scholarly journals RAI1 Regulates Activity-Dependent Nascent Transcription and Synaptic Scaling

2019 ◽  
Author(s):  
Patricia M. Garay ◽  
Alex Chen ◽  
Takao Tsukahara ◽  
Rafi Kohen ◽  
J. Christian Althaus ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Network Activity ◽  
Neuronal Cultures ◽  
Synaptic Scaling ◽  
Primary Neuronal Cultures ◽  
Transcriptional Dynamics ◽  
Chromatin Regulator ◽  
Transcriptional Changes ◽  
Bona Fide ◽  
Activity Dependent

AbstractLong-lasting forms of synaptic plasticity such as synaptic scaling are critically dependent on transcription. Activity-dependent transcriptional dynamics in neurons, however, have not been fully characterized, because most previous efforts relied on measurement of steady-state mRNAs. Here, we profiled transcriptional dynamics of primary neuronal cultures undergoing network activity shifts using nascent RNA sequencing. We found pervasive transcriptional changes, in which ~45% of expressed genes respond to network activity shifts. Notably, the majority of these genes respond to increases or decreases of network activity uniquely, rather than reciprocally. We further linked the chromatin regulator Retinoic acid induced 1 (RAI1), the Smith-Magenis Syndrome gene, to the specific transcriptional program driven by reduced network activity. Finally, we show that RAI1 is essential for homeostatic synaptic upscaling but not downscaling. These results demonstrate the utility of bona fide transcription profiling to discover mechanisms of activity-dependent chromatin remodeling that underlie normal and pathological synaptic plasticity.

Validation of long-term primary neuronal cultures and network activity through the integration of reversibly bonded microbioreactors and MEA substrates

2011 ◽  
Vol 109 (1) ◽  
pp. 166-175 ◽  
Author(s):  
Emilia Biffi ◽  
Andrea Menegon ◽  
Francesco Piraino ◽  
Alessandra Pedrocchi ◽  
Gianfranco B. Fiore ◽  
...  
Keyword(s):  
Network Activity ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures

scholarly journals Interaction and Subcellular Association of PRRT1/SynDIG4 With AMPA Receptors

2021 ◽  
Vol 13 ◽  
Author(s):  
Emily Eischen Martin ◽  
Erica Wleklinski ◽  
Hanh T. M. Hoang ◽  
Mohiuddin Ahmad
Keyword(s):  
Synaptic Plasticity ◽  
Ampa Receptors ◽  
Transmembrane Protein ◽  
Brain Regions ◽  
Membrane Topology ◽  
Neuronal Cultures ◽  
Physical Interaction ◽  
Primary Neuronal Cultures ◽  
Recycling Endosomes ◽  
Localization Analysis

AMPA receptors (AMPAR) are organized into supramolecular complexes in association with other membrane proteins that provide exquisite regulation of their biophysical properties and subcellular trafficking. Proline-rich transmembrane protein 1 (PRRT1), also named as SynDIG4, is a component of native AMPAR complexes in multiple brain regions. Deletion of PRRT1 leads to altered surface levels and phosphorylation status of AMPARs, as well as impaired forms of synaptic plasticity. Here, we have investigated the mechanisms underlying the observed regulation of AMPARs by investigating the interaction properties and subcellular localization of PRRT1. Our results show that PRRT1 can interact physically with all AMPAR subunits GluA1-GluA4. We decipher the membrane topology of PRRT1 to find that contrary to the predicted dual membrane pass, only the second hydrophobic segment spans the membrane completely, and is involved in mediating the interaction with AMPARs. We also report a physical interaction of PRRT1 with phosphatase PP2B that dephosphorylates AMPARs during synaptic plasticity. Our co-localization analysis in primary neuronal cultures identifies that PRRT1 associates with AMPARs extrasynaptically where it localizes to early and recycling endosomes as well as to the plasma membrane. These findings advance the understanding of the mechanisms by which PRRT1 regulates AMPARs under basal conditions and during synaptic plasticity.

scholarly journals Borna Disease Virus Infection Impairs Synaptic Plasticity

2007 ◽  
Vol 81 (16) ◽  
pp. 8833-8837 ◽  
Author(s):  
Romain Volmer ◽  
Christine M. A. Prat ◽  
Gwendal Le Masson ◽  
André Garenne ◽  
Daniel Gonzalez-Dunia
Keyword(s):  
Synaptic Plasticity ◽  
Disease Virus ◽  
Network Activity ◽  
Multielectrode Arrays ◽  
Neuronal Function ◽  
Borna Disease Virus ◽  
Electrophysiological Properties ◽  
Neuronal Network Activity ◽  
Activity Dependent ◽  
Borna Disease

ABSTRACT The mechanisms whereby Borna disease virus (BDV) can impair neuronal function and lead to neurobehavioral disease are not well understood. To analyze the electrophysiological properties of neurons infected with BDV, we used cultures of neurons grown on multielectrode arrays, allowing a real-time monitoring of the electrical activity across the network shaped by synaptic transmission. Although infection did not affect spontaneous neuronal activity, it selectively blocked activity-dependent enhancement of neuronal network activity, one form of synaptic plasticity thought to be important for learning and memory. These findings highlight the original mechanism of the neuronal dysfunction caused by noncytolytic infection with BDV.

