The emergence, localization, and maturation of neurotransmitter systems during development of the retina inxenopus laevis: II. Glycine

Abstract

The high-affinity uptake and release of glycine was studied in retinas of Xenopus laevis. In the toad and tadpole retina, ³H-glycine was accumulated by a population of cells located predominantly in the inner nuclear layer. When retinas preloaded with ³H-glycine were subjected to high K⁺-concentrations, these retinas released large amounts of ³H-glycine by a Ca⁺⁺-dependent mechanism. The appearance and maturation of these putative glycinergic properties was followed during retinal development. Our results indicate that the high-affinity uptake of glycine first appears around stage 33/34 whereas K⁺-stimulated glycine release cannot be detected until stage 42.