Cell-specific Expression of<i>N</i>-Methyl-D-Aspartate Receptor Subunits in Muller Glia and Neurons from the Chick Retina

Abstract

Pharmacologic characteristics of NMDAR coagonist-site differ in Müller glia and neurons from the retina, in agreement with the distinct subunit expression profile found. Whereas NMDARs in Müller glia contain exclusively exon 5 that lacks NR1 subunits, receptors in distinct subtypes of neurons may contain NR1 with or without exon 5, suggesting a cell-specific assembly of the NMDAR complex. Structural differences in NMDARs could underlie the differential participation of neurons and glia in the physiologic control of glutamate transmission in the retina.