The role of GABAergic modulation in motor function related neuronal network activity

The effects of elevated endogenous GABA levels on movement-related network oscillations

“…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 GABA A receptor mediated process while PMBR may be GABA B receptor mediated.…”

Whole-brain functional connectivity increases with extended duration of focal epileptiform activity

“…areas in our study was surprising, and raises several questions. Increases in beta activity have been seen in areas of increased GABAergic modulation (particularly with GABA-A receptor activation), thought to reflect increased inhibitory interneuron activity [4,15]. These findings have been previously demonstrated with the administration of GABA-A agonists such as diazepam [15], which is also utilized prominently as an antiepileptic rescue medication.…”

Cortical beta oscillations and motor thresholds differ across the spectrum of post-stroke motor impairment, a preliminary MEG and TMS study

“…This suggests that beta-ERS is sensitive to global levels of corticomotor excitability post-stroke, and that the integrity of descending motor pathways such as the corticospinal tract, which are known to be important for the presence of MEPs (Stinear et al, 2007), may also influence the presence of a clearly identifiable beta-ERS. Magnetic resonance spectroscopy (Gaetz et al, 2011) and experimental pharmacological modulation of inhibitory neurotransmitter GABA (Hall, et al, 2011;Muthukumaraswamy et al, 2013) have demonstrated a positive association between beta-ERS strength and resting GABA levels. Thus beta-ERS may represent a decrease in cortical excitability and/or active inhibition following task execution (Pfurtscheller et al, 1996;Salmelin et al, 1995) so that a reduced or absent beta-ERS could be interpreted as disinhibition or increased excitability within the cortex.…”

“…A rebound event-related synchronisation (ERS) or increase in beta power above baseline is typically observed following movement (Pfurtscheller et al, 1996). Pharmacological (Hall et al, 2011;Muthukumaraswamy et al, 2013) and TMS (Aono et al, 2013;Chen et al, 1998;Takemi et al, 2013) studies suggest that the strength and peak frequency of beta oscillations are related to cortical excitability.…”