The effects of sodium benzoate exposure on learning and neurobehavior during the prepubertal period in rats

Abstract Objectives Exposure to food additives, especially during the critical development period, has been associated with some behavioral disorders and learning difficulties in childhood. In this study, we aimed to evaluate the impact of sodium benzoate (NaB) on learning and neurobehavior in prepubertal rats. Methods 42 male rats (4-week-old) were divided into three groups as the control (CG), experiment 1 (NaB-ADI (acceptable daily intake) dose, Exp1G), and experiment 2 (NaB-NOAEL (no observed adverse effect level) dose, Exp2G) groups and NaB was administered by oral gavage for six weeks. Changes in learning, memory, motor activity and neurobehavior were evaluated by Morris water maze and open field tests. At the end of the experiment, rats’ hippocampi were extracted; NR1, NR2A, NR2B, and nAChRα7 receptor concentrations and mRNA expressions were determined. Results Neurobehavioral tests supported the possibility of increased anxiety and decreased motivation in the Exp1G. Also, molecular tests showed that NR2B receptor protein and mRNA expression levels significantly increased in Exp2G compared to CG. Conclusions Our study showed that NaB administration in the prepubertal period may cause increased anxiety, decreased motivation, and attention with ADI dose. Furthermore, NOAEL dose administration may lead to an increase in NR2B receptor levels. In light of these results, NaB consumption in childhood may affect hippocampal functions related to learning and neurobehavior.