EFFECT OF ARSENIC EXPOSURE ON BEHAVIOR OF RATS OF VARIOUS AGE GROUPS.

Arsenic is ranked first among toxicants posing a significant potential threat to human health based on known or suspected toxicity. Recent animal studies suggest that the brain is the major target of arsenic exposure. The present study demonstrates the effect of Arsenic compounds on behavior changes in different age (young and adult) groups of rats. In order to study anxiety behavior, learning and memory processes we used open field, elevated plus maze, spontaneous alteration behavior and multi-branched maze tests. Our experiments revealed that 68 mg/L (35 ppm) Sodium (meta) arsenite (when animals got arsenic from drinking water for three months) induces more significant effect on body weight gain in adult rats rather than in young ones. Arsenic exposure may result in rat's emotional instability despite the animals' age. According to the spontaneous alteration test, obtained data revealed that behavior is changed only in adult rats compared to control ones. Also it was found that Arsenic consumption at the same concentration induces considerable difficulties in learning process (multi-branched maze test results) in the adult arsenic exposed group. We have found differences in maze test performance, during fulfilling memory tasks by arsenic exposed animals in comparison to control ones. This distinction was mostly notable in young groups. These data show that Arsenic exposure affects short-term memory more dramatically in adult animals rather than of young ones, whereas difficulties in long-term memory were detected among young animals.