共查询到20条相似文献，搜索用时 156 毫秒
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目的:阐明下丘脑室旁核(the paraventricular nucleus of hypothalamus,PVN)兴奋后对心交感神经放电及心肌收缩力的影响.方法:不同条件下(神经完整、切断双侧颈迷走神经干、静脉注射心得安),电刺激猫的下丘脑室旁核.同时记录刺激前、后下心交感神经放电及心肌收缩力.结果:不同条件下,电刺激猫的下丘脑室旁核,刺激前与刺激后相比,下心交感神经放电均增加;左心室收缩压也均升高,经t检验有统计学意义.结论:电刺激PVN可引起心肌收缩力增加,其中间途径和机制是心交感神经兴奋变力效应改变的结果. 相似文献
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利用细胞内微电极技术和组织学技术,对82只琢鼠主动脉前庭的自发电活动和13例该部组织的形态学特征进行了观察和分析。结果发现,在82例该组织的游离标本上,有16例(19.5％)可自行出现自律性电活动;61例(74.4％)在电刺激诱导下也可出现自律性电活动。在主动脉前庭大部分区域记录到的自发电位,其形态与普通心室肌的动作电位基本相同,属快反应电位。而在主动脉瓣右瓣与后瓣交界处以下约2.0×1.5mm区域内的表疲疲部位,可记录到0相去极化缓慢、幅值较小,且4相自动去极化明显的动作电位,其形态与慢反应自律细胞的动作电位十位相似。肾上腺素可使其频率增快;钙拮抗剂硝苯吡啶、Mn~(2十)可阻断其自律性电活动。而且上述大部分区它归快反应电位随此慢反应电位的节律而变化,并随其被阻断而消失。说明在主动脉前庭的局部存在有慢反应自律细胞,其的部位的自发节律系由该部引起。经光镜和电镜观察,该部组织与普通心肌有明显不同,而与慢反应自律组织的结构相似。本实验提示:在发生上由动脉球变化而来的主动脉前庭部组织,先保持有自律性等与普通心室肌不同的电生理特征。因而在心脏泵血过程中,可能具有某些特殊功能。 相似文献
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目的观察牵拉刺激（刺激强度）及其它实验因素对肌梭放电频率的影响。方法制备蟾蜍离体坐骨神经-缝匠肌标本,用BL-420生物机能系统记录牵拉刺激及实验因素对肌梭传入放电活动的影响。结果牵拉刺激增强,肌梭的传入放电频率增加;牵拉力度相同时,快速牵拉较缓慢牵拉引发更多的肌梭放电。结论肌梭是肌肉长度感受器,有快适应和慢适应两种现象,其敏感性受肌肉长度及温度的影响。 相似文献
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由于教材难度不宜过大,在《生物的呼吸》一章中关于呼吸的若干概念,讲解不甚清楚。现辨析如下: 一、呼吸运动在神经系统控制下,呼吸肌(主要是肋间肌和膈肌)有节律地舒缩,使胸廓运动,从而完成肺泡与外界气体交换的过程,叫做呼吸运动。 相似文献
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目的:研究心得安对异丙肾上腺素所致左心室流出道自律性电活动改变的影响.方法:本实验采用标准玻璃微电极细胞内引导技术在记录离体豚鼠该部位自发慢反应电位的基础上,观测了心得安对异丙肾上腺素作用的影响.结果:100μmol/L异丙肾上腺素(Iso)可使自发放电频率(RPF)和4期自动去极速度(VDD)显著加快,动作电位幅度(APA)显著增大,0期最大去极速度(Vmax)明显加速,复极50%时间(APD50)缩短(P＜0.01或P＜0.001);5μmol/L心得安可拮抗100μmol/L Iso的电生理效应.结论:Iso可提高左心室流出道组织的自律性电活动,其效应可被心得安阻断. 相似文献
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利用细胞内微电极记录技术,观察了34例家兔左心室流出道离体组织的自律性电活动及其动作电位特征。结果:31例(91.18％)(包括电刺激诱导部分)可出现自律性电活动,并且可在局部组织记录到典型的慢反应动作电位。提示:家兔左心室流出道组织也具有自律性,这进一步证明哺乳类动物左心室流出道组织具有与普通心室肌不同的电生理特性,其生理功能也有待进一步研究。 相似文献
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《淮北师范大学学报》2021,42(2)
为探讨直立位强腹式呼吸时腹直肌表面的肌电特征.通过意大利生产的无线表面肌电测试仪Wave plus以及亿乐体育生产的倒立机,记录共19名大学生志愿者为研究对象,其中男性9名,平均年龄(23±1)岁、平均身高(175±8)cm、平均体重(70±14)kg;女性10名,平均年龄(23±1)岁、平均身高(164±5)cm,平均体重(60±14)kg,测试强腹式呼吸时不同直立角度对腹直肌表面肌电信号的变化,用T检验、异方差进行男女生之间的差异检验.通过对安庆师范大学19名在校大学生进行直立位最大强腹式呼吸以及直立位、平卧位、倒立30°、倒立90°的强腹式呼吸的测试,观察腹直肌表面肌电变化.平卧位积分肌电平均值(μV·S)男生为23 269.35±11 283.15,女生为9 673.24±4 579.26,男女生之间差异性检验(p0.05),差异具有显著性.倒立位90°积分肌电值男生为27 508.20±14 464.18,女生为9 671.26±4 727.64,男女生之间差异性检验(p0.05),差异显著性;倒立位均方根振幅值男生为35.99±18.95,女生为29.18±6.95,男女生之间差异性检验(p0.05),差异具有显著性.根据体位变化,其肌电变化情况为:积分肌电值男女生随直立位、平卧位、倒立30°、倒立90°4种体位的变化总体呈"V"字型变化.中心频率男生呈现上升趋势变化,女生呈现下降趋势.均方根振幅男女生随体位的变化总体呈现"V"字型变化.结果表明,倒立位90°的各项指标以及平卧位的积分肌电值男女性都呈现显著性差异,且直立位与倒立位的体位对于腹直肌的训练效果最佳. 相似文献
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功能性电刺激是一种治疗运动功能受损的有效治疗方案。在现有功能性电刺激基础上,提出基于表面肌电信号的动态跟随型反馈电刺激方法,采用动态标志阈,与实时表面肌电信号进行即时对比,控制电刺激输出强度大小;交替实现肌电采集和电刺激,提高处理频率,加强实时性;根据患者个体肌电的差异,动态设定刺激初始值,实现个性化治疗;增加疲劳动态识别功能并及时停止刺激。实验结果表明,系统能实时动态调节电刺激强度大小,动态跟随时间缩短到3s,患者运动过程中动态标志阈改变次数增多,治疗时间内电刺激强度变化增大,提高了治疗的有效性;患者一旦出现疲劳,系统能即刻识别并停止电刺激,有效地保护了患者。 相似文献
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用微电极技术研究表明,尼卡地平对兔窦房结细胞自发电活动有抑制作用。当用尼卡地平0.5,1和5μmol/L 灌流10min,其自发节律分别降低42,47和70%;而动作电位幅度则分别降低32,41和78%。尼卡地平能抑制异丙肾上腺素和烟碱对窦房结细胞的阳性变时效应。结果提示,尼卡地平能阻滞兔窦房结起搏细胞的 Ca~(2 )内流。 相似文献
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本文将10%HRP 溶液注入12例成龄描的横结肠肠壁中,研究了猫横结肠的神经支配问题,得出如下结论:①初级感觉神经起自双侧 T_8—L_5 和 L_7—S_3的脊神经节,左右无显著差异,细胞以中型为主。②交感神经节后纤维来自两侧 T_8—S_1交感节,左右标记细胞数,无显著差异。③副交感神经元标记细胞位于迷走神经背核闩的上下的外侧分。 相似文献
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Ze-wei Tao Long-gui Li Zhao-hua Geng Tao Dang Shan-jun Zhu 《Journal of Zhejiang University. Science. B》2010,11(4):238-248
