Rabbit Retina Class A Horizontal Cells Dopamine D1 Receptor Localization And Connexin57, 50 Mrna Identified

Dopamine is an important neuromodulater regulating light-dark adaptation in the retina. The secretion of dopamine changes with the light intensity. Previous studies showed dopamine can modulate gap junction permeability between A-type horizontal cells in light-dark adaptation. The effect of dopamine is widespread and dependent on the localization of its receptors. We performed single-cell RT-PCR from dissociated A-type horizontal cells and provided positive evidence of both dopamine D1 receptor mRNA and protein on visually identified A-type horizontal cells from rabbit retina. The sequenced PCR products share 82% identity to that of rat D1 receptor and 87% to human. Also we did intracellular injection, immunocytochemistry, and detected the localization of D1 receptors in rabbit A-type horizontal cell soma and dentrites. This is the first time that single-cell RT-PCR has been performed on rabbit A-type horizontal cells. These findings strongly supported the previous observations that dopamine can uncouple A-type horizontal cells via D1 receptors.