Institute of Biology , Biologie Cellulaire de la Synapse, Inserm U1024, CNRS 8197, École Normale Supérieure (ENS), 46 rue d'Ulm, Paris 75005, France.
Neurophotonics. 2016 Oct;3(4):041805. doi: 10.1117/1.NPh.3.4.041805. Epub 2016 Jun 3.
The ability to count molecules is essential to elucidating cellular mechanisms, as these often depend on the absolute numbers and concentrations of molecules within specific compartments. Such is the case at chemical synapses, where the transmission of information from presynaptic to postsynaptic terminals requires complex interactions between small sets of molecules. Be it the subunit stoichiometry specifying neurotransmitter receptor properties, the copy numbers of scaffold proteins setting the limit of receptor accumulation at synapses, or protein packing densities shaping the molecular organization and plasticity of the postsynaptic density, all of these depend on exact quantities of components. A variety of proteomic, electrophysiological, and quantitative imaging techniques have yielded insights into the molecular composition of synaptic complexes. In this review, we compare the different quantitative approaches and consider the potential of single molecule imaging techniques for the quantification of synaptic components. We also discuss specific neurobiological data to contextualize the obtained numbers and to explain how they aid our understanding of synaptic structure and function.
计数分子的能力对于阐明细胞机制至关重要，因为这些机制通常取决于特定隔室中分子的绝对数量和浓度。在化学突触中就是如此，信息从突触前末梢传递到突触后末梢需要小分子量分子之间的复杂相互作用。无论是指定神经递质受体特性的亚基比例，还是决定受体在突触处积累极限的支架蛋白拷贝数，还是决定突触后密度的分子组织和可塑性的蛋白包装密度，所有这些都取决于成分的确切数量。多种蛋白质组学、电生理学和定量成像技术已经深入了解了突触复合物的分子组成。在这篇综述中，我们比较了不同的定量方法，并考虑了单分子成像技术在定量突触成分方面的潜力。我们还讨论了特定的神经生物学数据，以将获得的数字置于上下文中，并解释它们如何帮助我们理解突触的结构和功能。
