scholarly journals Continuous and intermittent theta burst stimulation to the visual cortex do not alter GABA and glutamate concentrations measured by magnetic resonance spectroscopy

2022 ◽  
Author(s):  
Karlene S. Stoby ◽  
Sara A. Rafique ◽  
Georg Oeltzschner ◽  
Jennifer K. E. Steeves
Keyword(s):  
Visual Cortex ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Theta Burst

scholarly journals Intermittent Theta-Burst Stimulation Transcranial Magnetic Stimulation Increases GABA in the Medial Prefrontal Cortex: A Preliminary Sham-Controlled Magnetic Resonance Spectroscopy Study in Acute Bipolar Depression

2021 ◽  
Vol 12 ◽  
Author(s):  
Chad Diederichs ◽  
Marilena M. DeMayo ◽  
Jaeden Cole ◽  
Lakshmi N. Yatham ◽  
Ashley D. Harris ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Magnetic Stimulation ◽  
Rating Scale ◽  
Bipolar Depression ◽  
Resonance Spectroscopy ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Theta Burst

Background: Magnetic resonance spectroscopy (MRS) has been used to identify gamma-aminobutyric acid (GABA) alterations in mood disorders, particularly in the medial prefrontal cortex (mPFC) where decreased concentrations have been associated with anhedonia. In major depressive disorder (MDD), prior work suggests that repetitive transcranial magnetic stimulation (rTMS) increases mPFC GABA concentrations proportional to antidepressant response. To our knowledge, this has not been examined in acute bipolar depression.Methods: As part of a multicentre 4-week randomized, double-blind, sham-controlled trial using intermittent theta-burst stimulation (iTBS) of the left dorsolateral prefrontal cortex (DLPFC) in individuals with acute bipolar depression, we quantified mPFC GABA and Glx (glutamate+glutamine) concentrations using a 3T MRS scan at baseline and after the intervention. Depressive symptoms were measured using the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating Scale-17 (HRDS-17), and anhedonia was measured using the Snaith-Hamilton Pleasure Scale (SHAPS).Results: The trial was terminated for futility and magnetic resonance spectroscopy data was acquired for 18 participants. At baseline, there were no associations between GABA or Glx concentrations and anhedonia, however GABA was negative correlated with depressive symptom severity on the HRDS-17. Compared to the sham-iTBS group, participants receiving active-iTBS had a significant increase in mPFC GABA concentrations. This was unrelated to antidepressant outcomes or improvements in anhedonia.Conclusion: Our data suggests that iTBS targeting the DLPFC is associated with physiological changes in the mPFC. In acute bipolar depression, our preliminary data suggests that mPFC GABA is dissociated from antidepressant iTBS treatment outcomes and anhedonia.

scholarly journals Neurochemical Effects of Theta Burst Stimulation as Assessed by Magnetic Resonance Spectroscopy

2009 ◽  
Vol 101 (6) ◽  
pp. 2872-2877 ◽  
Author(s):  
C. J. Stagg ◽  
M. Wylezinska ◽  
P. M. Matthews ◽  
H. Johansen-Berg ◽  
P. Jezzard ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Primary Motor Cortex ◽  
Control Site ◽  
Significant Inhibition ◽  
Resonance Spectroscopy ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
New Hypothesis ◽  
Theta Burst

Continuous theta burst stimulation (cTBS) is a novel transcranial stimulation technique that causes significant inhibition of synaptic transmission for ≤1 h when applied over the primary motor cortex (M1) in humans. Here we use magnetic resonance spectroscopy to define mechanisms mediating this inhibition by noninvasively measuring local changes in the cortical concentrations of γ-aminobutyric acid (GABA) and glutamate/glutamine (Glx). cTBS to the left M1 led to an increase in GABA compared with stimulation at a control site without significant change in Glx. This direct evidence for increased GABAergic interneuronal activity is framed in terms of a new hypothesis regarding mechanisms underlying cTBS.

scholarly journals Spatial inhibition and the visual cortex: A magnetic resonance spectroscopy imaging study

