Intrahippocampal dose-dependent effects of aluminum injection on affective and cognitive response in male Wistar rat: potential role of oxidative stress

Abstract

Aluminum (Al) is one of the more widespread metals in the environment and the most abundant known for its neurotoxicity in both humans and animals and could be a potential factor inducing behavioral changes, oxidative stress (OS) and loss of synapses and neurons in the hippocampal areas. The main objective of this study is to determine the impact of a single intracerebral injection of AlCl3 at different doses on the right hippocampus on affective and cognitive behaviors, on levels of OS and morphological changes in male Wistar rats. Rats were treated with a single intrahippocampal injection of 2 μL of NaCl (0.9%) (Control) or successively with 2 μL of AlCl3 at 0.5 (Al-0.5), 1 (Al-1) and 2 mg/kg (Al-2). Five days following surgical procedures, neurobehavioral tests were performed for all groups and the brain were taken to evaluate OS markers and morphological changes in the hippocampus. The results clearly demonstrate that Al induced anxiety and depressive-like behaviors, cognitive deficit, increased lipid peroxidation, nitric oxide levels, decreased superoxide dismutase activity and mediates progressive alterations characterized by disorganization in the pyramidal cellular arrangement and a decrease in neuronal density in the CA3 hippocampal area. In conclusion, a single intrahippocampal injection of Al induced anxiety-like, depression-like, memory impairment, OS and morphological alterations in the hippocampus.