Chronic copper exposure leads to hippocampus oxidative stress and impaired learning and memory in male and female rats

Abstract

Environmental and occupational exposures to copper (Cu) play a pivotal role in the etiology of some neurological diseases and reduced cognitive functions. However, the precise mechanisms of its effects on cognitive function have not been yet thoroughly established. In our study, we aimed to investigate the behavior and neurochemical alterations in hippocampus of male and female rats, chronically exposed to copper chloride (CuCl 2 ) and the possible involvement of oxidative stress. Twenty-four rats, for each gender, were divided into control and three test groups (n = 6), and were injected intraperitoneally with saline (0.9% NaCl) or CuCl 2 (0.25 mg/kg, 0.5 mg/kg and 1 mg/kg) for 8 weeks. After the treatment period, Y-maze test was used for the evaluation of spatial working memory and the Morris Water Maze (MWM) to test the spatial learning and memory. Biochemical determination of oxidative stress levels in hippocampus was performed. The main results of the present work are working memory impairment in spatial Y-maze which induced by higher Cu intake (1 mg/kg) in male and female rats. Also, In the MWM test, the spatial learning and memory were significantly impaired in rats treated with Cu at dose of 1 mg/kg. Additionally, markers of oxidative stress such as catalase, superoxide dismutase, lipid peroxidation products and nitric oxide levels were significantly altered following Cu treatments. These data propose that compromised behavior following Cu exposure is associated with increase in oxidative stress.

Nano-Curcumin Prevents Cardiac Injury, Oxidative Stress and Inflammation, and Modulates TLR4/NF-κB and MAPK Signaling in Copper Sulfate-Intoxicated Rats

“…Cu can disturb the redox homeostasis, and provoke oxidative stress and cellular damage, leading to several diseases. Hepatotoxicity, kidney injury, and neurodegenerative disorders were associated with the exposure to Cu [ 7 , 8 , 9 , 10 , 12 ]; however, the toxic effects of Cu on the heart are less documented. Herein, we evaluated the possible involvement of oxidative stress, and TLR4/NF-κB and MAPK signaling, in the cardiotoxic effect of Cu in rats, and the protective effect of CUR and N-CUR.…”

“…Despite its pivotal roles, Cu becomes harmful when the normal limit is surpassed, and chronic exposure has been associated with neurodegenerative disorders, including Alzheimer’s and Parkinson’s diseases [ 7 , 8 ]. In addition, multiorgan dysfunction, such as liver, kidney, and neurological injuries, which could be fatal, are caused by Cu intoxication [ 9 , 10 ]. The liver is the major target for Cu toxicity, and hepatotoxicity is usually seen in individuals with Wilson disease and cirrhosis syndromes [ 9 ].…”

“…Oxidative stress has been demonstrated in the hippocampus and frontal cortex of rats that received CuSO 4 [ 25 ]. Impairment of memory and learning was associated with oxidative stress in the hippocampus of rats treated with Cu chloride [ 10 ]. These studies demonstrated the significant role of oxidative stress in Cu toxicity.…”

Neuroprotective effect of melatonin on nickel-induced affective and cognitive disorders and oxidative damage in rats

“…Our previous study showed that chronic Ni exposure induced depression-like, anxiety-like, memory deficit, and alterations in OS markers in the hippocampus [13], a crucial brain region in learning, memory processes, and emotion regulation [14,15]. These effects are similar to those induced by other heavy metals such as Copper(Cu), Cadmium(Cd) and Aluminum(Al) [16][17][18][19]. Certain…”

Heavy metal pollutants have additive negative effects on honey bee cognition

“…mice: Anderson et al, 2016;humans: Mason et al, 2014) and Cu (e.g. mice: Lamtai et al, 2020;Pal et al, 2013;flies: Zamberlan, 2020). Recent studies showed that low doses of Pb (Monchanin et al, 2020a) and selenium (Se) (Burden et al, 2016) also impair behaviour and cognition in honey bees, suggesting a widespread impact on pollinators.…”