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See detailFunctional morphology of the sonic apparatus in Ophidion barbatum (Teleostei, Ophidiidae)
Parmentier, Eric ULg; Fontenelle, N.; Fine, M. L. et al

in Journal of Morphology (2006), 267(12), 1461-1468

Most soniferous fishes producing sounds with their swimbladder utilize relatively simple mechanisms: contraction and relaxation of a unique pair of sonic muscles cause rapid movements of the swimbladder ... [more ▼]

Most soniferous fishes producing sounds with their swimbladder utilize relatively simple mechanisms: contraction and relaxation of a unique pair of sonic muscles cause rapid movements of the swimbladder resulting in sound production. Here we describe the sonic mechanism for Ophidion barbatum, which includes three pairs of sonic muscles, highly transformed vertebral centra and ribs, a neural arch that pivots and a swimbladder whose anterior end is modified into a bony structure, the rocker bone. The ventral and intermediate muscles cause the rocker bone to swivel inward, compressing the swimbladder, and this action is antagonized by the dorsal muscle. Unlike other sonic systems in which the muscle contraction rate determines sound fundamental frequency, we hypothesize that slow contraction of these antagonistic muscles produces a series of cycles of swimbladder vibration. [less ▲]

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See detailFunctional morphology of the sonic apparatus in the fawn cusk-eel Lepophidium profundorum (Gill, 1863)
Fine, M. L.; Lin, H.; Nguyen, B. B. et al

in Journal of Morphology (2007), 268(11), 953-966

Recent reports of high frequency sound production by cusk-eels cannot be explained adequately by known mechanisms, i.e., a forced response driven by fast sonic muscles on the swimbladder. Time to complete ... [more ▼]

Recent reports of high frequency sound production by cusk-eels cannot be explained adequately by known mechanisms, i.e., a forced response driven by fast sonic muscles on the swimbladder. Time to complete a contraction-relaxation cycle places a ceiling on frequency and is unlikely to explain sounds with dominant frequencies above 1 kHz. We investigated sonic morphology in the fawn cusk-eel Lepophidium profundorum to determine morphology potentially associated with high frequency sound production and quantified development and sexual dimorphism of sonic structures. Unlike other sonic systems in fishes in which muscle relaxation is caused by internal pressure or swimbladder elasticity, this system utilizes antagonistic pairs of muscles: ventral and intermediate muscles pull the winglike process and swimbladder forward and pivot the neural arch (neural rocker) above the first vertebra backward. This action stretches a fenestra in the swimbladder wall and imparts strain energy to epineural ribs, tendons and ligaments connected to the anterior swimbladder. Relatively short antagonistic dorsal and dorsomedial muscles pull on the neural rocker, releasing strain energy, and use a lever advantage to restore the winglike process and swimbladder to their resting position. Sonic components grow isometrically and are typically larger in males although the tiny intermediate muscles are larger in females. Although external morphology is relatively conservative in ophidiids, sonic morphology is extremely variable within the family. [less ▲]

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See detailFunctional muscle impairment in facioscapulohumeral muscular dystrophy is correlated with oxidative stress and mitochondrial dysfunction.
Turki, Ahmed; Hayot, Maurice; Carnac, Gilles et al

in Free Radical Biology & Medicine (2012), 53(5), 1068-79

Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms ... [more ▼]

Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms, legs, and trunk. FSHD is genetically linked to contractions of the D4Z4 repeat array causing activation of several genes. One of these maps in the repeat itself and expresses the DUX4 (the double homeobox 4) transcription factor causing a gene deregulation cascade. In addition, analyses of the RNA or protein expression profiles in muscle have indicated deregulations in the oxidative stress response. Since oxidative stress affects peripheral muscle function, we investigated mitochondrial function and oxidative stress in skeletal muscle biopsies and blood samples from patients with FSHD and age-matched healthy controls, and evaluated their association with physical performances. We show that specifically, oxidative stress (lipid peroxidation and protein carbonylation), oxidative damage (lipofuscin accumulation), and antioxidant enzymes (catalase, copper-zinc-dependent superoxide dismutase, and glutathione reductase) were higher in FSHD than in control muscles. FSHD muscles also presented abnormal mitochondrial function (decreased cytochrome c oxidase activity and reduced ATP synthesis). In addition, the ratio between reduced (GSH) and oxidized glutathione (GSSG) was strongly decreased in all FSHD blood samples as a consequence of GSSG accumulation. Patients with FSHD also had reduced systemic antioxidative response molecules, such as low levels of zinc (a SOD cofactor), selenium (a GPx cofactor involved in the elimination of lipid peroxides), and vitamin C. Half of them had a low ratio of gamma/alpha tocopherol and higher ferritin concentrations. Both systemic oxidative stress and mitochondrial dysfunction were correlated with functional muscle impairment. Mitochondrial ATP production was significantly correlated with both quadriceps endurance (T(LimQ)) and maximal voluntary contraction (MVC(Q)) values (rho=0.79, P=0.003; rho=0.62, P=0.05, respectively). The plasma concentration of oxidized glutathione was negatively correlated with the T(LimQ), MVC(Q) values, and the 2-min walk distance (MWT) values (rho=-0.60, P=0.03; rho=-0.56, P=0.04; rho=-0.93, P<0.0001, respectively). Our data characterized oxidative stress in patients with FSHD and demonstrated a correlation with their peripheral skeletal muscle dysfunction. They suggest that antioxidants that might modulate or delay oxidative insult may be useful in maintaining FSHD muscle functions. [less ▲]

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See detailFunctional nanogels as platforms for imparting antibacterial, antibiofilm, and antiadhesion activities to stainless steel
Faure, Emilie ULg; Falentin, Céline ULg; Svaldo Lanero, Tiziana ULg et al

in Advanced Functional Materials (2012), 22(24), 5271-5282

In this work, long-term antibacterial, antiadhesion, and antibiofilm activities are afforded to industrial stainless steel surfaces following a green and bio-inspired strategy. Starting from catechol ... [more ▼]

In this work, long-term antibacterial, antiadhesion, and antibiofilm activities are afforded to industrial stainless steel surfaces following a green and bio-inspired strategy. Starting from catechol bearing synthetic polymers, the film cross-linking and the grafting of active (bio)molecules are possible under environmentally friendly conditions (in aqueous media and at room temperature). A bio-inspired polyelectrolyte, a polycation-bearing catechol, is used as the film-anchoring polymer while a poly(methacrylamide)-bearing quinone groups serves as the cross-linking agent in combination with a polymer bearing primary amine groups. The amine/quinone reaction is exploited to prepare stable solutions of nanogels in water at room temperature that can be easily deposited to stainless steel. This coating provides quinonefunctionalized surfaces that are then used to covalently anchor active (bio) molecules (antibiofi lm enzyme and antiadhesion polymer) through thiol/ quinone reactions. [less ▲]

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See detailFunctional nanoobjects by means of polymers
Van Butsele, Kathy; Aqil, Abdelhafid ULg; Jérôme, Christine ULg

Conference (2008, September 08)

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See detailFunctional neuroanatomy of disorders of consciousness
Di Perri, Carol; Stender, Johan; Laureys, Steven ULg et al

in CAVANNA, Andrea (Ed.) Epilepsy and behavior Alteration of Counsciousness in Epilepsy (2013)

Our understanding of the mechanisms of loss and recovery of consciousness, following severe brain injury or during anesthesia, is changing rapidly. Recent neuroimaging studies have shown that patients ... [more ▼]

