Differences in Ca(2+) permeability of AMPA-type glutamate receptor channels in neocortical neurons caused by differential GluR-B subunit expression Journal Article


Author(s): Jonas, Peter; Racca, Claudia; Sakmann, Bert; Seeburg, Peter H; Monyer, Hannah
Article Title: Differences in Ca(2+) permeability of AMPA-type glutamate receptor channels in neocortical neurons caused by differential GluR-B subunit expression
Affiliation
Abstract: Fast excitatory synaptic transmission in the CNS is mediated by AMPA-type glutamate receptor (GluR) channels. Heterologous expression suggested that the Ca2+ permeability of these receptors critically depends on the subunit composition. Using patch-clamp techniques in brain slices, we found that the Ca2+ permeability of native AMPA-type GluRs was markedly higher in nonpyramidal (P(Ca)/P(K) ≃ 0.63) than in pyramidal (P(Ca)/P(K) ≃ 0.05) neurons of rat neocortex. Analysis of mRNA in single cells indicated that the relative abundance of GluR-B-specific mRNA was significantly lower in nonpyramidal (GluR-B/GluR-non-B ≃ 0.3) than in pyramidal (GluR-B/GluR-non-B ≃ 3) cells. This suggests that differences in relative abundance of GluR-B- specific mRNA generate functional diversity of AMPA-type GluRs in neurons with respect to Ca2+ permeability.
Keywords: Animals; Rats; Molecular Sequence Data; Base Sequence; DNA Primers; Gene Expression; Polymerase Chain Reaction; Macromolecular Substances; Calcium; Calcium/metabolism; RNA, Messenger/biosynthesis; Pyramidal Cells/physiology; Receptors, AMPA/physiology; Rats, Wistar; Calcium Channels/physiology; Membrane Potentials/physiology; RNA, Messenger; Receptors, AMPA; Calcium Channels; Receptors, Glutamate; Cerebral Cortex/physiology; Neurons/physiology; Receptors, Glutamate/biosynthesis; Visual Cortex/physiology
Journal Title: Neuron
Volume: 12
Issue 6
ISSN: 0896-6273
Publisher: Elsevier  
Date Published: 1994-06-01
Start Page: 1281
End Page: 1289
DOI: 10.1016/0896-6273(94)90444-8
Open access: no