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心房肌细胞的防火墙

Firewalls in Atrial Myocytes
课程网址: http://videolectures.net/eccs07_thul_fam/  
主讲教师: Ruediger Thul
开课单位: 诺丁汉大学
开课时间: 2007-11-27
课程语种: 英语
中文简介:
心房肌细胞在心脏搏动的产生中起着重要作用。它们的收缩由钙信号控制,钙信号在细胞周边出现,然后向心进行以接合产生肌丝的力。实验证明,这些初始信号需要在它们向内移动之前克服细胞膜正下方的屏障。由于心房肌细胞缺乏横向小管,所述横向小管将外部信号传递到细胞内部,例如,在心室肌细胞中,这样的防火墙代表了心房动力学的关键决定因素。例如,它允许心房肌细胞微调它们对各种重要刺激的反应。在这里,我们提出了一个计算上有利的模型来研究产生这些分级向心信号的机制。我们的框架考虑了心房肌细胞的三维组织,特别是从内部储存室中空间限制释放钙。我们采用火焰漫射火(FDF)模型来检查空间时间模式,并探测波传播对生理相关参数的依赖性。模拟可兴奋的介质,FDF方法反映了细胞内钙动力学中噪声的重要性。明确构建相应的格林函数可以进行详细分析。
课程简介: Atrial myocoytes play a prominent role in the generation of heart beats. Their contraction is controlled by Calcium signals that emerge at the cellular periphery and then proceed centripetally to engage the force-generating myofilaments. Experiments have demonstrated that these initial signals need to overcome a barrier just below the cell membrane before they move inward. Since atrial myoctes lack transverse tubules that transmit external signals to the cell interior as e.g. in ventricular myocytes, such a firewall represents a crucial determinant of atrial dynamics. For instances, it allows atrial myocytes to fine tune their responses to a wide range of vital stimuli. Here, we present a computationally advantageous model to investigate the mechanisms that give rise to these graded centripetal signals. Our framework takes into account the three dimensional organisation of atrial myocytes, especially the spatially restricted release of Calcium from internal storage compartments. We employ a fire-diffuse-fire (FDF) model to examine the spatio-temporal patterns and to probe the dependence of wave propagation on physiologically relevant parameters. Mimicking an excitable medium, the FDF approach reflects the significance of noise in intracellullar Calcium dynamics. The explicit construction of the corresponding Green's function allows for a detailed analysis.
关 键 词: 心房肌细胞; 心房动力学; 钙动力学
课程来源: 视频讲座网
最后编审: 2019-03-19:lxf
阅读次数: 57