scholarly journals Graphene Nanoplatelets Render Poly(3-Hydroxybutyrate) a Suitable Scaffold to Promote Neuronal Network Development

2021 ◽  
Vol 15 ◽  
Author(s):  
Matteo Moschetta ◽  
Martina Chiacchiaretta ◽  
Fabrizia Cesca ◽  
Ipsita Roy ◽  
Athanassia Athanassiou ◽  
...  
Keyword(s):  
Neuronal Network ◽  
Cortical Neurons ◽  
Neuronal Excitability ◽  
Network Formation ◽  
Firing Frequency ◽  
Graphene Nanoplatelets ◽  
Primary Neurons ◽  
Polymer Supports ◽  
Action Potential Waveform ◽  
Physiological Values

The use of composite biomaterials as innovative bio-friendly neuronal interfaces has been poorly developed so far. Smart strategies to target neuro-pathologies are currently exploiting the mixed and complementary characteristics of composite materials to better design future neural interfaces. Here we present a polymer-based scaffold that has been rendered suitable for primary neurons by embedding graphene nanoplatelets (GnP). In particular, the growth, network formation, and functionality of primary neurons on poly(3-hydroxybutyrate) [P(3HB)] polymer supports functionalized with various concentrations of GnP were explored. After growing primary cortical neurons onto the supports for 14 days, all specimens were found to be biocompatible, revealing physiological growth and maturation of the neuronal network. When network functionality was investigated by whole patch-clamp measurements, pure P(3HB) led to changes in the action potential waveform and reduction in firing frequency, resulting in decreased neuronal excitability. However, the addition of GnP to the polymer matrix restored the electrophysiological parameters to physiological values. Interestingly, a low concentration of graphene was able to promote firing activity at a low level of injected current. The results indicate that the P(3HB)/GnP composites show great potential for electrical interfacing with primary neurons to eventually target central nervous system disorders.

scholarly journals Mitochondrial fission and mitophagy are independent mechanisms regulating ischemia/reperfusion injury in primary neurons

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Anthony R. Anzell ◽  
Garrett M. Fogo ◽  
Zoya Gurm ◽  
Sarita Raghunayakula ◽  
Joseph M. Wider ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Ischemia Reperfusion Injury ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Conditional Knockout ◽  
Mitochondrial Morphology ◽  
Primary Neurons ◽  
Mitochondrial Fragmentation

AbstractMitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.

Abstract 3115: Low-Level Laser Therapy Protects Against OGD-induced Neurotoxicity Of Primary Cultured Mouse Cortical Neurons

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Zhanyang Yu ◽  
Ning Liu ◽  
Eng H Lo ◽  
Thomas J McCarthy ◽  
Xiaoying Wang
Keyword(s):  
Laser Therapy ◽  
Mitochondrial Function ◽  
Cortical Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Low Level Laser Therapy ◽  
Primary Neurons ◽  
Novel Therapy ◽  
Low Level ◽  
Mtt Reduction

Background: Low level light (or laser) therapy (LLLT) has been studied and practiced for promoting wound healing, reducing pain, inflammation, and ischemic tissue damage. Recently, a series of experimental and clinical investigations have suggested that LLLT may be a novel therapy against hypoxic/ischemic brain damage. A clinical trial of LLLT therapy for ischemic stroke is now on going. However, the molecular mechanism of LLLT-conferred neuroprotection remains poorly defined. In this study, we tested our hypothesis that LLLT may attenuate impairments of mitochondrial function induced by hypoxic/ischemic insults in primary cultured mouse cortical neurons. Method: At day 9 of culture, primary neurons were subjected to 4 hr OGD followed by reoxygenation. One 810-nm LLLT treatment was applied for 2 minutes at 2 hr after reoxygenation. Neurotoxicity was measured after 20 hr after reoxygenation by LDH release assay. We also measured MTT reduction and mitochondria membrane potential (MMP) at 2 hr after LLLT treatment as markers of mitochondrial function. Results: The neurotoxicity study showed that 4 hr OGD plus 20 hr reoxygenation caused 33.8± 3.4% neuronal cell death, while LLLT treatment significantly reduced the neuronal death rate to 23.6± 2.9% (30.2% reduction, n=6, p smaller than 0.05). Mitochondrial functional assays showed OGD decreased MTT reduction to 75.9± 2.68%, but LLLT treatment significantly rescued MTT reduction to 87.6±4.55% (15.4% improvement, n=6, p smaller than 0.05). Furthermore, after OGD, MMP was reduced to 48.9±4.39%, while LLLT treatment significantly ameliorated this reduction to 89.6± 13.9% (83% improvement, n=4, p smaller than 0.05) compared to normoxic controls. Conclusion: The present study suggests that LLLT treatment is protective against OGD-induced neurotoxicity of primary neurons and that this protection may be conferred through preservation or rescue of mitochondrial function.

