Effect of exposure to 2,5-hexanediol in light or darkness on the retina of albino and pigmented rats. I. Morphology

Male albino (Sprague Dawley) and pigmented (Norwegian Brown) rats received 1% 2,5-hexanediol (H) in their drinking water for 5 or 8 weeks, respectively. The rats were housed either in 12 h light (average 30 cd/cm2 inside cage) and 12 h darkness (group LH) or in total darkness (group DH). Two control groups (Light only, LC; Darkness only, DC) were studied in parallel under identical conditions. The animals were sacrificed at the end of H exposure or after an ensuing 13-week period without H but under the same lighting conditions. The retinas of albino rats in the LH group showed a reduction (compared to the LC, DH and DC groups) in the number of nuclei per unit area of the outer nuclear layer (ONL;p