scholarly journals Quantifying the effects of head movement on magnetic resonance spectroscopy estimates of gamma-aminobutyric acid

2018 ◽  
Author(s):  
Edward D. Cui ◽  
Richard J. Maddock ◽  
Michael H. Buonocore ◽  
Meric Ozturk ◽  
Jong H. Yoon
Keyword(s):  
Clinical Studies ◽  
Head Movement ◽  
Measurement Accuracy ◽  
Group Differences ◽  
Resonance Spectroscopy ◽  
Type I ◽  
Gamma Aminobutyric Acid ◽  
Two Parameters ◽  
True Group

AbstractThere has been keen interest in measuring in vivo GABA. However, GABA signal is low and typically measured using techniques vulnerable to the confounding effects of in-scanner head movement. This issue is particularly problematic for clinical studies since it may lead to Type I or II error in testing for group differences. While solutions to mitigate the effects of movement have been proposed, fundamental and largely unexamined issues are the nature and scale of this effect. We developed a method to quantify and characterize head movement during GABA spectroscopy and found that two parameters of movement, displacement and instantaneous movement, were inversely correlated with and accounted for 12.1% and 20.2% variance of GABA estimates respectively. We conclude that head movement can significantly affect GABA measurements and the application of methods to account for movement may improve of GABA measurement accuracy and the detection of true group differences in clinical studies.

scholarly journals In Vivo Measurement of Neurochemical Abnormalities in the Hippocampus in a Rat Model of Cuprizone-Induced Demyelination

Diagnostics ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 45
Author(s):  
Do-Wan Lee ◽  
Jae-Im Kwon ◽  
Chul-Woong Woo ◽  
Hwon Heo ◽  
Kyung Won Kim ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Rat Model ◽  
Resonance Spectroscopy ◽  
Chow Diet ◽  
Gamma Aminobutyric Acid ◽  
Sprague Dawley ◽  
In Vivo Measurement ◽  
Hippocampal Lesions ◽  
Total Creatine

This study quantitatively measured the changes in metabolites in the hippocampal lesions of a rat model of cuprizone-induced demyelination as detected using in vivo 7 T proton magnetic resonance spectroscopy. Nineteen Sprague Dawley rats were randomly divided into two groups and fed a normal chow diet or cuprizone (0.2%, w/w) for 7 weeks. Demyelinated hippocampal lesions were quantitatively measured using a 7 T magnetic resonance imaging scanner. All proton spectra were quantified for metabolite concentrations and relative ratios. Compared to those in the controls, the cuprizone-induced rats had significantly higher concentrations of glutamate (p = 0.001), gamma-aminobutyric acid (p = 0.019), and glutamate + glutamine (p = 0.001); however, creatine + phosphocreatine (p = 0.006) and myo-inositol (p = 0.001) concentrations were lower. In addition, we found that the glutamine and glutamate complex/total creatine (p < 0.001), glutamate/total creatine (p < 0.001), and GABA/total creatine (p = 0.002) ratios were significantly higher in cuprizone-treated rats than in control rats. Our results showed that cuprizone-induced neuronal demyelination may influence the severe abnormal metabolism in hippocampal lesions, and these responses could be caused by microglial activation, mitochondrial dysfunction, and astrocytic necrosis.

scholarly journals Nicotinamide Mononucleotide Administration Prevents Experimental Diabetes-Induced Cognitive Impairment and Loss of Hippocampal Neurons

2020 ◽  
Vol 21 (11) ◽  
pp. 3756
Author(s):  
Krish Chandrasekaran ◽  
Joungil Choi ◽  
Muhammed Ikbal Arvas ◽  
Mohammad Salimian ◽  
Sujal Singh ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Neuronal Loss ◽  
Memory Deficits ◽  
Diabetic Rats ◽  
Resonance Spectroscopy ◽  
Gamma Aminobutyric Acid ◽  
Sprague Dawley ◽  
Protein Levels ◽  
Nicotinamide Mononucleotide