Our understanding of the mechanisms of loss and recovery of consciousness, following severe brain injury or during anesthesia, is changing rapidly. Recent neuroimaging studies have shown that patients with chronic disorders of consciousness and subjects undergoing general anesthesia present a complex dysfunctionality in the architecture of brain connectivity. At present, the global hallmark of impaired consciousness appears to be amultifaceted dysfunctional connectivity pattern with both within-network loss of connectivity in awidespread frontoparietal network and between-network hyperconnectivity involving other regions such as the insula and ventral tegmental area. Despite ongoing efforts, the mechanisms underlying the emergence of consciousness after severe brain injury are not thoroughly understood. Important questions remain unanswered:What triggers the connectivity impairment leading to disorders of consciousness? Why do some patients recover from coma, while others with apparently similar brain injuries do not? Understanding these mechanisms could lead to a better comprehension of brain function and, hopefully, lead to new therapeutic strategies in this challenging patient population. [less ▲]

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See detailFunctional neuroanatomy of hypnotic state
Maquet, Pierre ULg; Faymonville, Marie-Elisabeth ULg; Degueldre, Christian ULg et al

in Biological Psychiatry (1999), 45(3), 327-333

BACKGROUND: The aim of the present study was to describe the distribution of regional cerebral blood flow during the hypnotic state (HS) in humans, using positron-emission tomography (PET) and statistical ... [more ▼]

BACKGROUND: The aim of the present study was to describe the distribution of regional cerebral blood flow during the hypnotic state (HS) in humans, using positron-emission tomography (PET) and statistical parametric mapping. METHODS: The hypnotic state relied on revivification of pleasant autobiographical memories and was compared to imaging autobiographical material in "normal alertness." A group of 9 subjects under polygraphic monitoring received six H215O infusions and was scanned in the following order: alert-HS-HS-HS with color hallucination-HS with color hallucination-alert. PET data were analyzed using statistical parametric mapping (SPM95). RESULTS: The group analysis showed that hypnotic state is related to the activation of a widespread, mainly left-sided, set of cortical areas involving occipital, parietal, precentral, premotor, and ventrolateral prefrontal cortices and a few right-sided regions: occipital and anterior cingulate cortices. CONCLUSIONS: The pattern of activation during hypnotic state differs from those induced in normal subjects by the simple evocation of autobiographical memories. It shares many similarities with mental imagery, from which it differs by the relative deactivation of precuneus. [less ▲]

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See detailFunctional neuroanatomy of the hypnotic state.
Faymonville, Marie-Elisabeth ULg; Boly, Mélanie ULg; Laureys, Steven ULg

in Journal of Physiology - Paris (2006), 99(4-6), 463-9

The neural mechanisms underlying hypnosis and especially the modulation of pain perception by hypnosis remain obscure. Using PET we first described the distribution of regional cerebral blood flow during ... [more ▼]

The neural mechanisms underlying hypnosis and especially the modulation of pain perception by hypnosis remain obscure. Using PET we first described the distribution of regional cerebral blood flow during the hypnotic state. Hypnosis relied on revivification of pleasant autobiographical memories and was compared to imaging autobiographical material in "normal alertness". The hypnotic state was related to the activation of a widespread set of cortical areas involving occipital, parietal, precentral, premotor, and ventrolateral prefrontal and anterior cingulate cortices. This pattern of activation shares some similarities with mental imagery, from which it mainly differs by the relative deactivation of precuneus. Second, we looked at the anti-nociceptive effects of hypnosis. Compared to the resting state, hypnosis reduced pain perception by approximately 50%. The hypnosis-induced reduction of affective and sensory responses to noxious thermal stimulation were modulated by the activity in the midcingulate cortex (area 24a'). Finally, we assessed changes in cerebral functional connectivity related to hypnosis. Compared to normal alertness (i.e., rest and mental imagery), the hypnotic state, significantly enhanced the functional modulation between midcingulate cortex and a large neural network involved in sensory, affective, cognitive and behavioral aspects of nociception. These findings show that not only pharmacological but also psychological strategies for pain control can modulate the cerebral network involved in noxious perception. [less ▲]

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See detailThe functional neuroanatomy of tinnitus: insights from resting-state fMRI
Maudoux, Audrey ULg

