Search results for "Neuronal"
showing 10 items of 556 documents
Postnatal Neurogenesis and Neuronal Regeneration
2004
The discovery of neurogenesis in the adult brain has challenged one of the central dogmas of neuroscience. Pioneer reports in rodents seed the ground for a detailed description in birds and reptiles, which was finally confirmed in discrete regions of several mammalian species including humans. This neurogenetical capability may serve as the basis for neuronal regeneration, as has already been described in the reptilian brain, and thus may represent a promising therapeutic approach. Consequently, in the last years there has been an important effort to deepen our knowledge of the biology, the functional significance and the regulation of adult neurogenesis.
Detection of Fibroblast Growth Factor Receptor 1 (FGFR1) Transactivation by Muscarinic Acetylcholine Receptors (mAChRs) in Primary Neuronal Hippocamp…
2018
In addition to their canonical intracellular signals involved in the regulation of neuronal plasticity, G-protein coupled receptors can also rapidly transactivate tyrosine kinase receptors and their downstream intracellular signaling in absence of specific ligands. Here we describe our protocol for dissociating and maintaining hippocampal primary neurons in high- and low-density culture, followed by a description of methods employed to evaluate neurite outgrowth and protein phosphorylation associated with fibroblast growth factor receptor 1 transactivation by muscarinic acetylcholine receptors. Our goal was to provide the reader with detailed protocols of the abovementioned techniques and t…
Rapid nucleus-scale reorganization of chromatin in neurons enables transcriptional adaptation for memory consolidation
2020
AbstractThe interphase nucleus is functionally organized in active and repressed territories defining the transcriptional status of the cell. However, it remains poorly understood how the nuclear architecture of neurons adapts in response to behaviorally relevant stimuli that trigger fast alterations in gene expression patterns. Imaging of fluorescently tagged nucleosomes revealed that pharmacological manipulation of neuronal activity in vitro and auditory cued fear conditioning in vivo induce nucleus-scale restructuring of chromatin within minutes. Furthermore, the acquisition of auditory fear memory is impaired after infusion of a drug into auditory cortex which blocks chromatin reorganiz…
Interactions between cholinergic and fibroblast growth factor receptors in brain trophism and plasticity
2014
Acetylcholine, acting on both nicotinic receptors (nAChRs) and muscarinic receptors (mAChRs), plays a role in the regulation of synaptic plasticity, being involved in the regulation of cellular processes and cognitive functions, such as learning, memory and attention. Recently, G protein coupled receptors (GPCRs), including mAChRs, have been reported to transactivate tyrosine-kinase receptors (RTK), such as epidermal growth factor receptor (EGFR), and initiate their intracellular signaling. In this minireview we have first analysed the RTK transactivation mechanisms, involving cholinergic receptors, and thereafter the interplay between AChR and neurotrophic factor systems built up by FGF2 a…
Modulation of neuronal plasticity by events produced in adolescence: role of environmental enrichment and cannabis consumption
2017
Según Linda Spear, la adolescencia es un período de transición entre la juventud y la madurez, caracterizado por la toma de riesgos a nivel de conductual, pero también por un aumento de las hormonas sexuales (Spear, 2000). Además, hay una transformación importante en el cerebro adolescente, particularmente en el hipocampo, la amígdala y la corteza prefrontal. En esas zonas, así como en otras, durante este período se produce una remodelado dendrítico, una intensa mielinización y un fortalecimiento de la neurocircuitería. Las monoaminas dopamina, serotonina y melatonina participan en estos procesos y son cruciales en el comportamiento del adolescente (Arain et al., 2013). Además, en este perí…
A critical role for VEGF and VEGFR2 in NMDA receptor synaptic function and fear-related behavior
2016
Vascular endothelial growth factor (VEGF) is known to be required for the action of antidepressant therapies but its impact on brain synaptic function is poorly characterized. Using a combination of electrophysiological, single-molecule imaging and conditional transgenic approaches, we identified the molecular basis of the VEGF effect on synaptic transmission and plasticity. VEGF increases the postsynaptic responses mediated by the N-methyl-D-aspartate type of glutamate receptors (GluNRs) in hippocampal neurons. This is concurrent with the formation of new synapses and with the synaptic recruitment of GluNR expressing the GluN2B subunit (GluNR-2B). VEGF induces a rapid redistribution of Glu…
Community detection‐based deep neural network architectures: A fully automated framework based on Likert‐scale data.
2020
Deep neural networks (DNNs) have emerged as a state‐of‐the‐art tool in very different research fields due to its adaptive power to the decision space since they do not presuppose any linear relationship between data. Some of the main disadvantages of these trending models are that the choice of the network underlying architecture profoundly influences the performance of the model and that the architecture design requires prior knowledge of the field of study. The use of questionnaires is hugely extended in social/behavioral sciences. The main contribution of this work is to automate the process of a DNN architecture design by using an agglomerative hierarchical algorithm that mimics the con…
PESACA : Post-édition semi-automatique à partir d’un corpus agroalimentaire
2022
Le projet PESACA vise, à travers l’entraînement d’un modèle de post-édition, à améliorer la qualité des sorties de systèmes de traduction automatique neuronale en français langue de spécialité, en prenant comme cas d’usage pilote le domaine agroalimentaire. Il s’inscrit dans la circulation des savoirs et des idées spécialisés puisque le modèle visé enrichira les processus et les mécanismes de transfert linguistique, en intégrant des données linguistiques issues de discours spécialisés rédigés en langue naturelle française
Electronic implementation of a non-linear oscillator subjected to noise : application to the modeling of neuronal information coding
2011
We study the nonlinear FitzHugh-Nagumo model witch describes the dynamics of excitable neural element. It is well known that this system exhibits three different possible responses. Indeed, the system can be mono-stable, oscillatory or bistable. In the oscillatory regime, the system periodically responds by generating action potential. By contrast, in the mono-stable state the system response remains constant after a transient. Under certain conditions, the system can undergo a bifurcation between the stable and the oscillatory regime via the so called Andronov-Hopf bifurcation. In this Phd thesis, we consider the FitzHugh-Nagumo model in the stable state, that is set near the Andronov-Hopf…
The multiple facets of Cajal-Retzius neurons.
2021
ABSTRACTCajal-Retzius neurons (CRs) are among the first-born neurons in the developing cortex of reptiles, birds and mammals, including humans. The peculiarity of CRs lies in the fact they are initially embedded into the immature neuronal network before being almost completely eliminated by cell death at the end of cortical development. CRs are best known for controlling the migration of glutamatergic neurons and the formation of cortical layers through the secretion of the glycoprotein reelin. However, they have been shown to play numerous additional key roles at many steps of cortical development, spanning from patterning and sizing functional areas to synaptogenesis. The use of genetic l…