内皮素受体拮抗剂对匹罗卡品诱导大鼠急性癫痫发作的影响

目的:通过观察经侧脑室注射内皮素受体(endothelin receptor,ETR)拮抗剂对匹罗卡品致痫大鼠急性癫痫发作的影响,进一步了解内源性内皮素(ET)以及ETR亚型在癫痫发生发展中的作用。方法:氯化锂联合匹罗卡品小剂量3次重复腹腔注射建立大鼠急性癫痫发作模型。在腹腔注射匹罗卡品之前,进行立体定位,在大鼠左侧脑室内分别注射1.5μL的生理盐水(NS)(空白对照组9只;模型组30只)、特异性内皮素A受体(ETAR)拮抗剂BQ123(15 nmol,18只)、特异性ETBR拮抗剂BQ788(15 nmol,18只)或ETABR非特异性拮抗剂PD145065(15nmol,18只)。建立模型后,观察大鼠的行为改变,行为学评分采用改良Racine标准。结果:空白对照组大鼠未见痫性发作,模型组大鼠有17只(56.7%)出现惊厥性痫性发作(4/5级痫性发作),其中15只(88.2%)出现癫痫持续状态(status epilepticus,SE)。BQ123能显著减少匹罗卡品诱导大鼠惊厥性痫性发作成功率(P0.05)。BQ788组大鼠匹罗卡品诱导SE发生率显著低于模型组(P0.05)。3个ETR拮抗剂均不影响匹罗卡品诱导大鼠惊厥性痫性发作平均潜伏期(P0.05)。结论:内源性ET至少部分参与了匹罗卡品诱导大鼠急性癫痫发作的发生发展过程。     

89次额叶癫痫发作期Video-EEG监测报告

利用ZN80 0 0型Video EEG监测系统对 10例额叶癫痫患者进行脑电和行为监测 ,旨在探讨额叶癫痫发作时的行为表现及脑电变化特征。结果表明 :额叶癫痫发作以运动症状为主 ,常于夜间发作 ,发作频繁而短暂。发作期EEG为额区癫痫样放电亦可为高幅慢波 ,与临床发作同步     

雌激素对戊四唑致痫大鼠海马内GABA和P38的影响

目的：分析月经性癫痫中,雌激素对大鼠海马内γ-氨基丁酸(γ-amiobutyric acid,GABA)和P38的影响,探讨雌激素促癫痫发作的作用机理。方法：利用去卵巢(ovaiectomized,OVX)SD大鼠,用雌激素替代疗法及戊四唑(petylenetetrazole,PTZ)致病,诱发大鼠癫痫发作,并采用免疫组织化学技术,对大鼠背侧海马不同脑区GABA和P38的免疫反应产物进行观察。结果：(1)GABA免疫组化检测结果显示,实验对照组(OVX NS PTZ)与空白对照组(OVX NS NS)相比及实验给药组(OVX E2 PTZ)与实验对照组相比,背侧海马门区内GABA免疫反应阳性神经元数目均显性减少。(2)P38免疫反应产物的观察：其免疫反应产物呈特征性点状或颗粒状。在CA1区始层和辐射层、CA3区透明层,空白对照组与实验对照组相比免疫反应强度无明显变化,实验给药组比实验对照组免疫反应增强。在齿状回分子层,3组的免疫反应强度无明显变化。结论：雌激素使海马门区GABA含量减少,从而降低了GABA对癫痫发作的抑制作用,增强了癫痫发作的敏感性。雌激素可使背侧海马CA1区始层和辐射层、CA3区透明层P38的表达增加(即使该区的突触密度增加),从而增加了海马内兴奋性递质的释放,使海马内的兴奋性增强。     

糖尿病大鼠脑干听觉诱发电位波幅间比率的动态变化

目的：探讨脑干听觉诱发电位(BAEP)的波幅问比率在糖尿病大鼠中的动态变化。方法：采用链脲佐菌素(SIZ)腹腔注射法，建立实验性糖尿病(ED)动物模型。在成模前后按时间顺序连续10周动态观测BAEP的波幅间比率的变化。结果：与正常对照组相比，ED组大鼠在病程2周时出现BAEP Ⅰ、Ⅲ、Ⅳ、Ⅴ波幅增高；在病程4周时出现BAEP各波波幅增高；病程6周时BAEP Ⅰ、Ⅱ、Ⅲ、Ⅳ波幅增高；病程8～10周时：BAEP Ⅰ、Ⅲ、Ⅳ、Ⅴ波幅增高。病程8周后BAEPⅤ／Ⅰ波幅比率下降；病程10周后BAEPⅢ与Ⅴ波幅比率降低；Ⅴ与Ⅰ、Ⅳ与Ⅰ波幅比率明显降低。结论：糖尿病大鼠BAEP的波幅和波幅比率有明显变化，这有助于糖尿病中枢神经病变的早期诊断。     

Sustained firing in auditory cortex evoked by preferred stimuli

It has been well documented that neurons in the auditory cortex of anaesthetized animals generally display transient responses to acoustic stimulation, and typically respond to a brief stimulus with one or fewer action potentials. The number of action potentials evoked by each stimulus usually does not increase with increasing stimulus duration. Such observations have long puzzled researchers across disciplines and raised serious questions regarding the role of the auditory cortex in encoding ongoing acoustic signals. Contrary to these long-held views, here we show that single neurons in both primary (area A1) and lateral belt areas of the auditory cortex of awake marmoset monkeys (Callithrix jacchus) are capable of firing in a sustained manner over a prolonged period of time, especially when they are driven by their preferred stimuli. In contrast, responses become more transient or phasic when auditory cortex neurons respond to non-preferred stimuli. These findings suggest that when the auditory cortex is stimulated by a sound, a particular population of neurons fire maximally throughout the duration of the sound. Responses of other, less optimally driven neurons fade away quickly after stimulus onset. This results in a selective representation of the sound across both neuronal population and time.     