Doctoral thesis (2012)

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See detailFunctional neuroanatomy underlying the clinical subcategorization of minimally conscious state patients.
Bruno, Marie-Aurélie ULg; Majerus, Steve ULg; Boly, Mélanie ULg et al

in Journal of Neurology (2012), 259(6), 1087-98

Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this ... [more ▼]

Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this entity can be subcategorized into MCS- (i.e., patients only showing nonreflex behavior such as visual pursuit, localization of noxious stimulation and/or contingent behavior) and MCS+ (i.e., patients showing command following).Patterns of cerebral glucose metabolism were studied using [(18)F]-fluorodeoxyglucose-PET in 39 healthy volunteers (aged 46 +/- 18 years) and 27 MCS patients of whom 13 were MCS- (aged 49 +/- 19 years; 4 traumatic; 21 +/- 23 months post injury) and 14 MCS+ (aged 43 +/- 19 years; 5 traumatic; 19 +/- 26 months post injury). Results were thresholded for significance at false discovery rate corrected p < 0.05.We observed a metabolic impairment in a bilateral subcortical (thalamus and caudate) and cortical (fronto-temporo-parietal) network in nontraumatic and traumatic MCS patients. Compared to MCS-, patients in MCS+ showed higher cerebral metabolism in left-sided cortical areas encompassing the language network, premotor, presupplementary motor, and sensorimotor cortices. A functional connectivity study showed that Broca's region was disconnected from the rest of the language network, mesiofrontal and cerebellar areas in MCS- as compared to MCS+ patients.The proposed subcategorization of MCS based on the presence or absence of command following showed a different functional neuroanatomy. MCS- is characterized by preserved right hemispheric cortical metabolism interpreted as evidence of residual sensory consciousness. MCS+ patients showed preserved metabolism and functional connectivity in language networks arguably reflecting some additional higher order or extended consciousness albeit devoid of clinical verbal or nonverbal expression. [less ▲]

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See detailFunctional Neuroimaging Approaches to the Changing Borders of Consciousness
Noirhomme, Quentin ULg; Soddu, Andrea ULg; Vanhaudenhuyse, Audrey ULg et al

in Journal of Psychophysiology (2010), 24(2), 68-75

The bedside diagnosis of vegetative and minimally conscious patients is extremely challenging, and prediction of individual long-term outcome remains difficult. State-of the art neuroimaging methods could ... [more ▼]

The bedside diagnosis of vegetative and minimally conscious patients is extremely challenging, and prediction of individual long-term outcome remains difficult. State-of the art neuroimaging methods could help disentangle complex cases and offer new prognostic criteria. These methods can be divided into to three categories: First, new anatomical MRI neuroimaging methods, like diffusion tensor imaging (DTI) or spectroscopy, and passive functional imaging methods (looking at the brain’s activation induced by external stimuli), could provide new diagnostic and prognostic markers. Second, neuroimaging methods based on active collaboration from the patient could help to detect clinically unnoticed signs of consciousness. Third, developments in brain-computer interfaces based on EEG, functional MRI, or EMG offer communication possibilities in brain-damaged patients who can neither verbally nor nonverbally express their thoughts or wishes. These new approaches raise important issues not only from a clinical and ethical perspective (i.e., patients’ diagnosis, prognosis and management) but also from a neuroscientific standpoint, as they enrich our current understanding of the emergence and function of the conscious human mind. [less ▲]

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See detailFunctional Neuroimaging during Human Sleep
Kussé, Caroline ULg; Maquet, Pierre ULg

in Barrett, Deirdre; McNamara, Patrick (Eds.) Encyclopedia of sleep and dreams (2 volumes): the evolution, function, nature and mysteries of slumber (2012)

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See detailFunctional neuroimaging in sleep, sleep deprivation, and sleep disorders.
Desseilles, Martin ULg; Dang Vu, Thien Thanh ULg; Maquet, Pierre ULg

in Chokroverty, Sudhansu; Montagna, Pasquale (Eds.) Handbook of Clinical Neurology, Sleep Disorders, Part I (2011)

