Ultrastructural Alterations in the Photoreceptor Layer in Rats Following Induced Chronic Alcoholism

Abstract

Abstract: : Purpose:: the effects of ethanol on the nervous system are extensive and a variety of neuropathological and associated neuropsychological disorders have been observed in chronic alcoholics. The purpose of this study is to evaluate the effects of chronic ethanol feeding on the photoreceptor layer in an adult rat model. Methods:: five «treated» rats (TG) were fed with standard lab rodent chow and an ethanol-containing liquid,and 4 «control» animals (CG) were fed with chow and tap water for 40 weeks. The eyes were removed and the retina was prepared to ultrastructural examination. The cones and rods and the outer nuclear layer were evaluated by transmission electron microscopy, using a Phillips EM 301 electron microscope. Results:comparing both groups it was observed fewer mitochondria in the TG animals myoids. The outer nuclear layer in CG exhibited cellular nucleus with hexagonal shape and densely chromatin in the central nuclear area; the nuclei were surrounded by smaller portion of cytoplasm and the cells were displaced very closely. The TG animals presented more grumous chromatin and lost the preferential central distribution; spaces between the cell bodies were also observed. Conclusion:these findings suggest that chronic ethanol exposure induces photoreceptor degeneration in rats.

Keywords: 472 microscopy: electron microscopy • 517 photoreceptors • 506 pathology: experimental