背景:神经元钙传感蛋白的研究前沿和热点始终是这一领域的研究者共同关注的焦点。目的:从定量的层面探测神经元钙传感蛋白的前沿领域与研究热点。方法:以ISI的Web of Science数据库中1982至2014年363篇神经元钙传感蛋白相关文献为分析对...背景:神经元钙传感蛋白的研究前沿和热点始终是这一领域的研究者共同关注的焦点。目的:从定量的层面探测神经元钙传感蛋白的前沿领域与研究热点。方法:以ISI的Web of Science数据库中1982至2014年363篇神经元钙传感蛋白相关文献为分析对象,采用文献共被引分析方法和词频分析方法,运用CiteSpaceⅢ可视化软件绘制神经元钙传感蛋白文献共被引网络图谱和关键词共现图谱,结合突现节点文献二次检索的方法,梳理并揭示神经元钙传感蛋白的研究前沿与热点。结果与结论:神经元钙传感蛋白的研究前沿与热点是蛋白质的生理功能,研究热点转变的时间点是1994至1996年,2000年,2008年和2012年。在不同时间阶段,其研究热点也表现出一定的差异性,1992至2000年研究热点是蛋白质的结构和性质,2004至2012年主要集中于研究蛋白质的功能和作用机制。而2008至2014年研究热点是在蛋白质生理功能的研究基础上,更侧重于这一蛋白质的高级功能(如记忆)和各种疾病(如精神分裂症、肿瘤、抑郁症、老年痴呆症、神经元损伤等)的研究。神经元钙传感蛋白前沿领域与研究热点的确定,为今后的研究提供一定的参考。展开更多
背景:神经元钙传感蛋白的生理功能及其发挥、结构折叠与解折叠的研究多采用实验方法进行研究,并提出蛋白可能的作用机制模型及维持结构稳定的可能因素,但实验手段受到时间和空间分辨的局限以及蛋白结构的复杂性,研究受到一定的限制,导...背景:神经元钙传感蛋白的生理功能及其发挥、结构折叠与解折叠的研究多采用实验方法进行研究,并提出蛋白可能的作用机制模型及维持结构稳定的可能因素,但实验手段受到时间和空间分辨的局限以及蛋白结构的复杂性,研究受到一定的限制,导致实验中提出的很多理论模型无法得以检验。分子动力学能够从原子水平上观察并解释实验现象,对理论假设和(或)模型进行验证,为实验提供参考和启示;也可以预测新的结构和现象,为建立理论模型和作用机制提供依据。目的:分别对采用实验方法和分子动力学模拟的方法对神经元钙传感蛋白生理功能及其机制研究的进展进行梳理,并对今后的研究做一展望。方法:以"Neuronal Calcium Sensor-1 or Neuronal Calcium Sensor1 or Neuronal Calcium Sensor 1 or NCS-1"为主题词,检索Pub Med数据库中有关神经元钙传感蛋白研究的相关文献,下载全文进行阅读,排除与蛋白生理机制无关的文章,最终对72篇文献进行归纳总结。结果与结论:(1)实验中主要对神经元钙传感蛋白在不同条件、不同位置中调控分泌、调控多巴胺D2受体、在肝细胞内调控腺苷A2A受体以及调控不同刺激下心肌细胞质和细胞核Ca^(2+)等方面提出相关理论模型;(2)分子动力学模拟从结构的视角,对维持蛋白结构稳定的关键因素进行了分析和总结;(3)建议将两种方法结合起来,不断加深对蛋白生理机制的理解,共同推动研究的深入发展。展开更多
Objective Concentration of extracellular calcium ([Ca2+]o) in the central nervous system decreases substantially in different conditions. It results in facilitating neuronal excitability. The goal of this study is ...Objective Concentration of extracellular calcium ([Ca2+]o) in the central nervous system decreases substantially in different conditions. It results in facilitating neuronal excitability. The goal of this study is to examine the mechanisms of enhanced neuronal excitation in low [Ca2+]o in order to provide new clues to treat the hyperexcitability diseases in clinic. Methods Whole-cell patch-clamp technique and neuron culture were used in the study. Results The firing threshold of cultured hippocampal neurons decreased markedly in low [Ca2+]o saline. Unexpectedly, apamine and isoprenaline, antagonists of medium afterhyperpolarization (mAHP) and slow AHP (sAHP) respectively, had no statistic significant effect on excitability of neurons. TTX at a low concentration was sufficient to inhibit/Nap, which blocked the increase of firing frequency in low [Ca2+]o. It also reduced the number of spikes in normal [Ca2+]o. Conclusion These results suggest that in cultured hippocampal neurons, modulation of spiking threshold but not AHP may cause the increased excitability in low [Ca2+]o.展开更多
