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1.
Electrophysiologic responses in hamster superior colliculus evoked by regenerating retinal axons 总被引：7，自引：0，他引：7
S A Keirstead M Rasminsky Y Fukuda D A Carter A J Aguayo M Vidal-Sanz 《Science (New York, N.Y.)》1989,246(4927):255-257
Autologous peripheral nerve grafts were used to permit and direct the regrowth of retinal ganglion cell axons from the eye to the ipsilateral superior colliculus of adult hamsters in which the optic nerves had been transected within the orbit. Extracellular recordings in the superior colliculus 15 to 18 weeks after graft insertion revealed excitatory and inhibitory postsynaptic responses to visual stimulation. The finding of light-induced responses in neurons in the superficial layers of the superior colliculus close to the graft indicates that axons regenerating from axotomized retinal ganglion cells can establish electrophysiologically functional synapses with neurons in the superior colliculus of these adult mammals. 相似文献
2.
Electrical stimulation of area 18 of the cat visual cortex produces intense excitation of neurons in the superior colliculus. Excitation is followed by a period of decreased collicular responsiveness to light stimulation. These effects are seen in both directionally selective and nonselective units. The corticocollicular projection is retinotopically organized. 相似文献
3.
Stimulation of preganglionic sympathetic fibers to the superior cervical ganglia elevates the activity of pineal N-acetyltransferase. After the stimulation-induced rise in enzyme activity, a return toward baseline levels occurs whether or not nerve stimulation is continued. The ability of pineal N-acetyltransferase activity to fall in the presence of stimulation may account for the persistence of its rhythm in blinded animals. 相似文献
4.
Two- rather than three-dimensional representation of saccades in monkey superior colliculus 总被引：2，自引：0，他引：2
A J van Opstal K Hepp B J Hess D Straumann V Henn 《Science (New York, N.Y.)》1991,252(5010):1313-1315
Saccades are controlled by neurons in the brainstem reticular formation that receive input from the superior colliculus and cortex. Recently two quantitative models have been proposed for the role of the colliculus in the generation of three-dimensional eye movements. In order to test these models, three-dimensional eye movements were measured in the alert monkey to investigate whether the saccadic motor map of the superior colliculus is two-dimensional, representing retinal target vectors, or three-dimensional, representing three-dimensional motor error for the rotation of the eye. Electrical stimulation of the superior colliculus produced two-dimensional, not three-dimensional, eye movements. It is therefore concluded that the collicular motor map is two-dimensional. 相似文献
5.
M P Blaustein 《Science (New York, N.Y.)》1971,172(981):391-393
Isolated superior cervical ganglia of rats accumulate more calcium during preganglionic stimulation than do unstimulated controls; uptake of calcium-45 is approximately doubled by stimulation of 12 impulses per second. The extra uptake is markedly reduced by a high concentration of magnesium, but not by mecamylamine hydrochloride or tetraethylammonium chloride, although all three agents eliminate the postsynaptic action potential. Uptake of calcium-45 is also greatly increased by a high external concentration of potassium. 相似文献
6.
Depolarization and muscarinic excitation induced in a sympathetic ganglion by vasoactive intestinal polypeptide 总被引：2，自引：0，他引：2
The effects of vasoactive intestinal polypeptide (VIP) in the superior cervical ganglion of the cat were studied in vitro and in vivo with sucrose gap and multiunit recording, respectively. At a dose of 0.03 to 0.12 nanomole, VIP produced a dose-dependent, prolonged (3 to 15 minutes) depolarization of the ganglion and enhanced the ganglionic depolarization elicited by the muscarinic agonist acetyl-beta-methylcholine. At a dose of 1.8 to 10 nanomoles, the peptide enhanced and prolonged the postganglionic discharge elicited by acetyl-beta-methylcholine, enhanced muscarinic transmission in ganglia treated with an anticholinesterase agent, and enhanced the late muscarinic discharge elicited by acetylcholine. VIP did not affect the early nicotinic discharge elicited by acetylcholine or by electrical stimulation of the preganglionic nerve. It is concluded that VIP has a selective facilitatory action on muscarinic excitatory mechanisms in the superior cervical ganglion of the cat. 相似文献
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Radiant heat stimulation was applied to volunteers and rating scale responses were obtained to assess the analgesic properties of 33 percent nitrous oxide. The methodology of signal detection theory was applied to the data to demonstrate that nitrous oxide reduces both sensitivity to pain and willingness to report pain. This method is superior to threshold estimation for the evaluation of analgesics. 相似文献
9.
