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1.
采用CB—HRP跨神经节追踪技术,我们发现鸡躯体和内脏的初级传入投射在脊髓质的一些板层和延髓的一些核团内有重叠区。1腓肠肌外头与卵巢的初级传入在T6~L3及S3~S5脊髓节段的I、Ⅴ层有明显的投射重叠区;与睾丸的初级传入在T6~L2及S3~S5髓节的I、Ⅴ层有明显的投射重叠;与泄殖腔的初级传入在T7~L2及S3~S5髓节的I、Ⅴ层亦有明显的重叠投射。2跗部皮肤与泄殖腔的在L2及S3髓节的I、Ⅳ层,与卵巢的在L2~L3髓节的I、Ⅳ层,与睾丸的在L3及S3髓节的I、Ⅳ层均有轻度的投射重叠区。3挠神经与腺胃及胸腺的在延髓的楔束外核和弧束核的内侧亚核有重叠投射区,4挠神经与卵巢、睾丸的在孤束核的内侧亚核有重叠;推测鸡的躯体和内脏的初级传入在这些区域可能有汇聚。  相似文献   

2.
Inflammation and trauma lead to enhanced pain sensitivity (hyperalgesia), which is in part due to altered sensory processing in the spinal cord. The synaptic hypothesis of hyperalgesia, which postulates that hyperalgesia is induced by the activity-dependent long-term potentiation (LTP) in the spinal cord, has been challenged, because in previous studies of pain pathways, LTP was experimentally induced by nerve stimulation at high frequencies ( approximately 100 hertz). This does not, however, resemble the real low-frequency afferent barrage that occurs during inflammation. We identified a synaptic amplifier at the origin of an ascending pain pathway that is switched-on by low-level activity in nociceptive nerve fibers. This model integrates known signal transduction pathways of hyperalgesia without contradiction.  相似文献   

3.
Nociceptive neuronal circuits are formed during embryonic and postnatal times when painful stimuli are normally absent or limited. Today, medical procedures for neonates with health risks can involve tissue injury and pain for which the long-term effects are unknown. To investigate the impact of neonatal tissue injury and pain on development of nociceptive neuronal circuitry, we used an animal model of persistent hind paw peripheral inflammation. We found that, as adults, these animals exhibited spinal neuronal circuits with increased input and segmental changes in nociceptive primary afferent axons and altered responses to sensory stimulation.  相似文献   

4.
Bidirectional coupling of action potential activity occurs between unmyelinated fibers in the normal peripheral nerve of monkey. The site of coupling is near the cutaneous nociceptive receptor associated with one of the fibers. This coupling could be due to an electrical synapse and could provide the basis for the flare associated with the axon reflex.  相似文献   

5.
小菜蛾nAChR靶标敏感性与沙蚕毒素类药物的抗性关系   总被引:1,自引:0,他引:1  
【目的】研究抗杀虫双、杀螟丹和溴氰菊酯品系的神经乙酰胆碱受体及与它们对沙蚕毒素类药物的抗性间的关系。【方法】测定不同品系小菜蛾的神经乙酰胆碱受体与125I标记的α-银环蛇毒素的结合率。【结果】抗杀虫双、杀螟丹品系小菜蛾的神经乙酰胆碱受体对沙蚕毒素药物有显著的靶标不敏感性,它们与配体的结合率大约分别是敏感品系的66%和60%,在溴氰菊酯抗性品系中没有明显变化。【结论】神经乙酰胆碱受体对杀虫剂敏感性下降可能是小菜蛾对沙蚕毒素药物产生抗性的一种作用机理。  相似文献   

