Search results for "NEUROSCIENCE"

Perturbed Glucose Metabolism: Insights into Multiple Sclerosis Pathogenesis

2014

Multiple sclerosis (MS) is a complex debilitating disease of the central nervous system perceived to result from the autoimmune effect of T cells in damaging myelin sheath. However, the exact pathogenesis of the disease remains elusive. Initial studies describing the possibility of defective pyruvate metabolism in MS were performed in 1950s. The group observed elevated blood pyruvate level in both fasting and postprandial times in MS patients with relapse. Similarly, other investigators also reported increased fasting pyruvate level in this disease. These reports hint to a possible abnormality of pyruvate metabolism in MS patients. In addition, increase in levels of Krebs cycle acids like a…

PGC-1α: a master gene that is hard to master

2012

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a transcriptional coactivator that favorably affects mitochondrial function. This concept is supported by an increasing amount of data including studies in PGC-1α gene-deleted mice, suggesting that PGC-1α is a rescue factor capable of boosting cell metabolism and promoting cell survival. However, this view has now been called into question by a recent study showing that adeno-associated virus-mediated PGC-1α overexpression causes overt cell degeneration in dopaminergic neurons. How is this to be understood, and can these seemingly conflicting findings tell us something about the role of PGC-1α in cell stress and in cont…

Contribution of area 19 to the foreground-background-interaction of the cat: an analysis based on single cell recordings and behavioural experiments.

1990

The contribution of area 19 to pattern discrimination in the cat was studied by single cell recordings in this area and by behavioural experiments before and after bilateral lesions. In order to make quantitative comparisons between behavioural performance and that of cell systems, we introduced a new parameter that characterizes visual neurons by their signal-to-noise (S/N) thresholds. A structured visual background made up of Gaussian visual broadband noise which could be moved was superimposed on the signal (moving bars or outline patterns) and the S/N characteristics of the response were determined by varying the signal intensity. The detection performance of cats after bilateral lesion…

European vestibular experiments on the Spacelab-1 mission: 7. Ocular counterrolling measurements pre- and post-flight.

1986

The static ocular counterrolling (OCR) of the four scientific crew members in the first Spacelab mission was measured during baseline-data-collection before and after the flight of SL-1. It was presumed that the modification of otolithic responses during spaceflight will be reflected in specific changes of the OCR-gain on the first days after recovery. The magnitude of OCR was determined analysing colour-transparencies of subjects right eyes that were produced in different positions of lateral body tilt. In general, one subject did not show any changes at all; three subjects exhibited a significant decrease of OCR-gain after exposure to weightlessness, whereby differences could be found bet…

Reversed Polarity bi-tDCS over M1 during a Five Days Motor Task Training Did Not Influenced Motor Learning. A Triple-Blind Clinical Trial

2021

This article belongs to the Special Issue Applications of Neuromodulation on Pain and Motor Learning.

2018

Beyond the classical paradigm that presents the Anticipatory Postural Adjustments (APAs) as a manner to create forces that counteract disturbances arising from the moving segment during a pointing task, there is a controversial discussion about the role APAs to facilitate the movement and perform a task accurately. In addition, arm kinematics features are classically used to infer the content of motor planning for the execution and the control of arm movements. The present study aimed to disentangle the conflicting role of APAs during an arm-pointing task in which the subjects reach a central diode that suddenly turns on, while their postural stability was manipulated. Three postures were a…

Lack of Accredited Clinical Training in Movement Disorders in Europe, Egypt, and Tunisia.

2020

BACKGROUND: Little information is available on the official postgraduate and subspecialty training programs in movement disorders (MD) in Europe and North Africa.OBJECTIVE: To survey the accessible MD clinical training in these regions.METHODS: We designed a survey on clinical training in MD in different medical fields, at postgraduate and specialized levels. We assessed the characteristics of the participants and the facilities for MD care in their respective countries. We examined whether there are structured, or even accredited postgraduate, or subspecialty MD training programs in neurology, neurosurgery, internal medicine, geriatrics, neuroradiology, neuropediatrics, and general practic…

The role of vagus activity in the presynaptic control of noradrenaline release from rabbit atria.

1990

Abstract On various heart preparations with the autonomic innervation left intact, vagus nerve stimulation (VNS) has been found to reduce the amount of noradrenaline (NA) that is released in response to sympathetic nerve stimulation (SNS). The following experiments were carried out on an innervated rabbit perfused atria preparation in which the overflow of NA and acetylcholine (ACh) could be determined simultaneously. VNS impulses applied at a fixed time interval before the corresponding SNS impulses reduced NA overflow when the interval was 3–10 ms (early peak) or 200–283 ms (late peak of inhibition). VNS applied 30–167 ms before SNS had no significant effect (“ineffectual period”). Both i…

Electrically induced torque decrease reflects more than muscle fatigue

2014

The aim of the study was to compare the fatigue induced by different electrical stimulation (ES) protocols. The triceps surae muscle of 8 healthy subjects was fatigued with 4 protocols (30 Hz-500 μs, 30 Hz-1 ms, 100 Hz-1 ms, and 100 Hz-500 μs), composed of 60 trains (4 s on-6 s off), delivered at an intensity evoking 30% of maximal voluntary contraction (MVC). Fatigue was quantified by ES and MVC torque decreases. The amplitude of the twitch delivered at the intensity and pulse width used in each fatiguing protocol (twitch at Istim ) was analyzed. All parameters decreased significantly after all protocols. The ES torque decrease correlated positively with the twitch decrease elicited at Ist…

Effects of electrical stimulation pattern on quadriceps isometric force and fatigue in individuals with spinal cord injury

2015

Introduction Variable frequency trains (VFT) or train combinations have been suggested as useful strategies to offset the rapid fatigue induced by constant frequency trains (CFT) during electrical stimulation. However, most studies have been of short duration with limited functional application in those with spinal cord injury (SCI). We therefore tested force and fatigue in response to VFT, CFT, and combined patterns in strength training-like conditions (6-s contractions). Methods Ten SCI individuals underwent either CFT or VFT patterns until target torque was no longer produced and then switched immediately to the other pattern. Results Target torque was reached more times when VFT was use…