Sophie Pezet

Sophie Pezet
École Supérieure de Physique et de Chimie Industrielles | ESPCI · Laboratory 'Physics for Medicine'

PhD

About

87
Publications
16,219
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3,969
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Publications

Publications (87)
Article
Full-text available
The advent of neuroimaging has increased our understanding of brain function. While most brain-wide functional imaging modalities exploit neurovascular coupling to map brain activity at millimeter resolutions, the recording of functional responses at microscopic scale in mammals remains the privilege of invasive electrophysiological or optical appr...
Article
Full-text available
Background Non-invasive high-resolution imaging of the cerebral vascular anatomy and function is key for the study of intracranial aneurysms, stenosis, arteriovenous malformations, and stroke, but also neurological pathologies, such as degenerative diseases. Direct visualization of the microvascular networks in the whole brain remains however chall...
Article
Full-text available
Acute spinal cord injury (SCI) leads to severe damage to the microvascular network. The process of spontaneous repair is accompanied by formation of new blood vessels; their functionality, however, presumably very important for functional recovery, has never been clearly established, as most studies so far used fixed tissues. Here, combining ultraf...
Article
Full-text available
The functional imaging within the trigeminal ganglion (TG) is highly challenging due to its small size and deep localization. This study combined a methodological framework able to dive into the rat trigeminal nociceptive system by jointly providing 1) imaging of the TG blood vasculature at microscopic resolution, and 2) the measurement of hemodyna...
Preprint
Technologies to visualize whole organs across scales in vivo are essential for our understanding of biology in health and disease. To date, only post-mortem techniques achieve cellular resolution across entire organs. 2D ultrasound localization microscopy (ULM) suffers from reprojection issues and out-of-plane motion preventing complex blood flow q...
Preprint
Full-text available
Rapid-eye-movement sleep (REMS) or paradoxical sleep is associated with intense neuronal activity, fluctuations in autonomic control, body paralysis and brain-wide hyperemia. The mechanisms and functions of these energy-demanding patterns remain elusive and a global picture of brain activation during REMS is currently missing. In the present work,...
Preprint
Full-text available
Rapid-eye-movement sleep (REMS) or paradoxical sleep is associated with intense neuronal activity, fluctuations in autonomic control, body paralysis and brain-wide hyperemia. The mechanisms and functions of these energy-demanding patterns remain elusive and a global picture of brain activation during REMS is currently missing. In the present work,...
Preprint
Full-text available
Acute spinal cord injury (SCI) leads to severe damage to the microvascular network. The process of spontaneous repair is accompanied by formation of new blood vessels; their functionality, however, presumably very important for functional recovery, has never been clearly established, as most studies so far used fixed tissues. Here, combining ultraf...
Preprint
Full-text available
Technologies to visualize whole organs across scales in vivo are essential for our understanding of biology in health and disease. To date, only post-mortem techniques such as perfused computed tomography scanning or optical microscopy of cleared tissues achieve cellular resolution across entire organs and imaging methods with equal performance in...
Article
Full-text available
Recent advances in ultrasound imaging triggered by transmission of ultrafast plane waves have rendered functional ultrasound (fUS) imaging a valuable neuroimaging modality capable of mapping cerebral vascular networks, but also for the indirect capture of neuronal activity with high sensitivity thanks to the neurovascular coupling. However, the exp...
Preprint
Full-text available
The functional imaging of the neurovascular coupling within the trigeminal ganglion (TG) is highly challenging due to its small size and its deep localization. This study combined a methodological framework able to dive into the rat trigeminal nociceptive system by jointly providing first imaging of the trigeminal ganglion blood vasculature at micr...
Preprint
Full-text available
Recent advances in ultrasound imaging triggered by ultrafast plane waves transmission have rendered functional ultrasound (fUS) imaging a valuable neuroimaging modality capable of mapping cerebral vascular networks, but also to indirectly capture neuronal activity with high sensitivity thanks to the neurovascular coupling. However, the expansion of...
