Neonatal exposure to monosodium glutamate results in dysmorphology of orofacial lower motor neurons
| Autor: | J. Esper, Randy J. Kulesza, S. Laroia, C. Kupelian, L. Foran |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
medicine.medical_specialty
Histology Monosodium glutamate Excitotoxicity 010501 environmental sciences Biology medicine.disease_cause 01 natural sciences 03 medical and health sciences chemistry.chemical_compound symbols.namesake 0302 clinical medicine Internal medicine medicine Neurotransmitter 0105 earth and related environmental sciences Neurodegeneration Glutamate receptor Glutamic acid medicine.disease Endocrinology nervous system chemistry Anesthesia Nissl body symbols Brainstem Anatomy 030217 neurology & neurosurgery |
| Zdroj: | Folia morphologica. 76(4) |
| ISSN: | 0015-5659 |
| Popis: | Glutamate is the most abundant excitatory neurotransmitter in the central nervous system, and is stored and released by both neurons and astrocytes. Despite the important role of glutamate as a neurotransmitter, high levels of extracellular glutamate can result in excitotoxicity and apoptosis. Monosodium glutamate (MSG) is a naturally occurring sodium salt of glutamic acid that is used as a flavour enhancer in many processed foods. Neonatal exposure to MSG has been shown to result in neurodegeneration in several forebrain regions, characterised by neuronal loss and neuroendocrine abnormalities. However, the brainstem effects of neonatal MSG exposure have not been investigated. It is therefore hypothesized that MSG exposure during the early postnatal period would impact brainstem lower motor neurons involved in feeding behaviour. The effect of neonatal MSG exposure on brainstem lower motor neurons was investigated by exposing rat pups to either 4 mg/g MSG or saline from postnatal day (P) 4 through 10. On P28, brains were preserved by vascular perfusion with fixative, frozen sectioned and stained for Nissl substance. The number, size and shape of brainstem motor neurons were compared between MSG and saline-exposed animals. MSG exposure had no impact on the total number of neurons in the nuclei examined. However, MSG exposure was associated with a significant increase in the number of round somata in both the trigeminal and facial nuclei. Furthermore, MSG exposure resulted in significantly smaller neurons in all motor nuclei examined. These results suggest that neonatal exposure to MSG impacts the development of brainstem lower motor neurons which may impact feeding and swallowing behaviours in young animals. |
| Databáze: | OpenAIRE |
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