A5077959963- Functional Brain Connectivity Studies
- Advanced MRI Techniques and Applications
- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Advanced Neuroimaging Techniques and Applications
- Complex Systems and Time Series Analysis
- Optical Imaging and Spectroscopy Techniques
- Heart Rate Variability and Autonomic Control
- Time Series Analysis and Forecasting
- Thermal Regulation in Medicine
- Traumatic Brain Injury and Neurovascular Disturbances
- Olfactory and Sensory Function Studies
- Photoreceptor and optogenetics research
- Fractal and DNA sequence analysis
- Anesthesia and Neurotoxicity Research
- Atomic and Subatomic Physics Research
- Migraine and Headache Studies
- Mitochondrial Function and Pathology
- EEG and Brain-Computer Interfaces
- MRI in cancer diagnosis
- Spinal Cord Injury Research
- Hemoglobin structure and function
- Theoretical and Computational Physics
- Heme Oxygenase-1 and Carbon Monoxide
- Thermoregulation and physiological responses
Resonance Research (United States)
2013-2024
Yale University
2014-2024
Semmelweis University
2001-2012
Heidelberg University
2007
National Trauma Institute
2007
The University of Texas Health Science Center at San Antonio
2007
In-Q-Tel
2007
Ludwig-Maximilians-Universität München
2001
Long Island Jewish Medical Center
1986-1991
Albert Einstein College of Medicine
1991
The modified Beer–Lambert law (MBLL) is the basis of continuous-wave near-infrared tissue spectroscopy (cwNIRS). differential form MBLL (dMBLL) states that change in light attenuation proportional to changes concentrations chromophores, mainly oxy- and deoxyhaemoglobin. If are measured at two or more wavelengths, concentration can be calculated. dMBLL based on assumptions: (1) absorption homogeneously, (2) scattering loss constant. It known usually inhomogeneous, therefore underestimates...
The insatiable appetite for energy to support human brain function is mainly supplied by glucose oxidation (CMR glc(ox) ). But how much consumed signaling and nonsignaling processes in gray/white matter highly debated. We examined this issue combining metabolic measurements of a theoretical calculation bottom-up budget using biophysical properties neuronal/glial cells conjunction with species-exclusive electrophysiological morphological data. calculated CMR -derived confirmed it experimental...
Abstract Large-scale functional networks have been characterized in both rodent and human brains, typically by analyzing fMRI-BOLD signals. However, the relationship between underlying neural activity is complex incompletely understood, which poses challenges to interpreting network organization obtained using this technique. Additionally, most work has assumed a disjoint (i.e., brain regions belong one only network). Here, we employ wide-field Ca 2+ imaging simultaneously with mice...
Seizures have both local and remote effects on nervous system function. Whereas propagated seizures are known to disrupt cerebral activity, little work has been done network of that do not propagate. Human focal temporal lobe demonstrate changes including slow waves electroencephalography (EEG) decreased blood flow (CBF) in the neocortex. Ictal neocortical interpreted as seizure propagation; however, we hypothesize they reflect a depressed cortical state resembling sleep or coma. To...
Absence seizures are brief episodes of impaired consciousness, behavioral arrest, and unresponsiveness, with yet-unknown neuronal mechanisms. Here we report that an awake female rat model recapitulates the behavioral, electroencephalographic, cortical functional magnetic resonance imaging characteristics human absence seizures. Neuronally, feature overall decreased but rhythmic firing neurons in cortex thalamus. Individual thalamic express one four distinct patterns seizure-associated...
Energetics of resting and evoked fMRI signals were related to localized ensemble firing rates (nu) measured by electrophysiology in rats. Two different unstimulated, or baseline, states established anesthesia. Halothane alpha-chloralose baseline high low energy, respectively, which forepaw stimulation excited the contralateral primary somatosensory cortex (S1). With alpha-chloralose, induced strong reproducible activations S1, where was dominated slow signaling neurons (SSN; nu range 1-13...
Hypoglycemia occurs frequently during intensive insulin therapy in patients with both type 1 and 2 diabetes remains the single most important obstacle achieving tight glycemic control. Using a rodent model of hypoglycemia, we demonstrated that exposure to antecedent recurrent hypoglycemia leads adaptations brain metabolism so modest increments circulating lactate allow function normally under acute hypoglycemic conditions. We characterized 3 major factors underlying this effect. First,...
Regionally variable rates of aerobic glycolysis in brain networks identified by resting-state functional magnetic resonance imaging (R-fMRI) imply regionally adenosine triphosphate (ATP) regeneration. When regional glucose utilization is not matched to oxygen delivery, affected regions have correspondingly ATP and lactate production. We tested the extent which oxidative phosphorylation power R-fMRI measuring quantitative differences between index (OGI) extraction fraction (OEF) as measured...