体温过低对大鼠脑干听觉诱发电位快慢成分的影响

目的：探讨体温过低对大鼠脑干听觉诱发电位快慢成分的影响。方法：计算机平均叠加技术颅表记录大鼠脑干听觉诱发电位（BAEP）快慢成分，体表物理降温法逐渐降低大鼠体温，传感探头式数字体温计监测大鼠直肠温度，体温每降低1℃测试1次BAEP快慢成分，观察波峰潜伏期（PL）、波峰间潜伏期（IPL）和波幅的变化。结果：随体温逐渐降低（36－25℃），BAEP快慢成分PL逐渐延长，快成分I－Ⅲ、Ⅱ-Ⅳ和I－Ⅳ IPL也逐渐延长，但两者波幅未随体温降低而发生规律性显著变化。结论：体温过低对大鼠BAEP的快慢成分均有显著影响。     

Oxidant stress evoked by pacemaking in dopaminergic neurons is attenuated by DJ-1

Parkinson's disease is a pervasive, ageing-related neurodegenerative disease the cardinal motor symptoms of which reflect the loss of a small group of neurons, the dopaminergic neurons in the substantia nigra pars compacta (SNc). Mitochondrial oxidant stress is widely viewed as being responsible for this loss, but why these particular neurons should be stressed is a mystery. Here we show, using transgenic mice that expressed a redox-sensitive variant of green fluorescent protein targeted to the mitochondrial matrix, that the engagement of plasma membrane L-type calcium channels during normal autonomous pacemaking created an oxidant stress that was specific to vulnerable SNc dopaminergic neurons. The oxidant stress engaged defences that induced transient, mild mitochondrial depolarization or uncoupling. The mild uncoupling was not affected by deletion of cyclophilin D, which is a component of the permeability transition pore, but was attenuated by genipin and purine nucleotides, which are antagonists of cloned uncoupling proteins. Knocking out DJ-1 (also known as PARK7 in humans and Park7 in mice), which is a gene associated with an early-onset form of Parkinson's disease, downregulated the expression of two uncoupling proteins (UCP4 (SLC25A27) and UCP5 (SLC25A14)), compromised calcium-induced uncoupling and increased oxidation of matrix proteins specifically in SNc dopaminergic neurons. Because drugs approved for human use can antagonize calcium entry through L-type channels, these results point to a novel neuroprotective strategy for both idiopathic and familial forms of Parkinson's disease.     

Repetitive spikes in cytoplasmic calcium evoked by histamine in human endothelial cells

Measurement of cytoplasmic free calcium, [Ca2+]i, in single human endothelial cells has shown that low doses of the inflammatory mediator histamine evoke asynchronous repetitive spikes in [Ca2+]i whereas high doses cause a maintained elevated [Ca2+]i. We discuss possible regulatory mechanisms, and the potential physiological and pathological implications of such a frequency-modulated [Ca2+]i signalling system.     

一种人工智能核磁渗透率预测方法

针对目前常用预测方法难以较好地模拟核磁共振测量结果和渗透率之间复杂关系的问题,提出了一种应用人工智能算法预测核磁渗透率的新方法.在新方法中,采用了神经网络建立核磁测量结果和渗透率之间的关系;用遗传算法为神经网络选择最佳参数和初始值;用基于信息增益的数据挖掘技术对渗透率的相关参数进行优选.对来自松辽盆地的岩石样品进行试验...     

Whisker movements evoked by stimulation of single pyramidal cells in rat motor cortex

Neuronal activity in the motor cortex is understood to be correlated with movements, but the impact of action potentials (APs) in single cortical neurons on the generation of movement has not been fully determined. Here we show that trains of APs in single pyramidal cells of rat motor cortex can evoke long sequences of small whisker movements. For layer-5 pyramids, we find that evoked rhythmic movements have a constant phase relative to the AP train, indicating that single layer-5 pyramids can reset the rhythm of whisker movements. Action potentials evoked in layer-6 pyramids can generate bursts of rhythmic whisking, with a variable phase of movements relative to the AP train. An increasing number of APs decreases the latency to onset of movement, whereas AP frequency determines movement direction and amplitude. We find that the efficacy of cortical APs in evoking whisker movements is not dependent on background cortical activity and is greatly enhanced in waking rats. We conclude that in vibrissae motor cortex sparse AP activity can evoke movements.     

电刺激鸣禽高级发声中枢诱发叫声的声谱分析

栗Wu每侧高级发声中枢（HVC）均有发出简单音节的能力,并决定正常鸣转的音节时间和能量特征,电刺激两侧HVC均可以诱发简单的叫声,与正常的鸣转音节相比,声学特征上表现为音节时程长,频率幅度变化小,能量不集中且极少有复杂音节和陪音的出现,刺激左侧HVC所诱发的叫声,其基本音的频带起止均明显高于右侧诱发叫声,暗示左侧HVC控制频率较高,较复杂的音节,也为左侧优势理论提供了声学上的证据。