scholarly journals Neuronal network dysfunction in a model for Kleefstra syndrome mediated by enhanced NMDAR signaling

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Monica Frega ◽  
Katrin Linda ◽  
Jason M. Keller ◽  
Güvem Gümüş-Akay ◽  
Britt Mossink ◽  
...  
Keyword(s):  
Neuronal Network ◽  
Cortical Neurons ◽  
Neurodevelopmental Disorder ◽  
Control Networks ◽  
Human Neurons ◽  
Kleefstra Syndrome ◽  
Nmdar Subunit ◽  
Induced Pluripotent ◽  
Reduced Rate ◽  
The Impact

Abstract Kleefstra syndrome (KS) is a neurodevelopmental disorder caused by mutations in the histone methyltransferase EHMT1. To study the impact of decreased EHMT1 function in human cells, we generated excitatory cortical neurons from induced pluripotent stem (iPS) cells derived from KS patients. Neuronal networks of patient-derived cells exhibit network bursting with a reduced rate, longer duration, and increased temporal irregularity compared to control networks. We show that these changes are mediated by upregulation of NMDA receptor (NMDAR) subunit 1 correlating with reduced deposition of the repressive H3K9me2 mark, the catalytic product of EHMT1, at the GRIN1 promoter. In mice EHMT1 deficiency leads to similar neuronal network impairments with increased NMDAR function. Finally, we rescue the KS patient-derived neuronal network phenotypes by pharmacological inhibition of NMDARs. Summarized, we demonstrate a direct link between EHMT1 deficiency and NMDAR hyperfunction in human neurons, providing a potential basis for more targeted therapeutic approaches for KS.

scholarly journals Displacement Talbot lithography nanopatterned microsieve array for directional neuronal network formation in brain-on-chip

2016 ◽  
Vol 34 (6) ◽  
pp. 06KI02 ◽  
Author(s):  
Sijia Xie ◽  
Bart Schurink ◽  
Erwin J. W. Berenschot ◽  
Roald M. Tiggelaar ◽  
Han J. G. E. Gardeniers ◽  
...  
Keyword(s):  
Neuronal Network ◽  
Network Formation ◽  
On Chip

Abstract P201: Negative Regulation Of PVN Pre-sympathetic Neuronal Activity By Resident Microglia

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Peng Shi ◽  
Yunfan Lin ◽  
Qianqian Bi ◽  
Guo Cheng ◽  
Xiao Shen
Keyword(s):  
Neuronal Excitability ◽  
Sympathetic Neurons ◽  
Potassium Currents ◽  
Firing Frequency ◽  
Electrophysiological Recording ◽  
Recombinant Peptide ◽  
Regulatory Circuits ◽  
Brain Parenchymal ◽  
Parenchymal Cells

Hypothalamic paraventricular nucleus (PVN) is a critical integrating region in controlling peripheral sympathetic tonicity. While the vast studies have unraveled the regulatory circuits affecting PVN pre-sympathetic neurons, local factors for maintaining the homeostasis of neuronal excitability are barely understood. In the present study we investigated the role of microglia, the primary resident immune cells of the CNS, in this context. By electrophysiological recording, we found that loss of resident microglia induced an increased firing frequency and attenuated outward potassium currents in the PVN pre-sympathetic neurons, tachycardia and impaired heart rate variability. Combining the transcriptomics analysis of the PVN microglia, we identified a releasable factor, which was dominantly expressed in microglia compared to other brain parenchymal cells. ICV infusion of the recombinant peptide restored potassium currents in the PVN pre-sympathetic neurons and autonomic function in microglia-depleted mice. In summary, our results provided a novel intrinsic regulatory mechanism by which microglia suppress neuronal over excitation in physiological condition.

scholarly journals Neuritin Up-regulates Kv4.2 α-Subunit of Potassium Channel Expression and Affects Neuronal Excitability by Regulating the Calcium-Calcineurin-NFATc4 Signaling Pathway

2016 ◽  
Vol 291 (33) ◽  
pp. 17369-17381 ◽  
Author(s):  
Jin-jing Yao ◽  
Qian-Ru Zhao ◽  
Dong-Dong Liu ◽  
Chi-Wing Chow ◽  
Yan-Ai Mei
Keyword(s):  
Signaling Pathway ◽  
Neural Development ◽  
Cortical Neurons ◽  
Molecular Mechanisms ◽  
Neuronal Excitability ◽  
Outward Current ◽  
Nuclear Accumulation ◽  
Luciferase Reporter ◽  
Activated T Cells ◽  
Α Subunit

