Stimulation-induced differential redistributions of clathrin and clathrin-coated vesicles in axons compared to soma/dendrites

Molecular Brain

Jung-Hwa Tao-Cheng¹ 

[1] NINDS Electron Microscopy Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 20892, Bethesda, MD, USA;

关键词: Electron microscopy;    Clathrin-coated vesicles;    Clathrin-coated pits;    Endocytosis;    Synaptic vesicle;    Multivesicular body;    Glutamate receptors;    Transferrin receptors;   

DOI  :  10.1186/s13041-020-00683-5

来源: Springer

【 摘 要 】

Clathrin-mediated endocytosis plays an important role in the recycling of synaptic vesicle in presynaptic terminals, and in the recycling of transmitter receptors in neuronal soma/dendrites. The present study uses electron microscopy (EM) and immunogold EM to document the different categories of clathrin-coated vesicles (CCV) and pits (CCP) in axons compared to soma/dendrites, and the depolarization-induced redistribution of clathrin in these two polarized compartments of the neuron. The size of CCVs in presynaptic terminals (~ 40 nm; similar to the size of synaptic vesicles) is considerably smaller than the size of CCVs in soma/dendrites (~ 90 nm). Furthermore, neuronal stimulation induces an increase in the number of CCV/CCP in presynaptic terminals, but a decrease in soma/dendrites. Immunogold labeling of clathrin revealed that in presynaptic terminals under resting conditions, the majority of clathrin molecules are unassembled and concentrated outside of synaptic vesicle clusters. Upon depolarization with high K+, label for clathrin became scattered among de-clustered synaptic vesicles and moved closer to the presynaptic active zone. In contrast to axons, clathrin-labeled CCVs and CCPs were prominent in soma/dendrites under resting conditions, and became inconspicuous upon depolarization with high K+. Thus, EM examination suggests that the regulation and mechanism of clathrin-mediated endocytosis differ between axon and dendrite, and that clathrin redistributes differently in these two neuronal compartments upon depolarization.

【 授权许可】

CC BY