The evolution of functional magnetic resonance imaging to resting state (R-fMRI) allows measurement changes in brain networks attributed changes, such as neuropsychiatric diseases versus healthy controls. Since these are observed by comparing normalized R-fMRI signals, it is difficult determine the metabolic basis group differences. To investigate network differences within a normal range, eyes open closed human subjects was used. recorded simultaneously with fluoro-deoxyglucose positron...
In the postnatal subventricular zone (SVZ), S phase entry of neural progenitor cells (NPCs) correlates with a local increase in blood flow. However, cellular mechanism controlling this hemodynamic response remains unknown. We show that subpopulation SVZ cells, astrocyte-like or B-cells, sends projections ensheathing pericytes on capillaries young mice. examined whether calcium increases B-cells led to vascular acute slices using P2Y(2/4) receptor (P2Y(2/4)R) agonist UTP, electrical...
Significance This work challenges the notion that conventional functional magnetic resonance imaging (fMRI), is, blood oxygenation level-dependent signal alone, can accurately reflect laminar neural activity. Instead, we show calibrated fMRI methods for metabolic and hemodynamic measurements better neuronal activities.
This article will be positioned on our previous work demonstrating the importance of adhering to a carefully selected set criteria when choosing suitable method from those available ensuring its adequate performance applied real temporal signals, such as fMRI BOLD, evaluate one important facet their behavior, fractality. Earlier, we have reviewed range monofractal tools and evaluated performance. Given advance in fractal field, this discuss most widely used implementations multifractal...
Physiological processes—such as brain's resting-state electrical activity or hemodynamic fluctuations—exhibit scale-free temporal structuring. However impacts, such noise, multiple signal generators filtering by transport function, common in biological systems results multimodal scaling that cannot be reliably assessed standard analytical tools these assume unimodal scaling. Here we present two methods to identify breakpoints crossovers multifractal functions. These incorporated the robust...
Energetic basis of neural activity provides a solid foundation for noninvasive neuroimaging with calibrated functional magnetic resonance imaging (fMRI). Calculating dynamic changes in cerebral oxidative energy utilization (CMR O 2 ) is limited by uncertainties about whether or not the conventional blood oxygenation level-dependent (BOLD) model can be applied transiently using multimodal measurements flow (CBF) and volume (CBV) that affect BOLD signal. A prerequisite fMRI testing linearity...
There is broad agreement that generalized tonic–clonic seizures (GTCS) and normal somatosensory stimulation are associated with increases in regional CBF. However, the data regarding CBF changes during absence controversial. Electrophysiologic studies WAG/Rij rats, an established animal model of seizures, have shown spike-wave discharges (SWD) largest perioral cortex while sparing visual cortex. Recent functional magnetic resonance imaging (fMRI) same also localized fMRI signals SWD. Because...
Functional magnetic resonance imaging (fMRI) with blood-oxygenation level dependent (BOLD) contrast is an important tool for mapping brain activity. Interest in quantitative fMRI has renewed awareness importance of oxidative neuroenergetics, as reflected by cerebral metabolic rate oxygen consumption(CMRO2), supporting function. Relationships between BOLD signal and the underlying neurophysiological parameters have been elucidated to allow determination dynamic changes inCMRO2 "calibrated...
Local calcium (Ca 2 + ) changes regulate central nervous system metabolism and communication integrated by subcellular processes including mitochondrial Ca uptake. Mitochondria take up through the uniporter (mCU) aided cytoplasmic microdomains of high . Known only in vitro, vivo impact mCU activity may reveal -mediated roles mitochondria brain signaling metabolism. From vitro studies sequestration cycling various cell types system, we evaluated ranges spontaneous activity-induced...
The in vivo rat model is a workhorse neuroscience research, preclinical studies and drug development. A repertoire of MR tools has been developed for its investigation; however, high levels B 0 magnetic field homogeneity are required meaningful results. homogenization fields the brain, i.e. shimming, difficult task because multitude complex, susceptibility‐induced distortions. Conventional shimming with spherical harmonic (SH) functions capable compensating shallow distortions limited areas,...
Biosensor imaging of redundant deviation in shifts (BIRDS), an ultrafast chemical shift technique, requires infusion paramagnetic probes such as 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetrakis methylene phosphonate (DOTP 8− ) complexed with thulium (Tm 3+ ion (i.e. TmDOTP 5− ), where the pH‐sensitive resonances hyperfine‐shifted non‐exchangeable protons contained within probe are detected. While extracellular pH (pH e BIRDS meets important cancer research need by mapping...
Because the presence of pain impedes motor recovery in individuals with spinal cord injury (SCI), it is necessary to understand their supraspinal substrates translational animal models. Using functional magnetic resonance imaging (fMRI) a rat model hemicontusion cervical SCI, changes were mapped and correlated sensorimotor behavioral outcomes. Female adult rats underwent sham or SCI using 2.5 mm impactor 150 kdyn force. permanently impaired activity only ipsilesional forelimb along thermal...