scholarly journals Low myo-inositol and high glutamine levels in brain are associated with neuropsychological deterioration after induced hyperammonemia

2004 ◽  
Vol 287 (3) ◽  
pp. G503-G509 ◽  
Author(s):  
D. L. Shawcross ◽  
S. Balata ◽  
S. W. M. Olde Damink ◽  
P. C. Hayes ◽  
J. Wardlaw ◽  
...  
Keyword(s):  
Memory Test ◽  
Resonance Spectroscopy ◽  
Neuropsychological Function ◽  
Immediate Memory ◽  
Neuropsychological Effects ◽  
Overt Hepatic Encephalopathy ◽  
Hemoglobin Molecule ◽  
Neuropsychological Effect ◽  
Short Echo Time ◽  
The Brain

The neuropsychological effect of hyperammonemia is variable. This study tests the hypothesis that the effect of ammonia on the neuropsychological function in patients with cirrhosis is determined by the ability of the brain to buffer ammonia-induced increase in glutamine within the astrocyte by losing osmolytes like myo-inositol (mI) and not by the magnitude of the induced hyperammonemia. Fourteen cirrhotic patients with no evidence of overt hepatic encephalopathy were given a 75-g amino acid (aa) solution mimicking the hemoglobin molecule to induce hyperammonemia. Measurement of a battery of neuropsychological function tests including immediate memory, ammonia, aa, and short-echo time proton magnetic resonance spectroscopy were performed before and 4 h after administration of the aa solution. Eight patients showed deterioration in the Immediate Memory Test at 4 h. Demographic factors, severity of liver disease, change in plasma ammonia, and aa profiles after the aa solution were similar in those that showed a deterioration compared with those who did not. In patients who showed deterioration in the memory test, the mI-to-creatine ratio (mI/Cr) was significantly lower at baseline than those that did not deteriorate. In contrast, the glutamate/glutamine-to-Cr ratio was significantly greater in the patients that deteriorated. The observation that deterioration in the memory test scores was greater in those with lower mI/Cr supports the hypothesis that the neuropsychological effects of induced hyperammonemia is determined by the capacity of the brain to handle ammonia-induced increase in glutamine.

Positive Arousal Enhances the Consolidation of Item Memory

2015 ◽  
Vol 74 (2) ◽  
pp. 91-104 ◽  
Author(s):  
Bo Wang
Keyword(s):  
Episodic Memory ◽  
Memory Consolidation ◽  
Source Memory ◽  
Emotional Arousal ◽  
Theoretical Models ◽  
Memory Test ◽  
Learning Phase ◽  
Item Memory ◽  
Memory Tests ◽  
Immediate Memory

Emotional arousal induced after learning has been shown to modulate memory consolidation. However, it is unclear whether the effect of postlearning arousal can extend to different aspects of memory. This study examined the effect of postlearning positive arousal on both item memory and source memory. Participants learned a list of neutral words and took an immediate memory test. Then they watched a positive or a neutral videoclip and took delayed memory tests after either 25 minutes or 1 week had elapsed after the learning phase. In both delay conditions, positive arousal enhanced consolidation of item memory as measured by overall recognition. Furthermore, positive arousal enhanced consolidation of familiarity but not recollection. However, positive arousal appeared to have no effect on consolidation of source memory. These findings have implications for building theoretical models of the effect of emotional arousal on consolidation of episodic memory and for applying postlearning emotional arousal as a technique of memory intervention.

Neurometabolic Diseases in Children: Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy Features

2019 ◽  
Vol 15 (3) ◽  
pp. 255-268
Author(s):  
Direnç Özlem Aksoy ◽  
Alpay Alkan
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Metabolic Pathways ◽  
Wide Spectrum ◽  
Demyelinating Diseases ◽  
Resonance Spectroscopy ◽  
Resonance Imaging ◽  
Neurometabolic Disorders ◽  
Brain Involvement ◽  
The Brain

Background: Neurometabolic diseases are a group of diseases secondary to disorders in different metabolic pathways, which lead to white and/or gray matter of the brain involvement. </P><P> Discussion: Neurometabolic disorders are divided in two groups as dysmyelinating and demyelinating diseases. Because of wide spectrum of these disorders, there are many different classifications of neurometabolic diseases. We used the classification according to brain involvement areas. In radiological evaluation, MRI provides useful information for these disseases. Conclusion: Magnetic Resonance Spectroscopy (MRS) provides additional metabolic information for diagnosis and follow ups in childhood with neurometabolic diseases.

scholarly journals Relationship between fractional anisotropy and neuropsychological evaluation in sports-related concussion