6.
为探讨鸡肠道组织中肽能神经支配的途径及其功能,运用免疫组织化学超敏SP法,对不同生长阶段鸡肠道中血管活性肠肽(Vasoactive intestinal peptide,VIP)的分布特点进行了研究。结果显示,肠壁中VIP的表达范围较为广泛,涉及黏膜上皮和固有层、肌层和外膜,尤以固有层和肌层最为典型;随着日龄增加,黏膜上皮间VIP阳性细胞数量逐渐增多;从肠道不同部位的分布来看,十二指肠中VIP的表达强于同时期其他部位,空肠中的表达次之,回肠和盲肠的表达相对较弱。黏膜固有层和肌层一直分布有染色较深的VIP阳性神经纤维,呈串珠状、细线状或膨体状。提示鸡肠道是产生VIP的又一个重要部位,肠道中的VIP可参与鸡免疫器官的功能调节,并作为一种信息分子介导神经内分泌系统和黏膜免疫系统之间的相互作用。  相似文献   

7.
三种内源酸性植物激素与农垦58S育性转换的关系   总被引:24,自引:0,他引:24  
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8.
Alcohol dependence is a major public health challenge in need of new treatments. As alcoholism evolves, stress systems in the brain play an increasing role in motivating continued alcohol use and relapse. We investigated the role of the neurokinin 1 receptor (NK1R), a mediator of behavioral stress responses, in alcohol dependence and treatment. In preclinical studies, mice genetically deficient in NK1R showed a marked decrease in voluntary alcohol consumption and had an increased sensitivity to the sedative effects of alcohol. In a randomized controlled experimental study, we treated recently detoxified alcoholic inpatients with an NK1R antagonist (LY686017; n = 25) or placebo (n = 25). LY686017 suppressed spontaneous alcohol cravings, improved overall well-being, blunted cravings induced by a challenge procedure, and attenuated concomitant cortisol responses. Brain functional magnetic resonance imaging responses to affective stimuli likewise suggested beneficial LY686017 effects. Thus, as assessed by these surrogate markers of efficacy, NK1R antagonism warrants further investigation as a treatment in alcoholism.  相似文献   

9.
Empathy is thought to be unique to higher primates, possibly to humans alone. We report the modulation of pain sensitivity in mice produced solely by exposure to their cagemates, but not to strangers, in pain. Mice tested in dyads and given an identical noxious stimulus displayed increased pain behaviors with statistically greater co-occurrence, effects dependent on visual observation. When familiar mice were given noxious stimuli of different intensities, their pain behavior was influenced by their neighbor's status bidirectionally. Finally, observation of a cagemate in pain altered pain sensitivity of an entirely different modality, suggesting that nociceptive mechanisms in general are sensitized.  相似文献   

10.
The combinative rate measurement of (3-[I125] iodotyrosyl) α-bungarotoxin was applied in the analysis of the relation between nerve acetylcholine receptor and three types of insecticide resistance in diamondback moth, Plutella xylostella (L.). In the dimehypo-resistant strain and in the cartap-resistant strain, the nerve acetylcholine receptor showed the remarkable insensitivity to dimehypo and cartap, of which the binding rate to ligand was approximately 66 and 60%, respectively, of the susceptible strain. The sensitivity to deltamethrin in the deltamethrin-resistant strain did not show visible change. These results indicated that the decline in the sensitivity of nerve acetylcholine receptor to insecticide might be a potential mechanism to nereistoxin insecticides resistance in the diamondback moth.  相似文献   

11.
建立了花生矮化病毒(PSV)普通RT-PCR、SYBR Green I荧光RT-PCR和免疫捕获RT-PCR检测方法,并比较了它们的检测灵敏度。结果表明,以阳性对照为样品,普通RT-PCR灵敏度达到10-4,SYBR Green I荧光RT-PCR和免疫捕获RT-PCR的检测灵敏度相当,相对灵敏度均可达到10-6;检测混有PSV的大豆叶片样品,普通RT-PCR灵敏度为10-1,SYBR Green I荧光RT-PCR和免疫捕获RT-PCR的检测灵敏度为10-5;SYBR Green I荧光RT-PCR和免疫捕获RT-PCR方法比直接RT-PCR灵敏度高至少100倍,尤其在带毒植物叶片检测中优势更明显,而且灵敏、简便、同时重复性好。  相似文献   

