1. Inhibition, Disinhibition, and the Control of Action in Tourette Syndrome 
Georgina M. Jackson, Amelia Draper, Katherine Dyke, Sophia E. Pépés, Stephen R. Jackson 
Trends in Cognitive Sciences 
Volume 19, Issue 11, Pages (November 2015)
DOI: /j.tics
Copyright © 2015 The Authors Terms and Conditions

2. Figure 1
(A) Illustrates the altered gain in motor excitability [transcranial magnetic stimulation (TMS)-induced muscle response] for a group of adolescents with Tourette syndrome (TS) compared to a matched group of controls [54]. The graph illustrates how the TMS-induced muscle response (the motor evoked potential, MEP) increases at a different rate, in response to increases in TMS stimulator output, for the TS group compared to controls. Error bars are standard error (SE). (B) Illustrates the altered gain in motor excitability (TMS induced muscle response) during the movement preparation period of a Go/NoGo task for a group of adolescents with TS compared to a matched group of controls [58]. Error bars are SEM. (C) Illustrates the association between motor tic severity and the linear slope function, calculated for each TS participant, that describes the rise in motor excitability during the movement preparation period [58]. Reproduced from [58] with permission from John Wiley and Sons.
Trends in Cognitive Sciences  , DOI: ( /j.tics )
Copyright © 2015 The Authors Terms and Conditions

3. Figure 2
(A) fMRI BOLD signal change associated with a bimanual sequential finger-thumb opposition task (tap > rest contrast) for a single representative participant [54]. (B) Mean GABA concentration (GABA/NAA ratios) for the TS and control groups measured using MRS within separate V1, M1, and SMA voxels [54]. For the SMA voxel GABA concentrations are elevated relative to controls (* P<0.05). Error bars are standard deviation. (C) Scatter plot showing the negative association (r = −0.63, P<0.01) between individual GABA concentrations in the SMA voxel and fMRI BOLD signal change values within that same voxel [54]. Abbreviations: BOLD, blood oxygen level dependent; GABA, γ-amino butyric acid; M1, primary sensorimotor cortex MRS, magnetic resonance spectroscopy; NAA, N-acetyl aspartate; SMA, supplementary motor area; TS, Tourette syndrome; V1, primary visual cortex.
Trends in Cognitive Sciences  , DOI: ( /j.tics )
Copyright © 2015 The Authors Terms and Conditions

4. Figure I
Illustration of the Physiological Basis for the Release of GABA by Astrocytes. (A) The direction of GABA transport is dependent on concentrations of sodium (Na+) and concentrations of GABA within the intracellular and extracellular spaces. (B) High firing rates that result in low extracellular GABA induce reversal of the GABA transporter. GABA release from astrocytes may activate extrasynaptic GABA-A and GABA-B receptors (Figure reproduced from [60]).
Trends in Cognitive Sciences  , DOI: ( /j.tics )
Copyright © 2015 The Authors Terms and Conditions