A5090139110- Advanced MRI Techniques and Applications
- Functional Brain Connectivity Studies
- Advanced Neuroimaging Techniques and Applications
- Neural dynamics and brain function
- Neurological disorders and treatments
- Neuroscience and Neuropharmacology Research
- Advanced NMR Techniques and Applications
- EEG and Brain-Computer Interfaces
- Diabetes Management and Research
- Electron Spin Resonance Studies
- Transcranial Magnetic Stimulation Studies
- NMR spectroscopy and applications
- Multiple Sclerosis Research Studies
- MRI in cancer diagnosis
- Diet and metabolism studies
- Pancreatic function and diabetes
- Medical Imaging Techniques and Applications
- Heart Rate Variability and Autonomic Control
- Visual perception and processing mechanisms
- Genetic Neurodegenerative Diseases
- Mitochondrial Function and Pathology
- Parkinson's Disease Mechanisms and Treatments
- Optical Imaging and Spectroscopy Techniques
- Photoreceptor and optogenetics research
- Amino Acid Enzymes and Metabolism
University of Minnesota
2016-2025
Resonance Research (United States)
2016-2025
University of Minnesota System
2024-2025
Central European Institute of Technology
2020
Central European Institute of Technology – Masaryk University
2020
University of Salerno
2019
Enrico Fermi Center for Study and Research
2002-2004
Sapienza University of Rome
2002-2004
Istituto Nazionale per la Fisica della Materia
2001-2004
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2000
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)...
To date, functional 1 H NMR spectroscopy has been utilized to report the time courses of few metabolites, primarily lactate. Benefiting from sensitivity offered by ultra-high magnetic field (7 T), concentrations 17 metabolites were measured in human visual cortex during two paradigms stimulation lasting 5.3 and 10.6 mins. Significant concentration changes approximately 0.2 μmol/g observed for several metabolites: lactate increased 23% ± 5% ( P < 0.0005), glutamate 3% 1% 0.01), whereas...
Abstract Functional magnetic resonance spectroscopy (fMRS) allows the non‐invasive measurement of metabolite concentrations in human brain, including changes induced by variations neurotransmission activity. However, limited spatial and temporal resolution fMRS does not allow specific measurements metabolites different cell types. Thus, analysis data context compartmentalized metabolism requires formulation application mathematical models. In present study we utilized model introduced...
Zero echo time (zero-TE) pulse sequences provide a quiet and artifact-free alternative to conventional functional magnetic resonance imaging (fMRI) sequences. The fast readouts (<1 ms) utilized in zero-TE fMRI produce an image contrast with negligible contributions from blood oxygenation level-dependent (BOLD) mechanisms, yet the is highly sensitive brain function. However, precise relationship between neuronal activity has not been determined. Therefore, we aimed derive function model...
In this article, we examined theoretically the role of human cerebral glycogen in buffering metabolic requirement a 360-second brain stimulation, expanding our previous modeling study neurometabolic coupling. We found that synthesis and degradation affects relative amount glucose taken up by neurons versus astrocytes. Under conditions 175:115 mmol/L (∼1.5:1) neuronal astrocytic activation-induced Na(+) influx ratio, ∼12% is mobilized. This results rapid increase intracellular...
Abstract During transient brain activation cerebral blood flow (CBF) increases substantially more than metabolic rate of oxygen consumption (CMRO 2 ) resulting in hyperoxygenation, the basis BOLD‐fMRI contrast. Explanations for high CBF versus CMRO slope, termed neurovascular coupling (NVC) constant, focused on maintenance tissue oxygenation to support mitochondrial ATP production. However, paradoxically has a 3‐fold lower extraction fraction (OEF) other organs with energy requirements, like...
In this paper, we combined several mathematical models of cerebral metabolism and nutrient transport to investigate the energetic significance metabolite trafficking within brain parenchyma during a 360-secs activation. Glycolytic oxidative cellular were homogeneously modeled between neurons astrocytes, stimulation-induced neuronal versus astrocytic Na + inflow was set 3:1. These assumptions resemble physiologic conditions are supported by current literature. Simulations showed that glucose...
To improve the ability to move from preclinical trials in mouse models of Huntington's disease (HD) clinical humans, biomarkers are needed that can track similar aspects progression across species. Brain metabolites, detectable by magnetic resonance spectroscopy (MRS), have been suggested as potential HD. In this study, R6/2 transgenic model HD was used investigate relative sensitivity metabolite profiling and brain volumetry anticipate progression. Magnetic imaging (MRI) 1 H MRS data were...
Objective. This study investigated stimulation strategies to increase the selectivity of activating axonal pathways within brain based on their orientations relative clinical deep (DBS) lead implants. Approach. Previous work has shown how varying electrode shape and controlling primary electric field direction through preclinical arrays can produce orientation-selective stimulation. Here, we significantly extend those results using computational models evaluate degree which DBS leads direct...
In the present study, we aimed at determining metabolic responses of human visual cortex during presentation chromatic and achromatic stimuli, known to preferentially activate two separate clusters neuronal populations (called "blobs" "interblobs") with distinct sensitivity color or luminance features. Since blobs interblobs have different cytochrome-oxidase (COX) content micro-vascularization level (i.e., capacities for glucose oxidation), functional vs. stimuli may be expected. The were...
Abstract In vivo 1 H NMR spectroscopy at 7 T was utilized to measure the changes in lactate concentration upon repeated identical visual stimuli, each lasting for 2 min. The average amplitude of these increases found be reduced over time ( P < 0.01), from 0.13 ± 0.02 μmol/g during first half stimulation paradigm, 0.06 second paradigm. contrast, blood oxygen level‐dependent (BOLD) effect on fMRI water signal and height total creatine 3.03 ppm persistent whole observation period. This...
Slow μs/ms dynamics involved in protein folding, binding, catalysis, and allostery are currently detected using NMR dispersion experiments such as CPMG (Carr−Purcell−Meiboom−Gill) or spin-lock R1ρ. In these methods, obtained by analyzing relaxation curves from either changing the time spacing between 180° pulses effective spin-locking field strength. this Communication, we introduce a new method to induce of rates. Our approach relies on altering shape adiabatic full passage pulse is...
Objective. Target selectivity of deep brain stimulation (DBS) therapy is critical, as the precise locus and pattern dictates degree to which desired treatment responses are achieved adverse side effects avoided. There a clear clinical need improve DBS technology beyond currently available steering shaping approaches. We introduce orientation selective neural concept increase specificity target selection in DBS. Approach. This concept, involves orienting electric field along an axonal...