Effect of Depolarization and Calcium ION Deficiency on Copper and Zinc Distributions in Five Regions of Male Rat Brain

Changes in Cu and Zn ion levels have been reported in many nervous system disorders such as Alzheimer’s disease, Wilson’s disease and Pick’s disease. The relationship between ion levels and polarization/depolarization of cell membrane is important since ion levels affect the state of polarization and depolarization of the cells. In this study, synaptosomes from different brain areas including cerebellum, hypothalamus, stratum, midbrain and cortex were prepared and the rate of copper and zinc was measured in depolarized or Ca++ deficiency condition. In an interventional study, rat brains were taken out of their skulls immediately after killing them and the synaptosome of various brain areas was prepared according to standard procedures. Prepared synaptosmes were incubated with potassium ion(55m molar) or EGTA (as calcium chelators). At the end of incubation period synaptosomes were burnt to ashes and remaining Zn and Cu were measured. The results were analyzed by student’s t-test and significant values were calculated and reported. Based on the obtained results it was found out that in the presence of K+, the level of remaining copper in synaptosome of midbrain and cortex was higher than that of controls while Cu and Zn levels in cerebellum, hypothalamus and stratum were lower compared with those of controls. In this condition, the amount of remaining Zn was higher in cerebellum comparing with that of controls, while it was lower in hypothalamus, midbrain, stratum and cortex. In samples treated with EGTA the amount of Cu in cerebella, hypothalamus and stratum regions were higher but hypothalamus and midbrain showed decreased level. This study showed that there is a relationship between neural activity and Cu and Zn content of neural cells therefore, a disequilibrium in each ion level can lead to neural activity disorders presenting as a variety of neural disorders.