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 31 毫秒
1.
邓超 《动物学研究》1992,13(2):100-100,108
据文献报道,鸟类端脑有可能存在三个视觉代表区,上纹状体视区(Visual area in hyperstriatum)是其中之一。迄今虽在解剖学、生理学方面对上纹状体视区进行了一些研究,但有关视神经元对光刺激的反应特征却尚未见报道。本工作就家鸽上纹状体视神经元对光刺激的反应特征进行了研究。  相似文献   

2.
刺激家鸽上纹状体对丘脑背中腹前核神经元电活动的影响   总被引:1,自引:0,他引:1  
王彬  胡昌华 《生理学报》1993,45(2):172-177
在氨基甲酸乙酯麻醉的55只鸽上,记录和分析了丘脑背中腹前核(nueleus dorsalis inter-medius ventralis anterior thalami,DIVA)对桡神经传入冲动发生反应的88个躯体感觉单位的放电其中一部分单位还对刺激坐骨神经发生反应。电刺激上纹状体的躯体传入投射区,可引致上述DIVA躯体感觉单位的自发放电和对桡神经传入的反应发生明显抑制。对自发放电抑制的程度与上纹状体的刺激频率和刺激强度呈正相关的关系;对桡神经传入反应的抑制则是使反应潜伏期增长和锋电位减少。以上结果提示,DIVA确实隶属于躯体感觉系统,而上纹状体躯体传入投射区对其躯体感觉单位有下行的抑制性影响,这种下行抑制可能使上纹状体得以对感觉输入进行反馈控制。看来中枢神经系统高级部位与丘脑之间的这种功能联系,在鸟类和哺乳类具有相似之处。  相似文献   

3.
鸽丘脑听觉中继核团传出神经投射的研究   总被引:4,自引:0,他引:4  
左明雪 《动物学报》1998,44(1):35-40
应用神经示踪物生物素标记的葡聚糖对环鸽丘脑听觉中继核团的传出神经投射进行了研究。结果发现:(1)丘脑卵圆核的传出纤维投射至端脑新纹状体内侧的L2听区;(2)卵圆核壳的传出纤维投射至L1、L3和部分L2听区,在L区周围亦存在许多标记终末;(3)尾侧卵圆核壳的传出投射参与了卵圆核壳的形成并发出二束纤维分别投射至下丘脑腹内侧核和端脑新纹状体L区外侧的旁听区。本实验结果首次揭示在鸟类丘脑听中继核团、端脑新  相似文献   

4.
钟声  黄仲荪 《生理学报》1988,40(6):539-546
本实验在75只家兔身上进行。观察了腹部迷走神经及内脏大神经传入冲动在延髓投射的分布、潜伏期及反应型式等特征。结果表明,腹部迷走传入冲动相对集中地投射在孤束核(NTS)及其附近区域,并呈现基本对称的双侧性投射。测定了254个延髓细胞的反应潜伏期,平均值为257.44±44.57ms((?)±SD)。内脏大神经传入投射较弥散,而且在 NTS 也有相当数量的分布。在 NTS 中存在迷走-内脏神经传入冲动的汇聚。  相似文献   

5.
在5℃和15℃温度条件下,用牛蛙(Rana catesbeiana)离体坐骨神经标本测定0、24、48、96、120、144、168、192、216 h 9个时段的动作电位波幅和传导速度.结果表明:两个温度下离体坐骨神经的动作电位幅度在0 h和24 h差异均不显著,0 h时相对高温(15℃)下动作电位传导速度大于相对低温(5℃),24 h时两个温度下动作电位的传导速度差异不显著,相对高温下48 h时坐骨神经的兴奋性为零.相对低温条件下,坐骨神经兴奋性能维持7 d时间.  相似文献   

6.
P物质受体在大鼠纹状体边缘区内的表达   总被引:5,自引:0,他引:5  
我们以前的工作观察到纹状体边缘区内有密集的P物质纤维及终末分布,本用原位杂交和免疫组织化学方法研究了大鼠纹状体边缘区内P物质受体(SPR)的表达及分布,原位杂交结果发现P物质mRNA阳性杂交信号在纹状体内的分布不均匀,尾壳核内只有少量中等大小的阳性胞体,苍白球内只有少量较大的阳性胸体,而在尾壳核和苍白球之间的边缘区部位则可见许多中等大小的梭形阳性神经元胞体,并呈现密集的带关分布。免疫组织化学结果观察到P物质阳性神经元胞体在纹状体内的分布与原位杂交结果一致。推测大鼠纹体边缘区内可以合成P物质受体,具有接受和整合P物质神经递质的功能,推测边缘区内SPR神经元可能对SP递质的接受、调节有重要作用。  相似文献   

