Living Systems Institute, University of Exeter, Exeter, United Kingdom.
College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom.
PLoS Comput Biol. 2020 Apr 6;16(4):e1007769. doi: 10.1371/journal.pcbi.1007769. eCollection 2020 Apr.
Endocrine cells in the pituitary gland typically display either spiking or bursting electrical activity, which is related to the level of hormone secretion. Recent work, which combines mathematical modelling with dynamic clamp experiments, suggests the difference is due to the presence or absence of a few large-conductance potassium channels. Since endocrine cells only contain a handful of these channels, it is likely that stochastic effects play an important role in the pattern of electrical activity. Here, for the first time, we explicitly determine the effect of such noise by studying a mathematical model that includes the realistic noisy opening and closing of ion channels. This allows us to investigate how noise affects the electrical activity, examine the origin of spiking and bursting, and determine which channel types are responsible for the greatest noise. Further, for the first time, we address the role of cell size in endocrine cell electrical activity, finding that larger cells typically display more bursting, while the smallest cells almost always only exhibit spiking behaviour.
垂体中的内分泌细胞通常表现出尖峰或爆发式的电活动，这与激素分泌水平有关。最近的一项结合数学建模和动态钳位实验的研究表明，这种差异是由于少数大电导钾通道的存在或不存在所致。由于内分泌细胞中只含有少数几个这样的通道，因此随机效应很可能在电活动模式中发挥着重要作用。在这里，我们首次通过研究一个包含离子通道真实噪声开闭的数学模型，明确地确定了这种噪声的影响。这使我们能够研究噪声如何影响电活动，探究尖峰和爆发的起源，并确定哪种类型的通道对噪声的影响最大。此外，我们首次研究了细胞大小在内分泌细胞电活动中的作用，发现较大的细胞通常表现出更多的爆发活动，而最小的细胞几乎总是只表现出尖峰活动。
