The investigation of the role of nitric oxide system in the spatial memory of rats in experimental model of multiple sclerosis

Multiple sclerosis (MS (is one of the chronic autoimmune diseases of the central nervous system with unknown etiology. Nitric oxide (NO) as a free radical has contradictory effect on the central nervous system and on MS disease. Nitric oxide is one of the distractive factors of the immune system and is a factor in the destruction of myelin. On the other hand، there is an interaction between NO and memory. In this study، the effects of stimulation and suppression of the NO system have been investigated on the memory of MS. In this experimental 35 male rats were anesthetized and a cannula was placed in the hippocampus CA1 region، later were divided into five groups، including: control، sham، Ethidium Bromide (EB) (3 μL / rat)، L-Arginine (15/1 μg / rat and)، EB (3 μL / rat) + L-Arginine (15/1 μg / rat and). The Morris water maze was used for studying the spatial memory. Data analysis was performed by using one way ANOVA. Administration of EB as the inducer of MS disease caused the impairment of spatial memory، L-Arginine improved spatial learning and memory in healthy rats، L-Arginine improves spatial memory in rats with MS. In MS rats، L-Arginine improved the spatial memory. It seems that NO by activating intracellular secondary messenger pathways improves the declined spatial memory during MS disease.