Neuropeptide Y Receptors Y1 and Y2 are Present in Neurons and Glial Cells in Rat Retinal Cells in Culture

PURPOSE. Neuropeptide Y (NPY) is one of the most abundant peptides in the central nervous system (CNS), including the retina. This peptide activates various different G-coupled receptors (NPY Y-1, Y-2, Y-4, and Y-5) that are also present in the retina. However, the localization of NPY receptors in the several types of retinal cells is not completely known. In this study, we have looked at the distribution of NPY Y-1 and Y-2 receptors in rat retinal cells to reveal new perspectives on the role of NPY receptors in retina physiology. METHODS. Rat retinal neural cell cultures were prepared from newborn Wistar rats (P3-P5) and pure rat Muller cell culture was obtained after treatment of these cells with ascorbic acid. The presence of NPY Y-1 and Y-2 in retinal cell types was studied by immunocytochemistry. RESULTS. We show that NPY Y-1 and Y-2 receptors are present on every cell type of rat retinal cell cultures. Neurons, as photoreceptors, bipolar, horizontal, amacrine, and ganglion cells, express these two types of NPY receptors. NPY Y-1 and Y-2 receptors are also located in macroglial cells (Muller cells and astrocytes) and microglial cells. CONCLUSIONS. We have clarified the presence of the NPY Y-1 and Y-2 receptors in all different cell types that constitute the retina, which we believe will help open new perspectives for studying the physiology and the potential pathophysiologic function of NPY and its receptors in the retina. (Invest Ophthalmol Vis Sci. 2013;54:429-443) DOI: 10.1167/iovs.12-10776