Search results for " synaptic plasticity"
showing 7 items of 7 documents
The Guanine-Based Purinergic System: The Tale of An Orphan Neuromodulation.
2016
Guanine-based purines (GBPs) have been recently proposed to be not only metabolic agents but also extracellular signaling molecules that regulate important functions in the central nervous system. In such way, GBPs-mediated neuroprotection, behavioral responses and neuronal plasticity have been broadly described in the literature. However, while a number of these functions (i.e., GBPs neurothophic effects) have been well-established, the molecular mechanisms behind these GBPs-dependent effects are still unknown. Furthermore, no plasma membrane receptors for GBPs have been described so far, thus GBPs are still considered orphan neuromodulators. Interestingly, an intricate and controversial f…
Fast Regulation of GABAAR Diffusion Dynamics by Nogo-A Signaling.
2019
Summary: Precisely controlling the excitatory and inhibitory balance is crucial for the stability and information-processing ability of neuronal networks. However, the molecular mechanisms maintaining this balance during ongoing sensory experiences are largely unclear. We show that Nogo-A signaling reciprocally regulates excitatory and inhibitory transmission. Loss of function for Nogo-A signaling through S1PR2 rapidly increases GABAAR diffusion, thereby decreasing their number at synaptic sites and the amplitude of GABAergic mIPSCs at CA3 hippocampal neurons. This increase in GABAAR diffusion rate is correlated with an increase in Ca2+ influx and requires the calcineurin-mediated dephospho…
Binge-like ethanol treatment in adolescence impairs autophagy and hinders synaptic maturation: Role of TLR4.
2018
Abstract Adolescence is a developmental period of brain maturation in which remodeling and changes in synaptic plasticity and neural connectivity take place in some brain regions. A different mechanism participates in adolescent brain maturation, including autophagy processes that play a role in synaptic development and plasticity. Alcohol is a neurotoxic compound whose abuse in adolescence causes TLR4 response activation by triggering neuroinflammation, neural damage and behavioral alterations. However, the potential participation of autophagy in long-term neurochemical and cognitive dysfunctions induced by binge ethanol drinking in adolescence is uncertain. We therefore evaluated whether …
Hampered long-term depression and thin spine loss in the nucleus accumbens of ethanol-dependent rats.
2014
Alcoholism involves long-term cognitive deficits, including memory impairment, resulting in substantial cost to society. Neuronal refinement and stabilization are hypothesized to confer resilience to poor decision making and addictive-like behaviors, such as excessive ethanol drinking and dependence. Accordingly, structural abnormalities are likely to contribute to synaptic dysfunctions that occur from suddenly ceasing the use of alcohol after chronic ingestion. Here we show that ethanol-dependent rats display a loss of dendritic spines in medium spiny neurons of the nucleus accumbens (Nacc) shell, accompanied by a reduction of tyrosine hydroxylase immunostaining and postsynaptic density 95…
SHORT-TERM SYNAPTIC PLASTICITY IN MIGRAINE MOTOR CORTEX: EVIDENCE BY PRECONDITIONING OF HIGH-FREQUENCY REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION (…
2011
Background: Brief 5Hz repetitive transcranial magnetic stimulation (rTMS) trains at 120% of the resting- motorthreshold (RMT) intensity determine in healthy subjects a potentiation of motor evoked potentials (MEPs), likely due to short-term presynaptic plasticity facilitation. We recently showed paradoxical intensity-dependent MEP changes to 5Hz rTMS in migraine with MEP facilitation at 110% and inhibition at 130% RMT. This provides evidence of both hyper-responsivity and self-limiting hyperexcitability capacity in migraine, likely due to earlier activation of inhibitory homeostatic plasticity mechanisms. To explore this, we applied in migraineurs cathodal transcranial Direct Current Stimul…
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…
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…