Search results for "cortex"
showing 10 items of 1827 documents
INHIBITION OF CELLULAR GROWTH AND STEROID 11β-HYDROXYLATION INRAS-TRANSFORMED ADRENOCORTICAL CELLS BY THE FUNGAL TOXINS BETICOLINS
1996
Abstract The proliferation of GM16 and 4CDTras-transformed newborn rat adrenocortical (RTAC) cells and Y1 mouse adrenal tumor cells was inhibited by beticolins, the fungal toxins extracted fromCercospora beticola, at submicromolar concentrations in a dose-dependent manner. Inhibitory concentrations for half the maximum inhibition were 150, 75 and 25 n M for beticolin-1 and 230, 150 and 50 n M for beticolin-2 in GM16, 4CDT and Y1 cells respectively. Beticolins strongly inhibited the production of 11β-hydroxysteroids on the second and third days of treatment in a dose-dependent manner between 0.1 and 1 μ M . Beticolins were shown by confocal microscopy to be localized in cytoplasmic organelle…
EFFICACY OF REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION/TRANSCRANIAL DIRECT CURRENT STIMULATION IN COGNITIVE NEUROREHABILITATION
2008
Summary: Cognitive deficits are a common consequence of neurologic disease, in particular, of traumatic brain injury, stroke, and neurodegenerative disorders, and there is evidence that specific cognitive training may be effective in cognitive rehabilitation. Several investigations emphasize the fact that interacting with cortical activity, by means of cortical stimulation, can positively affect the short-term cognitive performance and improve the rehabilitation potential of neurologic patients. In this respect, preliminary evidence suggests that cortical stimulation may play a role in treating aphasia, unilateral neglect, and other cognitive disorders. Several possible mechanisms can accou…
Interhemispheric inhibition during mental actions of different complexity.
2013
International audience; Several investigations suggest that actual and mental actions trigger similar neural substrates. Yet, neurophysiological evidences on the nature of interhemispheric interactions during mental movements are still meagre. Here, we asked whether the content of mental images, investigated by task complexity, is finely represented in the inhibitory interactions between the two primary motor cortices (M1s). Subjects' left M1 was stimulated by means of transcranial magnetic stimulation (TMS) while they were performing actual or mental movements of increasing complexity with their right hand and exerting a maximum isometric force with their left thumb and index. Thus, we sim…
Enhancing memory performance with rTMS in healthy subjects and individuals with Mild Cognitive Impairment: the role of the right dorsolateral prefron…
2012
A debated question in the literature is the degree of anatomical and functional lateralization of the executive control processes subserved by the dorsolateral prefrontal cortex (DLPFC) during recognition memory retrieval. We investigated if transient inhibition and excitation of the left and right DLPFC at retrieval by means of repetitive transcranial magnetic stimulation (rTMS) modulate recognition memory performance in 100 healthy controls (HCs) and in 8 patients with Mild Cognitive Impairment (MCI). Recognition memory tasks of faces, buildings and words were used in different experiments. rTMS-inhibition of the right DLPFC enhanced recognition memory of verbal and non verbal material in…
P 96. Prismatic lenses as a novel tool to directionally manipulate motor cortex excitability: Evidence from paired-pulse TMS
2013
Introduction Prismatic adaptation (PA) is a visuo-motor procedure requiring participants to adapt to prismatic lenses shifting the visual scene horizontally. Such an adaptation produces a phenomenon called “after-effect”, opposite to the side of lenses deviation. The after-effect has been frequently associated with a shift of spatial attention in the same direction and with a restoration of hemispatial neglect symptoms. PA has captured the interest of neuroscientists in the last decades, since it affects high-order spatial cognition even thought consisting of low-level visuo-motor processes. Objectives Despite a huge literature on this procedure, the basic neural processes related to PA and…
From different neurophysiological methods to conflicting pathophysiological views in migraine: a critical review of literature.
2014
Abnormal increased cortical responsivity to various types of stimuli plays a major role in migraine pathogenesis. Neurophysiological studies, however, have provided ambiguous findings of either hypo or hyper cortical excitability. This is why the term "dysexcitability" has been recently proposed to indicate a more general dysregulation of cortical excitability. The aims of this review are: (1) to provide existing knowledge and research advances in migraine pathophysiology; (2) to propose a unitary interpretation of apparently conflicting neurophysiological findings. Data of studies conducted in migraine through various evoked potentials techniques and non-invasive brain stimulation methods …
Motor imagery and cortico-spinal excitability: A review
2016
International audience; Motor imagery (MI) has received a lot of interest during the last decades as its chronic or acute use has demonstrated several effects on improving sport performances or skills. The development of neuroimagery techniques also helped further our understanding of the neural correlates underlying MI. While some authors showed that MI, motor execution and action observation activated similar motor cortical regions, transcranial magnetic stimulation (TMS) studies brought great insights on the role of the primary motor cortex and on the activation of the cortico-spinal pathway during MI. After defining MI and describing the TMS technique, a short report of MI activities on…
Hemispheric Differences in Functional Interactions Between the Dorsal Lateral Prefrontal Cortex and Ipsilateral Motor Cortex
2020
Background: The dorsolateral prefrontal cortex (DLPFC) in both hemispheres have a central integrative function for motor control and behavior. Understanding the hemispheric difference between DLPFC and ipsilateral motor cortex connection in the resting-state will provide fundamental knowledge to explain the different roles DLPFC plays in motor behavior. Purpose: The current study tested the interactions between the ipsilateral DLPFC and the primary motor cortex (M1) in each hemisphere at rest. We hypothesized that left DLPFC has a greater inhibitory effect on the ipsilateral M1 compared to the right DLPFC. Methods: Fourteen right-handed subjects were tested in a dual-coil paired-pulse parad…
A Systematic Review of the Effectiveness of Non-Invasive Brain Stimulation Techniques to Reduce Violence Proneness by Interfering in Anger and Irrita…
2020
The field of neurocriminology has proposed several treatments (e.g., pharmacological, brain surgery, androgen-deprivation therapy, neurofeedback) to reduce violence proneness, but unfortunately, their effectiveness has been limited due to their side-effects. Therefore, it is necessary to explore alternative techniques to improve patients’ behavioural regulation with minimal undesirable effects. In this regard, non-invasive brain stimulation techniques, which are based on applying changing magnetic fields or electric currents to interfere with cortical excitability, have revealed their usefulness in alleviating the symptomatology of several mental disorders. However, to our knowledge, there …
What we learn about bipolar disorder from large-scale neuroimaging
2020
Abstract MRI‐derived brain measures offer a link between genes, the environment and behavior and have been widely studied in bipolar disorder (BD). However, many neuroimaging studies of BD have been underpowered, leading to varied results and uncertainty regarding effects. The Enhancing Neuro Imaging Genetics through Meta‐Analysis (ENIGMA) Bipolar Disorder Working Group was formed in 2012 to empower discoveries, generate consensus findings and inform future hypothesis‐driven studies of BD. Through this effort, over 150 researchers from 20 countries and 55 institutions pool data and resources to produce the largest neuroimaging studies of BD ever conducted. The ENIGMA Bipolar Disorder Workin…