Aim: To study the effects of rhynchophylline (Rhy) on the L type calcium channels in freshly dissociated cortical neurons of Wistar rats during acute hypoxia. Methods: Cell attached configuration of patch clamp tech...Aim: To study the effects of rhynchophylline (Rhy) on the L type calcium channels in freshly dissociated cortical neurons of Wistar rats during acute hypoxia. Methods: Cell attached configuration of patch clamp technique. L type calcium channel was activated by stepping from 40 mV to 0 mV. Results: The results showed that the L type calcium channels of cortical neurons were activated by acute hypoxia. The mean open time of the channel was increased, the mean close time decreased and the open state probability raised during acute hypoxia. Rhy (15 and 30μmol·L -1 ) in concentration dependent manner blocked activity of the channels. The drug shortened the mean open time of the channels from 8 87 ms to 3 03 ms and 2 23 ms ( P 【0 001), prolonged the mean close time from 9 23 ms to 38 84 ms and 54 43 ms ( P 【0 001), and decreased the open state probability from 0 142 to 0 031 and 0 025 ( P 【0 001) under the hypoxia condition, respectively. The effects of Rhy were similar to but weaker than those of verapamil (15 μmol·L -1 ). Conclusion: The study confirmed that Rhy has the blockade effects on L type calcium channels in cortical neurons of rats during hypoxia, by which it protects the brain from hypoxic injury.展开更多
Objective: To investigate the effects of motilin and erythromycin on intracellular Ca2+ mobi-lization in cultured myenteric neurons of rats. Methods: The cultured myenteric neurons were identified with immunofluoresce...Objective: To investigate the effects of motilin and erythromycin on intracellular Ca2+ mobi-lization in cultured myenteric neurons of rats. Methods: The cultured myenteric neurons were identified with immunofluorescence staining technique. Motilin-induced and erythromycin-induced intracellular Ca2+ mobilization was studied in primary cultures of myenteric neurons using the ratiometric Ca2+ indicator Furo3/AM, with a laser confocal microscope. Results: The effects of motilin and erythromycin on intracellular Ca2+ mobilization were as follows: (1)In Hank's solution, 10 -8, 10-7, 10-6 mol/L motilin could elevate intracellular Ca2+ concentration ([Ca2+]i)in a dose-dependent manner. (2) In Hank's solution, 10μg/ ml erythromycin also could induce the elevation of [Ca2+]i. (3) After pretreatment with antibody against the motilin receptor in Hank's solution, the Ca2+ response to erythromycin was almost restricted. Conclusion: It is suggested that motilin could increase [Ca2+]i in myenteric neurons in a dose-dependent manner, and erythromycin may also have this effectivenesss by binding to the motilin receptor.展开更多
