Matthews Hugh R, Reisert Johannes
Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK.
Curr Opin Neurobiol. 2003 Aug;13(4):469-75. doi: 10.1016/s0959-4388(03)00097-7.
Exposure of olfactory receptor cells to odour stimulates the influx of Ca(2+) through cyclic nucleotide-gated channels into the small volume within the cilia, the site of olfactory transduction. The consequent rise in intraciliary Ca(2+) concentration has two opposing effects: activation of an unusual excitatory Cl(-) conductance, and negative feedback actions on various stages of the odour transduction mechanism. Recent studies are beginning to unravel how Ca(2+) performs this dual function, and how the spatial and temporal dynamics of Ca(2+) modulate the odour response. The feedback actions of Ca(2+) on different elements of the transduction cascade seem to occur on different timescales, and are therefore responsible for shaping different parts of the receptor current response to odour stimulation.
嗅觉受体细胞暴露于气味中会刺激钙离子（Ca(2+)）通过环核苷酸门控通道流入纤毛内的微小空间，即嗅觉转导发生的部位。由此导致的纤毛内钙离子（Ca(2+)）浓度升高具有两种相反的作用：激活一种不同寻常的兴奋性氯离子（Cl(-)）电导，以及对气味转导机制的各个阶段产生负反馈作用。最近的研究开始揭示钙离子（Ca(2+)）如何发挥这种双重功能，以及钙离子（Ca(2+)）的时空动态如何调节气味反应。钙离子（Ca(2+)）对转导级联不同元件的反馈作用似乎发生在不同的时间尺度上，因此负责塑造受体电流对气味刺激反应的不同部分。
