Increased occlusal vertical dimension induces cortical plasticity in the rat face primary motor cortex.
Behav Brain Res
; 228(2): 254-60, 2012 Mar 17.
Article
em En
| MEDLINE
| ID: mdl-22123413
ABSTRACT
Previous studies have demonstrated that functional plasticity in the primary motor cortex (M1) is related to motor-skill learning and changes in the environment. Increased occlusal vertical dimension (iOVD) may modulate mastication, such as in the masticatory cycle, and the firing properties of jaw-muscle spindles. However, little is known about the changes in motor representation within the face primary motor cortex (face-M1) after iOVD. The purpose of the present study was to determine the effect of iOVD on the face-M1 using intracortical microstimulation (ICMS). In an iOVD group, the maxillary molars were built-up by 2mm with acrylic. The electromyographic (EMG) activities from the left (LAD) and right (RAD) anterior digastric (AD), masseter and genioglossus (GG) muscles elicited by ICMS within the right face-M1 were recorded 1, 2 and 8 weeks after iOVD. IOVD was associated with a significant increase in the number of sites within the face-M1 from which ICMS evoked LAD and/or GG EMG activities, as well as a lateral shift in the center of gravity of the RAD and LAD muscles at 1 and 2 weeks, but not at 8 weeks. These findings suggest that a time-dependent neuroplastic change within the rat face-M1 occurs in association with iOVD. This may be related to the animal's ability to adapt to a change in the oral environment.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Dimensão Vertical
/
Músculos Faciais
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Córtex Motor
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Plasticidade Neuronal
Limite:
Animals
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article