The AMPA receptors of auditory neurons

The ionotropic glutamate receptor (GluR) subtype known as the AMPA receptor , which mediates rapid excitatory synaptic transmission in many regions of the nervous system, is composed of four different protein subunits, termed GluRs 1-4. The functional properties of each AMPA receptor are determined b y the relative levels of GluRs 1-4 and by post-transcriptional modification s of these proteins through mRNA editing and alternative exon splicing. The present paper reviews the published evidence for (1) localization of mRNAs and immunoreactivity for GluRs 1-4 in the cochlea and subcortical central nervous system auditory pathways of mammals and birds, and (2) involvement of AMPA receptors in synaptic transmission in the auditory system. Recent b iochemical and electrophysiological evidence concerning the specialized pro perties of AMPA receptors on brainstem auditory neurons is also reviewed, a long with data concerning how these properties emerge during normal develop ment. (C) 2000 Elsevier Science B.V. All rights reserved.