Search results for "neuron"

Nerve growth factor and epidermal growth factor stimulate clusterin gene expression in PC12 cells

1999

Clusterin (apolipoprotein J) is an extracellular glycoprotein that might exert functions in development, cell death and lipid transport. Clusterin gene expression is elevated at sites of tissue remodelling, such as differentiation and apoptosis; however, the signals responsible for this regulation have not been identified. We use here the clusterin gene as a model system to examine expression in PC12 cells under the control of differentiation and proliferation signals produced by nerve growth factor (NGF) and by epidermal growth factor (EGF) respectively. NGF induced clusterin mRNA, which preceded neurite outgrowth typical of neuronal differentiation. EGF also activated the clusterin mRNA, …

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…

Neuropeptides in Primary Afferent Neurons

1990

Traditionally, the primary sensory neurons, having their perikarya in the spinal or cranial sensory ganglia with processes directed towards the periphery and the central nervous system, have been regarded to function as receptive and afferent systems which reflexly activate central effector systems.1 This, however, does not apply to the small diameter primary afferents as suggested by the observation made about a century ago that antidromic stimulation of transected dorsal roots or sensory nerves caused vasodilatation and inflammatory signs in the skin.2,3 The novel concept which has been confirmed by many investigators ascribes to small diameter (particularly unmyelinated C) primary sensor…

Modeling of neuron-astrocyte interaction : application to signal and image processing

2022

The introduction of the tripartite synapse and the discovery of calcium wave propagation motivated our research to explore the potential of astrocytes as active components in brain circuits. For decades, astrocytes have been considered passive cells whose primary function is metabolic and structural support to neurons; however, recent physiological measurements suggest that astrocytes modulate neural communication, strengthen synaptic efficacy, enhance synchronization, and promote homeostasis. Inspired by these biological functions, this research aimed to implement astrocytes in artificial spiking networks for deep learning applications. First, we modeled the biological interaction between …

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…

Driver's emotional state and vulnerable road user detection

2017

DDI 2017 - 5th International Conference on Driver Distraction and Inattention, PARIS, FRANCE, 20-/03/2017 - 22/03/2017; In 2014, slightly over 3380 deaths occurred on metropolitan French roads (Observatoire National Interministériel de Sécurité Routière [ONISR], 2015). For pedestrians and cyclists the percentage of fatal accidents increased by around 4, and 7% respectively since 2010. In addition, accidents involving pedestrians and cyclists are mostly caused by other road users as motorists, truck or bus drivers making pedestrians and cyclists vulnerable road users [VRU]. Previous investigations showed that VRU visibility for road users (drivers) was a crucial main issue. To address this i…

Direct activation of zebrafish neurons by ultrasonic stimulation revealed by whole CNS calcium imaging

2020

Abstract Objective. Ultrasounds (US) use in neural engineering is so far mainly limited to ablation through high intensity focused ultrasound, but interesting preliminary results show that low intensity low frequency ultrasound could be used instead to modulate neural activity. However, the extent of this modulatory ability of US is still unclear, as in in vivo studies it is hard to disentangle the contribution to neural responses of direct activation of the neuron by US stimulation and indirect activation due either to sensory response to mechanical stimulation associated to US, or to propagation of activity from neighboring areas. Here, we aim to show how to separate the three effects and…

Regulation of mRNA transport, localization and translation in the nervous system of mammals (Review).

2014

Post-transcriptional control of mRNA trafficking and metabolism plays a critical role in the actualization and fine tuning of the genetic program of cells, both in development and in differentiated tissues. Cis-acting signals, responsible for post-transcriptional regulation, reside in the RNA message itself, usually in untranslated regions, 5' or 3' to the coding sequence, and are recognized by trans-acting factors: RNA-binding proteins (RBPs) and/or non-coding RNAs (ncRNAs). ncRNAs bind short mRNA sequences usually present in the 3'-untranslated (3'-UTR) region of their target messages. RBPs recognize specific nucleotide sequences and/or secondary/tertiary structures. Most RBPs assemble on…

Co-activation of VEGF and NMDA receptors promotes synaptic targeting of AMPA receptors

2016

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…