Neurology ◽  
2018 ◽  
Vol 91 (23 Supplement 1) ◽  
pp. S17.1-S17
Author(s):  
Haruo Nakayama ◽  
Yu Hiramoto ◽  
Yuriko Numata ◽  
Satoshi Fujita ◽  
Nozomi Hirai ◽  
...  
Keyword(s):  
Processing Speed ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Neuropsychological Testing ◽  
Diffusion Tensor Mri ◽  
Neuropsychological Evaluation ◽  
Neuropsychological Function ◽  
Significant Fluctuation ◽  
The Relationship ◽  
The Brain

ObjectiveTo evaluate the relationship between functional anisotropy (FA) and neuropsychological evaluation in concussion.MethodsDiffusion tensor MRI included FA of the Brain and neuropsychological evaluation were conducted on 10 patients with concussion who were diagnosed from April 2017 to March 2018. FA was extracted from 2 regions of interest in Corpus callosum (CC) and corticospinal tract (CT). Detailed neuropsychological testing with an emphasis on Working memory (WM) and Processing speed (PS) was also conducted. The FA value in that 2 regions were compared between the 2 groups of 5 patients (group F) who failed either in WM or PS and 5 cases (group NF) who did not admit it.ResultsMean FA values in CC and CT in the Group F were 0.70 and 0.52. Mean FA values in CC and CT in the Group NF were 0.48 and 0.55.ConclusionsOur result suggests that the FA value of CC did not explain the significant fluctuation of the neuropsychological function. However, FA value in CT were shown to explain the fluctuation of WM and PS.

scholarly journals Assessment of Metabolic Fluxes in the Mouse Brain in Vivo Using 1H-[13C] NMR Spectroscopy at 14.1 Tesla

2015 ◽  
Vol 35 (5) ◽  
pp. 759-765 ◽  
Author(s):  
Lijing Xin ◽  
Bernard Lanz ◽  
gxia Lei ◽  
Rolf Gruetter
Keyword(s):  
Mouse Models ◽  
Mouse Brain ◽  
Conversion Rate ◽  
Tca Cycle ◽  
Compartment Model ◽  
13C Nmr Spectroscopy ◽  
Resonance Spectroscopy ◽  
Metabolic Fluxes ◽  
Short Echo Time

13C magnetic resonance spectroscopy (MRS) combined with the administration of 13C labeled substrates uniquely allows to measure metabolic fluxes in vivo in the brain of humans and rats. The extension to mouse models may provide exclusive prospect for the investigation of models of human diseases. In the present study, the short-echo-time (TE) full-sensitivity 1H-[13C] MRS sequence combined with high magnetic field (14.1 T) and infusion of [U-13C6] glucose was used to enhance the experimental sensitivity in vivo in the mouse brain and the 13C turnover curves of glutamate C4, glutamine C4, glutamate+glutamine C3, aspartate C2, lactate C3, alanine C3, γ-aminobutyric acid C2, C3 and C4 were obtained. A one-compartment model was used to fit 13C turnover curves and resulted in values of metabolic fluxes including the tricarboxylic acid (TCA) cycle flux VTCA (1.05 ± 0.04 μmol/g per minute), the exchange flux between 2-oxoglutarate and glutamate Vx (0.48 ± 0.02 μmol/g per minute), the glutamate-glutamine exchange rate Vgln (0.20 ± 0.02 μmol/g per minute), the pyruvate dilution factor Kdil (0.82 ± 0.01), and the ratio for the lactate conversion rate and the alanine conversion rate VLac/ VAla (10 ± 2). This study opens the prospect of studying transgenic mouse models of brain pathologies.

Effects of hypercapnia on ECoG and oxidative metabolism in neonatal dog brain

1995 ◽  
Vol 78 (6) ◽  
pp. 2272-2278 ◽  
Author(s):  
H. Yoshioka ◽  
H. Miyake ◽  
D. S. Smith ◽  
B. Chance ◽  
T. Sawada ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Resonance Spectroscopy ◽  
Respiratory Enzymes ◽  
Arterial Pco2 ◽  
A Value ◽  
Electrocorticogram Ecog ◽  
The Brain ◽  
Mitochondrial Respiratory