激素营养液对不同苗木生长效应的影响 总被引：1，自引：0，他引：1
该文对两种激素营养液与不同苗木的苗高、地径及生物量的生长关系进行了研究。结果表明：①两种激素营养液对实验树种的苗高、地径生长均有促进作用，且Ⅱ号激素营养液较Ⅰ号为优。②Ⅰ号激素营养液可提高苗木地径。 相似文献
10.
Sympathetic nervous control of cerebrospinal fluid production from the choroid plexus 总被引：6，自引：0，他引：6
The rabbit choroid plexus, responsible for the bulk production of cerebrospinal fluid, is well supplied by sympathetic nerves emanating in the superior cervical ganglia. Electrical stimulation of these nerves markedly reduces production of cerebrospinal fluid, measured by [14C] inulin dilution during ventricular perfusion, whereas sympathetic denervation enhances the rate of formation. 相似文献
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Brief tetanic stimulation of the preganglionic nerves to the superior cervical ganglion enhances the postganglionic response to single preganglionic stimuli for 1 to 3 hours. This long-term potentiation of transmission through the ganglion is apparently not attributable to a persistent muscarinic action of the preganglionic neurotransmitter, acetylcholine, since neither the magnitude nor the time course of the phenomenon is reduced by atropine. The decay of long-term potentiation can be described by a first-order kinetic process with a mean time constant of 80 minutes. We conclude that long-term potentiation, once considered a unique property of the hippocampus, is in fact a more general feature of synaptic function. This form of synaptic memory may significantly influence information processing and control in other regions of the nervous system, including autonomic ganglia. 相似文献
12.
Repetitive presynaptic stimulation elicited slow membrane depolarization in neurons of inferior mesenteric ganglia from guinea pigs. This response was not blocked by cholinergic antagonists but was specifically and reversibly inhibited by a substance P analog, (D-Pro2, D-Phe7, D-Trp9)-substance P, which also depressed the depolarization induced by exogenously applied substance P. The atropine-sensitive slow excitatory and slow inhibitory postsynaptic potentials evoked in neurons of rabbit superior cervical ganglia were not affected by the substance P analog. These and previous results provide strong support for the hypothesis that substance P or a closely related peptide is the transmitter mediating the slow depolarization. The latter may represent a sensory input from the gastrointestinal tract to neurons of the prevertebral ganglia. 相似文献
13.
目的 探讨中医耳穴压籽法联合穴位电生理在消化系统癌痛治疗中的应用效果。方法 纳入本院2014年11月至2017年11月收治的消化系统癌痛患者112例,利用随机数字表法分成对照组、观察组各56例。对照组采用穴位电生理治疗,观察组在对照组的基础上联合中医耳穴压籽法治疗,两组治疗时间为4周。观察两组患者治疗后临床效果,并比较两组患者治疗前后每日疼痛持续时间、数字疼痛评分法（numerical rating scale,NRS）评分的变化,采用欧洲五维健康量表（European quality of life 5-dimensions,EQ-5D）评价两组治疗前后的生存质量,记录患者不良反应发生率。结果 观察组总有效率为96.43%,高于对照组的83.93%,差异有统计学意义（P<0.05）;观察组治疗后的疼痛持续时间、NRS评分小于对照组,差异有统计学意义（P<0.05）;观察组治疗后的自我照顾能力、焦虑/抑郁、疼痛评分较对照组明显降低,差异有统计学意义（P<0.05）;观察组不良反应发生率与对照组比较差异无统计学意义（P>0.05）。结论 中医耳穴压籽法联合穴位电生理刺激治疗能缓解消化系统癌痛患者的疼痛感,缩短疼痛持续时间,提高生存质量,且优于单用穴位电生理治疗,值得临床推广。 相似文献
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Examination of the structural organization of the auditory system of the brain stem shows that the system is composed of a number of separate ascending pathways. This suggests that there may be at least two auditory systems, analogous to the rod and cone pathways in vision. We examined this possibility by investigating the variation in relative size of the medial and lateral superior olivary nuclei in a number of different mammalian species. The lateral superior olive is present in the hedgehog (an insectivore), cat (acarnivore), and squirrel monkey a(primate), but the medial superior olive is absent in the hedgehog. In a group of animals of the same taxonomic order (rodents) the lateral superior olive was present in all species examined, but the medial superior olive was almost wholly absent in the mouse and very prominent in the chinchilla and guinea pig. The absence of the medial superior olive in some animals is surprising because recent anatomical and physiological work has implicated the nucleus in auditory localization. Because of this implication, the medial and lateral olivary nuclei were examined in three species of bat and one dolphin, all echolocating animals. The medial superior olive was absent