Therapeutically delivered mesenchymal stem cells (MSCs) improve ventricular remodeling. However,the mechanism underlying MSC cardiac remodeling has not been clearly determined. Congestive heart failure (CHF) was induced in rats by cauterization of the left ventricular free wall. MSCs were cultured from autologous bone marrow and injected into the border zone and the remote myocardium 5 d after injury. Ten weeks later,when compared with sham operation,CHF significantly increased nucleus mitotic index,capilla... 相似文献
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The purpose of this study was to compare the efficacy of two auditory processing interventions for developmental dyslexia, one based on rhythm and one based on phonetic training. Thirty-three children with dyslexia participated and were assigned to one of three groups (a) a novel rhythmic processing intervention designed to highlight auditory rhythmic information in non-speech and speech stimuli; (b) a commercially-available phoneme discrimination intervention; and (c) a no-intervention control. The intervention lasted for 6 weeks. Both interventions yielded equivalent and significant gains on measures of phonological awareness (at both rhyme and phoneme levels), with large effect sizes at the phoneme level. Both programs had medium effect sizes on literacy outcome measures, although gains were non-significant when compared to the controls. The data suggest that rhythmic training has an important role to play in developing the phonological skills that are critical for efficient literacy acquisition. It is suggested that combining both prosodic/rhythmic and phonemic cues in auditory training programs may offer advantages for children with developmental dyslexia. This may be especially true for those who appear resistant to conventional phonics training methods. 相似文献
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节奏特征对于语音的自然度有直接影响。针对普通话语音,本文比较了普通话母语者、母语为粤语的二语学习者、母语为英语的二语学习者的节奏模式。研究从含有轻声的孤立词开始,重点考察连续语流,通过11种时长指标的测量从客观上分析节奏模式。针对连续语流的研究发现,基于语速无关的或者语速归一化的时长指标,作为二语的普通话显示出与母语普通话非常接近的节奏模式;而基于未做语速归一化处理的时长指标,作为二语的普通话则向重音节拍模式的方向迁移,与说话人母语的节奏模式无关。这一结果,与孤立词情形下的结果并不一致,也违反了母语迁移效应的一般假设,但是与我们的听感基本吻合,其原因可以用二语与母语的语速差异、以及韵律结构变化带来的停延频次的差异来解释。 相似文献
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SYNOPSISAn increase in sympathetic nervous system (SNS) activity or reactivity in response to stimulation is usually interpreted as an index of heightened maladaptive distress. However, sympathetic activation also underlies promptness to action, so it is not clear whether the same relation could stand for parental responses to infant cry given that a ready and prompt parental response to infant cry favors more adaptive cognitive, social, and emotional development in the infant. Previous studies have not been consistent in the interpretation of sympathetic activation which occurs in response to infant cry. We discuss these two opposing proposed interpretations. A possible alternative interpretation may be that medium activation of the SNS is adaptive because it prepares the organism to act promptly, whereas too low or too high SNS activation is maladaptive because it underlies a lack of empathetic reaction or a highly distressed response. 相似文献
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图形和色彩张力的心理学解释 总被引：1，自引：0，他引：1
李歆 《泉州师范学院学报》2007,25(5):116-118
图形的张力来自图形本身内部结构矛盾之差异对比所形成的结构力对视觉产生的一种刺激力,由这种刺激力引起的视觉张力作用于视觉生理系统,并激发大脑接受由外部视觉刺激力传递过来的图形结构的时空秩序信息,由此唤起相应的视觉感知经验,泛化成丰富多彩的审美想象。 相似文献
