Down-regulation of AMPA-type glutamate receptor gene expression during goldfish optic nerve regeneration

An AMPA-type glutamate receptor cDNA, GFGR52, was cloned from a goldfish retinal cDNA library. GFGR52 is highly homologous to the AMPA D-FLOP-type glutamate receptor. In situ hybridization revealed GFGR52 gene expression in both retinal ganglion cells and optic tectum. This expression was reduced during optic nerve regeneration and this decreased level of gene expression lasted until the reinitiation of synaptogenesis. These findings suggest that interactions between optic nerve and its target, the optic tectum are necessary for maintaining AMPA D-type glutamate receptor gene expression in both retinal and tectal neurons.