Search results for "PLASTICITY"
showing 10 items of 765 documents
The NG2 Protein Is Not Required for Glutamatergic Neuron-NG2 Cell Synaptic Signaling.
2014
NG2 glial cells (as from now NG2 cells) are unique in receiving synaptic input from neurons. However, the components regulating formation and maintenance of these neuron–glia synapses remain elusive. The transmembrane protein NG2 has been considered a potential mediator of synapse formation and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) clustering, because it contains 2 extracellular Laminin G/Neurexin/Sex Hormone-Binding Globulin domains, which in neurons are crucial for formation of transsynaptic neuroligin– neurexin complexes. NG2 is connected via Glutamate Receptor-Interacting Protein with GluA2/3-containing AMPARs, thereby possibly mediating receptor clus…
Impact of Perineuronal Nets on Electrophysiology of Parvalbumin Interneurons, Principal Neurons, and Brain Oscillations: A Review
2021
Perineuronal nets (PNNs) are specialized extracellular matrix structures that surround specific neurons in the brain and spinal cord, appear during critical periods of development, and restrict plasticity during adulthood. Removal of PNNs can reinstate juvenile-like plasticity or, in cases of PNN removal during early developmental stages, PNN removal extends the critical plasticity period. PNNs surround mainly parvalbumin (PV)-containing, fast-spiking GABAergic interneurons in several brain regions. These inhibitory interneurons profoundly inhibit the network of surrounding neurons via their elaborate contacts with local pyramidal neurons, and they are key contributors to gamma oscillations…
Alterations in Tau Protein Level and Phosphorylation State in the Brain of the Autistic-Like Rats Induced by Prenatal Exposure to Valproic Acid
2021
Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficient social interaction and communication besides repetitive, stereotyped behaviours. A characteristic feature of ASD is altered dendritic spine density and morphology associated with synaptic plasticity disturbances. Since microtubules (MTs) regulate dendritic spine morphology and play an important role in spine development and plasticity the aim of the present study was to investigate the alterations in the content of neuronal α/β-tubulin and Tau protein level as well as phosphorylation state in the valproic acid (VPA)-induced rat model of autism. Our results indicated that maternal exposure to VPA indu…
Intra-neuronal Competition for Synaptic Partners Conserves the Amount of Dendritic Building Material
2017
Brain development requires correct targeting of multiple thousand synaptic terminals onto staggeringly complex dendritic arbors. The mechanisms by which input synapse numbers are matched to dendrite size, and by which synaptic inputs from different transmitter systems are correctly partitioned onto a postsynaptic arbor, are incompletely understood. By combining quantitative neuroanatomy with targeted genetic manipulation of synaptic input to an identified Drosophila neuron, we show that synaptic inputs of two different transmitter classes locally direct dendrite growth in a competitive manner. During development, the relative amounts of GABAergic and cholinergic synaptic drive shift dendrit…
Regulation of Dendritic Spine Morphology in Hippocampal Neurons by Copine-6.
2015
Dendritic spines compartmentalize information in the brain, and their morphological characteristics are thought to underly synaptic plasticity. Here we identify copine-6 as a novel modulator of dendritic spine morphology. We found that brain-derived neurotrophic factor (BDNF) - a molecule essential for long-term potentiation of synaptic strength - upregulated and recruited copine-6 to dendritic spines in hippocampal neurons. Overexpression of copine-6 increased mushroom spine number and decreased filopodia number, while copine-6 knockdown had the opposite effect and dramatically increased the number of filopodia, which lacked PSD95. Functionally, manipulation of post-synaptic copine-6 level…
Novel Insights of Effects of Pregabalin on Neural Mechanisms of Intracortical Disinhibition in Physiopathology of Fibromyalgia: An Explanatory, Rando…
2018
Submitted by DSpace Unilasalle (dspace@unilasalle.edu.br) on 2021-09-14T16:51:25Z No. of bitstreams: 1 adeitos.etal.pdf: 2278622 bytes, checksum: dd96bf75fdbab601238c2831da009c73 (MD5) Made available in DSpace on 2021-09-14T16:51:25Z (GMT). No. of bitstreams: 1 adeitos.etal.pdf: 2278622 bytes, checksum: dd96bf75fdbab601238c2831da009c73 (MD5) Previous issue date: 2018 Background: The fibromyalgia (FM) physiopathology involves an intracortical excitability/inhibition imbalance as measured by transcranial magnetic stimulation measures (TMS). TMS measures provide an index that can help to understand how the basal neuronal plasticity state (i.e., levels of the serum neurotrophins brain-derived n…
Atypical 1,4-dihydropyridine derivatives, an approach to neuroprotection and memory enhancement
2016
This mini review is devoted to the design and pharmacological studies of novel atypical 1,4-dihydropyridine (DHP) derivatives which differ to a great extent from the traditional DHPs either by lack of neuronal calcium channel blocking activity and/or inability to protect mitochondrial processes. About 100 new DHP derivatives were screened and the mostly active were selected for detailed studies. The compounds of the series of the amino acid ("free" plus "crypto")-containing DHPs and lipophilic di-cyclic DHPs demonstrated long-lasting neuroprotective and/or memory-enhancing action, particularly at low doses (0.005-0.05mg/kg) in different neurodeficiency rat or mice models, and exerted neurot…
Polysialic Acid Acute Depletion Induces Structural Plasticity in Interneurons and Impairs the Excitation/Inhibition Balance in Medial Prefrontal Cort…
2016
The structure and function of the medial prefrontal cortex (mPFC) is affected in several neuropsychiatric disorders, including schizophrenia and major depression. Recent studies suggest that imbalances between excitatory and inhibitory activity (E/I) may be responsible for this cortical dysfunction and, therefore, may underlie the core symptoms of these diseases. This E/I imbalance seems to be correlated with alterations in the plasticity of interneurons but there is still scarce information on the mechanisms that may link these phenomena. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is a good candidate, because it modulates the neuronal plasticity of interneurons…
Gonadal sexual differentiation of European sea bass (Dicentrarchus labrax, L. 1758) of fingerlings in different size classes
2016
This report describes a study of the gonad differentiation in fingerlings of European sea bass (Dicentrarchus labrax) belonging to different size groups. Fishes were divided into four groups according to their weight: Group 1 (4.5 ± 0.7 g), Group 2 (9.2 ± 0.8 g), Group 3 (14.8 ± 1.8 g), and Group 4 (21.8 ± 2.3 g). In all groups, low percentages of undifferentiated or early sexually differentiated fish were found. Higher percentages of fully differentiated ovaries were found in Groups 1 and 3. Fully differentiated testes occurred in 90% of Group 4. Ninety percent of fish in Group 2 had gonads with intratesticular oocytes. This highlights the occurrence of intersexual cases and suggests that …
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…