in these animals, and the lateral superior olive was prominent. These observations support the idea that the medial and lateral superior olives are nuclei on two different ascending auditory systems. It was also noted that the medial superior olive was always well developed in animals with well-developed eyes, and this suggested that the nucleus is in some way related to the visual system. We examined this idea by studying the relation between the numbers of cells in the medial superior olive and in the nucleus of the 6th cranial nerve (one of the motor nuclei concerned with eye movement) in a number of mammalian species. An approximately linear function was found between the sizes of the 6th nucleus and of the medial superior olive in three primates with cone-cell retinas (squirrel monkey, man, and macaque) and four rodents with rod-cell retinas (mouse, rat, guinea pig, and chinchilla). The cell numbers for the ground squirrel (a rodent with cone-cell retina) fitted an extension of the primate curve, and the cell numbers for the cat (in whose retina rods predominate) fitted an extension of the rodent curve. Thus, it is clear that the medial superior olive is related to the visual system, and that it is present in animals with cone-cell fovea and retina (diurnalanimals) and animals with rod-cell retina (that is, nocturnal animals) having good vision. In nonvisual nocturnal animals the nucleus is small or absent. The medial superior olive is probably not concerned with auditory localization in the psychophysical sense but is probably concerned with the movement of head and eyes in the direction of a sound in space. Localization in the psychophysical sense and fine auditory discrimination probably depend upon the ascending pathway which includes the lateral superior olive. 相似文献
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小麦强、弱势籽粒中淀粉粒度分布特征 总被引：1，自引：0，他引：1
以2个冬小麦品种鲁麦21和济南17为供试材料,对小麦强、弱势籽粒中淀粉粒的体积、数目和表面积的分布特征进行了研究。结果表明,小麦强、弱势籽粒均含有A(>9.8μm)、B(2.0~9.8μm)、C(<2.0μm)3种类型的淀粉粒,但不同类型淀粉粒的分布状况存在明显差异。在强势籽粒中,淀粉粒的体积和表面积分布均表现为三峰分布,而弱势籽粒中淀粉粒的体积和表面积分布则表现为双峰分布。与弱势粒相比较,强势粒中C型淀粉粒的体积百分比为7.25%~8.01%,表面积百分比为34.88%~37.21%,而弱势粒的体积和表面积百分比分别为5.33%~6.35%和26.31%~33.19%,表明强势粒中C型淀粉粒所占比例较大。强、弱势籽粒中小于0.6μm和0.6~2.0μm范围内的淀粉粒数目存在明显差异,弱势粒中小于0.6μm的淀粉粒所占比例较大,为36.21%~37.41%,而强势粒中0.6~2.0μm范围内的淀粉粒数目较多,为84.38%~87.76%。 相似文献
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Odor stimuli trigger influx of calcium into olfactory neurons of the channel catfish 总被引：26，自引：0，他引：26
Olfactory transduction is thought to be mediated by a G protein-coupled increase in intracellular adenosine 3',5'-monophosphate (cAMP) that triggers the opening of cAMP-gated cation channels and results in depolarization of the plasma membrane of olfactory neurons. In olfactory neurons isolated from the channel catfish, Ictalurus punctatus, stimulation with olfactory stimuli (amino acids) elicits an influx of calcium that leads to a rapid increase in intracellular calcium. In addition, in a reconstitution assay a plasma membrane calcium channel has been identified that is gated by inositol-1,4,5-trisphosphate (IP3), which could mediate this calcium influx. Together with previous studies indicating that stimulation with olfactory stimuli leads to stimulation of phosphoinositide turnover in olfactory cilia, these data suggest that an influx of calcium triggered by odor stimulation of phosphoinositide turnover may be an alternate or additional mechanism of olfactory transduction. 相似文献
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Rats were provided with opportunity to turn reinforcing hypothalamic stimulation on and off by traversing back and forth across a chamber. When provided with edible and inedible objects, all animals that self-stimulated carried them from the stimulation to the nonstimulation side. Neither food deprivation nor a history of stimulus-bound eating produced a preference for the edible objects. Equivalent stimulation provided without regard to the animals' location in the chamber did not elicit object-carrying. Results are interpreted in terms of the natural conditions which normally elicit this species-specific unit of behavior. Implications for understanding other behavior patterns elicited by hypothalamic stimulation are suggested. 相似文献
18.
