AUTHOR=Gookin Sara E. , Taylor Matthew R. , Schwartz Samantha L. , Kennedy Matthew J. , Dell’Acqua Mark L. , Crosby Kevin C. , Smith Katharine R. 

TITLE=Complementary Use of Super-Resolution Imaging Modalities to Study the Nanoscale Architecture of Inhibitory Synapses

JOURNAL=Frontiers in Synaptic Neuroscience

VOLUME=14

YEAR=2022

URL=https://www.frontiersin.org/journals/synaptic-neuroscience/articles/10.3389/fnsyn.2022.852227

DOI=10.3389/fnsyn.2022.852227

ISSN=1663-3563

ABSTRACT=<p>The nanoscale architecture of synapses has been investigated using multiple super-resolution methods, revealing a common modular structure for scaffolds, neurotransmitter receptors, and presynaptic proteins. This fundamental organization of proteins into subsynaptic domains (SSDs) is thought to be important for synaptic function and plasticity and common to many types of synapses. Using 3D super-resolution Structured Illumination Microscopy (3D-SIM), we recently showed that GABAergic inhibitory synapses exhibit this nanoscale organizational principle and are composed of SSDs of GABA<sub><italic>A</italic></sub> receptors (GABA<sub><italic>A</italic></sub>Rs), the inhibitory scaffold gephyrin, and the presynaptic active zone protein, RIM. Here, we have investigated the use of 3D-SIM and <italic>d</italic>STORM to analyze the nanoscale architecture of the inhibitory synaptic adhesion molecule, neuroligin-2 (NL2). NL2 is a crucial mediator of inhibitory synapse formation and organization, associating with both GABA<sub><italic>A</italic></sub>Rs and gephyrin. However, the nanoscale sub-synaptic distribution NL2 remains unknown. We found that 3D-SIM and <italic>d</italic>STORM provide complementary information regarding the distribution of NL2 at the inhibitory synapse, with NL2 forming nanoscale structures that have many similarities to gephyrin nanoscale architecture.</p>