7.
纹状体在药物成瘾有关的联想性学习中的作用   总被引:1,自引:0,他引:1  
Bao YF  Zheng XG  Sui N 《生理科学进展》2006,37(2):165-168
多种学习和记忆系统参与成瘾行为,其中联想性学习发挥着重要作用。药物相关的条件性刺激通过经典条件作用和操作性条件作用的异常结合,引起觅药行为的产生、巩固、加强,并参与习惯行为的获得和复吸的发生。这些影响是通过腹侧纹状体对皮层边缘系统的整合以及背侧纹状体的习惯化来调节的,而多巴胺在其中发挥重要作用。另外,基于鸟类纹状体发达的解剖特点,脑内多巴胺系统及与哺乳动物成瘾行为的相似性,相信可为以后的研究提供新的思路。  相似文献   

8.
基底神经节是皮层下随意运动控制乖调节的中心,其中纹状体则是接受大脑皮层信息输入的主要核团.纹状体通过表达不同多巴胺受体类型的中等棘状神经元(medium-sized spiny neurons,MSNs)分别参与直接通路和间接通路的运动调控.经典的运动控制模型认为,直接通路易化运动,间接通路抑制运动,两者起拮抗作用并呈...  相似文献   

9.
雌激素在大鼠杏仁核与纹状体多巴胺代谢中作用的差异   总被引:1,自引:0,他引:1  
Liu B  Xie JX 《生理学报》2002,54(2):121-124
为探讨雌激素对大鼠杏仁核(amygdala,Amy)与纹状体(striatum,Str)多巴胺(dopamine,DA)代谢的作用,本实验采用离体电化学检测技术--高效液相色谱法(high performance liquid chromatography,HPLC)测定正常雌鼠及经雌激素处理的去卵巢(ovariectomy,OVX)雌鼠Amy和Sr的DA及其代谢产物的组织含量。实验结果显示,OVX雌鼠经雌激素处理后,可引起Amy的DA及其代谢产物含量减少,而Str的DA及其代谢产物含量不受其影响。OVX雌鼠Amy的DA更新率低于正常及雌激素处理的OVX鼠,Amy组织的DA含量约是Str组织的1/6,而更新率是Str的2倍左右。以上结果提示,雌性大鼠血清雄激素浓度可影响其Amy组织的DA代谢及组织含量,而Str的DA组织含量不因雌激素浓度的改变而变化。  相似文献   

10.
徐爱丽  王华  周岩  刘红霞 《生物磁学》2009,(14):2649-2651
目的:观察七叶莲水煎液对蟾蜍离体坐骨神经复合动作电位的幅度及传导速度的影响,研究其对坐骨神经电生理特性的作用。方法:将制备的蟾蜍坐骨神经干分为4组,分别在任氏液和浓度为10%,20%,40%的七叶莲水煎液中浸泡,用MedLab生物信号采集处理系统引导神经干复合双相动作电位,并分别测定各组不同浸泡时间的坐骨神经干动作电位的幅度和传导速度两项电生理指标。记录不同浓度的七叶莲水煎液对蟾蜍离体坐骨神经复合动作电位的幅度和传导速度的影响。结果:10%,20%,40%3种浓度的七叶莲水煎液均使坐骨神经复合动作电位的幅度变小(P〈0.01),传导速度变慢(P〈0.01)并最终使坐骨神经动作电位消失,且经过一段时间后动作电位的幅度和传导速度均能恢复。结论:七叶莲能可逆地阻滞神经动作电位的传导。  相似文献   

11.
本文描述了大鼠脊髓L_1节段后柱、后索、侧索和前角的诱发电位及其损伤后的变化,并观察了切断L_4、L_5脊神经背、腹根与横断高位颈髓对电位的影响,以进行行电位来源分析。结果可见,上述四个区域的诱发电位基本由早反应三相波和晚反应组成。分别电解损毁这些部位后,电位波幅均普遍降低,晚期反应较早反应降低明显。后柱或后索受损对电位影响最大。局部损毁后可见L_1及T_(13)水平的硬膜上电位改变明显,尤其晚反应减弱、波峰平坦。反应时值与潜伏时未见明显改变。切断L_4脊神经背、腹根后、电位基本消失。去大脑对电位未见明显影响。结果表明,刺激坐骨神经诱发的脊髓电位起源于低位腰段传入神经和脊髓内多通路的兴奋传导,在一定程度上受腹根逆行活动的影响,与大脑及脊髓下行传导束活动无直接联系。脊髓诱发电位的幅度与波形改变可作为脊髓损伤的判断指标之一。  相似文献   

