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Sample records for neuronal cultures 14c-pbde

  1. Cultures of Cerebellar Granule Neurons

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Parizad M. Bilimoria and Azad Bonni1 Corresponding author ([]()) ### INTRODUCTION Primary cultures of granule neurons from the post-natal rat cerebellum provide an excellent model system for molecular and cell biological studies of neuronal development and function. The cerebellar cortex, with its highly organized structure and few neuronal subtypes, offers a well-characterized neural circuitry. Many fundamental insight...

  2. Advances in 3D neuronal cell culture

    NARCIS (Netherlands)

    Frimat, Jean Philippe; Xie, Sijia; Bastiaens, Alex; Schurink, Bart; Wolbers, Floor; Den Toonder, Jaap; Luttge, Regina

    2015-01-01

    In this contribution, the authors present our advances in three-dimensional (3D) neuronal cell culture platform technology contributing to controlled environments for microtissue engineering and analysis of cellular physiological and pathological responses. First, a micromachined silicon sieving

  3. Protocol for culturing low density pure rat hippocampal neurons supported by mature mixed neuron cultures.

    Science.gov (United States)

    Yang, Qian; Ke, Yini; Luo, Jianhong; Tang, Yang

    2017-02-01

    primary hippocampal neuron cultures allow for subcellular morphological dissection, easy access to drug treatment and electrophysiology analysis of individual neurons, and is therefore an ideal model for the study of neuron physiology. While neuron and glia mixed cultures are relatively easy to prepare, pure neurons are particular hard to culture at low densities which are suitable for morphology studies. This may be due to a lack of neurotrophic factors such as brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT3) and Glial cell line-derived neurotrophic factor (GDNF). In this study we used a two step protocol in which neuron-glia mixed cultures were initially prepared for maturation to support the growth of young neurons plated at very low densities. Our protocol showed that neurotrophic support resulted in physiologically functional hippocampal neurons with larger cell body, increased neurite length and decreased branching and complexity compared to cultures prepared using a conventional method. Our protocol provides a novel way to culture highly uniformed hippocampal neurons for acquiring high quality, neuron based data. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Effects of amyotrophic lateral sclerosis sera on cultured cholinergic neurons

    International Nuclear Information System (INIS)

    Touzeau, G.; Kato, A.C.

    1983-01-01

    Dissociated monolayer cultures of chick ciliary ganglion neurons have been used to study the effects of control and ALS sera. The cultured neurons survive and extend neurites for a minimum of 2 weeks in a standard tissue culture medium that contains 10% heat-inactivated human serum. Three parameters of the neurons have been examined when cultured in control and ALS sera for 8 to 12 days: (1) neuronal survival, (2) activity of the enzyme choline acetyltransferase, and (3) synthesis of 3 H-acetylcholine using 3 H-choline as precursor. ALS sera cause a small decrease in these three parameters, but this difference is not significant

  5. Inhibitory neurons modulate spontaneous signaling in cultured cortical neurons: density-dependent regulation of excitatory neuronal signaling

    International Nuclear Information System (INIS)

    Serra, Michael; Guaraldi, Mary; Shea, Thomas B

    2010-01-01

    Cortical neuronal activity depends on a balance between excitatory and inhibitory influences. Culturing of neurons on multi-electrode arrays (MEAs) has provided insight into the development and maintenance of neuronal networks. Herein, we seeded MEAs with murine embryonic cortical/hippocampal neurons at different densities ( 1000 cells mm −2 ) and monitored resultant spontaneous signaling. Sparsely seeded cultures displayed a large number of bipolar, rapid, high-amplitude individual signals with no apparent temporal regularity. By contrast, densely seeded cultures instead displayed clusters of signals at regular intervals. These patterns were observed even within thinner and thicker areas of the same culture. GABAergic neurons (25% of total neurons in our cultures) mediated the differential signal patterns observed above, since addition of the inhibitory antagonist bicuculline to dense cultures and hippocampal slice cultures induced the signal pattern characteristic of sparse cultures. Sparsely seeded cultures likely lacked sufficient inhibitory neurons to modulate excitatory activity. Differential seeding of MEAs can provide a unique model for analyses of pertubation in the interaction between excitatory and inhibitory function during aging and neuropathological conditions where dysregulation of GABAergic neurons is a significant component

  6. Towards neuronal organoids: a method for long-term culturing of high-density hippocampal neurons.

    Directory of Open Access Journals (Sweden)

    George K Todd

    Full Text Available One of the goals in neuroscience is to obtain tractable laboratory cultures that closely recapitulate in vivo systems while still providing ease of use in the lab. Because neurons can exist in the body over a lifetime, long-term culture systems are necessary so as to closely mimic the physiological conditions under laboratory culture conditions. Ideally, such a neuronal organoid culture would contain multiple cell types, be highly differentiated, and have a high density of interconnected cells. However, before these types of cultures can be created, certain problems associated with long-term neuronal culturing must be addressed. We sought to develop a new protocol which may further prolong the duration and integrity of E18 rat hippocampal cultures. We have developed a protocol that allows for culturing of E18 hippocampal neurons at high densities for more than 120 days. These cultured hippocampal neurons are (i well differentiated with high numbers of synapses, (ii anchored securely to their substrate, (iii have high levels of functional connectivity, and (iv form dense multi-layered cellular networks. We propose that our culture methodology is likely to be effective for multiple neuronal subtypes-particularly those that can be grown in Neurobasal/B27 media. This methodology presents new avenues for long-term functional studies in neurons.

  7. Rhynchophylline Protects Cultured Rat Neurons against Methamphetamine Cytotoxicity

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    Dan Dan Xu

    2012-01-01

    Full Text Available Rhynchophylline (Rhy is an active component isolated from species of the genus Uncaria which has been used for the treatment of ailments to the central nervous system in traditional Chinese medicine. Besides acting as a calcium channel blocker, Rhy was also reported to be able to protect against glutamate-induced neuronal death. We thus hypothesize that Rhy may have neuroprotective activity against methamphetamine (MA. The primary neurons were cultured directly from the cerebral cortex of neonatal rats, acting as in vitro model in the present study. The neurotoxicity of MA and the protective effect of Rhy were evaluated by MTT assay. The effects of MA, Rhy or their combination on intracellular free calcium concentration ([Ca2+]i were determined in individual neocortical neurons by the Fluo-3/AM tracing method. The MTT assay demonstrated that MA has a dose-dependent neurotoxicity in neuronal cultures. The addition of Rhy prior to the exposure to MA prevented neuronal death. Time course studies with the Fluo-3/AM probe showed that Rhy significantly decreased neuronal [Ca2+]i which was elevated by the exposure to MA. Our results suggested that Rhy can protect the neuronal cultures against MA exposure and promptly attenuate intracellular calcium overload triggered by MA challenge. This is the first report demonstrating an inhibitory effect of Rhy against MA impairment in cultured neurons in vitro.

  8. Desensitization of metabotropic glutamate receptors in neuronal cultures

    NARCIS (Netherlands)

    Catania, M. V.; Aronica, E.; Sortino, M. A.; Canonico, P. L.; Nicoletti, F.

    1991-01-01

    Preexposure of cultured cerebellar neurons to glutamate reduced the stimulation of polyphosphoinositide (PPI) hydrolysis induced by subsequent addition of glutamate without affecting the response to the muscarinic receptor agonist carbamylcholine. Desensitization of glutamate-stimulated PPI

  9. Primary Motor Neuron Culture to Promote Cellular Viability and Myelination.

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    Suh, Jun-Kyo Francis; Hyung, Sujin

    2018-01-01

    A culture system that can recapitulate myelination in vitro will not only help us to better understand the mechanism of myelination and demyelination but also identify possible therapeutic interventions for treating demyelinating diseases. Here, we introduce a simple and reproducible myelination culture system using mouse motor neurons (MNs) and Schwann cells (SCs). Dissociated motor neurons are plated on a feeder layer of SCs, which interact with and wrap around the axons of MNs as they differentiate in culture. In our MN-SC co-culture system, MNs survive over 3 weeks and extend long axons. Both viability and axon growth of MNs in the co-culture are markedly enhanced as compared to those of MN monocultures. Co-labeling of myelin basic proteins and neuronal cell microtubules reveals that SCs form myelin sheaths by wrapping around the axons of MNs.

  10. Rapid method for culturing embryonic neuron-glial cell cocultures

    DEFF Research Database (Denmark)

    Svenningsen, Åsa Fex; Shan, Wei-Song; Colman, David R

    2003-01-01

    A streamlined, simple technique for primary cell culture from E17 rat tissue is presented. In an attempt to standardize culturing methods for all neuronal cell types in the embryo, we evaluated a commercial medium without serum and used similar times for trypsinization and tested different surfaces...

  11. Leaders of neuronal cultures in a quorum percolation model

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    Jean-Pierre Eckmann

    2010-09-01

    Full Text Available We present a theoretical framework using quorum-percolation for describing the initiation of activity in a neural culture. The cultures are modeled as random graphs, whose nodes are neurons with $kin$ inputs and $kout$ outputs, and whose input degrees $kin=k$ obey given distribution functions $p_k$. We examine the firing activity of the population of neurons according to their input degree ($k$ classes and calculate for each class its firing probability $Phi_k(t$ as a function of $t$. The probability of a node to fire is found to be determined by its in-degree $k$, and the first-to-fire neurons are those that have a high $k$. A small minority of high-$k$ classes may be called ``Leaders,'' as they form an inter-connected subnetwork that consistently fires much before the rest of the culture. Once initiated, the activity spreads from the Leaders to the less connected majority of the culture. We then use the distribution of in-degree of the Leaders to study the growth rate of the number of neurons active in a burst, which was experimentally measured to be initially exponential. We find that this kind of growth rate is best described by a population that has an in-degree distribution that is a Gaussian centered around $k=75$ with width $sigma=31$ for the majority of the neurons, but also has a power law tail with exponent $-2$ for ten percent of the population. Neurons in the tail may have as many as $k=4,700$ inputs. We explore and discuss the correspondence between the degree distribution and a dynamic neuronal threshold, showing that from the functional point of view, structure and elementary dynamics are interchangeable. We discuss possible geometric origins of this distribution, and comment on the importance of size, or of having a large number of neurons, in the culture.

