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1.
"Copulation-reward site" in the posterior hypothalamus 总被引：2，自引：0，他引：2
Posterior hypothalamic selfstimulation of male rats, in which monopolar,platinum electrodes had been belaterally implanted, increased after systdmic injection of testosterone. constant stimulation to the same site elicited immediate copulation with estrous female rats. During constant stimulation males would press a bar to open a door for access to females. Even after ejaculation, males continued to open the door and to display sexual activity until stimulation terminated. Posterior hypothalamic stimulation is like normal sexual stimulation; it is rewarding, the reward varies with the amount of the sex hormone, and it elicits motivated copulation. 相似文献
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为了解农村留守儿童社会情感能力的发展状况,对江苏省徐州市2个区进行了实地调查,并运用多元回归分析方法探讨了影响留守儿童社会情感发展的因素。结果表明:农村留守儿童的社会情感发展总体状况良好,但在人际交往、社区融入和亲社会行为方面存在一定问题。农村留守儿童社会情感的发展受到不同因素的影响,其中年级、亲子间沟通频率、教师行为和社区基础设施条件对留守儿童社会情感发展的各个方面都有影响,此外,成绩排名、班级团结度对留守儿童的人际交往有显著影响,亲子分离形式、是否为独生子女、社区关爱留守儿童活动的开展情况对留守儿童的社区融入有显著影响,性别、校园活动的丰富度对留守儿童的亲社会行为有显著影响。 相似文献
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Langford DJ Crager SE Shehzad Z Smith SB Sotocinal SG Levenstadt JS Chanda ML Levitin DJ Mogil JS 《Science (New York, N.Y.)》2006,312(5782):1967-1970
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
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研究了在促进剂Ｃｕ２＋和抑制剂２,４－Ｄ及光的作用下,对产色素培养细胞紫草宁形成的影响。对４,１５,２５,３５和４５ｄ的紫草培养细胞的电镜观察和细胞超微结构分析的结果表明,１５ｄ加促进剂Ｃｕ２＋的新疆紫草培养细胞形成的色素颗粒（紫草宁）最多,４ｄ和加抑制剂２,４－Ｄ的培养细胞中均无明显的色素颗粒。 相似文献
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迄今还没有培育 BB·L/W 大鼠作为研究青少年型糖尿病动物模型的报告.本实验探讨了日粮因子对青少年型糖尿病发生的影响。常规雄性 BB·L/W 近交系大鼠从30至150日龄,每日每只饲喂12克日粮(40%限制的 A 组),或自由采食(对照的 B 组).结果表明,A 组的发病率为35.56%,B 组的发病率为36.36%,二者无差异,日粮限制对青少年型糖尿病的发病率无影响.A 组的糖尿病发作日龄较之 B 组推迟;A 组的2/3患病动物不经治疗于2周内死亡,但 B 组的2/3患病动物一般活存3周以上.日粮限制对动物的体重、体长、器官占体重的比例等有显著影响。 相似文献
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G G Ball 《Science (New York, N.Y.)》1972,178(56):72-73
Male Sprague-Dawley rats pressed a bar for electrical stimulation of the ventromedial hypothalamus. The threshold for such behavior correlated positively with the threshold to stop feeding and the threshold to escape from prolonged stimulation at the same electrode site. The results again open the question of the role that the ventromedial area is playing in positively reinforcing and punishment systems. 相似文献
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Prolactin stimulation of maternal behavior in female rats 总被引：9，自引：0，他引：9
Inexperienced, hypophysectomized female rats treated with steroids were used in experiments to investigate the roles of the pituitary gland and prolactin in the expression of maternal behavior. Administration of ovine prolactin or treatment with ectopic pituitary grafts, which release prolactin into the circulation, stimulated maternal care in these females toward rat young. Steroid treatment alone, while stimulating maternal behavior in rats with intact pituitary glands, did not facilitate maternal responsiveness in hypophysectomized females. These findings indicate a stimulatory behavioral role for pituitary prolactin in the establishment of maternal care and suggest that exposure to prolactin during pregnancy helps to stimulate the immediate onset of maternal behavior at parturition. 相似文献
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Acquisition of a behavioral response motivated by shock was enhanced in rats chronically treated with yeast ribonucleic acid, and resistance to extinction was greater in rats so treated than in controls. This extends the role of ribonucleic acid to include a behavioral effect in laboratory mammals treated with a purified preparation from yeast. 相似文献
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Addiction profoundly alters motivational circuits so that drugs become powerful reinforcers of behavior. The interoceptive system continuously updates homeostatic and emotional information that are important elements in motivational decisions. We tested the idea that interoceptive information is essential in drug craving and in the behavioral signs of malaise. We inactivated the primary interoceptive cortex in amphetamine-experienced rats, which prevented the urge to seek amphetamine in a place preference task. Interoceptive insula inactivation also blunted the signs of malaise induced by acute lithium administration. Drug-seeking and malaise both induced Fos expression, a marker of neuronal activation, in the insula. We conclude that the insular cortex is a key structure in the perception of bodily needs that provides direction to motivated behaviors. 相似文献
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Increased activity of calcium leak channels in myotubes of Duchenne human and mdx mouse origin 总被引：25，自引：0，他引：25
