The dynamic organization of the neuronal postsynaptic membrane

Abstract

This thesis explores the dynamic organization of glutamate receptors and membrane lipids in the postsynaptic membrane of neurons. It aims to understand how the arrangement of these components influences synaptic transmission and brain function. The study utilizes advanced super-resolution microscopy techniques to visualize and track individual molecules at the nanoscopic scale. The thesis begins with an overview of the importance of membrane composition in protein organization within the postsynapse. It highlights the challenges in studying this field and introduces the use of super-resolution microscopy for visualizing protein and lipid distribution. A protocol for single-molecule localization microscopy is presented to examine the subsynaptic localization of synaptic proteins. Next, the focus shifts to the dynamics of lipids and proteins within the synaptic membrane. The thesis delves into a methodology for tracking individual molecules in living cells and the subsequent analysis of their movement and diffusion. Simulated trajectories are employed to optimize experimental parameters for studying complex molecular organization. The subsequent chapters investigate specific glutamate receptor subtypes. Chapter 5 examines the AMPA receptor, particularly the GluA3-containing subtype. The distribution and dynamics of GluA3-containing AMPARs are compared to GluA1-containing AMPARs within the postsynaptic membrane. Chapter 6 focuses on the metabotropic glutamate receptor mGluR5, exploring its distribution and dynamics in relation to the postsynaptic density. The perisynaptic localization of mGluR5 and its significance are described. Chapter 7 explores methods for studying the dynamic organization of membrane lipids. This includes analyzing lipid diffusion behavior and distribution patterns, as well as investigating the effects of altering lipid composition on receptor organization. Overall, the thesis provides valuable insights into the nanoscale organization of glutamate receptors and membrane lipids in the postsynaptic membrane. It enhances our understanding of synaptic architecture and its impact on synaptic transmission and brain function.