The role of acetylcoline in the effects of different doses of sulphite on learning and memory

Objective: Although the negative effects of sulphite on learning and memory have been known, the information on molecular mechanisms is insufficient. In our study, the effects of different doses of sulfite, which is known to have neurotoxic effects, on learning and memory were evaluated by behavioral experiments and LTP recordings. The role of ACh in the effects of sulfite on learning and memory, and its possible mediating mechanisms were investigated. Method: Wistar rats were divided into three groups. Distilled water was given control group, sodium metabisulphite at dose of 100 mg/kg and 260 mg/kg was given the sulphite groups for 35 days by gavage. Behavioral changes were evaluated using the Morris Water Maze, Open Field and New Object Recognition test. After LTP recordings were taken, hippocampi were removed. ACh, Arc and synapsin levels, AChE and ChAT enzyme activities were measured in hippocampus tissues. Results: It has been observed that the total distance and average velocity performed in the Open Field test and Morris Water Maze prop trial were increased, the discrimination index in the New Object Recognition test decreased in the sulphite applied groups. While AChE activity decreased in the sulphite applied groups, ACh levels and ChAT activity increased. In addition, it has been observed that the EPSP slope and PS amplitude of the field potentials obtained in sulphite applied groups decreased. This deterioration was found to be accompanied by a decrease in Arc and synapsin 1 expression. Conclusion: In conclusion, it has been shown that sulphite intake in adults impairs learning and spatial memory, this impairment may be mediated by the cholinergic signal pathway. It is considered that the decrease in Arc and synapsin expression may play a role in the mechanism underlying the impairment in LTP responses caused by toxicity.