2011 ◽  
Vol 49 (5) ◽  
pp. 830-838 ◽  
Author(s):  
R. Salo ◽  
T.E. Nordahl ◽  
M.H. Buonocore ◽  
Y.T. Natsuaki ◽  
C.D. Moore ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Imaging Study ◽  
Resonance Spectroscopy ◽  
Magnetic Resonance Spectroscopy Imaging

scholarly journals Effect of Photic Stimulation on Human Visual Cortex Lactate and Phosphates Using 1H and 31P Magnetic Resonance Spectroscopy

1992 ◽  
Vol 12 (4) ◽  
pp. 584-592 ◽  
Author(s):  
D. Sappey-Marinier ◽  
G. Calabrese ◽  
G. Fein ◽  
J. W. Hugg ◽  
C. Biggins ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Visual Cortex ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Brain Activity ◽  
Atp Synthesis ◽  
High Energy ◽  
Significant Rise ◽  
Photic Stimulation ◽  
Resonance Spectroscopy

Previous animal and human studies showed that photic stimulation (PS) increased cerebral blood flow and glucose uptake much more than oxygen consumption, suggesting selective activation of anaerobic glycolysis. In the present studies, image-guided 1H and 31P magnetic resonance spectroscopy (MRS) was used to monitor the changes in lactate and high-energy phosphate concentrations produced by PS of visual cortex in six normal volunteers. PS initially produced a significant rise (to 250% of control, p < 0.01) in visual cortex lactate during the first 6.4 min of PS, followed by a significant decline ( p = 0.01) as PS continued. The PCr/Pi ratios decreased significantly from control values during the first 12.8 min of PS ( p < 0.05), and the pH was slightly increased. The positive P100 deflection of the visual evoked potential recorded between 100 and 172 ms after the strobe was significantly decreased from control at 12.8 min of PS ( p < 0.05). The finding that PS caused decreased PCr/Pi is consistent with the view that increased brain activity stimulated ATPase, causing a rise in ADP that shifted the creatine kinase reaction in the direction of ATP synthesis. The rise in lactate together with an increase in pH suggest that intracellular alkalosis, caused by the shift of creatine kinase, selectively stimulated glycolysis.

scholarly journals Continuous Theta Burst Stimulation to the Secondary Visual Cortex Does Not Impair Central Vision in Humans

2021 ◽  
Author(s):  
Carly A Lasagna ◽  
Stephan F Taylor ◽  
Taraz Lee ◽  
Saige Rutherford ◽  
Tristan Greathouse ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Bayes Factor ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Central Vision ◽  
Central Visual Field ◽  
Stimulus Detection ◽  
Theta Burst ◽  
Continuous Theta Burst Stimulation

Background: Continuous theta burst stimulation (cTBS) is a powerful form of repetitive transcranial magnetic stimulation capable of suppressing cortical excitability for up to 50 minutes. A growing number of studies have applied cTBS to the visual cortex in human subjects to investigate the neural dynamics of visual processing, but few studies have specifically examined its effects on central vision, which has crucial implications for safety and inference on downstream cognitive effects. Objective: Assess the safety of offline, neuronavigated cTBS to V2 by examining its effects on central vision performance on a computerized stimulus detection task. Methods: In a single-blind, randomized sham-controlled, crossover study, 17 healthy adults received cTBS and sham to V2 two weeks apart. Their central vision (≤8°) was tested at 1-minute (T1) and again at 50-minutes (T50) post-stimulation. Effects of condition (cTBS vs. sham) and time (T1 vs. T50) on accuracy and reaction time were examined using Bayes factor. Results: Bayes factor results suggested that cTBS did not impair stimulus detection over the entire central visual field nor subfields at T1 or T50. Conclusions: Our results offer the first explicit evidence supporting that cTBS applied to V2 does not create blind spots in the central visual field in humans. Any subtler changes to vision and downstream visual perception should be investigated in future studies.

scholarly journals Functional diffusion-weighted magnetic resonance spectroscopy of the human primary visual cortex at 7 T

2012 ◽  
Vol 69 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Francesca Branzoli ◽  
Aranee Techawiboonwong ◽  
Hermien Kan ◽  
Andrew Webb ◽  
Itamar Ronen
Keyword(s):  
Visual Cortex ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Primary Visual Cortex ◽  
Resonance Spectroscopy ◽  
Diffusion Weighted
Sign in / Sign up

Export Citation Format

Share Document