Several laboratories have consistently reported small concentration changes in lactate, glutamate, aspartate, and glucose the human cortex during prolonged stimuli. However, whether such correlate with blood oxygenation level—dependent functional magnetic resonance imaging (BOLD-fMRI) signals not been determined. The present study aimed at characterizing relationship between metabolite concentrations BOLD-fMRI a block-designed paradigm of visual stimulation. Functional spectroscopy (fMRS)...

Background Parkinson disease (PD) is characterized by the degeneration of nigrostriatal dopaminergic neurons. However, postmortem evidence indicates that pathology lower brainstem regions, such as pons and medulla, precedes nigral involvement. Consistently, pontomedullary damage was implicated structural PET imaging in early PD. Neurochemical correlates this pathological involvement PD are unknown. Methodology/Principal Finding To map biochemical alterations brains individuals with...

Purpose To determine the test‐retest reproducibility of neurochemical concentrations obtained with a highly optimized, short‐echo, single‐voxel proton MR spectroscopy (MRS) pulse sequence at 3T and 7T using state‐of‐the‐art hardware. Methods A semi‐LASER (echo time = 26–28 ms) was used to acquire spectra from posterior cingulate cerebellum six healthy volunteers who were scanned four times weekly on both scanners. Spectra quantified LCModel. Results More neurochemicals mean Cramér‐Rao lower...

Combined fMRI-MRS is a novel method to non-invasively investigate functional activation in the human brain using simultaneous acquisition of hemodynamic and neurochemical measures. The aim current study was quantify neural activity combined at 7 T. BOLD-fMRI semi-LASER localization MRS data were acquired from visual cortex 13 participants during short blocks (64 s) flickering checkerboards. We demonstrate correlation between glutamate time courses (R=0.381, p=0.031). In addition, we show...

To determine whether neurochemical concentrations obtained at two MRI sites using clinical 3T scanners can be pooled when a highly optimized, nonvendor short-echo, single-voxel proton MRS pulse sequence is used in conjunction with identical calibration and quantification procedures.A modified semi-LASER (TE = 28 ms) was to acquire spectra from brain regions (cerebellar vermis pons) on Siemens the same B0 B1 protocols different cohorts of healthy volunteers (N 24-33 per site) matched for age...

Balance of cortical excitation and inhibition (EI) is thought to be disrupted in several neuropsychiatric conditions, yet it not clear how maintained the healthy human brain. When EI balance disturbed during learning memory animal models, can restabilized via formation inhibitory replicas newly formed excitatory connections. Here we assess evidence for such selective rebalancing humans. Using fMRI repetition suppression measure associations We show that expression these reduces over time...

Abstract Mutations in the isocitrate dehydrogenase genes (IDH1/2) occur often diffuse gliomas, where they are associated with abnormal accumulation of oncometabolite 2-hydroxyglutarate (2-HG). Monitoring 2-HG levels could provide prognostic information this disease, but detection strategies that noninvasive and sufficiently quantitative have yet to be developed. In study, we address need by presenting a proton magnetic resonance spectroscopy (1H-MRS) acquisition scheme uses an ultrahigh...

Key points The ability to learn new motor skills is supported by plasticity in the structural and functional organisation of primary cortex human brain. Changes inhibitory signalling GABA are thought be crucial inducing plasticity. This study used magnetic resonance spectroscopy (MRS) quantify concentration during a period learning, as well movement at rest. We report evidence for reduction MRS‐measured specific learning. Further, early learning task was strongly correlated with magnitude...

Our experiences often overlap with each other, yet we are able to selectively recall individual memories guide decisions and future actions. The neural mechanisms that support such precise memory remain unclear. Here, using ultra-high field 7T MRI reveal two distinct protect from interference. first mechanism involves the hippocampus, where blood-oxygen-level-dependent (BOLD) signal predicts behavioral measures of interference, representations context-dependent pattern separated according...

