Effect of intra-hippocampal lead injection on affective and cognitive disorders in male WISTAR rats: Possible involvement of oxidative stress

Abstract

This paper is focused on affective and cognitive disorders induced by direct exposure to lead chloride (Pb) and the possible implication of oxidative stress in male WISTAR rats. Using stereotaxic surgery, a group of male wistar rats received an intracerebral injection of 3 μL of lead chloride (1 mg / L) into the right hippocampus or 3 μL of 0.9% Nacl for shame operated controls groups. After 4 days of rest, a series of benchmark neurobehavioral tests were made to evaluate affective and cognitive behaviors, such as open field test (OFT) and Elevated plus maze (EPM) for anxiety like behavior; Forced swim test (FST) for depressive like behavior; finally Y maze (Y-Maze) and Morris maze (MWM) tests for working memory, spatial learning and spatial memory. The data showed that Pb induces anxiogenic and depressogenic effects but does not induce a significant effect in memory. Then by measuring oxidative stress markers using the hippocampal assay of lead-treated rats, it’s appears that Pb can increase nitrogen monoxide, lipid peroxidation and reduces significantly the activity of superoxide dismutase. Therefore, our results showed that Pb is able to induce affective disorders and increase highly oxidative stress but has an insignificant effect on cognitive impairment.

Keywords

• depression
• anxiety
• oxidative stress
• chloride lead
• short-term memory
• spatial memory
• wistar rats