Monosodium glutamate (MSG), a flavor enhancer used in food, administered to neonatal rats causes neuronal lesions and leads to anxiety when adulthood.
Aims: We investigated the anxiolytic-like effect of diphenyl diselenide (PhSe)2 and its mechanisms on anxiety induced by MSG.
Main methods: Neonatal male and female Wistar rats received a subcutaneous injection of saline (0.9%) or MSG (4 g/kg/day) from the 1st to 10th postnatal day. At 60 days of life, the rats received (PhSe)2 (1mg/kg/day) or vehicle by the intragastric route for 7 days. The spontaneous locomotor activity (LAM), elevated plus maze test (EPM) and contextual fear conditioning test (CFC) as well as neurochemical ([(3)H]GABA and [(3)H]5-HT uptake) and molecular analyses (Akt and p-Akt and BDNF levels) were carried out after treatment with (PhSe)2.
Key findings: Neonatal exposure to MSG increased all anxiogenic parameters in LAM, EPM and CFC tests. MSG increased GABA and 5-HT uptake in hippocampus of rats, without changing uptake in cerebral cortex. The levels of BDNF and p-Akt were reduced in hippocampus of rats treated with MSG. The administration of (PhSe)2 to rats reversed all behavioral anxiogenic parameters altered by MSG. The increase in hippocampal GABA and 5-HT uptake induced by MSG was reversed by (PhSe)2. (PhSe)2 reversed the reduction in hippocampal BDNF and p-Akt levels induced by MSG.
Significance: In conclusion, the anxiolytic-like action of (PhSe)2 in rats exposed to MSG during their neonatal period is related to its modulation of hippocampal GABA and 5-HT uptake as well as the BDNF-Akt pathway.
Keywords: Anxiety; BDNF; Diphenyl diselenide; GABA; Monosodium glutamate; Serotonin.
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