  12. Optophysiological approach to resolve neuronal action potentials with high spatial and temporal resolution in cultured neurons

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    Stephane ePages

    2011-10-01

    Full Text Available Cell to cell communication in the central nervous system is encoded into transient and local membrane potential changes (ΔVm. Deciphering the rules that govern synaptic transmission and plasticity entails to be able to perform Vm recordings throughout the entire neuronal arborization. Classical electrophysiology is, in most cases, not able to do so within small and fragile neuronal subcompartments. Thus, optical techniques based on the use of fluorescent voltage-sensitive dyes (VSDs have been developed. However, reporting spontaneous or small ΔVm from neuronal ramifications has been challenging, in part due to the limited sensitivity and phototoxicity of VSD-based optical measurements. Here we demonstrate the use of water soluble VSD, ANNINE-6plus, with laser scanning microscopy to optically record ΔVm in cultured neurons. We show that the sensitivity (> 10 % of fluorescence change for 100 mV depolarization and time response (submillisecond of the dye allows the robust detection of action potentials (APs even without averaging, allowing the measurement of spontaneous neuronal firing patterns. In addition, we show that back-propagating APs can be recorded, along distinct dendritic sites and within dendritic spines. Importantly, our approach does not induce any detectable phototoxic effect on cultured neurons. This optophysiological approach provides a simple, minimally invasive and versatile optical method to measure electrical activity in cultured neurons with high temporal (ms resolution and high spatial (µm resolution.

  13. Identification of Neuronal Network Properties from the Spectral Analysis of Calcium Imaging Signals in Neuronal Cultures

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    Elisenda eTibau

    2013-12-01

    Full Text Available Neuronal networks in vitro are prominent systems to study the development of connections in living neuronal networks and the interplay between connectivity, activity and function. These cultured networks show a rich spontaneous activity that evolves concurrently with the connectivity of the underlying network. In this work we monitor the development of neuronal cultures, and record their activity using calcium fluorescence imaging. We use spectral analysis to characterize global dynamical and structural traits of the neuronal cultures. We first observe that the power spectrum can be used as a signature of the state of the network, for instance when inhibition is active or silent, as well as a measure of the network's connectivity strength. Second, the power spectrum identifies prominent developmental changes in the network such as GABAA switch. And third, the analysis of the spatial distribution of the spectral density, in experiments with a controlled disintegration of the network through CNQX, an AMPA-glutamate receptor antagonist in excitatory neurons, reveals the existence of communities of strongly connected, highly active neurons that display synchronous oscillations. Our work illustrates the interest of spectral analysis for the study of in vitro networks, and its potential use as a network-state indicator, for instance to compare healthy and diseased neuronal networks.

  14. Novel culturing platform for brain slices and neuronal cells

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya

    2015-01-01

    In this paper we demonstrate a novel culturing system for brain slices and neuronal cells, which can control the concentration of nutrients and the waste removal from the culture by adjusting the fluid flow within the device. The entire system can be placed in an incubator. The system has been te...... tested successfully with brain slices and PC12 cells. The culture substrate can be modified using metal electrodes and/or nanostructures for conducting electrical measurements while culturing and for better mimicking the in vivo conditions.......In this paper we demonstrate a novel culturing system for brain slices and neuronal cells, which can control the concentration of nutrients and the waste removal from the culture by adjusting the fluid flow within the device. The entire system can be placed in an incubator. The system has been...

  15. Studying endosomes in cultured neurons by live-cell imaging.

    Science.gov (United States)

    Lasiecka, Zofia M; Winckler, Bettina

    2016-01-01

    Endosomes play critical roles on regulating surface receptor levels as well as signaling cascades in all cell types, including neurons. Endocytosis and endosomal trafficking is routinely studied after fixation, but live imaging is increasingly being used to capture the dynamic nature of endosomes and is allowing increasingly sophisticated glimpses into trafficking processes in live neurons. In this chapter, we describe the basics of neuronal primary cultures, methods for expressing fluorescent proteins, and live imaging of cargos and endosomal regulators. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. A modified technique for culturing primary fetal rat cortical neurons.

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    Xu, Sui-Yi; Wu, Yong-Min; Ji, Zhong; Gao, Xiao-Ya; Pan, Su-Yue

    2012-01-01

    The study explored a modified primary culture system for fetal rat cortical neurons. Day E18 embryos from pregnant Sprague Dawley rats were microdissected under a stereoscope. To minimize enzymatic damage to the cultured neurons, we applied a sequential digestion protocol using papain and Dnase I. The resulting sifted cell suspension was seeded at a density of 50,000 cells per cm(2) onto 0.1 mg/mL L-PLL-covered vessels. After a four-hour incubation in high-glucose Dulbecco's Modified Eagle's Medium (HG-DMEM) to allow the neurons to adhere, the media was changed to neurobasal medium that was refreshed by changing half of the volume after three days followed by a complete medium change every week. The cells displayed progressively robust neurite extension, and nonneuronal-like cells could barely be detected by five days in vitro (DIV); cell growth was still substantial at 14 DIV. Neurons were identified by β-tubulin III immunofluorescence, and neuronal purity within the cultures was assessed at over 95% by both flow cytometry and by dark-field counting of β-tubulin III-positive cells. These results suggest that the protocol was successful and that the high purity of neurons in this system could be used as the basis for generating various cell models of neurological disease.

  17. A Modified Technique for Culturing Primary Fetal Rat Cortical Neurons

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    Sui-Yi Xu

    2012-01-01

    Full Text Available The study explored a modified primary culture system for fetal rat cortical neurons. Day E18 embryos from pregnant Sprague Dawley rats were microdissected under a stereoscope. To minimize enzymatic damage to the cultured neurons, we applied a sequential digestion protocol using papain and Dnase I. The resulting sifted cell suspension was seeded at a density of 50,000 cells per cm2 onto 0.1 mg/mL L-PLL-covered vessels. After a four-hour incubation in high-glucose Dulbecco’s Modified Eagle’s Medium (HG-DMEM to allow the neurons to adhere, the media was changed to neurobasal medium that was refreshed by changing half of the volume after three days followed by a complete medium change every week. The cells displayed progressively robust neurite extension, and nonneuronal-like cells could barely be detected by five days in vitro (DIV; cell growth was still substantial at 14 DIV. Neurons were identified by β-tubulin III immunofluorescence, and neuronal purity within the cultures was assessed at over 95% by both flow cytometry and by dark-field counting of β-tubulin III-positive cells. These results suggest that the protocol was successful and that the high purity of neurons in this system could be used as the basis for generating various cell models of neurological disease.

  18. Poliovirus replication and spread in primary neuron cultures.

    Science.gov (United States)

    Daley, John K; Gechman, Lisa A; Skipworth, Jason; Rall, Glenn F

    2005-09-15

    While some neurotropic viruses cause rapid central nervous system (CNS) disease upon entry into the brain parenchyma, other viruses that are cytolytic in the periphery either result in little neuropathology or are associated with a protracted course of CNS disease consistent with persistent infection. One such virus, poliovirus (PV), is an extremely lytic RNA virus that requires the expression of CD155, the poliovirus receptor (PVR), for infection. To compare the kinetics of PV infection in neuronal and non-neuronal cell types, primary hippocampal neurons and fibroblasts were isolated from CD155+ transgenic embryos and infected with the Mahoney and Sabin strains of PV. Despite similar levels of infection in these ex vivo cultures, PV-infected neurons produced 100-fold fewer infectious particles as compared to fibroblasts throughout infection, and death of PV-infected neurons was delayed approximately 48 h. Spread in neurons occurred primarily by trans-synaptic transmission and was CD155-dependent. Together, these results demonstrate that the magnitude and speed with which PV replication, spread, and subsequent cell death occur in neurons is decreased as compared to non-neuronal cells, implicating cell-specific effects on replication that may then influence viral pathogenesis.

  19. Understanding metal homeostasis in primary cultured neurons. Studies using single neuron subcellular and quantitative metallomics.