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See detailFunctional neuroimaging in the vegetative state
Laureys, Steven ULg

in NeuroRehabilitation (2004), 19(4), 335-341

The interest of functional imaging in patients in a vegetative state is twofold. First, the vegetative state continues to represent a major clinical and ethical problem, in terms of diagnosis, prognosis ... [more ▼]

The interest of functional imaging in patients in a vegetative state is twofold. First, the vegetative state continues to represent a major clinical and ethical problem, in terms of diagnosis, prognosis, treatment, everyday management and end-of-life decisions. Second, it offers a lesional approach to the study of human consciousness and adds to the international research effort on identifying the neural correlate of consciousness. Cerebral metabolism has been shown to be massively reduced in the vegetative state. However, recovery of consciousness from vegetative state seems not always associated with substantial changes in global metabolism. Recent PET data indicate that some vegetative patients are unconscious not just because of a global loss of neuronal function, but due to an altered activity in a critical fronto-parietal cortical network and to abolished functional connections within this network and with non-specific thalamic nuclei. Recovery of consciousness was shown to be paralleled by a restoration of this cortico-thalamo-cortical interaction. Despite the metabolic impairment, external stimulation still induces neuronal activation as shown by both auditory and noxious stimuli. However, this activation is limited to primary cortices and dissociated from higher-order associative cortices, thought to be necessary for conscious perception. [less ▲]

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See detailFunctional Neuroimaging Insights into the Physiology of Human Sleep
Dang Vu, Thien Thanh ULg; Schabus, Manuel; Desseilles, Martin ULg et al

in Sleep (2010), 33(12), 1589-1603

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See detailFunctional neuroimaging of auditory processing
Laureys, Steven ULg; Salmon, Eric ULg; Goldman, Serge et al

in Acta Oto-Rhino-Laryngologica Belgica (2003), 57(4), 267-273

There is a complex functional organization of the central auditory system from the brainstem to primary and associative auditory cortices. Functional neuroimaging has been used to visualize and confirm ... [more ▼]

There is a complex functional organization of the central auditory system from the brainstem to primary and associative auditory cortices. Functional neuroimaging has been used to visualize and confirm the spatial distribution of brain activation in temporal areas for the processing of simple acoustic stimuli. Brain activity is much more complex for words, and different networks can be recruited when phonological, lexical and semantic levels of processing are engaged. [less ▲]

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See detailFunctional neuroimaging of human REM sleep
Meyer, Christelle ULg; Jedidi, Zayd ULg; Muto, Vincenzo ULg et al

in Nofzinger, Eric; Maquet, Pierre; Thorpy, Michael J. (Eds.) Neuroimaging of sleep and sleep disorders (2013)

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See detailFunctional neuroimaging of semantic and episodic forms of self-knowledge
D'Argembeau, Arnaud ULg

Conference (2009, January 15)

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See detailFunctional neuroimaging of the reciprocal influences between sleep and wakefulness.
Jedidi, Zayd ULg; Rikir, Estelle ULg; Muto, Vincenzo ULg et al

in Pflugers Archiv : European journal of physiology (2011), 463(1), 103-9

The activity patterns adopted by brain neuronal populations differ dramatically between wakefulness and sleep. However, these vigilance states are not independent and they reciprocally interact. Here, we ... [more ▼]

The activity patterns adopted by brain neuronal populations differ dramatically between wakefulness and sleep. However, these vigilance states are not independent and they reciprocally interact. Here, we provide evidence that in humans, regional brain activity during wakefulness is influenced by sleep regulation, namely by the interaction between sleep homeostasis and circadian signals. We also show that, by contrast, regional brain activity during sleep is influenced by the experience acquired during the preceding waking period. These data reveal the dynamic interactions by which the succession of vigilance states support normal brain function and human cognition. [less ▲]

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