12.
新生大鼠脑低氧缺血早期对纹状体胆碱能系统的影响   总被引:1,自引:0,他引:1  
采用7日龄大鼠右侧颈总动脉结扎合并高温、低氧环境制作新生动物脑低氧缺血模型,观察了脑低氧缺血对新生动物纹状体胆碱能系统的影响。乙酰胆碱(ACh)放射免疫测定结果表明,低氧缺血损伤后24h,两侧纹状体ACh含量均比正常对照组明显下降。乙酰胆碱酯酶(AChE)组织化学图象定量提示,脑低氧缺血后24h,纹状体内拟胆碱能神经元数量未见减少,而胞体内AChE染色强度略有下降。胆碱能递质和该标志酶在新生鼠脑低氧缺血早期的一致改变,证明发育中纹状体胆碱能系统对低氧缺血敏感。鉴于动物不结扎动脉仅作低氧处理者双侧纹状体ACh含量出现与低氧缺血组相同的改变,故提示缺氧可能是造成胆碱能系统早期损伤的直接原因。  相似文献   

13.
    
Introduction  Brachial plexus lipomas are extremely rare benign tumors that may cause slow progression of neurological deficits leading to thoracic outlet syndrome. Up to now, surgery remains challenging. The aim of this study is to present our surgical treatment regime and long-term neurological outcome in three cases of giant brachial plexus lipomas and to show results of systematic review. Patients and Methods  Retrospective analysis of our database “peripheral nerve lesion” to identify patients suffering from brachial plexus lipomas between January 1, 2012, and December 31, 2019. Systematic review was performed for literature published until March 31, 2020, analyzing PubMed, Google Scholar, Scopus, and the Cochrane Collaboration Library independently by two authors. Results  Over the past years, three patients suffering from giant brachial plexus lipomas attended to our neurosurgical department. All patients underwent preoperative magnetic resonance imaging (MRI), ultrasound examinations, and electrophysiological testing. Tumors were removed microsurgically via anterior/posterior, supraclavicular/infraclavicular, and combined approaches. The patients were accessed postoperatively by MRI and clinical follow-up. Systematic review of the literature revealed 22 cases, which were analyzed in regard to demographics, surgical treatment, and neurological outcome. Conclusion  Brachial plexus lipomas are an extremely rare cause for brachial plexus compression. Total microsurgical removal with intraoperative electrophysiological monitoring is the treatment of choice with excellent long-term MRI and clinical outcome.  相似文献   

14.
15.
摘要 目的:探讨超声与周围神经刺激器引导技术用于上肢手术锁骨上阻滞的效果。方法:招募2019年5月~2021年4月在我院收治并接受上肢手术的100例患者为研究对象。所有患者均接受上臂丛神经阻滞。根据研究方案将患者随机均分为对照组和引导组。对照组采用神经刺激器辅助定位锁骨上臂丛神经阻滞,引导组采用超声与周围神经刺激器引导技术对上臂丛神经阻滞,统计分析临床麻醉完成时间等相关指标。结果:两组患者一般资料比较无差异(P>0.05)。引导组麻醉完成时间和神经阻滞起效时间较对照组缩短(P<0.05),引导组神经阻滞持续时间较对照组延长(P<0.05)。引导组麻醉效果优良率较对照组升高(P<0.05),引导组麻醉效果中差率较对照组低(P<0.05)。引导组总体并发症较对照组低(P<0.05)。引导组感觉评分、运动评分、应对评分和总评分较对照组升高(P<0.05)。引导组非常满意率和总满意率较对照组升高(P<0.05),引导组不满意率较对照组降低(P<0.05)。结论:与单独使用神经刺激器相比,超声引导辅助定位锁骨上臂丛神经阻滞具有起效快、阻滞完全、持续时间长等优点,超声与周围神经刺激器引导技术可提高麻醉的有效性、准确性和安全性,值得临床推广。  相似文献   

16.
摘要 目的:本研究旨在探讨斜角肌间臂丛阻滞影响心率变异性的危险因素及Logistic回归分析。方法:选取2021年5月至2022年3月于我院接受肩关节开放手术治疗的患者60例作为研究对象,按照麻醉方式不同随机分为实验组和对照组2组,其中实验组患者给与超声引导下斜角肌间臂丛神经阻滞,对照组患者进行单纯斜角肌间臂丛神经阻滞,统计患者的一般临床资料,对比分析阻滞前后心率变异指标、SpO2、心率和平均动脉压水平;同时研究危险因素与心率变异性之间的关系。结果:斜角肌间臂丛阻滞影响心率变异性的单因素分析显示,危险因素与性别、平均年龄、BMI、总胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白、合并慢性病(糖尿病、高血压)、吸烟史和饮酒史无关(P>0.05),镇痛维持时间较短、运动恢复时间较长、阻断节数较少的斜角肌间臂丛阻滞患者更易表现出心率变异性(P<0.05)。阻滞后,实验组LF、HF、LF/HF、RMSSD、SDNN和PNN50 %显著低于对照组(P<0.05),而阻滞后SpO2、心率和平均动脉压比较无差异(P>0.05)。影响心率变异性危险因素的多因素为镇痛维持时间(OR=6.224,P=0.001<0.05)、运动恢复时间(OR=9.556,P=0.002<0.05)、阻断节数(OR=7.591,P=0.001<0.05)。结论:斜角肌间臂丛阻滞出现心率变异性与镇痛维持时间、运动恢复时间、阻断节数有关。  相似文献   