    Science.gov (United States)

    Colvin, Robert A; Lai, Barry; Holmes, William R; Lee, Daewoo

    2015-07-01

    The purpose of this study was to demonstrate how single cell quantitative and subcellular metallomics inform us about both the spatial distribution and cellular mechanisms of metal buffering and homeostasis in primary cultured neurons from embryonic rat brain, which are often used as models of human disease involving metal dyshomeostasis. The present studies utilized synchrotron radiation X-ray fluorescence (SRXRF) and focused primarily on zinc and iron, two abundant metals in neurons that have been implicated in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Total single cell contents for calcium, iron, zinc, copper, manganese, and nickel were determined. Resting steady state zinc showed a diffuse distribution in both soma and processes, best defined by the mass profile of the neuron with an enrichment in the nucleus compared with the cytoplasm. Zinc buffering and homeostasis was studied using two modes of cellular zinc loading - transporter and ionophore (pyrithione) mediated. Single neuron zinc contents were shown to statistically significantly increase by either loading method - ionophore: 160 million to 7 billion; transporter 160 million to 280 million atoms per neuronal soma. The newly acquired and buffered zinc still showed a diffuse distribution. Soma and processes have about equal abilities to take up zinc via transporter mediated pathways. Copper levels are distributed diffusely as well, but are relatively higher in the processes relative to zinc levels. Prior studies have observed iron puncta in certain cell types, but others have not. In the present study, iron puncta were characterized in several primary neuronal types. The results show that iron puncta could be found in all neuronal types studied and can account for up to 50% of the total steady state content of iron in neuronal soma. Although other metals can be present in iron puncta, they are predominantly iron containing and do not appear to be

  20. Mild hypoxia affects synaptic connectivity in cultured neuronal networks.

    Science.gov (United States)

    Hofmeijer, Jeannette; Mulder, Alex T B; Farinha, Ana C; van Putten, Michel J A M; le Feber, Joost

    2014-04-04

    Eighty percent of patients with chronic mild cerebral ischemia/hypoxia resulting from chronic heart failure or pulmonary disease have cognitive impairment. Overt structural neuronal damage is lacking and the precise cause of neuronal damage is unclear. As almost half of the cerebral energy consumption is used for synaptic transmission, and synaptic failure is the first abrupt consequence of acute complete anoxia, synaptic dysfunction is a candidate mechanism for the cognitive deterioration in chronic mild ischemia/hypoxia. Because measurement of synaptic functioning in patients is problematic, we use cultured networks of cortical neurons from new born rats, grown over a multi-electrode array, as a model system. These were exposed to partial hypoxia (partial oxygen pressure of 150Torr lowered to 40-50Torr) during 3 (n=14) or 6 (n=8) hours. Synaptic functioning was assessed before, during, and after hypoxia by assessment of spontaneous network activity, functional connectivity, and synaptically driven network responses to electrical stimulation. Action potential heights and shapes and non-synaptic stimulus responses were used as measures of individual neuronal integrity. During hypoxia of 3 and 6h, there was a statistically significant decrease of spontaneous network activity, functional connectivity, and synaptically driven network responses, whereas direct responses and action potentials remained unchanged. These changes were largely reversible. Our results indicate that in cultured neuronal networks, partial hypoxia during 3 or 6h causes isolated disturbances of synaptic connectivity. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Generative modelling of regulated dynamical behavior in cultured neuronal networks

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    Volman, Vladislav; Baruchi, Itay; Persi, Erez; Ben-Jacob, Eshel

    2004-04-01

    The spontaneous activity of cultured in vitro neuronal networks exhibits rich dynamical behavior. Despite the artificial manner of their construction, the networks’ activity includes features which seemingly reflect the action of underlying regulating mechanism rather than arbitrary causes and effects. Here, we study the cultured networks dynamical behavior utilizing a generative modelling approach. The idea is to include the minimal required generic mechanisms to capture the non-autonomous features of the behavior, which can be reproduced by computer modelling, and then, to identify the additional features of biotic regulation in the observed behavior which are beyond the scope of the model. Our model neurons are composed of soma described by the two Morris-Lecar dynamical variables (voltage and fraction of open potassium channels), with dynamical synapses described by the Tsodyks-Markram three variables dynamics. The model neuron satisfies our self-consistency test: when fed with data recorded from a real cultured networks, it exhibits dynamical behavior very close to that of the networks’ “representative” neuron. Specifically, it shows similar statistical scaling properties (approximated by similar symmetric Lévy distribution with finite mean). A network of such M-L elements spontaneously generates (when weak “structured noise” is added) synchronized bursting events (SBEs) similar to the observed ones. Both the neuronal statistical scaling properties within the bursts and the properties of the SBEs time series show generative (a new discussed concept) agreement with the recorded data. Yet, the model network exhibits different structure of temporal variations and does not recover the observed hierarchical temporal ordering, unless fed with recorded special neurons (with much higher rates of activity), thus indicating the existence of self-regulation mechanisms. It also implies that the spontaneous activity is not simply noise-induced. Instead, the

  2. Ultrastructural description of rabies virus infection in cultured sensory neurons

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    Myriam L Velandia

    2007-06-01

    Full Text Available Primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (RABV infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. The monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. As previously reported, sensory neurons showed great susceptibility to infection by RABV; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. Instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. When infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. Sensory neurons infected in vitro by RABV produced a large amount of unassembled viral ribonucleoprotein. However, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. It can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy.

  3. Effects of Ranolazine on Astrocytes and Neurons in Primary Culture.

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    Martin Aldasoro

    Full Text Available Ranolazine (Rn is an antianginal agent used for the treatment of chronic angina pectoris when angina is not adequately controlled by other drugs. Rn also acts in the central nervous system and it has been proposed for the treatment of pain and epileptic disorders. Under the hypothesis that ranolazine could act as a neuroprotective drug, we studied its effects on astrocytes and neurons in primary culture. We incubated rat astrocytes and neurons in primary cultures for 24 hours with Rn (10-7, 10-6 and 10-5 M. Cell viability and proliferation were measured using trypan blue exclusion assay, MTT conversion assay and LDH release assay. Apoptosis was determined by Caspase 3 activity assay. The effects of Rn on pro-inflammatory mediators IL-β and TNF-α was determined by ELISA technique, and protein expression levels of Smac/Diablo, PPAR-γ, Mn-SOD and Cu/Zn-SOD by western blot technique. In cultured astrocytes, Rn significantly increased cell viability and proliferation at any concentration tested, and decreased LDH leakage, Smac/Diablo expression and Caspase 3 activity indicating less cell death. Rn also increased anti-inflammatory PPAR-γ protein expression and reduced pro-inflammatory proteins IL-1 β and TNFα levels. Furthermore, antioxidant proteins Cu/Zn-SOD and Mn-SOD significantly increased after Rn addition in cultured astrocytes. Conversely, Rn did not exert any effect on cultured neurons. In conclusion, Rn could act as a neuroprotective drug in the central nervous system by promoting astrocyte viability, preventing necrosis and apoptosis, inhibiting inflammatory phenomena and inducing anti-inflammatory and antioxidant agents.

  4. Rabies virus infection of cultured adult mouse dorsal root ganglion neurons

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    Jaime Castellanos

    1996-10-01

    Full Text Available An in vitro model of adult dorsal root ganglion neurons infection by rabies virus is described. Viral marked neurotropism is observed, and the percentage and the degree of infection of the neurons is higher than in non neuronal cells, even if neurons are the minority of the cells in the culture. The neuritic tree is also heavily infected by the virus.

  5. A high-throughput model for investigating neuronal function and synaptic transmission in cultured neuronal networks.

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    Virdee, Jasmeet K; Saro, Gabriella; Fouillet, Antoine; Findlay, Jeremy; Ferreira, Filipa; Eversden, Sarah; O'Neill, Michael J; Wolak, Joanna; Ursu, Daniel

    2017-11-03

    Loss of synapses or alteration of synaptic activity is associated with cognitive impairment observed in a number of psychiatric and neurological disorders, such as schizophrenia and Alzheimer's disease. Therefore successful development of in vitro methods that can investigate synaptic function in a high-throughput format could be highly impactful for neuroscience drug discovery. We present here the development, characterisation and validation of a novel high-throughput in vitro model for assessing neuronal function and synaptic transmission in primary rodent neurons. The novelty of our approach resides in the combination of the electrical field stimulation (EFS) with data acquisition in spatially separated areas of an interconnected neuronal network. We integrated our methodology with state of the art drug discovery instrumentation (FLIPR Tetra) and used selective tool compounds to perform a systematic pharmacological validation of the model. We investigated pharmacological modulators targeting pre- and post-synaptic receptors (AMPA, NMDA, GABA-A, mGluR2/3 receptors and Nav, Cav voltage-gated ion channels) and demonstrated the ability of our model to discriminate and measure synaptic transmission in cultured neuronal networks. Application of the model described here as an unbiased phenotypic screening approach will help with our long term goals of discovering novel therapeutic strategies for treating neurological disorders.

  6. Differential effects of synthetic progestagens on neuron survival and estrogen neuroprotection in cultured neurons.

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    Jayaraman, Anusha; Pike, Christian J

    2014-03-25

    Progesterone and other progestagens are used in combination with estrogens for clinical purposes, including contraception and postmenopausal hormone therapy. Progesterone and estrogens have interactive effects in brain, however interactions between synthetic progestagens and 17β-estradiol (E2) in neurons are not well understood. In this study, we investigated the effects of seven clinically relevant progestagens on estrogen receptor (ER) mRNA expression, E2-induced neuroprotection, and E2-induced BDNF mRNA expression. We found that medroxyprogesterone acetate decreased both ERα and ERβ expression and blocked E2-mediated neuroprotection and BDNF expression. Conversely, levonorgestrel and nesterone increased ERα and or ERβ expression, were neuroprotective, and failed to attenuate E2-mediated increases in neuron survival and BDNF expression. Other progestagens tested, including norethindrone, norethindrone acetate, norethynodrel, and norgestimate, had variable effects on the measured endpoints. Our results demonstrate a range of qualitatively different actions of progestagens in cultured neurons, suggesting significant variability in the neural effects of clinically utilized progestagens. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Vasoactive intestinal peptide and nitric oxide promote survival of adult rat myenteric neurons in culture

    DEFF Research Database (Denmark)

    Sandgren, Katarina; Lin, Zhong; Svenningsen, Åsa Fex

    2003-01-01

    Several motility disorders originate in the enteric nervous system (ENS). Our knowledge of factors governing survival of the ENS is poor. Changes in the expression of vasoactive intestinal peptide (VIP) and nitric oxide synthase (NOS) in enteric neurons occur after neuronal injury and in intestinal...... adaptation. The aim of this study was to evaluate whether VIP and nitric oxide (NO) influence survival of cultured, dissociated myenteric neurons. Neuronal survival was evaluated after 0, 4, and 8 days in culture. Influence of VIP and NO on neuronal survival was examined after culturing in the presence...