Article
Full-text available
Despite a century of research on the physiology/pathophysiology of the spinal cord in chronic pain condition, the properties of the spinal cord were rarely studied at the large-scale level from a neurovascular point of view. This is mostly due to the limited spatial and/or temporal resolution of the available techniques. Functional ultrasound imagi...
Article
Full-text available
There is a critical need for reliable quantitative biomarkers to assess functional brain alterations in mouse models of neuropsychiatric diseases, but current imaging methods measuring drug effects through the neurovascular coupling, face issues including poor sensitivity, drug-induced changes in global brain perfusion and the effects of anesthesia...
Poster
Full-text available
Sleep is one of the most universal and essential biological process of life. However, sleep disorders still affect up to one-third of the population and are associated with a wide range of deleterious health consequences including an increased risk of hypertension, diabetes, obesity, depression and stroke. A better understanding of the neurobiologi...
Poster
Sleep is one of the most universal and essential biological process of life. However, sleep disorders still affect up to one-third of the population and are associated with a wide range of deleterious health consequences including an increased risk of hypertension, diabetes, obesity, depression and stroke. A better understanding of the neurobiologi...
Article
Full-text available
Chronic pain pathologies, which are due to maladaptive changes in the peripheral and/or central nervous systems, are debilitating diseases that affect 20% of the European adult population. A better understanding of the mechanisms underlying this pathogenesis would facilitate the identification of novel therapeutic targets. Functional connectivity (...
Article
Full-text available
Objectif Le sommeil paradoxal (SP) est un processus complexe, impliquant de nombreuses régions dans le cerveau, largement sous étudié par rapport aux autres phases de sommeil. Les techniques standards d’imagerie (électrophysiologie, IRMf) n’offrent actuellement pas la possibilité d’étudier plusieurs zones simultanément avec une bonne résolution spa...
Article
Full-text available
We extended the capabilities of functional ultrasound to whole-brain four-dimensional (4D) neuroimaging. Our multiplane-wave transmission scheme on matrix arrays at thousands of frames per second provides volumetric recordings of cerebral blood volume changes at high spatiotemporal resolution. We illustrated the approach in rats while providing mul...
Article
While in vivo fluorescence imaging of cells immobilized within tissues provides a valuable tool to a broad range of biological studies, it still lacks the sensitivity required to visualize isolated cells circulating fast in the blood stream, due in particular to the autofluorescence from endogenous fluorophores. Time-gated imaging of near infrared...
Data
Transcranial functional ultrasound (fUS) imaging in an awake and freely moving mouse using our newly developed ultralight ultrasonic probe and fixation setup.
Article
Full-text available
Functional ultrasound (fUS) imaging by ultrasensitive Doppler detection of blood volume was reported to measure adult rat brain activation and functional connectivity with unmatched spatiotemporal sampling (100 µm, 1 ms), but skull-induced attenuation of ultrasonic waves imposed skull surgery or contrast agent use. Also, fUS feasibility remains to...
Article
Although it is well established that bulbo-spinal serotonergic projections contribute to pain control mechanisms, whether they exert anti- or pro-nociceptive modulations is still a matter of debate. In order to reappraise the role of 5-HT in descending controls, we used RNA interference to selectively inhibit 5-HT synthesis in B3 neurons and assess...
Article
Full-text available
Chronic pain is a long-lasting debilitating condition that is particularly difficult to treat due to the lack of identified underlying mechanisms. Although several key contributing processes have been described at the level of the spinal cord, very few studies have investigated the supraspinal mechanisms underlying chronic pain. Using a combination...
Data
Mini dataset presenting in different tabs individual results from Sham and ION treated animals. Each tab shows the results for the following items: ATF3 positive DRG neurons (Fig 1), behaviour (time spent drinking, which provides an indirect measure of mechanical hyperalgesia, Fig 2), intrinsic optical imaging (Fig 3), c-fos expression in the S1BF...
