Kratzer I.,University of Lyon |
Vasiljevic A.,University of Lyon |
Vasiljevic A.,Lyon Public Hospitals |
Rey C.,University of Lyon |
And 5 more authors.
Histochemistry and Cell Biology | Year: 2012
The choroid plexus epithelium controls the movement of solutes between the blood and the cerebrospinal fluid. It has been considered as a functionally more immature interface during brain development than in adult. The anatomical basis of this barrier is the interepithelial choroidal junction whose tightness has been attributed to the presence of claudins. We used quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry to identify different claudins in the choroid plexuses of developing and adult rats. Claudin-1, -2, and -3 were highly and selectively expressed in the choroid plexus as compared to brain or parenchyma microvessels and were localized at epithelial junctions. Claudin-6, -9, -19, and -22 also displayed a previously undescribed choroidal selectivity, while claudin-4, -5, and -16 were enriched in the cerebral microvessels. The choroidal pattern of tight junction protein expression in prenatal brains was already complex and included occludin and zonula occludens proteins. It differed from the adult pattern in that the poreforming claudin-2, claudin-9, and claudin-22 increased during development, while claudin-3 and claudin-6 decreased. Claudin-2 and claudin-11 presented a mirror image of abundance between lateral ventricle and fourth ventricle choroid plexuses. Imunohistochemical analysis of human fetal and postnatal brains for claudin-1, -2, and -3 demonstrated their early presence and localization at the apico-lateral border of the choroid plexus epithelial cells. Overall, choroidal epithelial tight junctions are already complex in developing brain. The observed differences in claudin expression between developing and adult choroid plexuses may indicate developmental differences in selective blood-cerebrospinal fluid transport functions. © Springer-Verlag 2012.
Vasylieva N.,Lyon Neuroscience Research Center |
Vasylieva N.,University Claude Bernard Lyon 1 |
Vasylieva N.,Lyon Institute of Nanotechnologies |
Maucler C.,Lyon Neuroscience Research Center |
And 9 more authors.
Analytical Chemistry | Year: 2013
Microelectrode biosensors are a promising technique to probe the brain interstitial fluid and estimate the extracellular concentration of neurotransmitters like glutamate. Their selectivity is largely based on maintaining high substrate specificity for the enzymes immobilized on microelectrodes. However, the effect of enzyme immobilization on substrate specificity is poorly understood. Furthermore, the accuracy of biosensor measurements for brain biological extracts has not been reliably established in comparison with conventional analytical techniques. In this study, microelectrode biosensors were prepared using different enzyme immobilization methods, including glutaraldehyde, a conventional cross-linker, and poly(ethylene glycol) diglycidyl ether (PEGDE), a milder immobilization reagent. Glutaraldehyde, but not PEGDE, significantly decreased the apparent substrate specificity of glutamate and glucose oxidase. For glutaraldehyde prepared biosensors, detection of secondary substrates by glutamate oxidase increased, resulting in a significant overestimate of glutamate levels. This effect was not observed with PEGDE-based biosensors, and when brain microdialysates were analyzed, the levels of glutamate detected by biosensors were consistent with those detected by capillary electrophoresis. In addition, basal concentrations of glutamate detected in vivo were approximately 10-fold lower than the levels detected with glutaraldehyde-based biosensors (e.g., 1.2 μM vs 16 μM, respectively). Overall, enzyme immobilization can significantly impact substrate specificity, and PEGDE is well-suited for the preparation of stable and selective biosensors. This development questions some of the previous biosensor studies aimed at detecting glutamate in the brain and opens new possibilities for specific neurotransmitter detection. © 2013 American Chemical Society.
Clement G.,International Space University |
Clement G.,Lyon Neuroscience Research Center |
Wood S.J.,Azusa Pacific University
PLoS ONE | Year: 2014
The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the lowfrequency range (i.e., at about 0.3 Hz) where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1-2 days. During dynamic linear acceleration (0.15-0.6 Hz, 61.7 m/s2) perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore-aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions. Copyright: © 2014 Zhou et al.
Debeaupte M.,University of Lyon |
Decullier E.,Hospices Civils de Lyon |
Decullier E.,University of Lyon |
Tringali S.,Center Hospitalier Lyon Sud |
And 6 more authors.
