scholarly journals Short echo-time Magnetic Resonance Spectroscopy in ALS, simultaneous quantification of glutamate and GABA at 3 T

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
J. U. Blicher ◽  
S. F. Eskildsen ◽  
T. G. Stærmose ◽  
A. T. Møller ◽  
K. Figlewski ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Magnetic Resonance Spectroscopy ◽  
Healthy Subjects ◽  
Primary Motor Cortex ◽  
Spin Echo ◽  
Occipital Lobe ◽  
Resonance Spectroscopy ◽  
Neuronal Marker ◽  
Cortical Hyperexcitability

AbstractCortical hyperexcitability has been found in early Amyotrophic Lateral Sclerosis (ALS) and is hypothesized to be a key factor in pathogenesis. The current pilot study aimed to investigate cortical inhibitory/excitatory balance in ALS using short-echo Magnetic Resonance Spectroscopy (MRS). Patients suffering from ALS were scanned on a 3 T Trio Siemens MR scanner using Spin Echo Full Intensity Acquired Localized (SPECIAL) Magnetic Resonance Spectroscopy in primary motor cortex and the occipital lobe. Data was compared to a group of healthy subjects. Nine patients completed the scan. MRS data was of an excellent quality allowing for quantification of a range of metabolites of interest in ALS. In motor cortex, patients had Glutamate/GABA and GABA/Cr- ratios comparable to healthy subjects. However, Glutamate/Cr (p = 0.002) and the neuronal marker N-acetyl-aspartate (NAA/Cr) (p = 0.034) were low, possibly due to grey-matter atrophy, whereas Glutathione/Cr (p = 0.04) was elevated. In patients, NAA levels correlated significantly with both hand strength (p = 0.027) and disease severity (p = 0.016). In summary SPECIAL MRS at 3 T allows of reliable quantification of a range of metabolites of interest in ALS, including both excitatory and inhibitory neurotransmitters. The method is a promising new technique as a biomarker for future studies on ALS pathophysiology and monitoring of disease progression.

scholarly journals GABA and primary motor cortex inhibition in young and older adults: a multimodal reliability study

2017 ◽  
Vol 118 (1) ◽  
pp. 425-433 ◽  
Author(s):  
Ronan A. Mooney ◽  
John Cirillo ◽  
Winston D. Byblow
Keyword(s):  
Older Adults ◽  
Magnetic Resonance ◽  
Motor Cortex ◽  
Magnetic Resonance Spectroscopy ◽  
Healthy Aging ◽  
Primary Motor Cortex ◽  
Silent Period ◽  
Resonance Spectroscopy ◽  
Gaba Concentration ◽  
Threshold Tracking

The effects of healthy aging on γ-aminobutyric acid (GABA) within primary motor cortex (M1) remain poorly understood. Studies have reported contrasting results, potentially due to limitations with the common assessment technique. The aim of the present study was to investigate the effect of healthy aging on M1 GABA concentration and neurotransmission using a multimodal approach. Fifteen young and sixteen older adults participated in this study. Magnetic resonance spectroscopy (MRS) was used to measure M1 GABA concentration. Single-pulse and threshold-tracking paired-pulse transcranial magnetic stimulation (TMS) protocols were used to examine cortical silent period duration, short- and long-interval intracortical inhibition (SICI and LICI), and late cortical disinhibition (LCD). The reliability of TMS measures was examined with intraclass correlation coefficient analyses. SICI at 1 ms was reduced in older adults (15.13 ± 2.59%) compared with young (25.66 ± 1.44%; P = 0.002). However, there was no age-related effect for cortical silent period duration, SICI at 3 ms, LICI, or LCD (all P > 0.66). The intersession reliability of threshold-tracking measures was good to excellent for both young (range 0.75–0.96) and older adults (range 0.88–0.93). Our findings indicate that extrasynaptic inhibition may be reduced with advancing age, whereas GABA concentration and synaptic inhibition are maintained. Furthermore, MRS and threshold-tracking TMS provide valid and reliable assessment of M1 GABA concentration and neurotransmission, respectively, in young and older adults. NEW & NOTEWORTHY γ-Aminobutyric acid (GABA) in primary motor cortex was assessed in young and older adults using magnetic resonance spectroscopy and threshold-tracking paired-pulse transcranial magnetic stimulation. Older adults exhibited reduced extrasynaptic inhibition (short-interval intracortical inhibition at 1 ms) compared with young, whereas GABA concentration and synaptic inhibition were similar between age groups. We demonstrate that magnetic resonance spectroscopy and threshold-tracking provide valid and reliable assessments of primary motor cortex GABA concentration and neurotransmission, respectively.

