RECOMBINANT AMPA RECEPTORS WITH LOW CA2-293 CELLS( PERMEABILITY INCREASE INTRACELLULAR CA2+ IN HEK)

ALTHOUGH AMPA receptor subunit configuration controls the Ca2+ permeab ility of the ion channel, not much is known about Ca2+ signals generat ed by different AMPA receptor subtypes. We examined the Ca2+ signaling properties of recombinant AMPA receptors using patch clamp to determi ne ionic permeability properties and Ca2+ imaging to examine changes i n intracellular Ca2+ level ([Ca2+](i)). Activation of recombinant AMPA receptors robustly increased [Ca2+](i) even in cells expressing heter omeric receptors containing edited GluRB, which harbored receptors wit h very low average Ca2+ permeability in patch clamp studies. The resul ts suggest that whereas the GluRB subunit controls Ca2+ permeability, Ca2+ signaling mediated by AMPA receptors correlates poorly with the p resence of GluRB.