Abstract Phosphorus-31 magnetic resonance spectroscopic imaging ( 31 P-MRSI) provides valuable non-invasivein vivoinformation on tissue metabolism but is burdened by poor sensitivity and prolonged scan duration. Ultra-short echo time (UTE) acquisitions minimize signal loss when probing signals with relatively short spin-spin relaxation (T 2 ), while also preventing first-order dephasing. Here, a three-dimensional (3D) UTE sequence rosette k-space trajectory (PETALUTE) applied to P-MRSI at...

Increased sensitivity and chemical shift dispersion at ultra‐high magnetic fields enable the precise quantification of an extended range brain metabolites from 1 H MRS. However, all previous neurochemical profiling studies using single‐voxel MRS 7 T have been limited to data acquired occipital lobe with half‐volume coils. The challenges human include short 2 complex B distribution that imposes limitations on maximum achievable strength. In this study, feasibility acquiring quantifying...

Abstract In this study, ascorbate (Asc) and glutathione (GSH) concentrations were quantified noninvasively using double‐edited 1 H MRS at 4 T in the occipital cortex of healthy young [age (mean ± standard deviation) = 20.4 1.4 years] elderly (age 76.6 6.1 years) human subjects. Elderly subjects had a lower GSH concentration than younger ( p < 0.05). The Asc was not significantly associated with age. Furthermore, lactate (Lac) higher Lower Lac are indications defective protection against...

The purpose of this work was to harmonize data acquisition and post‐processing single voxel proton MRS ( 1 H‐MRS) at 7 T, determine metabolite concentrations the accuracy reproducibility levels in adult human brain. This study performed compliance with local institutional ethics committees. same seven subjects were each examined twice using four different T MR systems from two vendors an identical semi‐localization by adiabatic selective refocusing spectroscopy sequence. Neurochemical...

Objective To investigate whether early neurochemical abnormalities are detectable by high‐field magnetic resonance spectroscopy (MRS) in individuals with spinocerebellar ataxias (SCAs) 1, 2, 3, and 6, including patients without manifestation of ataxia. Methods A cohort 100 subjects (N = 18–21 each SCA group, premanifest mutation carriers; mean score on the Scale for Assessment Rating Ataxia [SARA] <10 all genotypes, 22 matched controls) was scanned at 7 Tesla to obtain profiles cerebellum...

Learning a novel motor skill is dependent both on regional changes within the primary cortex (M1) contralateral to active hand and also modulation between anatomically distant but functionally connected brain regions. Interregional are particularly important in functional recovery after stroke, when critical plastic underpinning behavioral improvements observed ipsilesional contralesional M1s. It increasingly understood that reduction GABA M1 necessary allow learning of task. However,...

Spinocerebellar ataxias (SCAs) belong to polyglutamine repeat disorders and are characterized by a predominant atrophy of the cerebellum pons. Proton magnetic resonance spectroscopy ((1) H MRS) using an optimized semiadiabatic localization adiabatic selective refocusing (semi-LASER) protocol was performed at 3 T determine metabolite concentrations in cerebellar vermis pons cohort patients with SCA1 (n=16), SCA2 (n=12), SCA3 (n=21), SCA7 (n=12) healthy controls (n=33). Compared controls,...

Multiple data formats in the MRS community currently hinder sharing and integration. NIfTI-MRS is proposed as a standard spectroscopy format, implemented an extension to Neuroimaging informatics technology initiative (NIfTI) format. This standardized format can facilitate algorithm development well ease integration of analysis alongside other imaging modalities.

1H magnetic resonance spectroscopy (MRS) is unique among imaging modalities because signals from several metabolites are measured during a single examination period. Each metabolite reflects distinct intracellular process. Furthermore transverse (T2) relaxation times probe the viability of cell microenvironment, e.g., viscosity cellular fluids, microscopic susceptibility distribution within cells, and iron content. In this study, T2s brain were in occipital lobe eighteen young fourteen...