Title
The effects of elevated endogenous GABA levels on movement-related network oscillations.
Abstract
The EEG/MEG signal is generated primarily by the summation of the post-synaptic potentials of cortical principal cells. At a microcircuit level, these glutamatergic principal cells are reciprocally connected to GABAergic interneurons and cortical oscillations are thought to be dependent on the balance of excitation and inhibition between these cell types. To investigate the dependence of movement-related cortical oscillations on excitation–inhibition balance, we pharmacologically manipulated the GABA system using tiagabine, which blocks GABA Transporter 1(GAT-1), the GABA uptake transporter and increases endogenous GABA activity. In a blinded, placebo-controlled, crossover design, in 15 healthy participants we administered either 15mg of tiagabine or a placebo. We recorded whole-head magnetoencephalograms, while the participants performed a movement task, prior to, one hour post, three hour post and five hour post tiagabine ingestion. Using time-frequency analysis of beamformer source reconstructions, we quantified the baseline level of beta activity (15–30Hz), the post-movement beta rebound (PMBR), beta event-related desynchronisation (beta-ERD) and movement-related gamma synchronisation (MRGS) (60–90Hz). Our results demonstrated that tiagabine, and hence elevated endogenous GABA levels causes, an elevation of baseline beta power, enhanced beta-ERD and reduced PMBR, but no modulation of MRGS. Comparing our results to recent literature (Hall et al., 2011) we suggest that beta-ERD may be a GABAA receptor mediated process while PMBR may be GABAB receptor mediated.
Year
DOI
Venue
2013
10.1016/j.neuroimage.2012.10.054
NeuroImage
Keywords
Field
DocType
Magnetoencephalography,GABA,Tiagabine,Beta rhythm,Event-related desynchronisation,Gamma oscillations,Motor cortex
GABAergic,Neuroscience,Psychology,Tiagabine,Glutamatergic,GABAA receptor,Beta (finance),Beta Rhythm,GABAB receptor,GABA transporter 1
Journal
Volume
ISSN
Citations 
66
1053-8119
12
PageRank 
References 
Authors
0.87
10
7
Name
Order
Citations
PageRank
Suresh D. Muthukumaraswamy112010.62
J. F. M. Myers2121.21
S. J. Wilson3120.87
David J. Nutt4274.57
Anne Lingford-Hughes5202.72
Krish D. Singh629434.20
K Hamandi7644.81