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This paper examines the sustainability and outcome of Alternatives for Families: A Cognitive-Behavioral Therapy (AF-CBT) as delivered by practitioners in a community-based child protection program who had received training in the model several years earlier. Formerly described as Abuse-Focused CBT, AF-CBT is an evidence-based treatment (EBT) for child physical abuse and family aggression/conflict that was included in the National Child Traumatic Stress Network's initial EBT dissemination efforts in 2002. Seven practitioners participated in a year-long learning collaborative in AF-CBT and in similar training programs for 4 other EBTs. The agency's routine data collection system was used to document the clinical and adjustment outcomes of 52 families presenting with a physically abused child who received their services between 2 and 5 years after the AF-CBT training had ended. Measures of the use of all 5 EBTs documented their frequency, internal consistency, and intercorrelations. Controlling for the unique content of the other four EBTs, the amount of AF-CBT Abuse-specific content delivered was related to improvements on standardized parent rating scales (i.e., child externalizing behavior, anger, anxiety, social competence) and both parent and clinician ratings of the child's adjustment at discharge (i.e., child more safe, less scared/sad, more appropriate with peers). The amount of AF-CBT General content was related to a few discharge ratings (better child prognosis, helpfulness to parents). These novel data provide suggestive evidence for the sustainability and clinical benefits of AF-CBT in an existing community clinic serving physically abused children and their families, and are discussed in the context of key developments in the treatment model and dissemination literature. 相似文献
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5 studies examined contributions of syllable-ordering and rhythmic properties of syllable strings to 6- and 9-month-old infants' speech segmentation. A pair of methods measuring complementary properties of representational units was used: a noise detection task sensitive to perceived cohesiveness of pairs of syllables, and a discrimination maintenance task sensitive to compactness of representations of syllable pairs. For 9-month-olds, results show that a key pair of syllables was represented as a unit when the grouping of these syllables was supported by correlated regularities of ordering and rhythm in the set of stimulus strings, but not when such grouping was supported by only rhythmic or only syllable-ordering regularity. For 6-month-olds, results show that a key pair of syllables was represented as a unit whenever grouping was supported by rhythmic regularity in the stimulus strings, regardless of whether syllable-ordering regularity was also present. Thus, whereas 9-month-olds appear to be capable of integrating sequential and suprasegmental information in forming wordlike (multisyllabic) phonological percepts, 6-month-olds are not. The emergence of integrative abilities portends increased efficiency in speech processing and may contribute to the formation and use of an initial lexicon. 相似文献
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In a series of four experiments, the effects of the reactivation of an old memory in different states of vigilance were investigated. Rats were trained to run in a six-unit spatial discrimination maze for food reward with low-level electrical stimulation delivered to the ear when they entered blind alleys. Twenty-five days after training, electrotactile stimulation was given to animals as a reactivating treatment just before a retention test. When the cuing treatment was given during wakefulness, retention performance was improved. When it was given in slow-wave sleep, it had no effect. When it was given in paradoxical sleep, performance was poorer. The use of control groups permitted an assessment of the specificity of the cuing effect in each case: Pretest presentation of the same stimulus did not modify performance when it had no cue value. Together, these results show that the effect of the reactivation of an old memory depends upon the vigilance state in which reactivation takes place. They suggest that reorganization of an old memory could be accomplished during paradoxical sleep. 相似文献