兴奋性受体是否参与此调节,本实验应用细胞外记录方法,在乌拉坦麻醉的大鼠观察了杏仁中央核内微量注射6-氰基-7-硝基喹喔啉-2,3- 二酮(CNQX)前后臂旁核味觉神经元对四种基本味觉刺激反应的变化。结果表明,杏仁中央核内注射 CNQX 对 30% 的臂旁核神经元产生时间依赖性的抑制作用,此抑制作用以对盐酸和盐酸奎宁刺激引起的反应尤为明显(P<0.05)。根据对味觉刺激的优势反应,40% 的NaCl优势、30% 的HCl优势和20% 的奎宁优势反应神经元在注射CNQX 后对至少一种味觉刺激的反应降低;盐酸优势和奎宁优势反应神经元对各自的优势反应在杏仁中央核内注药后均明显降低(P<0.01)。相关性分析表明,在注射 CNQX 后,臂旁核味觉神经元对 NaCl 和其它三种味觉刺激物之间的分辨能力降低。以上结果表明,杏仁中央核内的AMPA 受体可能参与杏仁核对臂旁核味觉神经元的下行调控。  相似文献   

13.
Recent evidence has indicated an association between the rewarding effects of ethanol intake and endogenous opioid activity. The present studies examine the presence of differences in opioid peptide mRNA content and mu and kappa opioid receptor densities, between ethanol naive AA and ANA rats bred selectively for their high and low alcohol consumption, respectively. In situ hybridization was used to compare the content of proopiomelanocortin, proenkephalin and prodynorphin mRNA in distinct brain regions known to be involved in the reinforcing properties of addictive drugs, between rats from each line. Results indicated that AA rats had a significantly greater content of proopiomelanocortin mRNA in the arcuate nucleus of the hypothalamus, of proenkephalin mRNA in the prefrontal cortex and of prodynorphin mRNA in the mediodorsal nucleus of the thalamus (p < or = .05). Receptor autoradiography was performed using 3H-labeled ligands specific for mu and kappa opioid receptors. AA rats were found to have a greater density of mu opioid receptors in the shell region of the nucleus accumbens and prefrontal cortex, but a lower density of kappa opioid receptors in the ventromedial hypothalamus, compared to ANA rats. The present data demonstrate the presence of inherited differences in the activity of distinct components of the endogenous opioid system in some brain regions associated with the processes of reward and reinforcement; and as such, may play a role in determining differences in ethanol drinking between AA and ANA rats.  相似文献   

14.
Feeding elicited by the mu-selective agonist, [D-Ala2, M-Phe4, Gly-ol5]-encephalin administered into the nucleus accumbens is blocked by accumbal pre-treatment with mu, delta1, delta2 and kappa, but not mu1 opioid antagonists. Correspondingly, mu-agonist-induced feeding elicited from the ventral tegmental area is blocked by ventral tegmental area pre-treatment with mu and kappa, but not delta opioid antagonists. A bi-directional opioid-opioid feeding interaction has been firmly established such that mu-agonist-induced feeding elicited from the ventral tegmental area is blocked by accumbal naltrexone, and that accumbal mu-agonist-induced feeding is blocked by naltrexone pre-treatment in the ventral tegmental area. To determine which opioid receptor subtypes mediate the regional bi-directional opioid-opioid feeding interactions between these two sites, the present study examined the dose-dependent ability of either general (naltrexone), mu (beta-funaltrexamine), kappa (nor-binaltorphamine) or delta (naltrindole) opioid antagonists administered into one site to block mu-agonist-induced feeding elicited from the other site. General, mu and kappa, but not delta opioid receptor antagonist pre-treatment in the ventral tegmental area dose-dependently reduced mu-agonist-induced feeding elicited from the nucleus accumbens. General, mu and delta, and to a lesser degree kappa, opioid receptor antagonist pre-treatment in the nucleus accumbens dose-dependently reduced mu-agonist-induced feeding elicited from the ventral tegmental area. Thus, multiple, but different opioid receptor subtypes are involved in mediating opioid-opioid feeding interactions between the nucleus accumbens and ventral tegmental area regions.  相似文献   

