The effects of Intracerebellumal Injection of Estrogen on Anxiety-like Behavior and Parameters of Antioxidant System following Ethidium Bromide Injection in rat

Demyelination by Ethidium bromide is one of the ways that is usually used for preparing experimental models of MS. Treatment with estrogen protects oligodendrocyts from cell poisoning and stops lipidic peroxidation. The aim of this study is the evaluation of the effects of estrogen on anxiety like behavior and stress oxidative parameters after inducing demyelination by ethidium bromide to the cortex of cerebellum in rats. Induction of demyelination was carried out in cerebellum cortex by direct injection of Ethidium Bromide (EB) (0. 01%). One week after injection of EB، animals were treated with two doses of estrogen (2µg/μl and 4µg/μl) for 3 days. After the treatment stage، characteristics of anxiety were assessed by using Elevated plus Maze; moreover، the parameters of stress oxidative were evaluated. One-way Analysis of Variance (ANOVA) was performed. The results of this study showed that Open Arm Entry percentage and open arm time (anxiety index) in rats with estrogen treatment was significant relative to Ethidium Bromide group (p<0. 01); in addition، activity value of glutathione peroxidase and catalase showed significant increase compared to Ethidium Bromide group. Microinjection of estrogen can decrease anxiety as well as oxidative stress.