17.
In the present experiment we examined the spontaneous in vitro dopamine (DA) efflux from superfused corpus striatum (CS) of male rats at 3-hr intervals throughout a 24-hr photoperiod (lights on 0500-1900 hr). Maximal mean efflux, and post-superfusion DA concentrations were obtained at 0600 hr. With the exception of 0600 hr, mean efflux was lower during the light compared to the dark phase. Interestingly, the direction of the efflux profiles also varied as a function of time demonstrating increasing, decreasing and relatively stable profiles over the superfusion period. These changes in overall mean efflux, post-superfusion tissue concentration and efflux rate profile direction indicate that circadian processes play a complex role upon the synthesis/release process of DA from the nigrostriatal dopaminergic system that is revealed under the dynamic conditions of in vitro superfusion of isolated CS fragments.  相似文献   

18.
Abstract

Objective: We analysed the recovery function of somatosensory evoked potentials (SEPs) in juvenile myoclonic epilepsy (JME) patients. We hypothesized that there may be disinhibition in the recovery of SEPs at 20–100?ms intervals in JME patients.

Methods: We recorded SEPs and SEP recovery in 19 consecutive patients with JME admitted for a routine follow-up examination, and in a control group composed of 13 healthy subjects who were similar to the patient group regarding age and sex. The recovery function of SEPs was examined using paired stimuli at 30, 40, 60, and 100?ms intervals.

Results: The amplitudes of N20-P25 and P25-N33 components were higher in patients with JME. Ten patients had high-amplitude SEPs. By paired stimulation, there was inhibition of SEPs in both groups. The mean recovery percentages of N20-P25 and P25-N33 components at 30, 40, 60, and 100?ms were not different between healthy subjects and patients with JME.

Conclusions: The recovery function of SEP is normal in JME even in the presence of high-amplitude SEPs.  相似文献   

19.
    
Dopamine (DA), a highly significant neurotransmitter in the mammalian central nervous system, operates on multiple time scales to affect a diverse array of physiological functions. The significance of DA in human health is heightened by its role in a variety of pathologies. Voltammetric measurements of electrically evoked DA release have brought to light the existence of a patchwork of DA kinetic domains in the dorsal striatum (DS) of the rat. Thus, it becomes necessary to consider how these domains might be related to specific aspects of DA's functions. Responses evoked in the fast and slow domains are distinct in both amplitude and temporal profile. Herein, we report that responses evoked in fast domains can be further classified into four distinct types, types 1–4. The DS, therefore, exhibits a total of at least five distinct evoked responses (four fast types and one slow type). All five response types conform to kinetic models based entirely on first‐order rate expressions, which indicates that the heterogeneity among the response types arises from kinetic diversity within the DS terminal field. We report also that functionally distinct subregions of the DS express DA kinetic diversity in a selective manner. Thus, this study documents five response types, provides a thorough kinetic explanation for each of them, and confirms their differential association with functionally distinct subregions of this key DA terminal field.

  相似文献   


20.
    
Background  Characterizing the biomechanical failure responses of neonatal peripheral nerves is critical in understanding stretch-related peripheral nerve injury mechanisms in neonates. Objective  This in vitro study investigated the effects of prestretch magnitude and duration on the biomechanical failure behavior of neonatal piglet brachial plexus (BP) and tibial nerves. Methods  BP and tibial nerves from 32 neonatal piglets were harvested and prestretched to 0, 10, or 20% strain for 90 or 300 seconds. These prestretched samples were then subjected to tensile loading until failure. Failure stress and strain were calculated from the obtained load-displacement data. Results  Prestretch magnitude significantly affected failure stress but not the failure strain. BP nerves prestretched to 10 or 20% strain, exhibiting significantly lower failure stress than those prestretched to 0% strain for both prestretch durations (90 and 300 seconds). Likewise, tibial nerves prestretched to 10 or 20% strain for 300 seconds, exhibiting significantly lower failure stress than the 0% prestretch group. An effect of prestretch duration on failure stress was also observed in the BP nerves when subjected to 20% prestretch strain such that the failure stress was significantly lower for 300 seconds group than 90 seconds group. No significant differences in the failure strains were observed. When comparing BP and tibial nerve failure responses, significantly higher failure stress was reported in tibial nerve prestretched to 20% strain for 300 seconds than BP nerve. Conclusion  These data suggest that neonatal peripheral nerves exhibit lower injury thresholds with increasing prestretch magnitude and duration while exhibiting regional differences.  相似文献   

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