Glutamate and kainate are not directly toxic to developing amacrine cells: analysis in a Lucifer Yellow-labeled...

Lucifer Yellow (LY)-labeled retinal amacrine cells were examined for toxin sensitivity to glutamate (Glu) or kainate (KA) and for high-affinity uptake (HAU) of Glu. In vitro, a 24-h exposure to either toxin caused a 50% loss of neurons with no loss of LY neurons. A 1-h exposure of intact retina to the toxins resulted in a two-fold increase in non-viable cells with no change in LY neurons. While histological damage within the retina was seen following toxin exposure, the LY population appeared unaffected. HAU in vitro was found in 5% of neurons but never colocalized with LY neurons. These studies show that Glu and KA do not directly affect the LY-labeled amacrine cells and support the hypothesis that their eventual loss may be an indirect consequence of toxin exposure.