title: Neonatal exposure to monosodium glutamate induces morphological alterations in suprachiasmatic nucleus of adult rat.
abstract: Neonatal exposure to monosodium glutamate (MSG) induces circadian disorders in several physiological and behavioural processes regulated by the suprachiasmatic nucleus (SCN). The objective of this study was to evaluate the effects of neonatal exposure to MSG on locomotor activity, and on morphology, cellular density and expression of proteins, as evaluated by optical density (OD), of vasopressin (VP)-, vasoactive intestinal polypeptide (VIP)- and glial fibrillary acidic protein (GFAP)-immunoreactive cells in the SCN. Male Wistar rats were used: the MSG group was subcutaneously treated from 3 to 10 days of age with 3.5 mg/g/day. Locomotor activity was evaluated at 90 days of age using 'open-field' test, and the brains were processed for immunohistochemical studies. MSG exposure induced a significant decrease in locomotor activity. VP- and VIP-immunoreactive neuronal densities showed a significant decrease, while the somatic OD showed an increase. Major axes and somatic area were significantly increased in VIP neurons. The cellular and optical densities of GFAP-immunoreactive sections of SCN were significantly increased. These results demonstrated that newborn exposure to MSG induced morphological alterations in SCN cells, an alteration that could be the basis for behavioural disorders observed in the animals.
authors.affiliation: Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, México D.F., México.
authors.forename: Julio César
authors.initials: JC
authors.lastname: Rojas-Castañeda
authors.affiliation: Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, México D.F., México.|Departamento de Morfología, Facultad de Medicina Veterinaria y Zootécnia, UNAM, México D.F., México.
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Vigueras-Villaseñor
authors.affiliation: Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, México D.F., México.
authors.forename: Margarita
authors.initials: M
authors.lastname: Chávez-Saldaña
authors.affiliation: Laboratorio de Neurotoxicología, Instituto Nacional de Neurología y Neurocirugía, 'Manuel Velasco Suárez', México D.F., México.
authors.forename: Patricia
authors.initials: P
authors.lastname: Rojas
authors.affiliation: Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, México D.F., México.|Departamento de Morfología, Facultad de Medicina Veterinaria y Zootécnia, UNAM, México D.F., México.
authors.forename: Oscar
authors.initials: O
authors.lastname: Gutiérrez-Pérez
authors.affiliation: Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, UNAM, México D.F., México.
authors.forename: Carolina
authors.initials: C
authors.lastname: Rojas
authors.affiliation: Departamento de Biología de la Reproducción, UAM-Iztapalapa, México D.F., México.
authors.forename: Marcela
authors.initials: M
authors.lastname: Arteaga-Silva
mesh_terms: D000818:Animals; D002452:Cell Count; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D017208:Rats, Wistar; D012970:Sodium Glutamate / Q000494:pharmacology*; D013493:Suprachiasmatic Nucleus / Q000187:drug effects* / Q000254:growth & development*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism; D014667:Vasopressins / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D014667:Vasopressins; D014660:Vasoactive Intestinal Peptide; D012970:Sodium Glutamate
keywords: glial fibrillary acidic protein; locomotor activity; monosodium glutamate; suprachiasmatic nucleus; vasoactive intestinal polypeptide; vasopressin