scholarly journals Vitamin D and Caudal Primary Motor Cortex: A Magnetic Resonance Spectroscopy Study

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e87314 ◽  
Author(s):  
Cedric Annweiler ◽  
Olivier Beauchet ◽  
Robert Bartha ◽  
Vladimir Hachinski ◽  
Manuel Montero-Odasso ◽  
...  
Keyword(s):  
Vitamin D ◽  
Magnetic Resonance ◽  
Motor Cortex ◽  
Magnetic Resonance Spectroscopy ◽  
Primary Motor Cortex ◽  
Resonance Spectroscopy ◽  
Spectroscopy Study ◽  
Magnetic Resonance Spectroscopy Study

scholarly journals Sequential Finger-tapping Learning Mediated by the Primary Motor Cortex and Fronto-parietal Network: A Combined MRI-MRS Study

2021 ◽  
Author(s):  
Shuki Maruyama ◽  
Masaki Fukunaga ◽  
Sho K. Sugawara ◽  
Yuki H. Hamano ◽  
Tetsuya Yamamoto ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Motor Learning ◽  
Cognitive Control ◽  
Primary Motor Cortex ◽  
Local Variation ◽  
Finger Tapping ◽  
Resonance Spectroscopy ◽  
Parietal Region ◽  
Sensorimotor Network

Abstract The primary motor cortex (M1) is crucial for motor learning. However, the interaction of the M1 with other brain areas during motor learning remains unclear. We hypothesized that the fronto-parietal execution network (FPN) provides the learning-related information that is crucial for flexible cognitive control required for practice. We assessed the network-level changes during sequential finger-tapping learning “as fast and as accurately as possible”, by combining magnetic resonance spectroscopy, task functional magnetic resonance imaging (fMRI), and resting-state fMRI methods using a 7T MR machine. An increase in the glutamate/GABA ratio in the right M1 was positively correlated with task performance improvement. There was a motor learning-related increase in preparatory activity in the fronto-parietal region, with an overlap between the FPN and sensorimotor network (SMN). The learning-related increments in M1-seeded functional connectivity with the FPN, but not the SMN, were positively correlated with changes in the glutamate/GABA ratio in M1. These connectivity changes were more prominent in the parietal region than in the frontal region. Our findings indicate that motor learning driven by cognitive control is associated with local variation in the excitatory-inhibitory balance in the M1 that reflects remote connectivity with the FPN, thereby representing the formation of declarative procedural skills.

scholarly journals Cognitive control affects motor learning through local variations in GABA within the primary motor cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuki Maruyama ◽  
Masaki Fukunaga ◽  
Sho K. Sugawara ◽  
Yuki H. Hamano ◽  
Tetsuya Yamamoto ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Motor Learning ◽  
Cognitive Control ◽  
Primary Motor Cortex ◽  
Resonance Spectroscopy ◽  
Motor Sequence ◽  
Sensorimotor Network ◽  
Preparatory Activity ◽  
The Right

AbstractThe primary motor cortex (M1) is crucial for motor learning; however, its interaction with other brain areas during motor learning remains unclear. We hypothesized that the fronto-parietal execution network (FPN) provides learning-related information critical for the flexible cognitive control that is required for practice. We assessed network-level changes during sequential finger tapping learning under speed pressure by combining magnetic resonance spectroscopy and task and resting-state functional magnetic resonance imaging. There was a motor learning-related increase in preparatory activity in the fronto-parietal regions, including the right M1, overlapping the FPN and sensorimotor network (SMN). Learning-related increases in M1-seeded functional connectivity with the FPN, but not the SMN, were associated with decreased GABA/glutamate ratio in the M1, which were more prominent in the parietal than the frontal region. A decrease in the GABA/glutamate ratio in the right M1 was positively correlated with improvements in task performance (p = 0.042). Our findings indicate that motor learning driven by cognitive control is associated with local variations in the GABA/glutamate ratio in the M1 that reflects remote connectivity with the FPN, representing network-level motor sequence learning formations.

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