Neuritin is an important neurotrophin that regulates neural development, synaptic plasticity, and neuronal survival. Elucidating the downstream molecular signaling is important for potential therapeutic applications of neuritin in neuronal dysfunctions. We previously showed that neuritin up-regulates transient potassium outward current (IA) subunit Kv4.2 expression and increases IA densities, in part by activating the insulin receptor signaling pathway. Molecular mechanisms of neuritin-induced Kv4.2 expression remain elusive. Here, we report that the Ca2+/calcineurin (CaN)/nuclear factor of activated T-cells (NFAT) c4 axis is required for neuritin-induced Kv4.2 transcriptional expression and potentiation of IA densities in cerebellum granule neurons. We found that neuritin elevates intracellular Ca2+ and increases Kv4.2 expression and IA densities; this effect was sensitive to CaN inhibition and was eliminated in Nfatc4−/− mice but not in Nfatc2−/− mice. Stimulation with neuritin significantly increased nuclear accumulation of NFATc4 in cerebellum granule cells and HeLa cells, which expressed IR. Furthermore, NFATc4 was recruited to the Kv4.2 gene promoter loci detected by luciferase reporter and chromatin immunoprecipitation assays. More importantly, data obtained from cortical neurons following adeno-associated virus-mediated overexpression of neuritin indicated that reduced neuronal excitability and increased formation of dendritic spines were abrogated in the Nfatc4−/− mice. Together, these data demonstrate an indispensable role for the CaN/NFATc4 signaling pathway in neuritin-regulated neuronal functions.

scholarly journals Effect and Mechanism of 808 nm Light Pretreatment of Hypoxic Primary Neurons

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Xin Chen ◽  
Qiang-Li Wang ◽  
Shuang Li ◽  
Xian-qiang Mi
Keyword(s):  
Cell Viability ◽  
Cortical Neurons ◽  
Colorimetric Assay ◽  
Neuronal Morphology ◽  
Light Irradiation ◽  
Control Group ◽  
Primary Neurons ◽  
Atp Content ◽  
Low Intensity ◽  
Primary Mouse

This study investigated the effect of low intensity 808 nm light pretreatment of hypoxic primary neurons. Cobalt chloride (CoCl2) has been used to induce hypoxic injury in primary mouse cortical neurons. Low intensity 808 nm light was from light-emitting diode (LED). Cells were randomly divided into 4 groups: normal control group, CoCl2-induced group, CoCl2-induced group with 808 nm light irradiation pretreatment, and normal group with 808 nm light irradiation pretreatment. Effect of low intensity 808 nm light on neuronal morphology has been observed by microscope. MTT colorimetric assay has been used to detect the effect of low intensity 808 nm light on neuronal activity. Adenosine triphosphate (ATP) concentration and cytochrome C oxidase (COX) activity has been detected to study the effect of low intensity 808 nm light on neuronal mitochondria function. The results indicated that low intensity 808 nm light pretreatment alone did not affect cell viability, COX activity, and ATP content of neurons and low intensity 808 nm light pretreatment promoted the cell viability, COX activity, and ATP content of neurons with CoCl2exposure; however, low intensity 808 nm light pretreatment did not completely recover COX activity and cellular ATP content of primary neurons with CoCl2exposure to the level of the normal neurons.

scholarly journals Spatially resolved non-invasive chemical stimulation for modulation of signalling in reconstructed neuronal networks

2005 ◽  
Vol 3 (7) ◽  
pp. 333-343 ◽  
Author(s):  
Yulia Mourzina ◽  
Alfred Steffen ◽  
Dmitri Kaliaguine ◽  
Bernhard Wolfrum ◽  
Petra Schulte ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Network Architecture ◽  
Neuronal Networks ◽  
Network Formation ◽  
Microcontact Printing ◽  
Chemical Stimulation ◽  
Functional Coupling ◽  
Non Invasive ◽  
On Chip

Functional coupling of reconstructed neuronal networks with microelectronic circuits has potential for the development of bioelectronic devices, pharmacological assays and medical engineering. Modulation of the signal processing properties of on-chip reconstructed neuronal networks is an important aspect in such applications. It may be achieved by controlling the biochemical environment, preferably with cellular resolution. In this work, we attempt to design cell–cell and cell–medium interactions in confined geometries with the aim to manipulate non-invasively the activity pattern of an individual neuron in neuronal networks for long-term modulation. Therefore, we have developed a biohybrid system in which neuronal networks are reconstructed on microstructured silicon chips and interfaced to a microfluidic system. A high degree of geometrical control over the network architecture and alignment of the network with the substrate features has been achieved by means of aligned microcontact printing. Localized non-invasive on-chip chemical stimulation of micropatterned rat cortical neurons within a network has been demonstrated with an excitatory neurotransmitter glutamate. Our system will be useful for the investigation of the influence of localized chemical gradients on network formation and long-term modulation.

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