  8. A Neuronal Culture System to Detect Prion Synaptotoxicity.

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    Cheng Fang

    2016-05-01

    Full Text Available Synaptic pathology is an early feature of prion as well as other neurodegenerative diseases. Although the self-templating process by which prions propagate is well established, the mechanisms by which prions cause synaptotoxicity are poorly understood, due largely to the absence of experimentally tractable cell culture models. Here, we report that exposure of cultured hippocampal neurons to PrPSc, the infectious isoform of the prion protein, results in rapid retraction of dendritic spines. This effect is entirely dependent on expression of the cellular prion protein, PrPC, by target neurons, and on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic loss. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents.

  9. Endocannabinoids block status epilepticus in cultured hippocampal neurons

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    Deshpande, Laxmikant S.; Blair, Robert E.; Ziobro, Julie M.; Sombati, Sompong; Martin, Billy R.; DeLorenzo, Robert J.

    2008-01-01

    Status epilepticus is a serious neurological disorder associated with a significant morbidity and mortality. Antiepileptic drugs such as diazepam, phenobarbital and phenytoin are the mainstay of status epilepticus treatment. However, over 20% of status epilepticus cases are refractory to the initial treatment with two or more antiepileptic drugs. Endocannabinoids have been implicated as playing an important role in regulating seizure activity and seizure termination. This study evaluated the effects of the major endocannabinoids methanandamide and 2-arachidonylglycerol (2-AG) on status epilepticus in the low-Mg2+ hippocampal neuronal culture model. Status epilepticus in this model was resistant to treatment with phenobarbital and phenytoin. Methanandamide and 2-AG inhibited status epilepticus in a dose-dependent manner with an EC50 of 145±4.15 nM and 1.68±0.19 µM, respectively. In addition, the anti-status epilepticus effects of methanandamide and 2-AG were mediated by activation of the cannabinoid CB1 receptor since they were blocked by the cannabinoid CB1 receptor antagonist AM251. These results provide the first evidence that the endocannabinoids, methanandamide and 2-AG, are effective inhibitors of refractory status epilepticus in the hippocampal neuronal culture model and indicate that regulating the endocannabinoid system may provide a novel therapeutic approach for treating refractory status epilepticus. PMID:17174949

  10. Modeled channel distributions explain extracellular recordings from cultured neurons sealed to microelectrodes

    NARCIS (Netherlands)

    Buitenweg, Jan R.; Rutten, Wim; Marani, Enrico

    2002-01-01

    Amplitudes and shapes of extracellular recordings from single neurons cultured on a substrate embedded microelectrode depend not only on the volume conducting properties of the neuron-electrode interface, but might also depend on the distribution of voltage-sensitive channels over the neuronal

  11. Conditional intrinsic voltage oscillations in mature vertebrate neurons undergo specific changes in culture

    DEFF Research Database (Denmark)

    Guertin, Pierre A; Hounsgaard, Jørn

    2006-01-01

    Although intrinsic neuronal properties in invertebrates are well known to undergo specific adaptive changes in culture, long-term adaptation of similar properties in mature vertebrate neurons remain poorly understood. To investigate this, we used an organotypic slice preparation from the spinal...... cord of adult turtles maintainable for several weeks in culture conditions. N-methyl-D-aspartate (NMDA)-induced-tetrodotoxin (TTX)-resistant voltage oscillations in motoneurons were approximately 10 times faster in culture than in acute preparations. Oscillations in culture were abolished by NMDA...... to understanding further the potential for plasticity of mature vertebrate neurons....

  12. Falcarindiol inhibits nitric oxide-mediated neuronal death in lipopolysaccharide-treated organotypic hippocampal cultures.

    Science.gov (United States)

    Kim, Jeong Min; Lee, Pyeongjae; Son, Dongwook; Kim, Hocheol; Kim, Sun Yeou

    2003-10-27

    Excessive nitric oxide (NO) release from activated microglia has a predominant role in neuronal death. This study investigated the effect of falcarindiol, which was isolated from Cnidium officinale Makino, on the NO-mediated neuronal death in lipopolysaccharide (LPS)-treated organotypic hippocampal cultures. Falcarindiol dose-dependently reduced inducible NO synthase (iNOS)-mediated NO production without cytotoxic effects on LPS-activated BV-2 and microglia. Predictably, falcarindiol inhibited neuronal death by reducing NO production in the LPS-treated organotypic hippocampal cultures. N-monomethyl-L-arginine (NMMA), an iNOS inhibitor, also inhibited neuronal death at 500 microM. In contrast, massive neuronal death was induced by excessive NO production in the LPS-treated alone cultures. These results suggest that excessive NO production plays an important role in the neurotoxic effect, and falcarindiol is a potential inhibitor in NO-mediated neuronal death.

  13. Domoic acid disrupts the activity and connectivity of neuronal networks in organotypic brain slice cultures.

    Science.gov (United States)

    Hiolski, E M; Ito, S; Beggs, J M; Lefebvre, K A; Litke, A M; Smith, D R

    2016-09-01

    Domoic acid is a neurotoxin produced by algae and is found in seafood during harmful algal blooms. As a glutamate agonist, domoic acid inappropriately stimulates excitatory activity in neurons. At high doses, this leads to seizures and brain lesions, but it is unclear how lower, asymptomatic exposures disrupt neuronal activity. Domoic acid has been detected in an increasing variety of species across a greater geographical range than ever before, making it critical to understand the potential health impacts of low-level exposure on vulnerable marine mammal and human populations. To determine whether prolonged domoic acid exposure altered neuronal activity in hippocampal networks, we used a custom-made 512 multi-electrode array with high spatial and temporal resolution to record extracellular potentials (spikes) in mouse organotypic brain slice cultures. We identified individual neurons based on spike waveform and location, and measured the activity and functional connectivity within the neuronal networks of brain slice cultures. Domoic acid exposure significantly altered neuronal spiking activity patterns, and increased functional connectivity within exposed cultures, in the absence of overt cellular or neuronal toxicity. While the overall spiking activity of neurons in domoic acid-exposed cultures was comparable to controls, exposed neurons spiked significantly more often in bursts. We also identified a subset of neurons that were electrophysiologically silenced in exposed cultures, and putatively identified those neurons as fast-spiking inhibitory neurons. These results provide evidence that domoic acid affects neuronal activity in the absence of cytotoxicity, and suggest that neurodevelopmental exposure to domoic acid may alter neurological function in the absence of clinical symptoms. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Miniature excitatory synaptic currents in cultured hippocampal neurons.

    Science.gov (United States)

    Finch, D M; Fisher, R S; Jackson, M B

    1990-06-04

    We performed patch clamp recordings in the whole cell mode from cultured embryonic mouse hippocampal neurons. In bathing solutions containing tetrodotoxin (TTX), the cells showed spontaneous inward currents (SICs) ranging in size from 1 to 100 pA. Several observations indicated that the SICs were miniature excitatory synaptic currents mediated primarily by non-NMDA (N-methyl-D-aspartate) excitatory amino acid receptors: the rising phase of SICs was fast (1 ms to half amplitude at room temperature) and smooth, suggesting unitary events. The SICs were blocked by the broad-spectrum glutamate receptor antagonist gamma-D-glutamylglycine (DGG), but not by the selective NMDA-receptor antagonist D-2-amino-5-phosphonovaleric acid (5-APV). SICs were also blocked by desensitizing concentrations of quisqualate. Incubating cells in tetanus toxin, which blocks exocytotic transmitter release, eliminated SICs. The presence of SICs was consistent with the morphological arrangement of glutamatergic innervation in the cell cultures demonstrated immunohistochemically. Spontaneous outward currents (SOCs) were blocked by bicuculline and presumed to be mediated by GABAA receptors. This is consistent with immunohistochemical demonstration of GABAergic synapses. SIC frequency was increased in a calcium dependent manner by bathing the cells in a solution high in K+, and application of the dihydropyridine L-type calcium channel agonist BAY K 8644 increased the frequency of SICs. Increases in SIC frequency produced by high K+ solutions were reversed by Cd2+ and omega-conotoxin GVIA, but not by the selective L-type channel antagonist nimodipine. This suggested that presynaptic L-type channels were in a gating mode that was not blocked by nimodipine, and/or that another class of calcium channel makes a dominant contribution to excitatory transmitter release.