密穗与疏穗型小麦强、弱势籽粒淀粉积累及库强度的比较 总被引：3，自引：1，他引：2
【目的】研究小麦强、弱势籽粒淀粉积累与库容量、库活性间的关系及不同穗型间的差异。【方法】以密穗型小麦品种鲁麦21、济麦20和疏穗型小麦品种山农1391、山农12为材料,对籽粒发育过程中强、弱势粒淀粉积累、胚乳细胞数目及相关酶活性变化进行比较。【结果】两种类型小麦强势粒直、支链淀粉积累量均高于弱势粒,密穗型小麦籽粒直、支链淀粉积累量在强、弱势粒间的差异幅度高于疏穗型小麦。Logistic方程拟合籽粒淀粉积累进程表明,强势粒淀粉积累量较弱势粒高的原因是其积累启动时间较早和淀粉积累速率较高;密穗型小麦强、弱势粒淀粉积累速率的差异幅度较大,是造成其籽粒最终淀粉积累量在强、弱势粒间的差异幅度大于疏穗型的原因之一。小麦强势粒胚乳细胞数目显著高于弱势粒,与疏穗型小麦相比,密穗型小麦强、弱势粒胚乳细胞数目的差异幅度较大。4个小麦品种弱势粒蔗糖含量在灌浆期均高于强势粒,说明籽粒蔗糖含量即淀粉合成底物的供给并不是造成强、弱势粒淀粉积累存在差异的限制因子。小麦强势粒蔗糖合酶（SS）、腺苷二磷酸葡萄糖焦磷酸化酶（AGPP）、可溶性淀粉合酶（SSS）和颗粒结合态淀粉合酶（GBSS）活性均高于弱势粒,密穗型小麦强、弱势粒上述酶活性差异幅度均较疏穗型大。【结论】小麦库容量（胚乳细胞数目）和库活性（淀粉合成相关酶活性）是制约强、弱势粒淀粉积累的主要因素。密穗型小麦强、弱势粒间的胚乳细胞数目和淀粉合成相关酶活性差异较大,这可能是造成密穗型小麦籽粒淀粉积累量在强、弱势粒间的差异幅度大于疏穗型的原因。 相似文献
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通过对西南桦Betula alnoides 分布区的调查, 实测了25 个县261 株西南桦候选优树的数量性状、质量性状及环境因子, 对候选优树9 个性状进行相关分析后选择出材积和通直度作为西南桦选优的主要性状。采用数量化回归的方法来制定优树选择的指标, 建立了各立地因子、林分类型和树龄与材积的多元数量化模型, 其复相关系数达0.920 815 。西南桦材积实测值与理论值间差值的频率分布呈正态分布, 以其差值作为西南桦优树选择的选择指标Ii , 以I 0.5 作为分级依据, 结合通直度制定出西南桦优树选择的标准为①Ⅰ级优树:通直度为Ⅰ级, 同时Ii 0.381 257 。②Ⅱ级优树:通直度为Ⅰ级或Ⅱ级, -0.381 257 Ii 0.381 257 。③一般林木(Ⅲ级木):Ii -0.381 257 。用此标准筛选出西南桦I 级优树46 株,占候选优树的17.62 %, Ⅱ级优树145 株, 占候选优树的55.56 %。图2 表2 参11 相似文献