15.
采用电生理学方法,观察电刺激大鼠下丘脑弓状核(ARC)或垂体前叶(AL),对丘脑束旁核(Pf)神经元伤害性反应的影响。实验结果表明,电刺激ARC能抑制Pf神经元的伤害性放电,这种抑制很快出现,也很快恢复,称为即时抑制。电刺激A辄能抑制Pf神经元的伤害性放电,这种抑制的出现有一定的潜伏期,并持续较长时间,称为延迟抑制。摘除垂体减弱刺激ARC的即时抑制,而损毁ARC则减弱刺激AL的延迟抑制。地塞米松预  相似文献   

16.
Smooth muscle cells were isolated from the fundus of the canine gallbladder and examined for the presence of opioid receptors. The cells contracted in a concentration-dependent manner in response to three opioid peptides (Met-enkephalin, dynorphin1-13 and Leu-enkephalin), which are known derivatives of opioid precursors present in myenteric neurons of the gut. The order of potency was Met-enkephalin greater than dynorphin1-13 greater than Leu-enkephalin. The contractile response to opioid agonists was selectively inhibited by opioid antagonists (naloxone and Mr2266) but not by muscarinic, CCK/gastrin or tachykinin antagonists. Equivalent responses to the three opioid peptides exhibited differential sensitivity to preferential antagonists of mu (naloxone) and kappa (Mr2266) opioid receptors consistent with the presence of the three main types of opioid receptors (mu, delta and kappa) on canine gallbladder muscle cells.  相似文献   

17.
Prejunctional effects of opioids were examined in the perfused mesentery of two species: the rat and rabbit. Use of agonists selective for subtypes of mu, delta, and kappa opioid receptors produced no effect on contractile responses to adrenergic nerve stimulation in the rat perfused mesentery, except for small effects of the kappa agonist EKC, which may be non specific. In contrast, mu, delta and kappa receptors appear to be present in the rabbit. The mu selective agonist, DAMGO, kappa agonist, ethylketocyclazocine, and delta agonists, DPDPE and [Leu5]-enkephalin, all produced significant inhibition of contractile responses to transmural nerve stimulation. The inhibitory effect was greatest for ethylketocyclazocine. To test the possibility that prejunctional activation of alpha 2 adrenoceptors with endogenous norepinephrine might decrease the activity of prejunctional opioid receptors in the rabbit, inhibitory effects of delta and kappa selective agonists were tested in the presence of 10(-7) M yohimbine. Inhibitory responses of the kappa selective agonist ethylketocyclazocine were enhanced, while that of delta selective agonists [Leu5]-enkephalin and DPDPE remained unchanged when yohimbine was present. Thus, the effects of opioids vary and depend on the tissue and receptor subtypes they act upon. Furthermore, the enhanced inhibitory effect of opioid receptor activation in the presence of yohimbine is not found for all opioid receptors.  相似文献   

18.
A mechanism of opioid and substance P-mediated modulation of a cortical signal transduction through the striatum is suggested. According to this mechanism, an activation of postsynaptic receptors, bound to Gi/0 proteins, should increase the magnitude of NMDA-dependent (NMDA-independent) LTD (LTP) of excitatory inputs and LTP (LTD) of inhibitory inputs to all types of striatal cells. An activation of postsynaptic receptors, bound to Gs or Gq/11 proteins, should oppositely modulate LTD and LTD in the same inputs. It follows from the model that the negative feedback loops can held the activity of a striatal output cells at the stable level due to recurrent activation by endogenous opioids of delta receptors on striatopallidal cells, mu and kappa receptors on striatonigral cells of striosomes and matrix, respectively, and subsequent suppression of the efficacy of corticostriatal inputs. Cholinergic interneurons, affected by enkephalin and substance P, are also involved in these feedback loops. We hypothesized that an activation of mu and delta receptors and/or inactivation of kappa receptors on striatal spiny cells might alleviate parkinsonian symptoms and recover locomotor activity.  相似文献   

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