Data
Table reporting the number of animals included in the initial experimental design, and the reasons for the exclusion of some of them during the course of the study. For instance, some animals were excluded from the imaging experiments when they lost some of their whiskers, or from the behavioural analysis if they were not drinking during the habitu...
Article
Full-text available
Non-invasive imaging deep into organs at microscopic scales remains an open quest in biomedical imaging. Although optical microscopy is still limited to surface imaging owing to optical wave diffusion and fast decorrelation in tissue, revolutionary approaches such as fluorescence photo-activated localization microscopy led to a striking increase in...
Article
Activation of neuronal nitric oxide synthase, and consequent production of nitric oxide (NO), contributes to spinal hyperexcitability and enhanced pain sensation. All NOS isoforms are inhibited endogenously by asymmetric dimethylarginine, which itself is metabolised by dimethylarginine dimethylaminohydrolase (DDAH). Inhibition of DDAH can indirectl...
Article
Full-text available
Functional ultrasound (fUS) is a novel neuroimaging technique, based on high-sensitivity ultrafast Doppler imaging of cerebral blood volume, capable of measuring brain activation and connectivity in rodents with high spatiotemporal resolution (100 μm, 1 ms). However, the skull attenuates acoustic waves, so fUS in rats currently requires craniotomy...
Article
Numerous reported data support the idea that Brain Derived Neurotrophic Factor (BDNF) is critically involved in both depression and comorbid pain. The possible direct effect of BDNF on pain mechanisms was assessed here and compared with behavioral/neurobiological features of neuropathic pain caused by chronic constriction injury to the sciatic nerv...
Article
Activation of neuronal nitric oxide synthase (nNOS), and consequent production of nitric oxide (NO), contributes to spinal hyperexcitability and enhanced pain sensation. All NOS isoforms are inhibited endogenously by asymmetric dimethylarginine (ADMA), which itself is metabolised by dimethylarginine dimethylaminohydrolase (DDAH). Inhibition of DDAH...
Article
Each year, millions of people worldwide are treated for primary or recurrent pelvic malignancies, involving radiotherapy in almost 50% of cases. Delayed development of visceral complications after radiotherapy is recognized in cancer survivors. Therapeutic doses of radiation may lead to the damage of healthy tissue around the tumor and abdominal pa...
Article
Full-text available
Painful experiences are multilayered, composed of sensory, affective, cognitive and behavioral facets. Whereas it is well accepted that the development of chronic pain is due to maladaptive neuronal changes, the underlying molecular mechanisms, their relationship to the different pain modalities, and indeed the localization of these changes are sti...
Article
Full-text available
Long-range coherences in spontaneous brain activity reflect functional connectivity. Here we propose a novel, highly resolved connectivity mapping approach, using ultrafast functional ultrasound (fUS), which enables imaging of cerebral microvascular haemodynamics deep in the anaesthetized rodent brain, through a large thinned-skull cranial window,...
Article
Full-text available
Neurotrophins are a family of trophic factors well known for their effects on neuronal survival, growth and neuronal differentiation. During the last decade, a large literature has shown in humans and in animal models that nerve growth factor (NGF) is a peripheral mediator of pain, especially in the states of inflammatory pain. NGF synthesis is ind...
Article
Full-text available
Oxycodone is a μ-opioid receptor agonist, used for the treatment of a large variety of painful disorders. Several studies have reported that oxycodone is a more potent pain reliever than morphine, and that it improves the quality of life of patients. However, the neurobiological mechanisms underlying the therapeutic action of these two opioids are...
Article
Full-text available
Vincristine is one of the most common anti-cancer drug therapies administered for the treatment of many types of cancer. Its dose-limiting side effect is the emergence of peripheral neuropathy, resulting in chronic neuropathic pain in many patients. This study sought to understand the mechanisms underlying the development of neuropathic pain by vin...
Article
Full-text available
Chronic cannabinoid exposure results in tolerance due to region-specific desensitization and down-regulation of CB1 cannabinoid receptors (CB1Rs). For most G-protein-coupled receptors, internalization closely follows rapid desensitization as an important component of long-term down-regulation. However, in vivo patterns of CB1R internalization are n...