  15. Falcarindiol allosterically modulates GABAergic currents in cultured rat hippocampal neurons.

    Science.gov (United States)

    Wyrembek, Paulina; Negri, Roberto; Kaczor, Przemysław; Czyżewska, Marta; Appendino, Giovanni; Mozrzymas, Jerzy Wladyslaw

    2012-04-27

    Falcarindiol (1), a C-17 polyacetylenic diol, shows a pleiotropic profile of bioactivity, but the mechanism(s) underlying its actions are largely unknown. Large amounts of 1 co-occur in water hemlock (Oenanthe crocata) along with the convulsant polyacetylenic toxin oenanthotoxin (2), a potent GABA(A) receptor (GABA(A)R) inhibitor. Since these compounds are structurally and biogenetically related, it was considered of interest to evaluate whether 1 could affect GABAergic activity, and for this purpose a model of hippocampal cultured neurons was used. Compound 1 significantly increased the amplitude of miniature inhibitory postsynaptic currents, accelerated their onset, and prolonged the decay kinetics. This compound enhanced also the amplitude of currents elicited by 3 μM GABA and accelerated their fading, reducing, however, currents evoked by a saturating (10 mM) GABA concentration. Moreover, kinetic analysis of responses to 10 mM GABA revealed that 1 upregulated the rate and extent of desensitization and slowed the current onset and deactivation. Taken together, these data show that 1 exerts a potent modulatory action on GABA(A)Rs, possibly by modulating agonist binding and desensitization, overall potentially decreasing the toxicity of co-occurring GABA-inhibiting convulsant toxins. © 2012 American Chemical Society and American Society of Pharmacognosy

  16. Comparison of prostanoid forming capacity of neuronal and astroglial cells in primary cultures.

    Science.gov (United States)

    Keller, M; Jackisch, R; Seregi, A; Hertting, G

    1985-01-01

    Prostaglandin (PG) and thromboxane (TX) biosynthesis in primary neuronal and astroglial cell cultures was studied. Cultures obtained from fetal (15-16 days old) and neonatal rat brain hemispheres were characterized by chemical and immunocytochemical staining techniques as predominantly neurons or mature and immature astrocytes, respectively. Six-day old neuronal cell cultures grown in the presence of cytosine arabinoside (2 ?M) from the day 3 onwards were contaminated up to 10% with glioblasts. In astroglial cultures up to 3% of the cells were postively stained with a marker for oligodendroglial cells. Fibroblast contamination was below 1% in both cultures. Prostanoid formation (measured by specific radioimmunoassays) in 6-day old neuronal cell cultures was low (sum of the amount of PGs and TX formed: 1.16 +/- 0.17 (ng/mg protein/15 min) as compared to 14-day old cultured astroglial cells: 21.27 +/- 2.53 (ng/mg protein/15 min). Also the pattern of prostanoids formed was different in neuronal (PGD(2) ? PGF(2?) > TXB(2) ? PGE(2)) and astroglial cells (PGD(2) > TXB(2) ? PGF(2?) ? PGE(2) ? 6-ketoPGF(1?)). Preincubation with arachidonic acid (1 ?g/ml) did not affect prostanoid formation in both cultures, whereas it was stimulated 4-6-fold by addition of the calcium ionophore A23187 (1 ?M). These results, although found on cultured neuronal and glial cells of different stages of development, support the view that astroglial cells might play a crucial role in brain prostanoid synthesis.

  17. Simulation of Code Spectrum and Code Flow of Cultured Neuronal Networks.

    Science.gov (United States)

    Tamura, Shinichi; Nishitani, Yoshi; Hosokawa, Chie; Miyoshi, Tomomitsu; Sawai, Hajime

    2016-01-01

    It has been shown that, in cultured neuronal networks on a multielectrode, pseudorandom-like sequences (codes) are detected, and they flow with some spatial decay constant. Each cultured neuronal network is characterized by a specific spectrum curve. That is, we may consider the spectrum curve as a "signature" of its associated neuronal network that is dependent on the characteristics of neurons and network configuration, including the weight distribution. In the present study, we used an integrate-and-fire model of neurons with intrinsic and instantaneous fluctuations of characteristics for performing a simulation of a code spectrum from multielectrodes on a 2D mesh neural network. We showed that it is possible to estimate the characteristics of neurons such as the distribution of number of neurons around each electrode and their refractory periods. Although this process is a reverse problem and theoretically the solutions are not sufficiently guaranteed, the parameters seem to be consistent with those of neurons. That is, the proposed neural network model may adequately reflect the behavior of a cultured neuronal network. Furthermore, such prospect is discussed that code analysis will provide a base of communication within a neural network that will also create a base of natural intelligence.

  18. Effects of combined BDNF and GDNF treatment on cultured dopaminergic midbrain neurons

    DEFF Research Database (Denmark)

    Sautter, J; Meyer, Morten; Spenger, C

    1998-01-01

    -derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), or a combination of both. Dopamine content of the culture medium, the number of tyrosine hydroxylase-immunoreactive neurons, and culture volumes were moderately increased in the BDNF- and GDNF-treated cultures but significantly...

  19. Geometry based finite element modeling of the electrical contact between a cultured neuron and a microelectrode

    NARCIS (Netherlands)

    Buitenweg, Jan R.; Rutten, Wim; Marani, Enrico

    2003-01-01

    The electrical contact between a substrate embedded microelectrode and a cultured neuron depends on the geometry of the neuron-electrode interface. Interpretation and improvement of these contacts requires proper modeling of all coupling mechanisms. In literature, it is common practice to model the

  20. Neurotrophic requirements of human motor neurons defined using amplified and purified stem cell-derived cultures.

    Directory of Open Access Journals (Sweden)

    Nuno Jorge Lamas

    Full Text Available Human motor neurons derived from embryonic and induced pluripotent stem cells (hESCs and hiPSCs are a potentially important tool for studying motor neuron survival and pathological cell death. However, their basic survival requirements remain poorly characterized. Here, we sought to optimize a robust survival assay and characterize their response to different neurotrophic factors. First, to increase motor neuron yield, we screened a small-molecule collection and found that the Rho-associated kinase (ROCK inhibitor Y-27632 enhances motor neuron progenitor proliferation up to 4-fold in hESC and hiPSC cultures. Next, we FACS-purified motor neurons expressing the Hb9::GFP reporter from Y-27632-amplified embryoid bodies and cultured them in the presence of mitotic inhibitors to eliminate dividing progenitors. Survival of these purified motor neurons in the absence of any other cell type was strongly dependent on neurotrophic support. GDNF, BDNF and CNTF all showed potent survival effects (EC(50 1-2 pM. The number of surviving motor neurons was further enhanced in the presence of forskolin and IBMX, agents that increase endogenous cAMP levels. As a demonstration of the ability of the assay to detect novel neurotrophic agents, Y-27632 itself was found to support human motor neuron survival. Thus, purified human stem cell-derived motor neurons show survival requirements similar to those of primary rodent motor neurons and can be used for rigorous cell-based screening.

  1. Down-regulation of protein kinase C protects cerebellar granule neurons in primary culture from glutamate-induced neuronal death

    International Nuclear Information System (INIS)

    Favaron, M.; Manev, H.; Bertolino, M.; Szekely, A.M.; DeErausquin, G.; Guidotti, A.; Costa, E.; Siman, R.

    1990-01-01

    Exposing primary cultures of cerebellar granule neurons to 100 nM phorbol 12-myristate 13-acetate (PMA) for 24 hr decreases the Ca 2+ /phosphatidylserine/diolein-dependent protein kinase C. Immunoblot analysis of the homogenates with polyclonal antibodies raised against either the β-type PKC peptide or total rat brain PKC reveals a virtual loss of 78-kDa PKC immunoreactivity in the supernatant and marked decrease of PKC immunoreactivity in the pellet. Exposure of the cultures to 50 μM glutamate for 15 min (no Mg 2+ ) induces the translocation of supernatant PKC immunoreactivity to the pellet. PMA-induced down-regulation of PKC decreases glutamate-elicited neurotoxicity. Yet, the culture exposure to 100 nM PMA fails to decrease the high-affinity binding of [ 3 H]glutamate to neuronal membranes and does not reduce glutamate-induced activation of ionotropic or metabolotropic receptors (assayed as total membrane current measured in whole-cell voltage-clamped neurons, 45 Ca 2+ uptake in intact monolayers, inositolphospholipid hydrolysis, and transcriptional activation and translation of c-fos mRNA). On the other hand, PMA-induced PKC down-regulation reduces any increase in 45 Ca 2+ uptake or Ca 2+ -dependent proteolysis after glutamate withdrawal. These results support the view that PKC translocation is operative in glutamate-induced destabilization of cytosolic ionized Ca 2+ homeostasis and neuronal death

  2. Effects of combined BDNF and GDNF treatment on cultured dopaminergic midbrain neurons

    DEFF Research Database (Denmark)

    Sautter, J; Meyer, Morten; Spenger, C

    1998-01-01

    Neural transplantation is an experimental therapy for Parkinson's disease. Pretreatment of fetal donor tissue with neurotrophic factors may improve survival of grafted dopaminergic neurons. Free-floating roller tube cultures of fetal rat ventral mesencephalon were treated with brain...

  3. AlGaN/GaN-based HEMTs for electrical stimulation of neuronal cell cultures

    International Nuclear Information System (INIS)

    Witte, H; Warnke, C; Krost, A; Voigt, T; De Lima, A; Ivanov, I; Vidakovic-Koch, T R; Sundmacher, K

    2011-01-01

    Unipolar source-drain voltage pulses of GaN/AlGaN-high electron mobility transistors (HEMTs) were used for stimulation of cultured neuronal networks obtained from embryonic rat cerebral cortex. The HEMT sensor was grown by metal organic vapour phase epitaxy on a 2 inch sapphire substrate consisting of 10 single HEMTs concentrically arranged around the wafer centre. Electrolytic reactions between the HEMT sensor surface and the culture medium were not detected using cyclic voltammetry. During voltage pulses and resulting neuronal excitation, capacitances were recharged giving indications of the contributions of the AlGaN and AlO x isolation layers between the two-dimensional electron gas channel and the neuron culture. The resulting threshold current for stimulation of neuron activity strongly depended on the culture and HEMT position on the sensor surface under consideration which was caused by different impedances of each neuron culture and position within the culture. The differences of culture impedances could be explained by variations of composition, thickness and conductivity of the culture areas.

  4. AlGaN/GaN-based HEMTs for electrical stimulation of neuronal cell cultures

    Science.gov (United States)

    Witte, H.; Warnke, C.; Voigt, T.; de Lima, A.; Ivanov, I.; Vidakovic-Koch, T. R.; Sundmacher, K.; Krost, A.

