Search results for "Brain"

Fractalkine Signaling and Microglia Functions in the Developing Brain.

2015

Microglial cells are the resident macrophages of the central nervous system (CNS). Besides their classical roles in pathological conditions, these immune cells also dynamically interact with neurons and influence their structure and function in physiological conditions. The neuronal chemokine fractalkine and its microglial receptor CX3CR1 are one important signaling pathway involved in these reciprocal interactions. In the present review, we will discuss recent evidence indicating that fractalkine signaling also determines several functions of microglial cells during normal CNS development. It has been known for a decade that microglial cells influence the neuronal death that normally occur…

N-ACETYL-ASPARTATE ABNORMALITIES IN INTERNAL-TEMPORAL EPILEPTICUS FOCUS USING PROTON MAGNETIC-RESONANCE SPECTROSCOPY

1995

International audience; Abstract: The aim of this study was to characterize the neurochemical abnormalities related to N-acetyl-aspartate which is a neuronal marker, within an epilepticus focus located in the internal-temporal area, using proton magnetic resonance spectroscopy, Eleven patients,with a mono-hippocampal epilepticus focus on clinical and per-critical electroencephalographical criteria, were matched with II controls by age, sex and laterality. Proton spectroscopy of a volume of 8 cm(3) was performed within the ipsilateral and the contralateral internal-temporal area and within the 2 hippocampus of controls. Volumetry of the ipsilateral and the contralateral hippocampus and of th…

La ciència com a cerca. Don Quixot, la neurociència i l'interrogatori de la veritat

2014

El neurocientifi c Rodrigo Quian Quiroga es va preguntar si «els cientifi cs, embarcats en cerques personals i quixotesques croades, es passen el temps pensant». Aquesta invocacio adjectival del Quixot de Cervantes presenta la ciencia com una cerca epica que equipara la racionalitat cientifi ca amb els deliris de Don Quixot. Es la cerca de la veritat per part de la ciencia, quixotesca i literaria, un «racionalisme neurotic», en paraules del fi losof Nicholas Maxwell?

Continuous neuronal integration in the cerebral cortex of rodents and humans

2021

La plasticidad neuronal es la capacidad del sistema nervioso para realizar cambios funcionales adaptativos, durante el desarrollo y la edad adulta. Se refiere a todo tipo de cambios que modifican la forma y estructura de las neuronas y de las células gliales del sistema nervioso central (SNC). Entre los diferentes niveles de plasticidad que ocurren en el cerebro adulto, la neurogénesis es un tipo de plasticidad cerebral, que implica la producción e incorporación continua de nuevas neuronas en las redes neuronales funcionales. En el cerebro de los mamíferos adultos, las nuevas neuronas se generan tradicionalmente en dos "nichos neurogénicos canónicos": la zona subventricular (SVZ) y la zona …

Editorial: Unawareness of Illness in Neurological Disorders: A Focussed Neurocognitive Approach Shedding Light on Neuropsychological Deficits and Neu…

2020

Mental fatigue induced by prolonged self-regulation does not exacerbate central fatigue during subsequent whole-body endurance exercise

2015

International audience; It has been shown that the mental fatigue induced by prolonged self-regulation increases perception of effort and reduces performance during subsequent endurance exercise. However, the physiological mechanisms underlying these negative effects of mental fatigue are unclear. The primary aim of this study was to test the hypothesis that mental fatigue exacerbates central fatigue induced by whole-body endurance exercise. Twelve subjects performed 30 min of either an incongruent Stroop task to induce a condition of mental fatigue or a congruent Stroop task (control condition) in a random and counterbalanced order. Both cognitive tasks (CTs) were followed by a whole-body …

Nicotinic receptor agonists as neuroprotective/neurotrophic drugs. Progress in molecular mechanisms

2007

In the present work we reviewed recent advances concerning neuroprotective/neurotrophic effects of acute or chronic nicotine exposure, and the signalling pathways mediating these effects, including mechanisms implicated in nicotine addiction and nAChR desensitization. Experimental and clinical data largely indicate long-lasting effects of nicotine and nicotinic agonists that imply a neuroprotective/neurotrophic role of nAChR activation, involving mainly alpha 7 and alpha 4 beta 2 nAChR subtypes, as evidenced using selective nAChR agonists. Compounds interacting with neuronal nAChRs have the potential to be neuroprotective and treatment with nAChR agonists elicits long-lasting neurotrophic e…

Brain Source Correlates of Speech Perception and Reading Processes in Children With and Without Reading Difficulties

2022

Neural correlates in reading and speech processing have been addressed extensively in the literature. While reading skills and speech perception have been shown to be associated with each other, their relationship remains debatable. In this study, we investigated reading skills, speech perception, reading, and their correlates with brain source activity in auditory and visual modalities. We used high-density event-related potentials (ERPs), fixation-related potentials (FRPs), and the source reconstruction method. The analysis was conducted on 12–13-year-old schoolchildren who had different reading levels. Brain ERP source indices were computed from frequently repeated Finnish speech stimuli…

Red Light Optogenetics in Neuroscience

2022

Optogenetics, a field concentrating on controlling cellular functions by means of light-activated proteins, has shown tremendous potential in neuroscience. It possesses superior spatiotemporal resolution compared to the surgical, electrical, and pharmacological methods traditionally used in studying brain function. A multitude of optogenetic tools for neuroscience have been created that, for example, enable the control of action potential generation via light-activated ion channels. Other optogenetic proteins have been used in the brain, for example, to control long-term potentiation or to ablate specific subtypes of neurons. In in vivo applications, however, the majority of optogenetic too…

Exploring Cell Biodiversity

2015

Brain tissue is a really complex system composed of different cell types that change in shape and size. A single neuron itself has a cell body, dendrites and an axon. About 80% of cerebral tissue consists of water molecules that are confined (intra and extra cellular) in its disordered biologic networks. Using neutron scattering on IN13 we are able to explore hydrogens (H) dynamics in time scale at about 40 ps and in size scale at about 1 Å. Such characteristic make it suitable to investigate brain tissue heterogeneity exploiting hydrogens as a probe since major constituent of macromolecules and water. Elastic neutron scattering (ENS) gives information about means square displacement (MSDs)…