Department of Mathematics and Statistics, University of Canterbury, Christchurch, New Zealand.
Bull Math Biol. 2013 Mar;75(3):428-43. doi: 10.1007/s11538-013-9813-x. Epub 2013 Jan 29.
Neurovascular coupling is the well-documented link between neural stimulation and constriction or dilation of the surrounding vasculature. Glial cells mediate this response via their unique anatomy, which connects neurons to arterioles. It is believed that calcium transients and the release of secondary messengers by these cells influence the vascular response. We present a model of intracellular calcium dynamics in an astrocyte (glial cell) and show that stable oscillatory behaviour is possible under certain conditions. We then couple this to a novel model for the relationship between calcium concentration and the production of vasoactive secondary messengers through a fatty-acid intermediate. The two secondary messengers modelled are epoxyeicosatrienoic and 20-hydroxyeicosatetraenoic acids (EET and 20-HETE, respectively). These secondary messengers are produced on different time scales, and we show how this supports the observation that the vasculature dilates rapidly in response to neural stimulation, before returning to baseline levels on a slower time scale.
神经血管耦联是神经刺激与周围血管收缩或扩张之间有充分记录的联系。神经胶质细胞通过其独特的解剖结构介导这种反应，这种结构将神经元与小动脉连接起来。据信，这些细胞中的钙瞬变和第二信使的释放影响血管反应。我们提出了一种星形胶质细胞（神经胶质细胞）细胞内钙动力学的模型，并表明在某些条件下可以实现稳定的振荡行为。然后，我们将其与一种新的模型耦合，该模型描述了钙浓度与通过脂肪酸中间体产生血管活性第二信使之间的关系。所模拟的两种第二信使是环氧二十碳三烯酸和 20-羟二十碳四烯酸（分别为 EET 和 20-HETE）。这些第二信使的产生时间尺度不同，我们展示了这如何支持这样的观察结果，即血管在对神经刺激的快速反应中扩张，然后在较慢的时间尺度上恢复到基线水平。