    2011-09-01

    Unipolar source-drain voltage pulses of GaN/AlGaN-high electron mobility transistors (HEMTs) were used for stimulation of cultured neuronal networks obtained from embryonic rat cerebral cortex. The HEMT sensor was grown by metal organic vapour phase epitaxy on a 2 inch sapphire substrate consisting of 10 single HEMTs concentrically arranged around the wafer centre. Electrolytic reactions between the HEMT sensor surface and the culture medium were not detected using cyclic voltammetry. During voltage pulses and resulting neuronal excitation, capacitances were recharged giving indications of the contributions of the AlGaN and AlOx isolation layers between the two-dimensional electron gas channel and the neuron culture. The resulting threshold current for stimulation of neuron activity strongly depended on the culture and HEMT position on the sensor surface under consideration which was caused by different impedances of each neuron culture and position within the culture. The differences of culture impedances could be explained by variations of composition, thickness and conductivity of the culture areas.

  5. Optogenetic control of human neurons in organotypic brain cultures

    DEFF Research Database (Denmark)

    Andersson, My; Avaliani, Natalia; Svensson, Andreas

    2016-01-01

    Optogenetics is one of the most powerful tools in neuroscience, allowing for selective control of specific neuronal populations in the brain of experimental animals, including mammals. We report, for the first time, the application of optogenetic tools to human brain tissue providing a proof......-of-concept for the use of optogenetics in neuromodulation of human cortical and hippocampal neurons as a possible tool to explore network mechanisms and develop future therapeutic strategies....

  6. Steps in the formation of neurites and synapses studied in cultured leech neurons

    Directory of Open Access Journals (Sweden)

    De-Miguel F.F.

    2000-01-01

    Full Text Available Leech neurons in culture have provided novel insights into the steps in the formation of neurite outgrowth patterns, target recognition and synapse formation. Identified adult neurons from the central nervous system of the leech can be removed individually and plated in culture under well-controlled conditions, where they retain their characteristic physiological properties, grow neurites and form specific chemical or electrical synapses. Different identified neurons develop distinctive outgrowth patterns that depend on their identities and on the molecular composition of the substrate. On native substrates, the patterns displayed by these neurons reproduce characteristics from the adult or the developing neurons. In addition, the substrate may induce selective directed growth between pairs of neurons that normally make contact in the ganglion. Upon contact, pairs of cultured leech neurons form chemical or electrical synapses, or both types depending on the neuronal identities. Anterograde and retrograde signals during membrane contact and synapse formation modify the distribution of synaptic terminals, calcium currents, and responses to 5-hydroxytryptamine.

  7. PYRETHROID MODULATION OF SPONTANEOUS NEURONAL EXCITABILITY AND NEUROTRANSMISSION IN HIPPOCAMPAL NEURONS IN CULTURE

    Science.gov (United States)

    Pyrethroid insecticides have potent actions on voltage-gated sodium channels, inhibiting inactivation and increasing channel open times. These are thought to underlie, at least in part, the clinical symptoms of pyrethroid intoxication. However, disruption of neuronal activity at ...

  8. Optophysiological Approach to Resolve Neuronal Action Potentials with High Spatial and Temporal Resolution in Cultured Neurons

    OpenAIRE

    Pagès, Stéphane; Côté, Daniel; De Koninck, Paul

    2011-01-01

    Cell to cell communication in the central nervous system is encoded into transient and local membrane potential changes (?Vm). Deciphering the rules that govern synaptic transmission and plasticity entails to be able to perform V m recordings throughout the entire neuronal arborization. Classical electrophysiology is, in most cases, not able to do so within small and fragile neuronal subcompartments. Thus, optical techniques based on the use of fluorescent voltage-sensitive dyes (VSDs) have b...

  9. Rapid metabolism of exogenous angiotensin II by catecholaminergic neuronal cells in culture media.

    Science.gov (United States)

    Basu, Urmi; Seravalli, Javier; Madayiputhiya, Nandakumar; Adamec, Jiri; Case, Adam J; Zimmerman, Matthew C

    2015-02-01

    Angiotensin II (AngII) acts on central neurons to increase neuronal firing and induce sympathoexcitation, which contribute to the pathogenesis of cardiovascular diseases including hypertension and heart failure. Numerous studies have examined the precise AngII-induced intraneuronal signaling mechanism in an attempt to identify new therapeutic targets for these diseases. Considering the technical challenges in studying specific intraneuronal signaling pathways in vivo, especially in the cardiovascular control brain regions, most studies have relied on neuronal cell culture models. However, there are numerous limitations in using cell culture models to study AngII intraneuronal signaling, including the lack of evidence indicating the stability of AngII in culture media. Herein, we tested the hypothesis that exogenous AngII is rapidly metabolized in neuronal cell culture media. Using liquid chromatography-tandem mass spectrometry, we measured levels of AngII and its metabolites, Ang III, Ang IV, and Ang-1-7, in neuronal cell culture media after administration of exogenous AngII (100 nmol/L) to a neuronal cell culture model (CATH.a neurons). AngII levels rapidly declined in the media, returning to near baseline levels within 3 h of administration. Additionally, levels of Ang III and Ang-1-7 acutely increased, while levels of Ang IV remained unchanged. Replenishing the media with exogenous AngII every 3 h for 24 h resulted in a consistent and significant increase in AngII levels for the duration of the treatment period. These data indicate that AngII is rapidly metabolized in neuronal cell culture media, and replenishing the media at least every 3 h is needed to sustain chronically elevated levels. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  10. Polyethyleneimine-mediated transfection of cultured postmitotic neurons from rat sympathetic ganglia and adult human retina

    Directory of Open Access Journals (Sweden)

    Higgins Dennis

    2001-02-01

    Full Text Available Abstract Background Chemical methods of transfection that have proven successful with cell lines often do not work with primary cultures of neurons. Recent data, however, suggest that linear polymers of the cation polyethyleneimine (PEI can facilitate the uptake of nucleic acids by neurons. Consequently, we examined the ability of a commercial PEI preparation to allow the introduction of foreign genes into postmitotic mammalian neurons. Sympathetic neurons were obtained from perinatal rat pups and maintained for 5 days in vitro in the absence of nonneuronal cells. Cultures were then transfected with varying amounts of a plasmid encoding either E. coli β-galactosidase or enhanced green fluorescence protein (EGFP using PEI. Results Optimal transfection efficiency was observed with 1 μg/ml of plasmid DNA and 5 μg/ml PEI. Expression of β-galactosidase was both rapid and stable, beginning within 6 hours and lasting for at least 21 days. A maximum yield was obtained within 72 hours with ∼ 9% of the neurons expressing β-galactosidase, as assessed by both histochemistry and antibody staining. Cotransfection of two plasmids encoding reporter genes was achieved. Postmitotic neurons from adult human retinal cultures also demonstrated an ability to take up and express foreign DNA using PEI as a vector. Conclusions These data suggest that PEI is a useful agent for the stable expression of plasmid-encoded genes in neuronal cultures.

  11. Direct Signaling from Astrocytes to Neurons in Cultures of Mammalian Brain Cells

    Science.gov (United States)

    Nedergaard, Maiken

    1994-03-01

    Although astrocytes have been considered to be supportive, rather than transmissive, in the adult nervous system, recent studies have challenged this assumption by demonstrating that astrocytes possess functional neurotransmitter receptors. Astrocytes are now shown to directly modulate the free cytosolic calcium, and hence transmission characteristics, of neighboring neurons. When a focal electric field potential was applied to single astrocytes in mixed cultures of rat forebrain astrocytes and neurons, a prompt elevation of calcium occurred in the target cell. This in turn triggered a wave of calcium increase, which propagated from astrocyte to astrocyte. Neurons resting on these astrocytes responded with large increases in their concentration of cytosolic calcium. The gap junction blocker octanol attenuated the neuronal response, which suggests that the astrocytic-neuronal signaling is mediated through intercellular connections rather than synaptically. This neuronal response to local astrocytic stimulation may mediate local intercellular communication within the brain.

  12. Effects of Forskolin on Trefoil factor 1 expression in cultured ventral mesencephalic dopaminergic neurons

    DEFF Research Database (Denmark)

    Jensen, Pia; Ducray, A D; Widmer, H R

    2015-01-01

    , suggesting that Forskolin induced TFF1 expression through diverse signaling pathways. In conclusion, distinct populations of cultured dopaminergic neurons express TFF1, and their numbers can be increased by factors known to influence survival and differentiation of dopaminergic cells....... shown that TFF1 is expressed in developing and adult rat ventral mesencephalic tyrosine hydroxylase-immunoreactive (TH-ir) dopaminergic neurons. Here, we investigated the expression of TFF1 in rat ventral mesencephalic dopaminergic neurons (embryonic day 14) grown in culture for 5, 7 or 10days...... to neuronal cells, and the percentage of TH/TFF1 co-expressing cells was increased to the same extent in GDNF and Forskolin-treated cultures (4-fold) as compared to controls. Interestingly, the combination of GDNF and Forskolin resulted in a significantly increased co-expression (8-fold) of TH/TFF1, which...

  13. Chronic lithium treatment increased intracellular S100ß levels in rat primary neuronal culture.

    Directory of Open Access Journals (Sweden)

    Masoumeh Emamghoreishi

    2015-02-01

    Full Text Available S100ß a neurotrophic factor mainly released by astrocytes, has been implicated in the pathogenesis of bipolar disorder. Thus, lithium may exert its neuroprotective effects to some extent through S100ß. Furthermore, the possible effects of lithium on astrocytes as well as on interactions between neurons and astrocytes as a part of its mechanisms of actions are unknown. This study was undertaken to determine the effect of lithium on S100β in neurons, astrocytes and a mixture of neurons and astrocytes. Rat primary astrocyte, neuronal and mixed neuro-astroglia cultures were prepared from cortices of 18-day's embryos. Cell cultures were exposed to lithium (1mM or vehicle for 1day (acute or 7 days (chronic. RT-PCR and ELISA determined S100β mRNA and intra- and extracellular protein levels. Chronic lithium treatment significantly increased intracellular S100β in neuronal and neuro-astroglia cultures in comparison to control cultures (P<0.05. Acute and chronic lithium treatments exerted no significant effects on intracellular S100β protein levels in astrocytes, and extracellular S100β protein levels in three studied cultures as compared to control cultures. Acute and chronic lithium treatments did not significantly alter S100β mRNA levels in three studied cultures, compared to control cultures. Chronic lithium treatment increased intracellular S100ß protein levels in a cell-type specific manner which may favor its neuroprotective action. The findings of this study suggest that lithium may exert its neuroprotective action, at least partly, by increasing neuronal S100ß level, with no effect on astrocytes or interaction between neurons and astrocytes.