It has been revealed experimentally that astrocytes can participate in synaptic transmission by modulating and responding to the release of neurotransmitters with calcium elevations. Researches suggest that seizure-li...It has been revealed experimentally that astrocytes can participate in synaptic transmission by modulating and responding to the release of neurotransmitters with calcium elevations. Researches suggest that seizure-like discharges(SDs) or seizure-like firings(SFs) in neurons, characterizing neurological disorder, may arise locally in restricted areas(focal area) and then propagate throughout the brain. But the underlying mechanism remains unclear. To study the possible role astrocytes playing in the SDs propagation, we construct a minimal neuron-astrocyte network model by connecting a neurons chain and an astrocytes chain.The focal area is modelled by an IP3 reservoir which provides persistent IP3 out-flux. The study suggests that calcium wave propagation in astrocytes determines the propagation of SDs in the connected neurons. On the other hand, SDs in neurons allows the calcium wave propagates longer distance in the astrocytes, which suggests the mutually cooperating of astrocytes and neurons in accomplishing SD propagation. Furthermore, once SDs propagate and occupy the neuron network, it could not be terminated by recovery of the focal area. The results may imply that treatment of brain disorders should not only focus on local area but the whole neuron network.展开更多
文摘背景:神经元钙传感蛋白的研究前沿和热点始终是这一领域的研究者共同关注的焦点。目的:从定量的层面探测神经元钙传感蛋白的前沿领域与研究热点。方法:以ISI的Web of Science数据库中1982至2014年363篇神经元钙传感蛋白相关文献为分析对象,采用文献共被引分析方法和词频分析方法,运用CiteSpaceⅢ可视化软件绘制神经元钙传感蛋白文献共被引网络图谱和关键词共现图谱,结合突现节点文献二次检索的方法,梳理并揭示神经元钙传感蛋白的研究前沿与热点。结果与结论:神经元钙传感蛋白的研究前沿与热点是蛋白质的生理功能,研究热点转变的时间点是1994至1996年,2000年,2008年和2012年。在不同时间阶段,其研究热点也表现出一定的差异性,1992至2000年研究热点是蛋白质的结构和性质,2004至2012年主要集中于研究蛋白质的功能和作用机制。而2008至2014年研究热点是在蛋白质生理功能的研究基础上,更侧重于这一蛋白质的高级功能(如记忆)和各种疾病(如精神分裂症、肿瘤、抑郁症、老年痴呆症、神经元损伤等)的研究。神经元钙传感蛋白前沿领域与研究热点的确定,为今后的研究提供一定的参考。
文摘背景:神经元钙传感蛋白的生理功能及其发挥、结构折叠与解折叠的研究多采用实验方法进行研究,并提出蛋白可能的作用机制模型及维持结构稳定的可能因素,但实验手段受到时间和空间分辨的局限以及蛋白结构的复杂性,研究受到一定的限制,导致实验中提出的很多理论模型无法得以检验。分子动力学能够从原子水平上观察并解释实验现象,对理论假设和(或)模型进行验证,为实验提供参考和启示;也可以预测新的结构和现象,为建立理论模型和作用机制提供依据。目的:分别对采用实验方法和分子动力学模拟的方法对神经元钙传感蛋白生理功能及其机制研究的进展进行梳理,并对今后的研究做一展望。方法:以"Neuronal Calcium Sensor-1 or Neuronal Calcium Sensor1 or Neuronal Calcium Sensor 1 or NCS-1"为主题词,检索Pub Med数据库中有关神经元钙传感蛋白研究的相关文献,下载全文进行阅读,排除与蛋白生理机制无关的文章,最终对72篇文献进行归纳总结。结果与结论:(1)实验中主要对神经元钙传感蛋白在不同条件、不同位置中调控分泌、调控多巴胺D2受体、在肝细胞内调控腺苷A2A受体以及调控不同刺激下心肌细胞质和细胞核Ca^(2+)等方面提出相关理论模型;(2)分子动力学模拟从结构的视角,对维持蛋白结构稳定的关键因素进行了分析和总结;(3)建议将两种方法结合起来,不断加深对蛋白生理机制的理解,共同推动研究的深入发展。
基金supported by Sci-ence Foundation of Heilongjiang Province(No.LC06C28)PhD Research Fund of the Second Affiliated Hospital of Harbin Medical University(No.BS2007-09)Science Foun-dation of Education Department of Heilongjiang Province(No.10553050).
