首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
目的:观察下丘脑外侧区(lateral hypothalamic area,LHA)对胃缺血-再灌注损伤(gastric ischemia-reperfusion injury,GI-RI)的影响,并对LHA的调控通路进行了初步分析。方法:采用夹闭大鼠腹腔动脉30min,松开动脉夹血流复灌60min的GI-RI模型,用电和化学刺激,电损毁和核团微量注射等方法。结果:(1)电或化学刺激LHA均显著加重GI-RI;(2)背侧迷走复合体(dorsal vagal complex,DVC)内微量注射五肽胃泌素后,对GI-RI的效应与电刺激一致;(3)电解损毁双侧DVC或DVC内微量注射胃泌素受体阻断剂丙谷胺均可取消电刺激LHA加重GI-RI的作用。(4)切断膈下迷走神经后电刺激LHA,GI-RI则减轻。结论:LHA具有加重大鼠GI-RI的作用;LHA的这种作用可能是因电或化学刺激后,激活了其中的胃泌素能神经元,经其下行投射纤维释放胃泌素作用于DVC神经元上的胃泌素受体,并通过迷走神经介导,从而影响GI-RI。  相似文献   

2.
采用夹闭大鼠腹腔动脉30min,松开动脉夹血流复灌1h的胃缺血-再灌注损伤模型,观察了电和化学刺激以及电损毁下丘脑室旁核(paraventricular nucleus,PVN)对大鼠胃缺血-再灌注损伤(gastric ischemia-reperfu-sion injury,GI-RI)的影响,并对其调控的神经机制进行了初步研究。结果表明:①电刺激PVN或PVN内注射L-谷氨酸后,GI-RI均显著减轻;②电解损毁双侧PVN则能加重GI-RI;③损毁双侧孤束核(nucleus tractus solitarius,NTS)后,能取消电刺激PVN对GI-RI的减轻作用;④去除脑垂体后不影响电刺激PVN对GI-RI的作用;⑤分别切断膈下迷走神经和切除腹腔交感神经节后,电刺激PVN使GI-RI较单纯电刺激PVN组明显减轻。提示:PVN是对GI-RI具有保护作用的特异性中枢部位,孤束核以及外周迷走神经、交感神经均参与了PVN对GI-RI的调控,而与室旁核-垂体通路似无关系。  相似文献   

3.
目的 研究ACh对正常大鼠和吗啡成瘾大鼠海马CA1区痛兴奋神经元(pain-excitation neurons,PEN)和痛抑制神经元(pain-inhibitation neurons,PIN)电活动的影响,进一步探讨ACh对正常和吗啡成瘾状态下CA1区痛觉调制的作用及机制.方法 电刺激坐骨神经作为伤害性电刺激,在细胞外用玻璃微电极记录CA1区PEN和PIN的放电,观察ACh对正常大鼠和吗啡成瘾大鼠CA1区PEN和PIN电活动的影响.结果 伤害性刺激能够增强PEN的电活动,而减弱PIN的电活动.正常大鼠中,ACh使PEN的痛诱发放电频率降低,PIN的放电频率增加;ACh的作用在注射后4 min达到峰值.吗啡成瘾大鼠中,ACh同样也抑制了PEN的电活动,兴奋PIN的电活动,但是作用的高峰出现在注射后6min.胆碱能受体拮抗剂阿托品可阻断ACh的作用.结论 海马CA1区内的胆碱能神经元和毒蕈碱受体参与了伤害性信息的处理,并且起到了镇痛作用.吗啡成瘾可以降低CA1区痛反应神经元对伤害性刺激的敏感性.  相似文献   

