Neurotransmitter receptor trafficking in and out synapses has emerged as a key process to regulate synaptic transmission during synaptic development and plasticity both at excitatory and inhibitory synapses. Lateral diffusion of surface neurotransmitter receptors has recently emerged as a key pathway to regulate receptor trafficking to and from synapses. Receptors enter and exit synapses mainly by lateral diffusion within the plane of the membrane while their retrieval and addition from and to the plasma membrane by endo and exocytotic processes occur largely at extrasynaptic sites. As a consequence, regulation of receptor surface trafficking is likely to be a major process to regulate receptor numbers at synapses. Measurement of receptor surface diffusion has required the development of new experimental approaches to specifically label and track surface receptor with appropriate time- and space-resolutions. In this review, we first discuss the approaches that have been used to measure receptor surface diffusion, such as the ensemble approach that measure average diffusion of a defined surface receptor population and the single molecule/particle approaches that measure the surface diffusion of isolated receptors. To date, surface diffusion has been described for a variety of neurotransmitter receptors that exhibit common as well as specific features. These points are discussed in a comparative manner and emerging rules of surface trafficking as well as potential interplay between receptor classes are further commented. Because our knowledge on neurotransmitter receptor surface diffusion is fairly recent, open questions and experimental challenges facing the field are highlighted throughout the review.

中文翻译：

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神经递质受体表面运输的测量和特征（综述）。

神经递质受体向内和向外突触的运输已经成为调节突触发育和兴奋性突触和抑制性突触可塑性过程中突触传递的关键过程。表面神经递质受体的侧向扩散最近已成为调节受体进入和流出突触的关键途径。受体主要通过膜平面内的侧向扩散进入和离开突触，而它们通过内吞和胞吐过程从质膜中取出和添加到质膜的过程主要发生在突触外部位。结果，调节受体表面运输可能是调节突触中受体数量的主要过程。受体表面扩散的测量需要开发新的实验方法，以适当的时间和空间分辨率专门标记和跟踪表面受体。在这篇综述中，我们首先讨论用于测量受体表面扩散的方法，例如测量定义的表面受体总体平均扩散的整体方法和测量分离的受体表面扩散的单分子/颗粒方法。迄今为止，已经描述了表现出共同以及特定特征的多种神经递质受体的表面扩散。将以比较的方式讨论这些问题，并进一步评论表面运输的新兴规则以及受体类别之间的潜在相互作用。