Search results for "CORTEX"
showing 10 items of 1827 documents
Somatosensory evoked potentials after posterior tibial nerve stimulation — normative data in children
2000
We report normative data of somatosensory evoked potentials to posterior tibial nerve stimulation from 47 children 4–15 years of age. We recorded near-field potentials from the peripheral nerve, the cauda equina, the lumbar spinal cord and the somatosensory cortex. Far-field potentials were recorded from the scalp electrodes with a reference at Erb's point and on the earlobe. The near-field potentials N8 (peripheral nerve) and P40 (cortex) were present in all children. N20 (near-field from the cauda equina) was recorded in 38 subjects. N22 (near-field from the lumbar spinal cord), P30 and N37 ( both farfield waveforms probably generated in the brainstem) were recorded in 46 subjects each. T…
Tocilizumab induces corticosteroid sparing in rheumatoid arthritis patients in clinical practice
2015
International audience; Objective. The aim of this study was to evaluate the impact of introducing tocilizumab (TCZ) as co-therapy with CS in patients with RA.Methods. This study was an open, observational, retrospective multicentre study. RA patients treated with oral CS for >3 months who started treatment with TCZ between December 2009 and June 2011 in five centres were included. Variables included demographic data, disease history, co-treatments, disease activity and dose of CS at inclusion and at weeks 4, 8, 12 and 24. The evolution of disease activity and of the dose of CS (analysis of variance with repeated measures) were analysed, searching for factors correlated with changes in the …
Predicting domain-specific actions in expert table tennis players activates the semantic brain network.
2018
Motor expertise acquired during long-term training in sports enables top athletes to predict the outcomes of domain-specific actions better than nonexperts do. However, whether expert players encode actions, in addition to the concrete sensorimotor level, also at a more abstract, conceptual level, remains unclear. The present study manipulated the congruence between body kinematics and the subsequent ball trajectory in videos of an expert player performing table tennis serves. By using functional magnetic resonance imaging, the brain activity was evaluated in expert and nonexpert table tennis players during their predictions on the fate of the ball trajectory in congruent versus incongruent…
Action expertise reduces brain activity for audiovisual matching actions: An fMRI study with expert drummers
2011
When we observe someone perform a familiar action, we can usually predict what kind of sound that action will produce. Musical actions are over-experienced by musicians and not by non-musicians, and thus offer a unique way to examine how action expertise affects brain processes when the predictability of the produced sound is manipulated. We used functional magnetic resonance imaging to scan 11 drummers and 11 age- and gender-matched novices who made judgments on point-light drumming movements presented with sound. In Experiment 1, sound was synchronized or desynchronized with drumming strikes, while in Experiment 2 sound was always synchronized, but the natural covariation between sound in…
Cytopathologic and neurochemical correlates of progression to motor/cognitive impairment in SIV-infected rhesus monkeys.
1994
Neurochemical, pathologic, virologic, and histochemical correlates of simian immunodeficiency virus (SIV)-associated central nervous system (CNS) dysfunction were assessed serially or at necropsy in rhesus monkeys that exhibited motor and cognitive deficits after SIV infection. Some infected monkeys presented with signs of acquired immunodeficiency disease (AIDS) at the time of sacrifice. Seven of eight animals exhibited motor skill impairment which was associated with elevated quinolinic acid in cerebrospinal fluid (CSF). Examination of the brains revealed diffuse increases in glial fibrillary acidic protein immunoreacti vity in cerebral cortex in all animals, regardless of evidence of imm…
Detection performance of normal cats and those lacking areas 17 and 18: a behavioral approach to analyse pattern recognition deficits.
1986
The ability of cats to discriminate between two geometrical outline patterns in the presence of superimposed Gaussian visual noise was tested before and after bilateral removal of cortical area 17 and parts of area 18. The detection probability PD was measured as a function of the signal-to-noise ratio for the parameters: noise bandwidth, spatial frequency content and rate of movement of patterns. In both normal and lesioned cats a broadband noise was found to be most effective in masking the large patterns while two other types of noise, a medium frequency noise and a high frequency noise had little or no masking effect. For recognition of the smaller patterns in normal cats the medium fre…
V1 non-linear properties emerge from local-to-global non-linear ICA
2006
It has been argued that the aim of non-linearities in different visual and auditory mechanisms may be to remove the relations between the coefficients of the signal after global linear ICA-like stages. Specifically, in Schwartz and Simoncelli (2001), it was shown that masking effects are reproduced by fitting the parameters of a particular non-linearity in order to remove the dependencies between the energy of wavelet coefficients. In this work, we present a different result that supports the same efficient encoding hypothesis. However, this result is more general because, instead of assuming any specific functional form for the non-linearity, we show that by using an unconstrained approach…
Hyaluronic Acid-Based Micelles as Ocular Platform to Modulate the Loading, Release, and Corneal Permeation of Corticosteroids
2017
The aim of this work is to prepare hyaluronic acid-based micelles as a platform to load corticosteroid drugs and to improve their corneal permeation after administration on the ocular surface. Three amphiphilic derivatives of hyaluronic acid (HA) are synthesized using different amounts of hexadecylamine (C16 -NH2 ). HAC16 a, HAC16 b, and HAC16 c derivatives are able to form micelles by the cosolvent evaporation method and to entrap corticosteroids (dexamethasone, triamcinolone, triamcinolone acetonide). HAC16 a and HAC16 b micelles show the best results in terms of drug loading and particle size. They are also able to improve drug release compared to free drug solution or suspension. In add…
Regional blood flow in deep structures of the brain measured in acute cat experiments by means of a new beta-sensitive semiconductor needle detector.
1967
Regional cerebral blood flow was measured by means of isotope clearance with a new type of solid state beta-sensitive needle detector (diameter 0.9 mm) introduced into the brain tissue in acute cat experiments. The flow values obtained within the cortex were compared with values recorded above the same cortical region with the same needle detector, or with a small GM-tube. The insertion of the needle detector into the brain tissue gave rise to injury (checked histologically) which deformed the clearance curves in a manner suggesting that the normal circulation had been destroyed within the tissue from which the measurements were made.
PSA-NCAM immunocytochemistry in the cerebral cortex and other telencephalic areas of the lizard Podarcis hispanica: differential expression during me…
2002
The lizard medial cortex, a region homologous to the mammalian dentate gyrus, shows postnatal neurogenesis and the surprising ability to replace its neurons after being lesioned specifically with the neurotoxin 3-acetylpyridine. As the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is expressed during neuronal migration and differentiation, we have studied its distribution in adult lizards and also during the lesion-regeneration process. In the medial cortex of control animals, many labeled fusiform somata, presumably corresponding to migratory neuroblasts, appeared in the inner plexiform layer. There were also scattered immunoreactive granule neurons in the cell layer.…