Diabetes predisposes to cognitive decline leading to dementia and is associated with decreased brain NAD+ levels. This has triggered an intense interest in boosting nicotinamide adenine dinucleotide (NAD+) levels to prevent dementia. We tested if the administration of the precursor of NAD+, nicotinamide mononucleotide (NMN), can prevent diabetes-induced memory deficits. Diabetes was induced in Sprague-Dawley rats by the administration of streptozotocin (STZ). After 3 months of diabetes, hippocampal NAD+ levels were decreased (p = 0.011). In vivo localized high-resolution proton magnetic resonance spectroscopy (MRS) of the hippocampus showed an increase in the levels of glucose (p < 0.001), glutamate (p < 0.001), gamma aminobutyric acid (p = 0.018), myo-inositol (p = 0.018), and taurine (p < 0.001) and decreased levels of N-acetyl aspartate (p = 0.002) and glutathione (p < 0.001). There was a significant decrease in hippocampal CA1 neuronal volume (p < 0.001) and neuronal number (p < 0.001) in the Diabetic rats. Diabetic rats showed hippocampal related memory deficits. Intraperitoneal NMN (100 mg/kg) was given after induction and confirmation of diabetes and was provided on alternate days for 3 months. NMN increased brain NAD+ levels, normalized the levels of glutamate, taurine, N-acetyl aspartate (NAA), and glutathione. NMN-treatment prevented the loss of CA1 neurons and rescued the memory deficits despite having no significant effect on hyperglycemic or lipidemic control. In hippocampal protein extracts from Diabetic rats, SIRT1 and PGC-1α protein levels were decreased, and acetylation of proteins increased. NMN treatment prevented the diabetes-induced decrease in both SIRT1 and PGC-1α and promoted deacetylation of proteins. Our results indicate that NMN increased brain NAD+, activated the SIRT1 pathway, preserved mitochondrial oxidative phosphorylation (OXPHOS) function, prevented neuronal loss, and preserved cognition in Diabetic rats.

scholarly journals In Vivo Metabolism of [1,6-13C2]Glucose Reveals Distinct Neuroenergetic Functionality between Mouse Hippocampus and Hypothalamus

Metabolites ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 50
Author(s):  
Antoine Cherix ◽  
Rajesh Sonti ◽  
Bernard Lanz ◽  
Hongxia Lei
Keyword(s):  
Metabolic Flux ◽  
Aerobic Glycolysis ◽  
Resonance Spectroscopy ◽  
Flux Analysis ◽  
Gamma Aminobutyric Acid ◽  
Atp Production ◽  
Functional Features ◽  
Metabolic Dependence ◽  
The Brain

Glucose is a major energy fuel for the brain, however, less is known about specificities of its metabolism in distinct cerebral areas. Here we examined the regional differences in glucose utilization between the hypothalamus and hippocampus using in vivo indirect 13C magnetic resonance spectroscopy (1H-[13C]-MRS) upon infusion of [1,6-13C2]glucose. Using a metabolic flux analysis with a 1-compartment mathematical model of brain metabolism, we report that compared to hippocampus, hypothalamus shows higher levels of aerobic glycolysis associated with a marked gamma-aminobutyric acid-ergic (GABAergic) and astrocytic metabolic dependence. In addition, our analysis suggests a higher rate of ATP production in hypothalamus that is accompanied by an excess of cytosolic nicotinamide adenine dinucleotide (NADH) production that does not fuel mitochondria via the malate-aspartate shuttle (MAS). In conclusion, our results reveal significant metabolic differences, which might be attributable to respective cell populations or functional features of both structures.

scholarly journals Increased ventricular cerebrospinal fluid lactate in depressed adolescents

2016 ◽  
Vol 32 ◽  
pp. 1-8 ◽  
Author(s):  
K.A.L. Bradley ◽  
X. Mao ◽  
J.A.C. Case ◽  
G. Kang ◽  
D.C. Shungu ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Mitochondrial Dysfunction ◽  
Group Differences ◽  
Resonance Spectroscopy ◽  
Healthy Controls ◽  
Network Function ◽  
Depressed Group ◽  
Total Creatine ◽  
State Feature