12.
The capsaicin (vanilloid) receptor VR1 is a cation channel expressed by primary sensory neurons of the "pain" pathway. Heterologously expressed VR1 can be activated by vanilloid compounds, protons, or heat (>43 degrees C), but whether this channel contributes to chemical or thermal sensitivity in vivo is not known. Here, we demonstrate that sensory neurons from mice lacking VR1 are severely deficient in their responses to each of these noxious stimuli. VR1-/- mice showed normal responses to noxious mechanical stimuli but exhibited no vanilloid-evoked pain behavior, were impaired in the detection of painful heat, and showed little thermal hypersensitivity in the setting of inflammation. Thus, VR1 is essential for selective modalities of pain sensation and for tissue injury-induced thermal hyperalgesia.  相似文献   

13.
分析植物叶片性状种内水平的异速生长关系有助于加深理解生长发育过程中叶片的资源利用模式。分析了东灵山3个主要林型(白桦林、胡桃楸林、辽东栎林)中五角枫成树、幼树、幼苗的叶面积、叶体积、叶含水量与叶干重之间的异速生长关系。结果表明:成树叶面积增长速度小于叶干重的增长速度,幼树、幼苗叶面积与叶干重保持同速增长;成树、幼树叶干重与叶体积保持同速增长,幼苗叶体积的增长速度超过了干重的增长速度;成树叶含水量的增长速度小于叶干重的增长速度,幼树、幼苗两性状间保持等速增长。叶含水量与叶干重的异速生长指数在不同的林型间有显著差异,白桦林叶含水量的增长速度小于叶干重的增长速度,其余两个林型均为等速增长趋势。这些结果揭示了不同发育阶段五角枫资源利用方式的转变。随叶干重的增加,成树将更多的叶生物量投资于同化和支持结构;幼树则保持对光合面积和光合同化结构的稳步投资;而幼苗主要投资于叶面积的增大。叶含水量与叶干重的异速曲线在不同林型间的差异说明叶片代谢活性相较于其他叶性状可塑性更高。  相似文献   

14.
Ethics for an international health profession   总被引:1,自引:0,他引:1  
These thoughts about an ethic of international health can be summarized in a very free revision of the Hippocratic Oath: I will share the science and art by precept, by demonstration, and by every mode of teaching with other physicians regardless of their national origin. I will try to help secure for the physicians in each country the esteem of their own people, and in collaborative work see that they get full credit. I will strive to eliminate sources of disease everywhere in the world and not merely set up barriers to the spread of disease to my own people. I will work for understanding of the diverse causes of disease, including the social, economic, and environmental. I will promote the well-being of mankind in all its aspects, not merely the bodily, with sympathy and consideration for a people's culture and beliefs. I will strive to prevent painful and untimely death, and also to help parents to achieve a family size conforming to their desires and to their ability to care for their children. In my concern with whole communities I will never forget the needs of its individual members.  相似文献   

15.
对天女木兰7个分布区11份标本的叶片形态特征进行主成分和聚类分析.结果表明:主成分分析选出3个主成分,差方累计贡献率达到90.454%,叶片长、叶柄长/叶片长、叶宽分别是第1,2,3主成分的主导因子;7个分布区的11份天女木兰种质资源可分为两类,第一类包括取自吉林石湖的SH1及SH2和河北祖山的zs,表现为叶片大而薄,叶尖钝尖,叶基呈楔形或圆状楔形;第二类包括取自浙江清凉峰的QLF、安徽黄山的HS1及HS2、贵州雷公山的LGS1及LGS2、贵州麻江的MJ、广西猫儿山的MES1及MES2,表现为叶片普遍较厚,叶尖急尖或渐尖,叶基呈圆形或心形.聚类分析结果表明:种群间的亲缘关系远近与地理位置密切相关.  相似文献   

