GABA and glutamate levels in occlusal splint-wearing males with possible bruxism

Shalmali Dharmadhikari, Laura M. Romito, Mario Dzemidzic, Ulrike Dydak, Jun Xu, Cynthia L. Bodkin, Shalini Manchanda, Kenneth E. Byrd

Research output: Contribution to journalArticle

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Abstract

Objective: The inhibitory neurotransmitter γ-aminobutyric acid (GABA) plays an important role in the pathophysiology of anxiety behavioural disorders such as panic disorder and post-traumatic stress disorder and is also implicated in the manifestation of tooth-grinding and clenching behaviours generally known as bruxism. In order to test whether the stress-related behaviours of tooth-grinding and clenching share similar underlying mechanisms involving GABA and other metabolites as do anxiety-related behavioural disorders, we performed a Magnetic Resonance Spectroscopy (MRS) study for accurate, in vivo metabolite quantification in anxiety-related brain regions. Design: MRS was performed in the right hippocampus and right thalamus involved in the hypothalamic-pituitary-adrenal axis system, together with a motor planning region (dorsal anterior cingulate cortex/pre-supplementary motor area) and right dorsolateral prefrontal cortex (DLPFC). Eight occlusal splint-wearing men (OCS) with possible tooth-grinding and clenching behaviours and nine male controls (CON) with no such behaviour were studied. Results: Repeated-measures ANOVA showed significant Group × Region interaction for GABA+ (p = 0.001) and glutamate (Glu) (p = 0.031). Between-group post hoc ANOVA showed significantly lower levels of GABA+ (p = 0.003) and higher levels of Glu (p = 0.002) in DLPFC of OCS subjects. These GABA+ and Glu group differences remained significant (GABA+, p = 0.049; Glu, p = 0.039) after the inclusion of anxiety as a covariate. Additionally, GABA and Glu levels in the DLPFC of all subjects were negatively related (Pearson's r = -0.75, p = 0.003). Conclusions: These findings indicate that the oral behaviours of tooth-grinding and clenching, generally known as bruxism, may be associated with disturbances in brain GABAergic and glutamatergic systems.

Original languageEnglish (US)
Pages (from-to)1021-1029
Number of pages9
JournalArchives of Oral Biology
Volume60
Issue number7
DOIs
StatePublished - Jul 1 2015

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Keywords

  • Anxiety
  • Bruxism
  • GABA
  • Metabolites
  • MRS
  • Pathophysiology

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Cell Biology
  • Dentistry(all)

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