Elevated free Ca2+ concentrations found in adult dystrophic muscle fibers result in enhanced protein degradation. Since the difference in concentrations may reflect differences in entry, Ca2+ leak channels in cultures of normal and Duchenne human myotubes, and normal and mdx murine myotubes, have been identified and characterized. The open probability of leak channels is markedly increased in dystrophic myotubes. Other channel properties, such as mean open times, single channel conductance, ion selectivity, and behavior in the presence of pharmacological agents, were similar among myotube types. Compared to the Ca2+ concentrations in normal human and normal mouse myotubes, intracellular resting free Ca2+ concentrations ([Ca2+]i) in myotubes of Duchenne and mdx origin were significantly higher at a time when dystrophin is first expressed in normal tissue. Taken together, these findings suggest that the increased open probability of Ca2+ leak channels contributes to the elevated free intracellular Ca2+ concentration in Duchenne human and mdx mouse myotubes. 相似文献
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浅谈开放式城市中心公园边界空间的处理——以绵阳市人民公园为例 总被引：2，自引：0，他引：2
随着城市的不断发展,人们所承受的工作压力、就业压力、生活压力都在不断地增大,在诸多压力之下,人们迫切地渴望一片能够放松、休憩的"世外桃源"。城市中心公园是现代城市人们的这种行为习惯寄托的唯一途径。以绵阳市人民公园为例,阐述了开放式城市中心公园边界空间的处理。 相似文献
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[目的]探讨快速分离柱高效液相色谱法测定巧克力中的香兰素的效果。[方法]采用快速分离柱高效液相色谱法测定巧克力中的香兰素。[结果]选用40％甲醇40ml超声振荡10min提取巧克力中的香兰素,然后用固相萃取预分离,以ZORBAX Stable Bound（4．6×50mm,1．8μm）C18为固定相,甲醇-水（35：65）为流动相分离,流速为10ml／min,用紫外二极管矩阵检测器检测。在该色谱条件下,香兰素在1．0min内可达到基线分离。样品的标准回收率为98％-103％,相对标准偏差为0．46％一0．58％。和常规色谱相比可缩短85％以上的分离时间。[结论]该方法简便快速,结果可靠,在一定程度上为巧克力中香兰素的快速测定提供了方法。 相似文献
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Rat resistance to schistosomiasis: platelet-mediated cytotoxicity induced by C-reactive protein 总被引：6，自引：0，他引：6
In rats infected with the parasite Schistosoma mansoni, the concentration of C-reactive protein in the serum increases after the lung stage of infection and is at its highest at the time of terminal worm rejection. The peak of platelet-mediated cytotoxicity induced by infected serum that has been heated (and is free of immunoglobulin E) as well as the time course for the development of platelet cytotoxic activity in infected rats was found to be correlated with the concentration of C-reactive protein. Rat and human platelets treated with homologous serum obtained during an acute phase of inflammation or with purified C-reactive protein were able to kill the immature forms of the worm in vitro. Platelets treated with C-reactive protein were furthermore capable of conferring significant protection against schistosomiasis in transfer experiments. Collectively these data indicate that a system that includes C-reactive protein and platelets participates in the natural resistance of the rat to schistosomal infection. 相似文献
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家蚕赤蚁突变基因作为标志基因在遗传分析、连锁检索和基因定位研究中发挥了重要的作用。用家蚕显性赤蚁Ia品种(09-041)与非显性赤蚁品种(08-101)杂交,经F1自交,取F2代的显性赤蚁与非赤蚁个体为材料,采取混合样品分析法进行RAPD多态性分析．通过250个RAPD随机引物,分别在显性赤蚁与非显性赤蚁中获得扩增带1089条和1083条,共有220个引物在2个材料中有扩增片段,其中有8个引物在显性赤蚁中扩增出多态性特异带,有2个引物在非显性赤蚁中扩增出多态性特异带,有30个引物在2个材料中无扩增产物。实验初步获得8个与家蚕显性赤蚁基因可能连锁的RAPD分子标记,为进一步的Ia基因定位、克隆及遗传分析等工作奠定了一定的基础。 相似文献
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[目的]通过对大鼠的90 d喂养试验,评价脱毒菜籽多肽的食用安全性。[方法]将动物随机分为4组,分别为低、中、高剂量组和对照组。试验组分别在基础饲料中添加1.65、3.30和6.60 g/kg脱毒菜籽多肽,按80 g/kg的日摄入量以自由采食的方式喂养大鼠90 d,观察脱毒菜籽多肽对大鼠体重、进食量、食物利用率、血清学、脏器系数以及组织病理学等指标的影响。[结果]与对照组相比,各剂量组大鼠体重、进食量、食物利用率、脏器绝对重量和脏体比均无显著差异(P0.05),大鼠血液学指标检测值、生化指标检测值均在正常范围内;高剂量组各大鼠脏器均未出现明显的组织病理变化。[结论]脱毒菜籽多肽对大鼠的生长发育、血浆、生化功能及脏体比等指标均未见不良影响。 相似文献
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Hypertension in the recently weaned Dahl salt-sensitive rat despite a diet deficient in sodium chloride 总被引：1，自引：0，他引：1
The Dahl rat is used as a model of hypertension that is "sensitive" to dietary salt (sodium chloride, NaCl). When dietary salt is supplemented in the Dahl rat, the arterial blood pressure of the "salt-sensitive" strain (S) becomes much greater than that of the "salt-resistant" strain (R). It has been widely reported that arterial blood pressure of the young Dahl S rat is not greater than that of the young Dahl R rat before dietary salt is supplemented. In the present study, however, mean arterial pressure directly measured in unanesthetized, unrestrained S rats was greater than in R rats, both when they had been recently weaned and for at least 10 weeks thereafter, despite their having been fed a diet frankly deficient in salt. In weanling S rats, the ratio of heart weight to body weight was also significantly greater than that in weanling R rats, suggesting that the greater blood pressure in the S rat causes cardiac hypertrophy. Thus, biologic differences demonstrated between the S rat and the R rat after weaning, including the phenomenon of salt-sensitivity, could be a consequence of, or be dependent on, an already extant difference in arterial blood pressure between the two strains. 相似文献
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The rat as an experimental animal 总被引：10，自引：0，他引：10