The effect of light exposure following an intraocular injection of [3H]N-acetylmannosamine on the labeling of gangliosides and glycoproteins of retina ganglion cells and optic tectum of singly caged chickens.

Ten-day-old chickens that after a 2-day-period of adaptation to dark received an intraocular injection of [3H]N-acetylamannosamine ([3H]ManNAc) and were exposed, individually housed, to light, have more labeling in the gangliosides and glycoproteins of the ganglion cell layer of retina and in the contralateral optic tectum compared to their counterparts that remained in darkness. No differences were found in the labeling of the acid soluble fraction of the ganglion cell layer between the animals in dark and light at 0.5 and 5 h after the injection of [3H]ManNAc. No differences could be observed in the quality or storage of the gangliosides labeled in light with respect to those labeled in dark, but those labeled in light had a higher percent of labeling released by neuraminidase at 5 h after the intraocular injection of the labelled precursor. In animals exposed to intermittent light, the increased labeling with respect to dark was smaller than that found in animals exposed continuously to light.