Article
Oxaliplatin is a third-generation platinum-based chemotherapy drug that has gained importance in the treatment of advanced metastatic colorectal cancer. Its dose-limiting side effect is the production of chronic peripheral neuropathy. Using a modified model of oxaliplatin-induced sensory neuropathy, we investigated plastic changes at the cortical l...
Article
Full-text available
Central sensitization requires the activation of various intracellular signalling pathways within spinal dorsal horn neurons, leading to a lowering of activation threshold and enhanced responsiveness of these cells. Such plasticity contributes to the manifestation of chronic pain states and displays a number of features of long-term potentiation (L...
Data
Intrathecal Tat-NR2B9c selectively reduces active pain-related licking and biting behaviors following intraplantar formalin. (a) Time course of licking and biting behavior after injection of formalin into the hindpaw following intrathecal pre-treatment with Tat-NR2BAA (1.25 μg, n = 10) or Tat-NR2B9c (12.5 ng, n = 10; 125 ng, n = 6). (b) Total licki...
Data
Representative poststimulus histogram (PSTH) of electrically evoked responses of a WDR neuron to electrical stimulation of the hindpaw. A train of 16 transcutaneous electrical stimuli (2 ms wide pulses, 0.5 Hz, 3 x C-fiber threshold) was applied to the receptive field via two stimulating needles inserted under the skin of the hindpaw. Aβ- (0-20 ms)...
Data
Full-text available
Formalin electrophysiology experiment WDR cell characteristics. Cells were characterized prior to drug administration and formalin injection. There was no difference between cells recorded in any of the treatment groups. All data are expressed as mean ± SEM.
Data
Full-text available
Predrug control responses induced by transcutaneous electrical stimulation of the hindpaw receptive field of WDR neurons in naive rats. There were no differences between cells recorded in each treatment group for any measure prior to drug delivery. All data are expressed as mean ± SEM.
Data
Full-text available
Predrug control responses induced by natural stimulation of the hindpaw receptive field of WDR neurons in sham and SNL rats. There were no differences between cells recorded in each surgical group for any measure prior to drug treatment. All data are expressed as mean ± SEM.
Data
Full-text available
Predrug control responses induced by transcutaneous electrical stimulation of the hindpaw receptive field of WDR neurons in sham and SNL rats. There were no differences between cells recorded in each surgical group for any measure prior to treatment. All data are expressed as mean ± SEM.
Article
Multiple sclerosis is a chronic inflammatory demyelinating disease, associated, in 50-80% of patients, with persistent pain. While the type of pain that affects these patients is being more documented, the mechanisms underlying this pathology are still poorly understood and animal models of such chronic pain associated with MS are required. The aim...
Article
Full-text available
Peripheral inflammation or nerve injury induces a primary afferent barrage into the spinal cord, which can cause N-methyl D-aspartate (NMDA) receptor-dependent alterations in the responses of dorsal horn sensory neurons to subsequent afferent inputs. This plasticity, such as "wind-up" and central sensitization, contributes to the hyperexcitability...
Article
Full-text available
In pathological states, repetitive inputs from the ascending pathways involved in the genesis and integration of nociception, leads to molecular, anatomical and electrophysiological adaptive changes of these pathways, contributing to the development of pain chronicity. In the past, neurotrophic factors have been implicated in neuronal plasticity in...
Article
Full-text available
Experimental therapeutics designed to enhance recovery from spinal cord injury (SCI) primarily focus on augmenting the growth of damaged axons by elevating their intrinsic growth potential and/or by nullifying the influence of inhibitory proteins present in the mature CNS. However, these strategies may also influence the wiring of intact pathways....
Article
Full-text available
Here, we show that phosphatidylinositol 3-kinase (PI3K) is a key player in the establishment of central sensitization, the spinal cord phenomenon associated with persistent afferent inputs and contributing to chronic pain states. We demonstrated electrophysiologically that PI3K is required for the full expression of spinal neuronal wind-up. In an i...