Localization and possible function of P2Y4 receptors in the rodent retina

Abstract

Extracellular ATP acts as a neurotransmitter in the retina, via the activation of ionotropic P2X receptors and metabotropic P2Y receptors. The expression of various P2X and P2Y receptor subtypes has been demonstrated in the retina, but the localization of P2Y receptors and their role in retinal signaling remains ill defined. In this study, we were interested in determining the localization of the P2Y4 receptor subtype in the rat retina, and using the electroretinogram (ERG) to assess whether activation of these receptors modulated visual transmission. Using light and electron microscopy, we demonstrated that P2Y4 receptors were expressed pre-synaptically in rod bipolar cells and in processes..