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19 janvier 2018
- handle: 10670/1.9xfb66
- doi: 10.1017/S0007114515003062
Mots-clés
AP action potential GABA γ-aminobutyric acid INaP sodium persistent current Masseter muscle Masticatory efficiency N nourished NMDA N-methyl-d-aspartate NVsnpr trigeminal main sensory nucleus RB regular bursts Trigeminal nucleus U undernourished UndernutritionSujets proches
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Kelli N. Ferraz-Pereira et al., « Neonatal low-protein diet reduces the masticatory efficiency in rats », Papyrus : le dépôt institutionnel de l'Université de Montréal, ID : 10.1017/S0007114515003062
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Résumé
Little is known about the effects of undernutrition on the specific muscles and neuronal circuits involved in mastication. The aim of this study was to document the effects of neonatal low-protein diet on masticatory efficiency. Newborn rats whose mothers were fed 17 % (nourished (N), n 60) or 8% (undernourished (U), n 56) protein were compared. Their weight was monitored and their masticatory jaw movements were video-recorded. Whole-cell patch-clamp recordings were performed in brainstem slice preparations to investigate the intrinsic membrane properties and N-methyl-Daspartate- induced bursting characteristics of the rhythmogenic neurons (N, n 43; U, n 39) within the trigeminal main sensory nucleus (NVsnpr). Morphometric analysis (N, n 4; U, n 5) were conducted on masseteric muscles serial cross-sections. Our results showed that undernourished animals had lower numbers of masticatory sequences (P=0·049) and cycles (P=0·045) and slower chewing frequencies (P=0·004) (N, n 32; U, n 28). Undernutrition reduced body weight but had little effect on many basic NVsnpr neuronal electrophysiological parameters. It did, however, affect sag potentials (P