Detection of Neurons Expressing Calcium-Permeable AMPA Receptors Using Kainate-Induced Cobalt Uptake

α-Amino-3-hydroxy-5-methyl-4-isoxaxole propionic acid (AMPA) receptors are a family of ligand-gated ion channels sensitive to the excitatory neurotransmitter glutamate. Many of these receptors are localized postsynaptically along with other glutamate-sensitive receptors such as Nmethyl-D-aspartate (NMDA) receptors. Some AMPA receptors are permeable to Ca2+, whereas all molecular configurations of NMDA receptors studied thus far are permeable to Ca2+. Postsynaptic Ca2+ influx through both NMDA receptors and the less well-known Ca2+-permeable AMPA receptors has been shown to mediate long term changes in synaptic strength (,). Thus efforts have intensified in recent years to identify which neurons express Ca2+-permeable AMPA receptors to help understand the role of these receptors in nervous system function.