GluK2, but Not GluK5 or Neto2, Is Required for Synaptic Localization of KARs in the Cerebellum The GluK2 Cytoplasmic Domain Is Indispensable for Receptor Complex Formation in the Brain The GluK2 Cytoplasmic Domain Mediates Synaptic Stabilization, but Not Surface Expression, of KARs in the Cerebellum The GluK2 Cytoplasmic Domain Stabilizes Receptors at Synapses in Hippocampus Synapse Specificity Is Mediated by the High-Affinity KAR Subunits Mechanisms of Stabilization of KARs at Synapses...