Otology and Neurotology | Year: 2015
Objective: To describe the reliability of the fully implantable middle ear transducer after successive technological changes. Study Design: Prospective, observational, multicenter study. Setting: Eight tertiary referral centers. Patients: One hundred twenty-three adults were implanted with one of the five successive versions of the fully implantable middle ear implant between September 2005 and July 2012. Methods: The reliability of each generation 2 years after implantation or at the maximal lifetime was reported by means of survival curves. Only technological failures were considered; non-technological failures were excluded from the analysis of reliability. Results: One hundred fifty-seven devices were implanted during the period of study. Fifteen explantations were related to non-technological problems (e.g., infections, extrusions, etc.). One hundred forty-two implants were followed in the analysis of reliability. We observed 32 technical failures at 2 years. At the maximal lifetime of follow-up, 46 implants failed. The end of the follow-up was the first of November 2012. Survival rates at 2 years were 0%, 76.1%, 84.2%, 81.8%, and 100% for each of the successive available versions, respectively. Conclusion: The reliability of the fully implantable middle ear implant improved over generations thanks to successive technological modifications that corrected the observed failures. The latest generation seems to be a reliable fully implantable middle ear implant system up to 22 months after implantation. The need to know the reliability of these active middle ear implants incites the creation of a follow-up register including patient's data and device failures to improve patient management. © 2015, Otology & Neurotology, Inc.
Schon D.,Aix - Marseille University |
Schon D.,French Institute of Health and Medical Research |
Tillmann B.,Lyon Neuroscience Research Center |
Tillmann B.,University of Lyon
Annals of the New York Academy of Sciences | Year: 2015
This paper brings together different perspectives on the investigation and understanding of temporal processing and temporal expectations. We aim to bridge different temporal deficit hypotheses in dyslexia, dysphasia, or deafness in a larger framework, taking into account multiple nested temporal scales. We present data testing the hypothesis that temporal attention can be influenced by external rhythmic auditory stimulation (i.e., musical rhythm) and benefits subsequent language processing, including syntax processing and speech production. We also present data testing the hypothesis that phonological awareness can be influenced by several months of musical training and, more particularly, rhythmic training, which in turn improves reading skills. Together, our data support the hypothesis of a causal role of rhythm-based processing for language processing and acquisition. These results open new avenues for music-based remediation of language and hearing impairment. © 2015 New York Academy of Sciences.
Tillmann B.,Lyon Neuroscience Research Center |
Tillmann B.,University of Lyon |
Albouy P.,Lyon Neuroscience Research Center |
Albouy P.,University of Lyon |
And 2 more authors.
Handbook of Clinical Neurology | Year: 2015
In contrast to the sophisticated music processing reported in the general population, individuals with congenital amusia show deficits in music perception and production. Congenital amusia occurs without brain damage, sensory or cognitive deficits, and has been suggested as a lifelong deficit with genetic origin. Even though recognized for a long time, this disorder has been systematically studied only relatively recently for its behavioral and neural correlates. The currently most investigated hypothesis about the underlying deficits concerns the pitch dimension, notably with impaired pitch discrimination and memory. Anatomic and functional investigations of pitch processing revealed that the amusic brain presents abnormalities in the auditory and inferior frontal cortices, associated with decreased connectivity between these structures. The deficit also impairs processing of pitch in speech material and processing of the time dimension in music for some of the amusic individuals, but does not seem to affect spatial processing. Some studies suggest at least partial dissociation in the disorder between perception and production. Recent studies revealed spared implicit pitch perception in congenital amusia, supporting the power of implicit cognition in the music domain. Current challenges consist in defining different subtypes of congenital amusia as well as developing rehabilitation programs for this "musical handicap.". © 2015 Elsevier B.V.
El Yacoubi M.,Lyon Neuroscience Research Center |
Rappeneau V.,Lyon Neuroscience Research Center |
Champion E.,Lyon Neuroscience Research Center |
Malleret G.,Lyon Neuroscience Research Center |
Vaugeois J.-M.,Lyon Neuroscience Research Center
Behavioural Brain Research | Year: 2013
Cardinal symptoms of depression include helplessness and anhedonia. In addition, depression and anxiety are often comorbid disorders. H/Rouen mice, a genetic mouse model of depression, display helpless behavior in the tail suspension test, whereas non-helpless NH/Rouen mice show the opposite behavior. It is unknown whether H/Rouen mice display an anxious behavior as compared to NH/Rouen mice, and is unclear whether they display anhedonia. Time spent in the periphery of an open-field, an index of anxiety, was found to be higher in male and female H/Rouen mice as compared to NH/Rouen mice. In the elevated plus-maze, a decrease in the number of entries and in the time spent in the open arms was observed in both male and female H/Rouen. In the light/dark box, the number of entries and the time spent in the anxiogenic bright compartment was significantly reduced in male and female H/Rouen mice. In addition, the preference of consumption of a 2% sucrose solution was significantly reduced in male and female H/Rouen mice as compared to NH/Rouen and I/Rouen mice in a two-bottle choice paradigm but was restored by a chronic (3 weeks) fluoxetine treatment. H/Rouen mice thus display both anxiety and anhedonia making them a potent animal model in the treatment of forms depression comorbidly expressed with anxiety. © 2013 .