The effects of hypercapnia on cerebral electrical activity and mitochondrial oxidative phosphorylation were studied in the anesthetized neonatal dog by using the electrocorticogram (ECoG) and 31P-magnetic resonance spectroscopy. Three levels of hypercapnia with arterial PCO2 values of approximately 70, 100, and 140 Torr reduced the intracellular pH of the brain from 7.11 to 6.99, 6.87, and 6.76, respectively. These levels of hypercapnia also reduced ADP concentration ([ADP]) from 21.5 to 18.1, 14.8, and 12.9 microM as well as the average ECoG power output by 20, 30, and 40%. A Michaelis-Menten relationship for the mitochondrial respiratory enzymes was fitted with [ADP] and the change in the average ECoG. The result suggests that mitochondrial respiration is regulated by [ADP] and that the in vivo Michaelis-Menten constant for ADP was 21 microM, a value close to the in vitro value. The mitochondrial maximal reaction velocity was reduced by only 10% during hypercapnia and showed no relationship with the degree of acidosis, suggesting that mitochondrial respiratory enzymes are not responsible for the inhibition of the brain electrical activity.

Differential energetic response of brain vs. skeletal muscle upon glycemic variations in healthy humans

2008 ◽  
Vol 294 (1) ◽  
pp. R12-R16 ◽  
Author(s):  
Kerstin M. Oltmanns ◽  
Uwe H. Melchert ◽  
Harald G. Scholand-Engler ◽  
Maria C. Howitz ◽  
Bernd Schultes ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Underlying Mechanism ◽  
High Energy ◽  
Resonance Spectroscopy ◽  
Energy Status ◽  
High Energy Phosphate ◽  
Available Energy ◽  
Healthy Humans ◽  
High Energy Phosphate Metabolism ◽  
The Brain

The brain regulates all metabolic processes within the organism, and therefore, its energy supply is preserved even during fasting. However, the underlying mechanism is unknown. Here, it is shown, using 31P-magnetic resonance spectroscopy that during short periods of hypoglycemia and hyperglycemia, the brain can rapidly increase its high-energy phosphate content, whereas there is no change in skeletal muscle. We investigated the key metabolites of high-energy phosphate metabolism as rapidly available energy stores by 31P MRS in brain and skeletal muscle of 17 healthy men. Measurements were performed at baseline and during dextrose or insulin-induced hyperglycemia and hypoglycemia. During hyperglycemia, phosphocreatine (PCr) concentrations increased significantly in the brain ( P = 0.013), while there was a similar trend in the hypopglycemic condition ( P = 0.055). Skeletal muscle content remained constant in both conditions ( P > 0.1). ANOVA analyses comparing changes from baseline to the respective glycemic plateau in brain (up to +15%) vs. muscle (up to −4%) revealed clear divergent effects in both conditions ( P < 0.05). These effects were reflected by PCr/Pi ratio ( P < 0.05). Total ATP concentrations revealed the observed divergency only during hyperglycemia ( P = 0.018). These data suggest that the brain, in contrast to peripheral organs, can activate some specific mechanisms to modulate its energy status during variations in glucose supply. A disturbance of these mechanisms may have far-reaching implications for metabolic dysregulation associated with obesity or diabetes mellitus.

scholarly journals Magnetic resonance spectroscopy of the brain in the diagnosis of temporal lobe epilepsy

2018 ◽  
Vol 10 (1S) ◽  
pp. 51-55
Author(s):  
E. S. Solomatova ◽  
N. A. Shnaider ◽  
A. A. Molgachev ◽  
D. V. Dmitrenko ◽  
I. G. Strotskaya
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
English Language ◽  
Russian Language ◽  
Resonance Spectroscopy ◽  
Epileptogenic Focus ◽  
Patients With Epilepsy ◽  
The Brain

The temporal lobe is the most epileptogenic region of the brain. 90% of patients with temporal ictal epileptomorphic EEG activity have a variable long history of seizures. Magnetic resonance spectroscopy  (MRS) may be useful in identifying an epileptogenic focus in patients  with epilepsy without apparent structural pathology at neuroimaging.Objective: to systematize the results of early studies on this issue.Materials and methods. An electronic search was carried out in two English-language (Medline, PubMed) and one Russian-language (eLIBRARY.RU) databases. The search queries found  18,019 citations, by which 12 full-text articles were selected.Results and discussion. The main criteria for the diagnosis of temporal lobe epilepsy by MRS is to lower the level of N-acetylaspartate (NAA), the ratio of NAA to creatinine + choline  (NAA/(Cr + Cho) in the brain region where there is neuronal death  or damage, as well as a change in the level of myo-inositol, the  elevated level of which indicates the presence of an epileptogenic  focus, while the decreased one shows the spread of pathological activity to the adjacent tissues.Conclusion. This review will contribute to a better diagnosis of temporal lobe epilepsy, as well as to the intravital noninvasive detection of metabolic changes in the brain long before the development of structural pathology.

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