scholarly journals Quantitation of Chronic and Acute Treatment Effects on Neuronal Network Activity Using Image and Signal Analysis

2013 ◽  
Vol 18 (7) ◽  
pp. 807-819 ◽  
Author(s):  
Frans Cornelissen ◽  
Peter Verstraelen ◽  
Tobias Verbeke ◽  
Isabel Pintelon ◽  
Jean-Pierre Timmermans ◽  
...  
Keyword(s):  
Neuronal Cell ◽  
Network Activity ◽  
Cell Segmentation ◽  
Neuronal Cultures ◽  
Nuclear Staining ◽  
Primary Neuronal Cultures ◽  
Independent Manner ◽  
Neuronal Network Activity ◽  
Decay Times

Upon maturation, primary neuronal cultures form an interconnected network based on neurite outgrowth and synaptogenesis in which spontaneous electrical activity arises. Measurement of network activity allows quantification of neuronal health and maturation. A fluorescent indicator was used to monitor secondary calcium influxes after the occurrence of action potentials, allowing us to examine activity of hippocampal cultures via confocal live cell imaging. Subsequently, nuclear staining with DAPI allows accurate cell segmentation. To analyze the calcium recording in a robust, observer-independent manner, we implemented an automated image- and signal-processing algorithm and validated it against a visual, interactive procedure. Both methods yielded similar results on the emergence of synchronized activity and allowed robust quantitative measurement of acute and chronic modulation of drugs on network activity. Both the number of days in vitro (DIV) and neutralization of nerve growth factor (NGF) have a significant effect on synchronous burst frequency and correlation. Acute effects are demonstrated using 5-HT (serotonin) and ethylene glycol tetra-acetic acid. Automated analysis allowed measuring additional features, such as peak decay times and bursting frequency of individual neurons. Based on neuronal cell cultures in 96-well plates and accurate calcium recordings, the analysis method allows development of an integrated high-content screening assay. Because molecular biological techniques can be applied to assess the influence of genes on network activity, it is applicable for neurotoxicity or neurotrophics screening as well as development of in vitro disease models via, for example, pharmacologic manipulation or RNAi.

scholarly journals Functional strengthening through synaptic scaling upon connectivity disruption in neuronal cultures

2020 ◽  
Vol 4 (4) ◽  
pp. 1160-1180
Author(s):  
Estefanía Estévez-Priego ◽  
Sara Teller ◽  
Clara Granell ◽  
Alex Arenas ◽  
Jordi Soriano
Keyword(s):  
Effective Connectivity ◽  
Neuronal Cultures ◽  
Second Phase ◽  
Synaptic Scaling ◽  
Network Information ◽  
Activity Dependent ◽  
Processing Network ◽  
Dependent Mechanism

An elusive phenomenon in network neuroscience is the extent of neuronal activity remodeling upon damage. Here, we investigate the action of gradual synaptic blockade on the effective connectivity in cortical networks in vitro. We use two neuronal cultures configurations—one formed by about 130 neuronal aggregates and another one formed by about 600 individual neurons—and monitor their spontaneous activity upon progressive weakening of excitatory connectivity. We report that the effective connectivity in all cultures exhibits a first phase of transient strengthening followed by a second phase of steady deterioration. We quantify these phases by measuring GEFF, the global efficiency in processing network information. We term hyperefficiency the sudden strengthening of GEFF upon network deterioration, which increases by 20–50% depending on culture type. Relying on numerical simulations we reveal the role of synaptic scaling, an activity–dependent mechanism for synaptic plasticity, in counteracting the perturbative action, neatly reproducing the observed hyperefficiency. Our results demonstrate the importance of synaptic scaling as resilience mechanism.

scholarly journals Protein Kinase D promotes activity-dependent AMPA receptor endocytosis in hippocampal neurons

2020 ◽  
Author(s):  
Carlos O. Oueslati Morales ◽  
Attila Ignácz ◽  
Norbert Bencsik ◽  
Anikó Erika Rátkai ◽  
Wolfgang S. Lieb ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Protein Kinase ◽  
Hippocampal Neurons ◽  
Molecular Mechanisms ◽  
Network Activity ◽  
Protein Kinase D ◽  
Neuronal Network Activity ◽  
Early Endosomes ◽  
Ampar Trafficking ◽  
Activity Dependent

AbstractAMPA type glutamate receptors (AMPARs) mediate the majority of fast excitatory neurotransmission in the brain. The continuous trafficking of AMPARs into and out of synapses is a core feature of synaptic plasticity, which is considered as the cellular basis of learning and memory. The molecular mechanisms underlying the postsynaptic AMPAR trafficking, however, are still not fully understood. In this work, we demonstrate that the Protein Kinase D (PKD) family promotes basal and activity-induced AMPAR endocytosis in primary hippocampal neurons. Pharmacological inhibition of PKD increased synaptic levels of GluA1-containing AMPARs, slowed down their endocytic trafficking and increased neuronal network activity. By contrast, ectopic expression of constitutive active PKD decreased the synaptic level of AMPARs, while increasing their co-localization with early endosomes. On a molecular level, we identify phosphorylation of the Rab5 effector protein and PKD substrate Rabaptin-5 to be required for promoting activity-dependent AMPAR endocytosis. Our results thus establish an important role for PKD in the regulation of postsynaptic AMPAR trafficking during synaptic plasticity.

