title: Monosodium glutamate, a food additive, induces depressive-like and anxiogenic-like behaviors in young rats.
abstract: Monosodium glutamate (MSG) has been the target of research due to its toxicological effects.
  
  
  OBJECTIVE
  We investigated the depressive- and anxiogenic-like behaviors in rats exposed to neonatal subcutaneous injection of MSG. The involvement of the serotonergic system, by measuring [(3)H] serotonin (5-HT) uptake in cerebral cortices, and the hypothalamic pituitary adrenal (HPA) axis, by determining serum adrenocorticotropic hormone (ACTH) and corticosterone levels, was also examined.
  
  
  METHODS
  Male and female newborn Wistar rats were divided into control and MSG groups, which received, respectively, a daily subcutaneous injection of saline (0.9%) or MSG (4 g/kg/day) from the 1st to 5th postnatal day. The behavioral tests [spontaneous locomotor activity, contextual fear conditioning, and forced swimming test (FST)] were performed from the 60th to 64th postnatal day. MSG-treated animals showed alteration in the spontaneous locomotor activity, an increase in the number of fecal pellets and the number of animal's vocalizations and urine occurrence, and a decrease in the grooming time.
  
  
  RESULTS
  The MSG exposure increased the immobility time in the FST and the freezing reaction in the contextual fear conditioning. Additionally, MSG treatment increased the [(3)H]5-HT uptake in the cerebral cortices of rats and induced a deregulation of HPA axis function (by increasing serum ACTH and corticosterone levels).
  
  
  CONCLUSIONS
  In conclusion MSG-treated rats are more susceptible to develop anxiogenic- and depressive-like behaviors, which could be related to a dysfunction in the serotonergic system.
authors.affiliation: Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil.
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Quines
authors.affiliation: Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil.
authors.forename: Suzan G
authors.initials: SG
authors.lastname: Rosa
authors.affiliation: Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil.
authors.forename: Juliana T
authors.initials: JT
authors.lastname: Da Rocha
authors.affiliation: Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil.
authors.forename: Bibiana M
authors.initials: BM
authors.lastname: Gai
authors.affiliation: Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil.
authors.forename: Cristiani F
authors.initials: CF
authors.lastname: Bortolatto
authors.affiliation: Departamento de Ciências da Saúde, Universidade Luterana do Brasil, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Marta Maria M F
authors.initials: MM
authors.lastname: Duarte
authors.affiliation: Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil. Electronic address: criswn@quimica.ufsm.br.
authors.forename: Cristina W
authors.initials: CW
authors.lastname: Nogueira
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001008:Anxiety Disorders / Q000139:chemically induced* / Q000378:metabolism; D001522:Behavior, Animal / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects; D003345:Corticosterone / Q000378:metabolism; D003866:Depressive Disorder / Q000139:chemically induced* / Q000378:metabolism; D005239:Fear / Q000187:drug effects; D005260:Female; D005421:Flavoring Agents / Q000633:toxicity*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism; D007279:Injections, Subcutaneous; D008124:Locomotion / Q000187:drug effects; D008297:Male; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism; D012970:Sodium Glutamate / Q000633:toxicity*; D013550:Swimming / Q000502:physiology
chemical_list: D005421:Flavoring Agents; D012701:Serotonin; D000324:Adrenocorticotropic Hormone; D012970:Sodium Glutamate; D003345:Corticosterone
keywords: Anxiogenic-like behavior; Depressive-like behavior; HPA axis; Monosodium glutamate; Serotonin