16.
打叶复烤片烟结构特征及差异分析   总被引:6,自引:1,他引:5  
为探讨片烟结构分布状况及各种因素对片烟结构质量的影响,采集了我国10个打叶复烤企业2006~2008年的片烟样品290份,分析了片烟结构不同年份间、不同等级间、不同批次间、复烤前后、不同打叶复烤厂间的分布及差异性,描述了片烟结构指标的变异性,结果表明:不同年份间存在差异,上、中等烟的12.7mm叶片率逐年提高,小片率和叶含梗率逐年降低;不同等级间存在差异,上等烟与中等烟差异较小,下等烟的12.7mm叶片率、小片率与上、中等烟差异均显著,加工水平是上等烟中等烟下等烟;不同批次间存在差异;复烤前后差异极显著;不同打叶复烤厂有不同程度的差异;12.7mm叶片率变异程度弱,其他指标属于中等变异。  相似文献   

17.
基于EFAST方法的CERES-Wheat作物模型参数敏感性分析   总被引:4,自引:0,他引:4  
为有效识别作物模型关键参数,减少模型模拟的不适用性,根据中国农业大学上庄实验站小麦田间实测数据,应用EFAST方法对CERES-Wheat模型输入参数进行定量的全局敏感性分析,分析小麦模拟产量对作物参数、土壤参数和田间管理参数变化的敏感性。结果表明:CERES-Wheat模型的作物品种型参数中,标准籽粒质量参数对模拟结果影响最大,而生态型参数中影响最大的是营养生长末期叶片面积质量比率;土壤参数中的矿化系数对模拟结果影响最显著;管理参数中的施氮量、播种日期、施肥日期、播种深度对模拟结果影响较显著。基于EFAST方法的敏感性分析对作物模型修正具有指导意义,可为确定模型关键参数及模型进一步优化提供参考依据。  相似文献   

18.
The combinative rate measurement of (3-[Ⅰ125] iodotyrosyl) α-bungarotoxin was applied in the analysis of the relation between nerve acetylcholine receptor and three types of insecticide resistance in diamondback moth, Plutella xylostella (L.). In the dimehypo-resistant strain and in the cartap-resistant strain, the nerve acetylcholine receptor showed the remarkable insensitivity to dimehypo and cartap, of which the binding rate to ligand was approximately 66 and 60%, respectively, of the susceptible strain. The sensitivity to deltamethrin in the deltamethrin-resistant strain did not show visible change. These results indicated that the decline in the sensitivity of nerve acetylcholine receptor to insecticide might be a potential mechanism to nereistoxin insecticides resistance in the diamondback moth.  相似文献   

19.
片烟结构稳定性的综合评价   总被引:1,自引:0,他引:1  
通过灰色关联聚类分析、层次分析、变异分析等统计方法,对2009年10家打叶复烤厂225份样品片烟结构的稳定性进行评价。结果表明:(1)应用灰色关联聚类分析得出片烟结构的核心指标是:中片率、小片率、叶中含梗率、12.7 mm片率;(2)通过层次分析确定中片率、小片率、叶中含梗率、12.7 mm片率的权重依次为:0.25、0.15、0.10、0.50;(3)结合变异分析对片烟结构的稳定性进行了综合评价,结果表明本方法用于片烟结构稳定性评价是有效的。  相似文献   

20.
R R Fay 《Science (New York, N.Y.)》1984,225(4665):951-954
Auditory and vestibular nerve fibers of the goldfish are strongly directionally sensitive to whole-body acceleration at audio frequencies. The three-dimensional pattern of sensitivity shows that input from a receptor ensemble (hair cells) is essentially equivalent to that expected from a single hair cell having a given three-dimensional orientation of best sensitivity. Fibers from the sacculus, lagena, and utriculus differ with respect to distributions of directional orientation, but are similar in best threshold (less than 1 nanometer, root mean square, at 140 hertz). In combination with other mechanisms for detection of sound pressure, this directionality is a likely basis for directional hearing in fishes, and it could allow the determination of underwater acoustic intensity.  相似文献   

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