Silent Synapses Antibody Sampler Kit

Background

AMPA- (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid), kainate-, and NMDA- (N-methyl-D-aspartate) receptors are the three main families of ionotropic glutamate-gated ion channels. AMPA receptors (AMPARs) are composed of four subunits (GluA1-4), which assemble as homo- or hetero-tetramers to mediate the majority of fast excitatory transmissions in the central nervous system. AMPARs are implicated in synapse formation, stabilization, and plasticity (1). In contrast to GluA2-containing AMPARs, AMPARs that lack GluA2 are permeable to calcium (2). Post-transcriptional modifications (alternative splicing, nuclear RNA editing) and post-translational modifications (glycosylation, phosphorylation) result in a very large number of permutations, fine-tuning the kinetic properties and surface expression of AMPARs representing key pathways to mediate synaptic plasticity (3). During development and mature states, some synapses exhibit “silent synapses” that lack functional AMPAR-mediated transmission. Synapses become “unsilenced” by post-translational modification of GluAs, particularly GluA1, which alters its kinetic properties and/or surface expression while other synaptic components, such as other glutamate receptors like NMDARs and postsynaptic scaffolding proteins like PSD95, remain unaltered. Conversely, reducing the AMPAR kinetic properties and surface expression can silence synapses. Key post-translational modifications implicated in regulating these processes include phosphorylation of GluA1 at Ser831 and Ser845 (4). Research studies have implicated activity-dependent changes in AMPARs in a variety of diseases, including Alzheimer’s, amyotrophic lateral sclerosis (ALS), stroke, and epilepsy (1).