  14. Resveratrol Produces Neurotrophic Effects on Cultured Dopaminergic Neurons through Prompting Astroglial BDNF and GDNF Release

    Directory of Open Access Journals (Sweden)

    Feng Zhang

    2012-01-01

    Full Text Available Increasing evidence indicated astroglia-derived neurotrophic factors generation might hold a promising therapy for Parkinson’s disease (PD. Resveratrol, naturally present in red wine and grapes with potential benefit for health, is well known to possess a number of pharmacological activities. Besides the antineuroinflammatory properties, we hypothesized the neuroprotective potency of resveratrol is partially due to its additional neurotrophic effects. Here, primary rat midbrain neuron-glia cultures were applied to investigate the neurotrophic effects mediated by resveratrol on dopamine (DA neurons and further explore the role of neurotrophic factors in its actions. Results showed resveratrol produced neurotrophic effects on cultured DA neurons. Additionally, astroglia-derived neurotrophic factors release was responsible for resveratrol-mediated neurotrophic properties as evidenced by the following observations: (1 resveratrol failed to exert neurotrophic effects on DA neurons in the cultures without astroglia; (2 the astroglia-conditioned medium prepared from astroglia-enriched cultures treated with resveratrol produced neurotrophic effects in neuron-enriched cultures; (3 resveratrol increased neurotrophic factors release in the concentration- and time-dependent manners; (4 resveratrol-mediated neurotrophic effects were suppressed by blocking the action of the neurotrophic factors. Together, resveratrol could produce neurotrophic effects on DA neurons through prompting neurotrophic factors release, and these effects might open new alternative avenues for neurotrophic factor-based therapy targeting PD.

  15. Prolactin mediates neuroprotection against excitotoxicity in primary cell cultures of hippocampal neurons via its receptor.

    Science.gov (United States)

    Vergara-Castañeda, E; Grattan, D R; Pasantes-Morales, H; Pérez-Domínguez, M; Cabrera-Reyes, E A; Morales, T; Cerbón, M

    2016-04-01

    Recently it has been reported that prolactin (PRL) exerts a neuroprotective effect against excitotoxicity in hippocampus in the rat in vivo models. However, the exact mechanism by which PRL mediates this effect is not completely understood. The aim of our study was to assess whether prolactin exerts neuroprotection against excitotoxicity in an in vitro model using primary cell cultures of hippocampal neurons, and to determine whether this effect is mediated via the prolactin receptor (PRLR). Primary cell cultures of rat hippocampal neurons were used in all experiments, gene expression was evaluated by RT-qPCR, and protein expression was assessed by Western blot analysis and immunocytochemistry. Cell viability was assessed by using the MTT method. The results demonstrated that PRL treatment of neurons from primary cultures did not modify cell viability, but that it exerted a neuroprotective effect, with cells treated with PRL showing a significant increase of viability after glutamate (Glu)--induced excitotoxicity as compared with neurons treated with Glu alone. Cultured neurons expressed mRNA for both PRL and its receptor (PRLR), and both PRL and PRLR expression levels changed after the excitotoxic insult. Interestingly, the PRLR protein was detected as two main isoforms of 100 and 40 kDa as compared with that expressed in hypothalamic cells, which was present only as a 30 kDa variant. On the other hand, PRL was not detected in neuron cultures, either by western blot or by immunohistochemistry. Neuroprotection induced by PRL was significantly blocked by specific oligonucleotides against PRLR, thus suggesting that the PRL role is mediated by its receptor expressed in these neurons. The overall results indicated that PRL induces neuroprotection in neurons from primary cell cultures. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A possible role of the non-GAT1 GABA transporters in transfer of GABA from GABAergic to glutamatergic neurons in mouse cerebellar neuronal cultures

    DEFF Research Database (Denmark)

    Suñol, C; Babot, Z; Cristòfol, R

    2010-01-01

    Cultures of dissociated cerebellum from 7-day-old mice were used to investigate the mechanism involved in synthesis and cellular redistribution of GABA in these cultures consisting primarily of glutamatergic granule neurons and a smaller population of GABAergic Golgi and stellate neurons......3 transporters. Only a small population of cells were immuno-stained for GAD while many cells exhibited VGlut-1 like immuno-reactivity which, however, never co-localized with GAD positive neurons. This likely reflects the small number of GABAergic neurons compared to the glutamatergic granule......M concentrations (95%). Essentially all neurons showed GABA like immunostaining albeit with differences in intensity. The results indicate that GABA which is synthesized in a small population of GAD-positive neurons is redistributed to essentially all neurons including the glutamatergic granule cells. GAT1...

  17. Synchronization of neurons in micro-electrode array cultures

    Science.gov (United States)

    Esposti, F.; Signorini, M. G.

    2008-12-01

    A lot of methods were created in last decade for the spatio-temporal analysis of multi-electrode array (MEA) neuronal data sets. In this paper we show how a new simple analysis approach that considers the total network activity, is able to show interesting neuronal network system dynamical features. In particular, we perform two different analyses: a neuronal connectivity examination studying networks at different days in vitro (div) and an analysis of the long per- iod effects of the administration of two common neuroactive drugs, Tetrodotoxin (TTX) and D-2-amino-5-phosphonovalerate (AP5), to spontaneously spiking mature neuronal networks. Our analysis is performed considering burst topology, i.e., cataloguing network bursts as Global (if they involve more than the 25% of the MEA channels) or Local (if less that 25%). In the first analysis, this division allows to understand the network connectivity developments. The networking increases from div 1 to 6 building up an undifferentiated highly connected network. From div 6 to 10 the networking decreases (pruning) till reaching a plateau in a small-world like organization. The second analysis highlights substantial differences between long period effects of TTX and AP5. Results show that AP5, selectively blocking NMDA receptors and inhibiting long term potentiation, is unable to produce activity twisting in a network that already reached a developmental plateau, but it is able to desynchronize sub-network (Local) activity. TTX, on the other side, blocking any type of electrical communication among neurons, acts on the whole network synchronization. The important activity increment in the post-TTX epoch (+66%), together with the Global activity explosion, suggests the possibility of a long-term inhibitory-synapse depression mechanism.

  18. Inhibition of microRNA 128 promotes excitability of cultured cortical neuronal networks.

    Science.gov (United States)

    McSweeney, K Melodi; Gussow, Ayal B; Bradrick, Shelton S; Dugger, Sarah A; Gelfman, Sahar; Wang, Quanli; Petrovski, Slavé; Frankel, Wayne N; Boland, Michael J; Goldstein, David B

    2016-10-01

    Cultured neuronal networks monitored with microelectrode arrays (MEAs) have been used widely to evaluate pharmaceutical compounds for potential neurotoxic effects. A newer application of MEAs has been in the development of in vitro models of neurological disease. Here, we directly evaluated the utility of MEAs to recapitulate in vivo phenotypes of mature microRNA-128 (miR-128) deficiency, which causes fatal seizures in mice. We show that inhibition of miR-128 results in significantly increased neuronal activity in cultured neuronal networks derived from primary mouse cortical neurons. These results support the utility of MEAs in developing in vitro models of neuroexcitability disorders, such as epilepsy, and further suggest that MEAs provide an effective tool for the rapid identification of microRNAs that promote seizures when dysregulated. © 2016 McSweeney et al.; Published by Cold Spring Harbor Laboratory Press.

  19. Modeling chronic brain exposure to amphetamines using primary rat neuronal cortical cultures.

    Science.gov (United States)

    Nogueira, T B; da Costa Araújo, S; Carvalho, F; Pereira, F C; Fernandes, E; Bastos, M L; Costa, V M; Capela, J P

    2014-09-26

    Amphetamine-type psychostimulants (ATS) are used worldwide by millions of patients for several psychiatric disorders. Amphetamine (AMPH) and "ecstasy" (3,4-methylenedioxymethamphetamine or MDMA) are common drugs of abuse. The impact of chronic ATS exposure to neurons and brain aging is still undisclosed. Current neuronal culture paradigms are designed to access acute ATS toxicity. We report for the first time a model of chronic exposure to AMPH and MDMA using long-term rat cortical cultures. In two paradigms, ATS were applied to neurons at day 1 in vitro (DIV) (0, 1, 10 and 100 μM of each drug) up to 28 days (200 μM was applied to cultures up to 14 DIV). Our reincubation protocol assured no decrease in the neuronal media's drug concentration. Chronic exposure of neurons to concentrations equal to or above 100 μM of ATS up to 28 DIV promoted significant mitochondrial dysfunction and elicited neuronal death, which was not prevented by glutamate receptor antagonists at 14 DIV. ATS failed to promote accelerated senescence as no increase in β-galactosidase activity at 21 DIV was found. In younger cultures (4 or 8 DIV), AMPH promoted mitochondrial dysfunction and neuronal death earlier than MDMA. Overall, AMPH proved more toxic and was the only drug that decreased intraneuronal glutathione levels. Meanwhile, caspase 3 activity increased for either drug at 200 μM in younger cultures at 8 DIV, but not at 14 DIV. At 8 DIV, ATS promoted a significant change in the percentage of neurons and astroglia present in culture, promoting a global decrease in the number of both cells. Importantly, concentrations equal to or below 10 μM of either drug did not promote neuronal death or oxidative stress. Our paradigm of neuronal cultures long-term exposure to low micromolar concentrations of ATS closely reproduces the in vivo scenario, being valuable to study the chronic impact of ATS. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Comparative Analysis of Human and Rodent Brain Primary Neuronal Culture Spontaneous Activity Using Micro-Electrode Array Technology.

