A5019014082- Optical Imaging and Spectroscopy Techniques
- Advanced MRI Techniques and Applications
- Traumatic Brain Injury and Neurovascular Disturbances
- Functional Brain Connectivity Studies
- Advanced Neuroimaging Techniques and Applications
- Neural dynamics and brain function
- Cardiovascular Health and Disease Prevention
- Neuroscience and Neuropharmacology Research
- Photoreceptor and optogenetics research
- Non-Invasive Vital Sign Monitoring
- Photoacoustic and Ultrasonic Imaging
- MRI in cancer diagnosis
- Neuroinflammation and Neurodegeneration Mechanisms
- Infrared Thermography in Medicine
- Hearing, Cochlea, Tinnitus, Genetics
- Barrier Structure and Function Studies
- Thermoregulation and physiological responses
- Analytical Chemistry and Sensors
- Thermal Regulation in Medicine
- Thyroid Disorders and Treatments
- Cerebrovascular and Carotid Artery Diseases
- Tryptophan and brain disorders
- Blood Pressure and Hypertension Studies
- Glaucoma and retinal disorders
- Neuroscience and Neural Engineering
Université Laval
1972-2025
Centre hospitalier de l'Université Laval
1985-2024
Université de Technologie de Compiègne
2024
University of California, San Diego
2016-2020
Centre hospitalier universitaire de Québec
2019
Polytechnique Montréal
2008-2017
Université de Montréal
1985-2017
Hôpital du Sacré-Cœur de Montréal
2017
Canadian Sleep & Circadian Network
2017
Institut Universitaire de Gériatrie de Montréal
2009-2015
Identification of the cellular players and molecular messengers that communicate neuronal activity to vasculature driving cerebral hemodynamics is important for (1) basic understanding cerebrovascular regulation (2) interpretation functional Magnetic Resonance Imaging (fMRI) signals. Using a combination optogenetic stimulation 2-photon imaging in mice, we demonstrate selective activation cortical excitation inhibition elicits distinct vascular responses identify vasoconstrictive mechanism as...
Aim: Many studies have suggested that physical exercise training improves cognition and more selectively executive functions. There is a growing interest to clarify the neurophysiological mechanisms underlie this effect. The aim of current study was evaluate changes in cerebral oxygenation associated with fitness level Method: In study, 22 younger 36 older women underwent maximal graded continuous test (i.e., O2max) order classifyassign them into group (higher vs. lower fit). All...
Abstract Recent advances in optical technologies such as multi-photon microscopy and optogenetics have revolutionized our ability to record manipulate neuronal activity. Combining techniques with electrical recordings is of critical importance connect the large body neuroscience knowledge obtained from animal models human studies mainly relying on electrophysiological brain-scale However, integration modalities challenging due generation light-induced artifacts. Here we report a transparent...
Our understanding of how capillary blood flow and oxygen distribute across cortical layers to meet the local metabolic demand is incomplete. We addressed this question by using two-photon imaging resting-state microvascular partial pressure (PO2) in whisker barrel cortex awake mice. measurements I-V show that red-blood-cell flux oxygenation heterogeneity, intracapillary resistance delivery, all decrease with depth, reaching a minimum around layer IV, while depth-dependent extraction fraction...
In this work, diffuse correlation spectroscopy (DCS) is explored in multi-layered geometries. A quantitative comparison of an homogeneous versus a two-layered model efficiencies to recover flow changes presented. By simulating realistic human head with MRI anatomical data, we show that the allows distinction between superficial layers and brain. We also provides better estimate change than one. Experimental measurements dynamical phantom confirm ability analytical distinguish increase each layer.
Chronic cranial windows allow for longitudinal brain imaging experiments in awake, behaving mice. Different technologies have their unique advantages and combining multiple modalities offers measurements of a wide spectrum neuronal, glial, vascular, metabolic parameters needed comprehensive investigation physiological pathophysiological mechanisms. Here, we detail suite surgical techniques installation different targeted specific combination. Following these practices will yield higher...
The cerebral cortex has a number of conserved morphological and functional characteristics across brain regions species. Among them, the laminar differences in microvascular density mitochondrial cytochrome c oxidase staining suggest potential variability baseline O 2 metabolism and/or both demand hemodynamic response. Here, we investigate profile stimulus-induced intravascular partial pressure (pO2) transients to neuronal activation fully awake mice using two-photon phosphorescence lifetime...
The cerebral cortex is organized in cortical layers that differ their cellular density, composition, and wiring. Cortical laminar architecture also readily revealed by staining for cytochrome oxidase—the last enzyme the respiratory electron transport chain located inner mitochondrial membrane. It has been hypothesized a high-density band of oxidase layer IV reflects higher oxygen consumption under baseline (unstimulated) conditions. Here, we tested above hypothesis using direct measurements...
Like other neuroimaging techniques assessing cerebral blood oxygenation, near-infrared spectroscopy (NIRS) has been applied in many neurocognitive studies. With NIRS, neural activation can be explored indirectly via hemodynamic changes the imaged region. In studies of aging, baseline physiology and brain anatomy confound NIRS measures seeking to investigate age-related neuronal activity. The field is thus hampered by complexity aging process itself, statistical inferences from functional...
Diffuse, optical near infrared imaging is increasingly being used in various neurocognitive contexts where changes signals are interpreted through activation maps. Statistical population comparison of different age or clinical groups rely on the relative homogeneous distribution measurements across subjects order to infer brain function. In context an increasing use diffuse with older adult populations, tissue properties and anatomy adds additional confounds. Few studies investigated these...