AbstractBackgroundMitochondrial dysfunction has been increasingly examined as a potential pathogenic event in psychiatric disorders, although its role early in the course of major depressive disorder (MDD) is unclear. Therefore, the purpose of this study was to investigate mitochondrial dysfunction in medication-free adolescents with MDD through in vivo measurements of neurometabolites using high-spatial resolution multislice/multivoxel proton magnetic resonance spectroscopy.MethodsTwenty-three adolescents with MDD and 29 healthy controls, ages 12–20, were scanned at 3 T and concentrations of ventricular cerebrospinal fluid lactate, as well as N-acetyl-aspartate (NAA), total creatine (tCr), and total choline (tCho) in the bilateral caudate, putamen, and thalamus were reported.ResultsAdolescents with MDD exhibited increased ventricular lactate compared to healthy controls [F(1,41) = 6.98, P = 0.01]. However, there were no group differences in the other neurometabolites. Dimensional analyses in the depressed group showed no relation between any of the neurometabolites and symptomatology, including anhedonia and fatigue.ConclusionsIncreased ventricular lactate in depressed adolescents suggests mitochondrial dysfunction may be present early in the course of MDD; however it is still not known whether the presence of mitochondrial dysfunction is a trait vulnerability of individuals predisposed to psychopathology or a state feature of the disorder. Therefore, there is a need for larger multimodal studies to clarify these chemical findings in the context of network function.

scholarly journals Monitoring the Neurotransmitter Response to Glycemic Changes Using an Advanced Magnetic Resonance Spectroscopy Protocol at 7T

2021 ◽  
Vol 12 ◽  
Author(s):  
Young Woo Park ◽  
Dinesh K. Deelchand ◽  
James M. Joers ◽  
Anjali Kumar ◽  
Alison Bunio Alvear ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Signal To Noise Ratio ◽  
Occipital Cortex ◽  
Quality Data ◽  
Resonance Spectroscopy ◽  
Gamma Aminobutyric Acid ◽  
Signal To Noise ◽  
Noise Ratio

The primary excitatory and inhibitory neurotransmitters glutamate (Glu) and gamma-aminobutyric acid (GABA) are thought to be involved in the response of the brain to changes in glycemia. Therefore, their reliable measurement is critical for understanding the dynamics of these responses. The concentrations of Glu and GABA, as well as glucose (Glc) in brain tissue, can be measured in vivo using proton (1H) magnetic resonance spectroscopy (MRS). Advanced MRS methodology at ultrahigh field allows reliable monitoring of these metabolites under changing metabolic states. However, the long acquisition times needed for these experiments while maintaining blood Glc levels at predetermined targets present many challenges. We present an advanced MRS acquisition protocol that combines commercial 7T hardware (Siemens Scanner and Nova Medical head coil), BaTiO3 dielectric padding, optical motion tracking, and dynamic frequency and B0 shim updates to ensure the acquisition of reproducibly high-quality data. Data were acquired with a semi-LASER sequence [repetition time/echo time (TR/TE) = 5,000/26 ms] from volumes of interest (VOIs) in the prefrontal cortex (PFC) and hypothalamus (HTL). Five healthy volunteers were scanned to evaluate the effect of the BaTiO3 pads on B1+ distribution. Use of BaTiO3 padding resulted in a 60% gain in signal-to-noise ratio in the PFC VOI over the acquisition without the pad. The protocol was tested in six patients with type 1 diabetes during a clamp study where euglycemic (~100 mg/dL) and hypoglycemic (~50 mg/dL) blood Glc levels were maintained in the scanner. The new protocol allowed retention of all HTL data compared with our prior experience of having to exclude approximately half of the HTL data in similar clamp experiments in the 7T scanner due to subject motion. The advanced MRS protocol showed excellent data quality (reliable quantification of 11–12 metabolites) and stability (p &gt; 0.05 for both signal-to-noise ratio and water linewidths) between euglycemia and hypoglycemia. Decreased brain Glc levels under hypoglycemia were reliably detected in both VOIs. In addition, mean Glu level trended lower at hypoglycemia than euglycemia for both VOIs, consistent with prior observations in the occipital cortex. This protocol will allow robust mechanistic investigations of the primary neurotransmitters, Glu and GABA, under changing glycemic conditions.

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