scholarly journals Difluoroboron β-diketonate polylactic acid oxygen nanosensors for intracellular neuronal imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meng Zhuang ◽  
Suchitra Joshi ◽  
Huayu Sun ◽  
Tamal Batabyal ◽  
Cassandra L. Fraser ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Oxygen Sensing ◽  
Brain Slices ◽  
Neuronal Cell ◽  
Quantum Yields ◽  
Poly Lactic Acid ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
Non Invasive ◽  
Mitotracker Red

AbstractCritical for metabolism, oxygen plays an essential role in maintaining the structure and function of neurons. Oxygen sensing is important in common neurological disorders such as strokes, seizures, or neonatal hypoxic–ischemic injuries, which result from an imbalance between metabolic demand and oxygen supply. Phosphorescence quenching by oxygen provides a non-invasive optical method to measure oxygen levels within cells and tissues. Difluoroboron β-diketonates are a family of luminophores with high quantum yields and tunable fluorescence and phosphorescence when embedded in certain rigid matrices such as poly (lactic acid) (PLA). Boron nanoparticles (BNPs) can be fabricated from dye-PLA materials for oxygen mapping in a variety of biological milieu. These dual-emissive nanoparticles have oxygen-insensitive fluorescence, oxygen-sensitive phosphorescence, and rigid matrix all in one, enabling real-time ratiometric oxygen sensing at micron-level spatial and millisecond-level temporal resolution. In this study, BNPs are applied in mouse brain slices to investigate oxygen distributions and neuronal activity. The optical properties and physical stability of BNPs in a biologically relevant buffer were stable. Primary neuronal cultures were labeled by BNPs and the mitochondria membrane probe MitoTracker Red FM. BNPs were taken up by neuronal cell bodies, at dendrites, and at synapses, and the localization of BNPs was consistent with that of MitoTracker Red FM. The brain slices were stained with the BNPs, and the BNPs did not significantly affect the electrophysiological properties of neurons. Oxygen maps were generated in living brain slices where oxygen is found to be mostly consumed by mitochondria near synapses. Finally, the BNPs exhibited excellent response when the conditions varied from normoxic to hypoxic and when the neuronal activity was increased by increasing K+ concentration. This work demonstrates the capability of BNPs as a non-invasive tool in oxygen sensing and could provide fundamental insight into neuronal mechanisms and excitability research.

scholarly journals Altered network properties in C9ORF72 repeat expansion cortical neurons are due to synaptic dysfunction

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Emma M. Perkins ◽  
Karen Burr ◽  
Poulomi Banerjee ◽  
Arpan R. Mehta ◽  
Owen Dando ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Synaptic Vesicle ◽  
Cortical Neurons ◽  
Electrode Array ◽  
Repeat Expansion ◽  
Cortical Network ◽  
Synaptic Function ◽  
Network Activity ◽  
Cortical Function ◽  
Network Function

Abstract Background Physiological disturbances in cortical network excitability and plasticity are established and widespread in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients, including those harbouring the C9ORF72 repeat expansion (C9ORF72RE) mutation – the most common genetic impairment causal to ALS and FTD. Noting that perturbations in cortical function are evidenced pre-symptomatically, and that the cortex is associated with widespread pathology, cortical dysfunction is thought to be an early driver of neurodegenerative disease progression. However, our understanding of how altered network function manifests at the cellular and molecular level is not clear. Methods To address this we have generated cortical neurons from patient-derived iPSCs harbouring C9ORF72RE mutations, as well as from their isogenic expansion-corrected controls. We have established a model of network activity in these neurons using multi-electrode array electrophysiology. We have then mechanistically examined the physiological processes underpinning network dysfunction using a combination of patch-clamp electrophysiology, immunocytochemistry, pharmacology and transcriptomic profiling. Results We find that C9ORF72RE causes elevated network burst activity, associated with enhanced synaptic input, yet lower burst duration, attributable to impaired pre-synaptic vesicle dynamics. We also show that the C9ORF72RE is associated with impaired synaptic plasticity. Moreover, RNA-seq analysis revealed dysregulated molecular pathways impacting on synaptic function. All molecular, cellular and network deficits are rescued by CRISPR/Cas9 correction of C9ORF72RE. Our study provides a mechanistic view of the early dysregulated processes that underpin cortical network dysfunction in ALS-FTD. Conclusion These findings suggest synaptic pathophysiology is widespread in ALS-FTD and has an early and fundamental role in driving altered network function that is thought to contribute to neurodegenerative processes in these patients. The overall importance is the identification of previously unidentified defects in pre and postsynaptic compartments affecting synaptic plasticity, synaptic vesicle stores, and network propagation, which directly impact upon cortical function.

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