A Study on the Effects of Orally Administered Copper Sulfate on Learning and Spatial Memory of Wistar Rats

BACKGROUND AND OBJECTIVE: Copper is one of the main micronutrients in the human body. Malfunction in copper homeostasis results in Menkes syndrome and Wilson’s disease, which are associated with complications such as seizure and impairments in learning and memory. Use of high copper concentrations can cause permanent damage to the cells and neurons. The aim of this study was to examine the toxic effects of orally administered copper sulfate on rats’ learning in Morris water maze. METHODS: In this experimental study, 39 Wistar rats were divided into male (n=21) and female (n=18) groups. These two groups were each randomly divided into three sub-groups. The control group received distilled water, while the other two groups were administrated 1 and 1.5 mM of copper sulfate, dissolved in distilled water for a period of one month. After this period, the Morris water maze was incorporated to evaluate the spatial memory of rats. FINDINGS: In male rats, copper sulfate, which was added to drinking water, made no significant changes in the distance traveled to find the platform (24.09%±3.01 in the control group, 26.06%±2.95 in the 1 mm copper sulfate group, and 25.68%±1.82 in the 1.5 mM copper sulfate group), the time spent to find the platform (23.93±2.87 in the control group, 25.54±3.47 in the 1 mM copper sulfate group, and 25.33±1.92 in the 1.5 mM copper sulfate group), or the swimming speed. The comparison of female groups showed that 1 and 1.5 mM concentrations of copper sulfate could not cause any significant impairments in learning of rats. CONCLUSION: The results showed that the addition of copper sulfate to drinking water have no detrimental impacts on the memory or learning of male and female rats.