Arsenic-induced inhibition of hippocampal neurogenesis and its reversibility (original) (raw)

Arsenic is a common environmental and occupational contaminant distributed worldwide. It may exist in the well water or food. Millions of people consumed arsenic contaminated drinking water in the countries of Argentina, Bangladesh, China, India and Mexico (Ratnaike, 2003). The health of workers with high occupational exposures, such as employees in the semiconductor manufacturing industry, was badly affected (Chen, 2007). Since 1990s, arsenic trioxide is recognized as a highly effective drug for the treatment of acute promyelocytic leukemia (APL) (Wang and Chen, 2008). As 2 O 3 and its metabolites can be detected in the plasma and cerebrospinal fluid of APL patients during treatment (Au et al., 2008; Kiguchi et al., 2010). Chronic arsenic exposure can result in multisystem diseases and the neurological system is a major target. The common neurological manifestation is peripheral neuropathy, however, central nervous system is involved (Ratnaike, 2003; Grandjean and Landrigan, 2006). Long term exposure to arsenic led to increased prevalence of cerebral infarction in adults (Chiou et al., 1997), impaired pattern memory and switching attention in adolescence (Tsai et al., 2003). In Mexican children, verbal intelligence quotient and long-term memory were decreased (Calderon et al., 2001). Children exposed to arsenic from drinking water were associated with low intellectual function and verbal comprehension in Bangladesh (Wasserman et al., 2004, 2011). In Swedish copper smelter workers, subclinical nerve injuries were detected (Lagerkvist and Zetterlund, 1994). In arsenic exposed animals, decreased spatial memory and locomotor behavior were observed (