    Science.gov (United States)

    Napoli, Alessandro; Obeid, Iyad

    2016-03-01

    Electrical activity in embryonic brain tissue has typically been studied using Micro Electrode Array (MEA) technology to make dozens of simultaneous recordings from dissociated neuronal cultures, brain stem cell progenitors, or brain slices from fetal rodents. Although these rodent neuronal primary culture electrical properties are mostly investigated, it has not been yet established to what extent the electrical characteristics of rodent brain neuronal cultures can be generalized to those of humans. A direct comparison of spontaneous spiking activity between rodent and human primary neurons grown under the same in vitro conditions using MEA technology has never been carried out before and will be described in the present study. Human and rodent dissociated fetal brain neuronal cultures were established in-vitro by culturing on a glass grid of 60 planar microelectrodes neurons under identical conditions. Three different cultures of human neurons were produced from tissue sourced from a single aborted fetus (at 16-18 gestational weeks) and these were compared with seven different cultures of embryonic rat neurons (at 18 gestational days) originally isolated from a single rat. The results show that the human and rodent cultures behaved significantly differently. Whereas the rodent cultures demonstrated robust spontaneous activation and network activity after only 10 days, the human cultures required nearly 40 days to achieve a substantially weaker level of electrical function. These results suggest that rat neuron preparations may yield inferences that do not necessarily transfer to humans. © 2015 Wiley Periodicals, Inc.

  1. Vector-averaged gravity alters myocyte and neuron properties in cell culture

    Science.gov (United States)

    Gruener, Raphael; Hoeger, Glenn

    1991-01-01

    The effect of changes in the gravitational field of developing neurons and myocytes on the development of these cells was investigated using observations of rotated cultures of embryonic spinal neurons and myocytes in a horizontal clinostat, in which rotation produces, from the cells' perspective, a 'vector-free' gravity environment by continous averaging of the vector, thus simulating the microgravity of space. It was found that, at rotation rates between 1 and 50 rpm, cellular and nuclear areas of myocytes become significantly enlarged and the number of presumptive nucleoli increase; in neurons, frequent and large swellings appeared along neuritic shafts. Some of these changes were reversible after the cessation of rotation.

  2. ELECTROPHYSIOLOGICAL CHARACTERIZATION OF DOPAMINERGIC AND NONDOPAMINERGIC NEURONS IN ORGANOTYPIC SLICE CULTURES OF THE RAT VENTRAL MESENCEPHALON

    DEFF Research Database (Denmark)

    STEENSEN, BH; NEDERGAARD, S; OSTERGAARD, K

    1995-01-01

    -old organotypic slice cultures of the ventral mesencephalon prepared from newborn rats. Dopaminergic neurones were distinguished from non-dopaminergic neurones by staining with the autofluorescent serotonin analogue 5,7-dihydroxytryptamine and briefly viewing the preparation with short exposures to ultraviolet...... 81 M Omega), were silent or fired spontaneously at a low frequency (0-9 Hz), and no spontaneous GABA(A)-ergic inhibitory postsynaptic potentials or inward rectification were present. In contrast, non-dopaminergic neurones had fast action potentials (0.6-3.2 ms), low input resistance (mean 32 M Omega...

  3. Availability of neurotransmitter glutamate is diminished when beta-hydroxybutyrate replaces glucose in cultured neurons

    DEFF Research Database (Denmark)

    Lund, Trine Meldgaard; Risa, Øystein; Sonnewald, Ursula

    2009-01-01

    ,4-(13)C]beta-hydroxybutyrate to that of [1,6-(13)C]glucose in cultured glutamatergic neurons and investigated the effect of neuronal activity focusing on the aspartate-glutamate homeostasis, an essential component of the excitatory activity in the brain. The amount of (13)C incorporation and cellular...... reduced malate-aspartate shuttle activity in neurons using beta-hydroxybutyrate. In the presence of glucose, the glutamate content decreased significantly upon activation of neurotransmitter release, whereas in the presence of only beta-hydroxybutyrate, no decrease in the glutamate content was observed...

  4. NRSF causes cAMP-sensitive suppression of sodium current in cultured hippocampal neurons

    Science.gov (United States)

    Nadeau, H.; Lester, H. A.

    2002-01-01

    The neuron restrictive silencer factor (NRSF/REST) has been shown to bind to the promoters of many neuron-specific genes and is able to suppress transcription of Na(+) channels in PC12 cells, although its functional effect in terminally differentiated neurons is unknown. We constructed lentiviral vectors to express NRSF as a bicistronic message with green fluorescent protein (GFP) and followed infected hippocampal neurons in culture over a period of 1-2 wk. NRSF-expressing neurons showed a time-dependent suppression of Na(+) channel function as measured by whole cell electrophysiology. Suppression was reversed or prevented by the addition of membrane-permeable cAMP analogues and enhanced by cAMP antagonists but not affected by increasing protein expression with a viral enhancer. Secondary effects, including altered sensitivity to glutamate and GABA and reduced outward K(+) currents, were duplicated by culturing GFP-infected control neurons in TTX. The striking similarity of the phenotypes makes NRSF potentially useful as a genetic "silencer" and also suggests avenues of further exploration that may elucidate the transcription factor's in vivo role in neuronal plasticity.

  5. Optimizing NTS-polyplex as a tool for gene transfer to cultured dopamine neurons.

    Directory of Open Access Journals (Sweden)

    Daniel Hernandez-Baltazar

    Full Text Available The study of signal transduction in dopamine (DA-containing neurons as well as the development of new therapeutic approaches for Parkinson's disease requires the selective expression of transgenes in such neurons. Here we describe optimization of the use of the NTS-polyplex, a gene carrier system taking advantage of neurotensin receptor internalization, to transfect mouse DA neurons in primary culture. The plasmids DsRed2 (4.7 kbp and VGLUT2-Venus (11 kbp were used to compare the ability of this carrier system to transfect plasmids of different sizes. We examined the impact of age of the neurons (1, 3, 5 and 8 days after seeding, of culture media used during the transfection (Neurobasal with B27 vs. conditioned medium and of three molar ratios of plasmid DNA to carrier. While the NTS-polyplex successfully transfected both plasmids in a control N1E-115 cell line, only the pDsRed2 plasmid could be transfected in primary cultured DA neurons. We achieved 20% transfection efficiency of pDsRed2 in DA neurons, with 80% cell viability. The transfection was demonstrated pharmacologically to be dependent on activation of neurotensin receptors and to be selective for DA neurons. The presence of conditioned medium for transfection was found to be required to insure cell viability. Highest transfection efficiency was achieved in the most mature neurons. In contrast, transfection with the VGLUT2-Venus plasmid produced cell damage, most likely due to the high molar ratios required, as evidenced by a 15% cell viability of DA neurons at the three molar ratios tested (1:36, 1:39 and 1:42. We conclude that, when used at molar ratios lower than 1:33, the NTS-polyplex can selectively transfect mature cultured DA neurons with only low levels of toxicity. Our results provide evidence that the NTS-polyplex has good potential for targeted gene delivery in cultured DA neurons, an in vitro system of great use for the screening of new therapeutic approaches for Parkinson

  6. Neuron-to-Cell Spread of Pseudorabies Virus in a Compartmented Neuronal Culture System

    OpenAIRE

    Ch'ng, T. H.; Enquist, L.W.

    2005-01-01

    Alphaherpesviruses are parasites of the peripheral nervous system in their natural hosts. After the initial infection of peripheral tissues such as mucosal cells, these neurotropic viruses will invade the peripheral nervous system that innervates the site of infection via long-distance axonal transport of the viral genome. In natural hosts, a latent and a nonproductive infection is usually established in the neuronal cell bodies. Upon reactivation, the newly replicated genome will be assemble...

  7. Voltage-sensitive dye recording from networks of cultured neurons

    Science.gov (United States)

    Chien, Chi-Bin

    This thesis describes the development and testing of a sensitive apparatus for recording electrical activity from microcultures of rat superior cervical ganglion (SCG) neurons by using voltage-sensitive fluorescent dyes.The apparatus comprises a feedback-regulated mercury arc light source, an inverted epifluorescence microscope, a novel fiber-optic camera with discrete photodiode detectors, and low-noise preamplifiers. Using an NA 0.75 objective and illuminating at 10 W/cm2 with the 546 nm mercury line, a typical SCG neuron stained with the styryl dye RH423 gives a detected photocurrent of 1 nA; the light source and optical detectors are quiet enough that the shot noise in this photocurrent--about.03% rms--dominates. The design, theory, and performance of this dye-recording apparatus are discussed in detail.Styryl dyes such as RH423 typically give signals of 1%/100 mV on these cells; the signals are linear in membrane potential, but do not appear to arise from a purely electrochromic mechanism. Given this voltage sensitivity and the noise level of the apparatus, it should be possible to detect both action potentials and subthreshold synaptic potentials from SCG cell bodies. In practice, dye recording can easily detect action potentials from every neuron in an SCG microculture, but small synaptic potentials are obscured by dye signals from the dense network of axons.In another microculture system that does not have such long and complex axons, this dye-recording apparatus should be able to detect synaptic potentials, making it possible to noninvasively map the synaptic connections in a microculture, and thus to study long-term synaptic plasticity.

  8. Dendritic outgrowth of myenteric plexus neurons in primary culture.

    Science.gov (United States)

    Mulholland, M W; