IMAGING OF GLUTAMATE RELEASE FROM THE GOLDFISH RETINAL SLICE

A fluorometric procedure to image release of the neurotransmitter glut amate from living retinal slices is described. Patterns of endogenous glutamate afflux were imaged with a cooled CCD camera in goldfish reti nal slices as NADH fluorescence produced by a cycling glutamate dehydr ogenase (GDH). Basal and potassium evoked glutamate effluxes were stro ngly localized to the outer and inner plexiform layers, supporting the model that photoreceptors and bipolar cells release glutamate as thei r prime fast neurotransmitter. (C) 1998 Elsevier Science Ltd. All righ ts reserved.