Intrahippocampal effects of Aluminum injection on affective and cognitive response in male Wistar rat: Potential role of oxidative stress

Abstract

Abstract Aluminum (Al) is one of the more widespread metals in the environment used in various fields 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 and cerebral cortical areas. The main objective of this study is to determine the short-term impact of a single 2 μl intracerebral injection of AlCl 3 at different doses on the right hippocampus on affective and cognitive behaviour, on levels of oxidative stress 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 AlCl 3 at 0.5 mg/Kg (Al-0.5), 1 mg/Kg (Al-1) and 2 mg/Kg (Al-2). Five days following surgical procedures, neurobehavioral tests were performed for all groups (OFT, EPM, FST, Y-maze and MWM) and the brain were taken to isolate the hippocampus from adjacent tissues to prepare homogenates for the determination of oxidative stress markers and to examine the morphological change in CA3 hippocampal area. The results clearly demonstrate that Al induced anxiety and depressive-like behaviours, cognitive deficit, increased lipid peroxidation (LPO), nitric oxide (NO) levels, decreased superoxide dismutase (SOD) activity in the hippocampus 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.