Differential expression of AMPA-type glutamate receptor subunits during development of the chick optic tectum

Abstract

Glutamate receptors have been often associated with developmental processes. We used immunohistochemical techniques to evaluate the expression of the AMPA-type glutamate receptor (GluR) subunits in the chick optic tectum (TeO). Chick embryos from the 5th through the 20th embryonic day (E5-E20) and one-day-old (P1) chicks were used. The three types of immunoreactivity evaluated (GluR1, GluR2/3, and GluR4) had different temporal and spatial expression patterns in the several layers of the TeO. The GluR1 subunit first appeared as moderate staining on E7 and then increased on E9. The mature GluR1 pattern included intense staining only in layer 5 of the TeO. The GluR2/3 subunits presented low expression on E5, which became intense on E7. The staining for GluR2/3 changed to very intense on E14 in tectal layer 13. Staining of layer 13 neurons is the most prominent feature of GluR immunoreactivity in the adult TeO. The GluR4 subunit generally presented the lowest expression starting on E7, which was similar to the adult pattern. Some instances of transient expression of GluR subunits were observed in specific cell populations from E9 through E20. These results demonstrate a differential expression of the GluR subunits in the embryonic TeO, adding information about their possible functions in the developmental processes of the visual system. Correspondence

Expression of the eight AMPA receptor subunit genes in the developing central nervous system and sensory organs of zebrafish

“…Strong expression of AMPA receptors was also observed in the infantile primate occipital lobe (Lidow and Rakic, 1995), in the ferret visual cortex at birth (Smith and Thompson, 1999), and in the infantile chick optic tectum (Batista et al, 2002).…”

Morphology, projection pattern, and neurochemical identity of Cajal's “centrifugal neurons”: The cells of origin of the tectoventrogeniculate pathway in pigeon (Columba livia) and chicken (Gallus gallus)

“…Retinal fibers ending in the superficial layers (2–5 and 7) of the optic tectum are glutamatergic (Henke et al, ; Morino et al, ; Theiss et al, ; Atoji, ). At the same time, retino‐recipient layers, including layer 7, express high levels of AMPA receptors Glu‐R1 (Pires and Britto, ; Batista et al, ). We suggest that layer 7 labeling of Glu‐R1 may correspond to the expression of these receptors in the dendritic side‐branch of vine‐neurons.…”

The Molecular Pharmacology and Cell Biology of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid Receptors

“…Developmental changes in the expression levels of AMPARs in hippocampal organotypic slice cultures (Fabian-Fine et al, 2000) and living cultured hippocampal neurons have also been reported (Pickard et al, 2000; Molnar et al, 2002), concluding that maturation of synapses may be retarded in vitro. AMPAR expression is also developmentally regulated in the spinal cord (Jakowec et al, 1995; Kalb and Fox, 1997), the visual system (Silveira dos Santos Bredariol and Hamassaki-Britto, 2001; Batista et al, 2002; Hack et al, 2002), and the auditory system (Sugden et al, 2002). During neonatal development, AMPAR incorporation into the plasma membrane occurs prior to synaptogenesis when GluR1-containing AMPARs cluster at potential postsynaptic sites (Martin et al, 1998).…”