RT Journal Article
SR Electronic
T1 Depolarization of Hippocampal Neurons Induces Formation of Nonsynaptic NMDA Receptor Islands Resembling Nascent Postsynaptic Densities
JF eneuro
JO eneuro
FD Society for Neuroscience
SP ENEURO.0066-15.2015
DO 10.1523/ENEURO.0066-15.2015
VO 2
IS 6
A1 Jung-Hwa Tao-Cheng
A1 Rita Azzam
A1 Virginia Crocker
A1 Christine A. Winters
A1 Tom Reese
YR 2015
UL http://www.eneuro.org/content/2/6/ENEURO.0066-15.2015.abstract
AB Depolarization of neurons in 3-week-old rat hippocampal cultures promotes a rapid increase in the density of surface NMDA receptors (NRs), accompanied by transient formation of nonsynaptic NMDA receptor clusters or NR islands. Islands exhibit cytoplasmic dense material resembling that at postsynaptic densities (PSDs), and contain typical PSD components, including MAGUKS (membrane-associated guanylate kinases), GKAP, Shank, Homer, and CaMKII detected by pre-embedding immunogold electron microscopy. In contrast to mature PSDs, islands contain more NMDA than AMPA receptors, and more SAP102 than PSD-95, features that are shared with nascent PSDs in developing synapses. Islands do not appear to be exocytosed or endocytosed directly as preformed packages because neurons lacked intracellular vacuoles containing island-like structures. Islands form and disassemble upon depolarization of neurons on a time scale of 2-3 min, perhaps representing an initial stage in synaptogenesis.