Detection and characterization of individual endocytosis of AMPA‐type glutamate receptor around postsynaptic membrane. (5th May 2017)

• Record Type: Journal Article
• Authors: Fujii, Shumpei; Tanaka, Hiromitsu; Hirano, Tomoo
• Is Part Of: Genes to cells. Volume 22:Number 6(2017)
• Page Start: 583
• Page End: 590
• Publication Date: 2017-05-05
• Subjects: Cytogenetics -- Periodicals; Cells -- Mechanical properties -- Periodicals; Molecular genetics -- Periodicals; Genes -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Biomechanics -- Periodicals; 571.6
• DOI: 10.1111/gtc.12493
• Languages: English
• ISSNs: 1356-9597

Abstract

Abstract : Synaptic plasticity such as long‐term depression (LTD) has been regarded as a cellular mechanism of learning and memory. LTD is expressed by the decrease in number of postsynaptic AMPA‐type receptor (AMPAR) at glutamatergic synapses. Although endocytosis is known to play an essential role in the decrease in AMPAR on postsynaptic membrane, the difficulty to detect individual endocytic events hampered clarification of AMPAR dynamics around synapses. Previously, we developed a method to induce formation of postsynaptic‐like membrane (PSLM) on the glass surface and observed pHluorin‐tagged AMPAR around PSLM with total internal reflection fluorescence microscopy. By this method, individual exocytosis of AMPAR‐pHluorin was recorded in both PSLM and non‐PSLM. In other studies, endocytic vesicles containing pHluorin‐tagged receptors were visualized by changing extracellular pH. Here, we have combined PSLM formation method and rapid pH change method, and detected individual endocytic events of AMPAR around PSLM with high spatial and temporal resolutions. Endocytic events of AMPAR were characterized by comparison with those of transferrin receptor. Constitutive endocytosis of AMPAR was not dependent on clathrin and dynamin in contrast to that of transferrin receptor. However, AMPAR endocytosis triggered by LTD‐inducing stimulation was clathrin‐ and dynamin‐dependent. Abstract : New methods to record individual endocytosis of AMPA‐type glutamate receptor around postsynaptic membrane has been established. Constitutive endocytosis of AMPA receptor was not dependent on clathrin and dynamin in contrast to that of transferrin receptor. Application of NMDA transiently induced clathrin‐ and dynamin‐dependent endocytosis of AMPA receptor around postsynaptic membrane.