The effects of sodium arsenite exposure on behavioral parameters in the rat

Arsenic is a metalloid widely present in the environment. It is found in we ll water, soil, and air, and is also released from mining residues and indu strial debris, among other anthropogenic sources. It has been previously re ported that the content of catecholamines in striatum, hippocampus, and oth er cerebral regions changes in mice and rats exposed to arsenic. Few studie s have examined behavioral alterations after intoxication with arsenic, and both increased and decreased locomotor activity, as well as learning defic its, have been described. In order to characterize the behavioral alteratio ns induced by arsenic exposure, we exposed adult male Sprague-Dawley rats t o 5, 10, and 20 mg/kg of arsenic by intragastric route for 2 or 4 weeks. Ex posed rats showed reduced locomotor activity, which returned to control lev els at the end of the intoxication period. We also found an increase in the number of errors in an egocentric task, alterations in monoamine content i n midbrain and cortex, and increases in arsenic brain concentration, which were related to time of the exposure but not dose. These results indicate t hat short-term arsenic exposure induces neural and behavioral changes that may reflect a neurotoxic effect, and that these alterations are correlated to dose, time of exposure, and experimental conditions. (C) 2001 Elsevier S cience Inc.