4.
目的研究ACh对正常大鼠和吗啡成瘾大鼠海马CA1区痛兴奋神经元(pain-excitation neurons,PEN)和痛抑制神经元(pain-inhibitationneurons,PIN)电活动的影响,进一步探讨ACh对正常和吗啡成瘾状态下CA1区痛觉调制的作用及机制。方法电刺激坐骨神经作为伤害性电刺激,在细胞外用玻璃微电极记录CA1区PEN和PIN的放电,观察ACh对正常大鼠和吗啡成瘾大鼠CA1区PEN和PIN电活动的影响。结果伤害性刺激能够增强PEN的电活动,而减弱PIN的电活动。正常大鼠中,ACh使PEN的痛诱发放电频率降低,PIN的放电频率增加;ACh的作用在注射后4 min达到峰值。吗啡成瘾大鼠中,ACh同样也抑制了PEN的电活动,兴奋PIN的电活动,但是作用的高峰出现在注射后6min。胆碱能受体拮抗剂阿托品可阻断ACh的作用。结论海马CA1区内的胆碱能神经元和毒蕈碱受体参与了伤害性信息的处理,并且起到了镇痛作用。吗啡成瘾可以降低CA1区痛反应神经元对伤害性刺激的敏感性。  相似文献   

5.
在氨基甲酸乙酯麻醉、制动的大鼠,研究尾端延髓腹外侧区(CVLM)中NMDA和非NMDA受体在介导动脉压力感受器反射(ABR)中的作用.双侧CVLM微量注射选择性NMDA受体拮抗剂氯胺酮(50mmol/L,100 n1)或非NMDA受体拮抗剂kynurenic acid(KYA,50 mmol/I.,100 nl)后平均动脉压(MAP)和心率(HR)均明显升高(P<0.05),同时观察到CVLM微量注射氯胺酮或KYA后电刺激主动脉神经(AN)导致的血压下降比对照有明显的减少,双侧CVLM微量注射氯胺酮和KYA的混合物(均为50mmol/L,50 nl)后能完全阻断电刺激AN后导致的降压反应.本研究结果提示CVLM中NMDA和非NM-DA受体在紧张性维持交感神经的兴奋活动和介导ABR中起十分重要的作用.  相似文献   

6.
以电刺激外周感受野诱发的大鼠脊髓背角WDR和NS神经元的晚串放电(C-反应)为指标,以串脉中刺激对侧大脑脚(CP)作为条件刺激,在C-反应受到明显抑制的神经元。分别观察了电解损毁红核(RN)和RN内注射兴奋性氨基酸的受体拮抗剂对刺激CP的下行抑制作用的影响。结果发现:损毁同侧RN后,刺激CP对C反应的抑制作用明显减弱,而损毁同侧RN背侧结构,对侧RN及假损毁RN均无此效应;RN内微量注射兴奋性氨基酸受体拮抗剂AP5和DNQX均可减弱刺激CP对C-反应的抑制。提示RN至少部分参与大脑皮质对脊髓伤害感受性传递的下行抑制作用。且以同侧RN为主;在与痛觉调制有关的皮质-RN通路中既有NMDA受体又有非NMDA受体的参与。  相似文献   

7.
目的:利用红藻氨酸(kainate,KA)致大鼠复杂部分性发作模型,观察海马及齿状回等易损脑区N-甲基-D-门冬氨酸受体1亚单位(NMDAR_1)的变化,以期进一步探明迷走神经刺激治疗癫(疒间)的作用机制。方法:免疫细胞化学法。结果:正常大鼠NMDAR_1阳性结构可见于海马各区及齿状回;KA给药后1h海马CA1、CA3、齿状回NMDAR_1的密度开始增高;3h达高峰,以后逐渐下降,24h后基本恢复正常;预先给予左侧迷走神经电刺激治疗的大鼠相应脑区NMDAR_1密度较KA致(疒间)组明显降低,具有统计学差异。结论:迷走神经刺激抑制癫(疒间)发作可能是通过降低易损脑区神经元NMDAR_1活性而发挥作用的。  相似文献   

