CYTOTOXIC EFFECTS OF CADMIUM CHLORIDE IN THE ZEBRAFISH BRAIN

Cadmium is indicated as a possible etiological factor in neurodegenerative diseases. In this study we have analysed the effects of 1mg/L cadmium chloride (CdCl2), a concentration found in industrial polluted water, on brain of adult zebrafish exposed to metal for 16 days. The brains were analysed at 2, 7 and 16 days from treatment. We evaluated the neurodegeneration by the Fluoro-Jade B stain and the myelin integrity by methasol fast blue staining. The expression of glial fibrillary acidic protein (GFAP), astroglial marker, and the accumulation levels of beta-Amyloid1-42 peptide were tested by ABC technique and western blotting. Collected data showed neurodegenerative effects time-dependent and a sensible reduction of affinity to the dye in neurons axons after 7 and 16 days of exposure respect the control. Moreover, a decrease in the levels of GFAP was observed after 2 days in the order of 40% compared with the control. This decrease arrived to 50% after 16 days. In particular, a reduction of GFAP positive fibers was revealed in midbrain and in cerebellum, in medulla oblongata and after 16 days in telencephalon. Instead the levels of beta-Amyloid1-42 increased as time passed, in telencephalon, cerebellum and medulla oblongata. These data confirm the toxicity of cadmium on neuroglia cells and represent a point for discovering possible correlations between cadmium and neurological disorders as Alzheimer’s disease for the data on beta-Amyloid1-42 peptide.