文摘Objective Concentration of extracellular calcium ([Ca2+]o) in the central nervous system decreases substantially in different conditions. It results in facilitating neuronal excitability. The goal of this study is to examine the mechanisms of enhanced neuronal excitation in low [Ca2+]o in order to provide new clues to treat the hyperexcitability diseases in clinic. Methods Whole-cell patch-clamp technique and neuron culture were used in the study. Results The firing threshold of cultured hippocampal neurons decreased markedly in low [Ca2+]o saline. Unexpectedly, apamine and isoprenaline, antagonists of medium afterhyperpolarization (mAHP) and slow AHP (sAHP) respectively, had no statistic significant effect on excitability of neurons. TTX at a low concentration was sufficient to inhibit/Nap, which blocked the increase of firing frequency in low [Ca2+]o. It also reduced the number of spikes in normal [Ca2+]o. Conclusion These results suggest that in cultured hippocampal neurons, modulation of spiking threshold but not AHP may cause the increased excitability in low [Ca2+]o.
文摘Aim: To study the effects of rhynchophylline (Rhy) on the L type calcium channels in freshly dissociated cortical neurons of Wistar rats during acute hypoxia. Methods: Cell attached configuration of patch clamp technique. L type calcium channel was activated by stepping from 40 mV to 0 mV. Results: The results showed that the L type calcium channels of cortical neurons were activated by acute hypoxia. The mean open time of the channel was increased, the mean close time decreased and the open state probability raised during acute hypoxia. Rhy (15 and 30μmol·L -1 ) in concentration dependent manner blocked activity of the channels. The drug shortened the mean open time of the channels from 8 87 ms to 3 03 ms and 2 23 ms ( P 【0 001), prolonged the mean close time from 9 23 ms to 38 84 ms and 54 43 ms ( P 【0 001), and decreased the open state probability from 0 142 to 0 031 and 0 025 ( P 【0 001) under the hypoxia condition, respectively. The effects of Rhy were similar to but weaker than those of verapamil (15 μmol·L -1 ). Conclusion: The study confirmed that Rhy has the blockade effects on L type calcium channels in cortical neurons of rats during hypoxia, by which it protects the brain from hypoxic injury.
基金Supported by the National Natural Science Foundation of China (No. 30170414)
文摘Objective: To investigate the effects of motilin and erythromycin on intracellular Ca2+ mobi-lization in cultured myenteric neurons of rats. Methods: The cultured myenteric neurons were identified with immunofluorescence staining technique. Motilin-induced and erythromycin-induced intracellular Ca2+ mobilization was studied in primary cultures of myenteric neurons using the ratiometric Ca2+ indicator Furo3/AM, with a laser confocal microscope. Results: The effects of motilin and erythromycin on intracellular Ca2+ mobilization were as follows: (1)In Hank's solution, 10 -8, 10-7, 10-6 mol/L motilin could elevate intracellular Ca2+ concentration ([Ca2+]i)in a dose-dependent manner. (2) In Hank's solution, 10μg/ ml erythromycin also could induce the elevation of [Ca2+]i. (3) After pretreatment with antibody against the motilin receptor in Hank's solution, the Ca2+ response to erythromycin was almost restricted. Conclusion: It is suggested that motilin could increase [Ca2+]i in myenteric neurons in a dose-dependent manner, and erythromycin may also have this effectivenesss by binding to the motilin receptor.
基金supported by the Fundamental Research Funds for the Central Universities of China(Grant No.2014QNA64(J.T.))
文摘It has been revealed experimentally that astrocytes can participate in synaptic transmission by modulating and responding to the release of neurotransmitters with calcium elevations. Researches suggest that seizure-like discharges(SDs) or seizure-like firings(SFs) in neurons, characterizing neurological disorder, may arise locally in restricted areas(focal area) and then propagate throughout the brain. But the underlying mechanism remains unclear. To study the possible role astrocytes playing in the SDs propagation, we construct a minimal neuron-astrocyte network model by connecting a neurons chain and an astrocytes chain.The focal area is modelled by an IP3 reservoir which provides persistent IP3 out-flux. The study suggests that calcium wave propagation in astrocytes determines the propagation of SDs in the connected neurons. On the other hand, SDs in neurons allows the calcium wave propagates longer distance in the astrocytes, which suggests the mutually cooperating of astrocytes and neurons in accomplishing SD propagation. Furthermore, once SDs propagate and occupy the neuron network, it could not be terminated by recovery of the focal area. The results may imply that treatment of brain disorders should not only focus on local area but the whole neuron network.