Strazielle N.,Lyon Neuroscience Research Center |
Ghersi-Egea J.F.,French Institute of Health and Medical Research
Molecular Pharmaceutics | Year: 2013
The brain develops and functions within a strictly controlled environment resulting from the coordinated action of different cellular interfaces located between the blood and the extracellular fluids of the brain, which include the interstitial fluid and the cerebrospinal fluid (CSF). As a correlate, the delivery of pharmacologically active molecules and especially macromolecules to the brain is challenged by the barrier properties of these interfaces. Blood-brain interfaces comprise both the blood-brain barrier located at the endothelium of the brain microvessels and the blood-CSF barrier located at the epithelium of the choroid plexuses. Although both barriers develop extensive surface areas of exchange between the blood and the neuropil or the CSF, the molecular fluxes across these interfaces are tightly regulated. Cerebral microvessels acquire a barrier phenotype early during cerebral vasculogenesis under the influence of the Wnt/β-catenin pathway, and of recruited pericytes. Later in development, astrocytes also play a role in blood-brain barrier maintenance. The tight choroid plexus epithelium develops very early during embryogenesis. It is specified by various signaling molecules from the embryonic dorsal midline, such as bone morphogenic proteins, and grows under the influence of Sonic hedgehog protein. Tight junctions at each barrier comprise a distinctive set of claudins from the pore-forming and tightening categories that determine their respective paracellular barrier characteristics. Vesicular traffic is limited in the cerebral endothelium and abundant in the choroidal epithelium, yet without evidence of active fluid phase transcytosis. Inorganic ion transport is highly regulated across the barriers. Small organic compounds such as nutrients, micronutrients and hormones are transported into the brain by specific solute carriers. Other bioactive metabolites, lipophilic toxic xenobiotics or pharmacological agents are restrained from accumulating in the brain by several ATP-binding cassette efflux transporters, multispecific solute carriers, and detoxifying enzymes. These various molecular effectors differently distribute between the two barriers. Receptor-mediated endocytotic and transcytotic mechanisms are active in the barriers. They enable brain penetration of selected polypeptides and proteins, or inversely macromolecule efflux as it is the case for immnoglobulins G. An additional mechanism specific to the BCSFB mediates the transport of selected plasma proteins from blood into CSF in the developing brain. All these mechanisms could be explored and manipulated to improve macromolecule delivery to the brain. © 2013 American Chemical Society.
PubMed | University of Rome La Sapienza, Lyon Neuroscience Research Center and Neuroimaging Laboratory Santa Lucia Foundation
Type: | Journal: NeuroImage | Year: 2016
Motivated by previous results obtained in vitro, we investigated the dependence of the anomalous diffusion (AD) MRI technique on local magnetic susceptibility differences () driven by magnetic field inhomogeneity in human brains. The AD-imaging contrast investigated here is quantified by the stretched-exponential parameter , extracted from diffusion weighted (DW) data collected by varying diffusion gradient strengths. We performed T
PubMed | Lyon Neuroscience Research Center
Type: Journal Article | Journal: Journal of musculoskeletal & neuronal interactions | Year: 2016
We review the studies that have evaluated intermittent short-radius centrifugation as a potential countermeasure for cardiovascular, musculoskeletal, and sensorimotor deconditioning in simulated weightlessness.The findings from 18 experimental protocols that have used bed rest and dry immersion for comparing the protective effects of centrifugation versus standing upright or walking, and the effects of continuous vs. periodic exposure to centrifugation are discussed.Centrifugation for as little as 30 min per day was found to be effective in mitigating orthostatic intolerance and strength in postural muscle after 5 days of bed rest, but it was not effective in mitigating plasma volume loss.To determine the optimal prescription for centrifugation as a countermeasure, we recommend further studies using (a) bed rest of longer duration, (b) individualized prescriptions of centrifugation combined with exercise, and