Colocalization of choline acetyltransferase and gamma-aminobutyric acid inthe developing and adult turtle retinas

Acetylcholine and gamma-aminobutyric acid (GABA) are putative neurotransmit ters in the adult vertebrate retina. In this study, cells that coexpress ch oline acetyltransferase (ChAT) and GABA or glutamic acid decarboxylase (GAD ) were investigated in turtle retinas from stage 14 (S14) to adulthood by u sing a double-labeling immunofluorescence technique. ChAT immunoreactivity was observed at S15 and included not only the presumptive starburst choline rgic amacrine cells but also a population in the ganglion cell layer (GCL) that expressed ChAT transiently during the embryonic stages. (C) 2000 Wiley -Liss, Inc.