8.
目的 以往的研究表明胃动素存在于大鼠的中枢神经系统,在中枢注射胃动素具有促进清醒大鼠胃运动的作用.但糖尿病大鼠中枢胃动素表达含量及中枢注射胃动素对糖尿病大鼠胃运动的潜在作用目前尚未报导.本研究探索糖尿病大鼠胃动素免疫阳性神经元在下丘脑的表达,观察侧脑室微量注射胃动素受体激动剂红霉素(erythromycin,EM)对正常和糖尿病大鼠胃运动的作用.方法 采用免疫组织化学方法测定下丘脑胃动素免疫阳性神经元的分布特征.在胃窦浆膜层植入应力传感器,测定清醒大鼠胃运动的幅度和频率.结果 糖尿病大鼠下丘脑室旁核和视上核胃动素免疫阳性神经元数量明显高于正常对照大鼠(P<0.05).脑室内微量注射EM可以明显促进糖尿病大鼠的胃运动.注射91.56 nmol的EM五分钟后,大鼠胃窦运动幅度升高(174.82±48.62)%(P<0.05),运动频率加快(70.43±27.11)%(P<0.05).在脑室内微量注射胃动素拮抗剂GM-109后,再注射EM,其促胃运动效应可被部分阻断.结论 糖尿病大鼠中枢胃动素对胃运动有一定的调制作用,而且脑室内微量注射的EM是通过脑内的胃动素受体介导而发挥其促胃动力效应.  相似文献   

9.
苍白球在电针镇痛及兴奋尾壳核镇痛中的作用   总被引:1,自引:0,他引:1  
用行为学和电生理学的方法 ,探讨苍白球在电针镇痛及兴奋尾壳核镇痛中的作用。结果表明 :电针可以延长辐射热引起的缩腿潜伏期 ,电针或兴奋尾壳核可抑制丘脑束旁核神经元的伤害性反应 ;苍白球微量注射红藻氨酸 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 ,与毁损前相比有显著性差异 (P <0 .0 5 ) ,与苍白球微量注射生理盐水 7d后 ,电针可延长大鼠缩腿潜伏期 ,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 )。结果提示 :苍白球在电针及兴奋尾壳核镇痛中发挥重要作用  相似文献   

10.
在氨基甲酸乙酯麻醉、制动的大鼠 ,研究尾端延髓腹外侧区 (CVLM)中 NMDA和非 NMDA受体在介导动脉压力感受器反射 (ABR)中的作用。双侧 CVLM微量注射选择性 NMDA受体拮抗剂氯胺酮 (50mmol/L ,1 0 0 nl)或非 NMDA受体拮抗剂 kynurenic acid(KYA,50 mmol/L ,1 0 0 nl)后平均动脉压 (MAP)和心率 (HR)均明显升高 (P<0 .0 5) ,同时观察到 CVLM微量注射氯胺酮或 KYA后电刺激主动脉神经(AN)导致的血压下降比对照有明显的减少 ,双侧 CVLM微量注射氯胺酮和 KYA的混合物 (均为 50mmol/L,50 nl)后能完全阻断电刺激 AN后导致的降压反应。本研究结果提示 CVLM中 NMDA和非 NM-DA受体在紧张性维持交感神经的兴奋活动和介导 ABR中起十分重要的作用  相似文献   

11.
12.
13.
A number of cross-sectional population studies have shown that a strong sense of coherence (SOC) is associated with various aspects of good perceived health. The association does not seem to be entirely attributable to underlying associations of SOC with other variables, such as age or level of education. OBJECTIVE: The aim of the study reported here was to determine whether SOC predicted subjective state of health. METHODS: The study was carried out as a two-way panel mail survey of 1976 individuals with 4 years interval for two collections of data. The statistical method used was multivariate cumulative logistic modeling. Age, initial subjective state of health, initial occupational training level, and initial degree of social integration were included as potential explanatory variables. RESULTS: A strong SOC predicted good health in women and men. CONCLUSIONS: SOC can be interpreted as an autonomous internal resource contributing to a favorable development of subjective state of health. SOC data should, however, be regarded as complementary to and not a substitute for information already known to be associated with increased risk of future ill health.  相似文献   

14.
Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.  相似文献   

15.
Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.  相似文献   

16.
17.
Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005  相似文献   

18.
19.
After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号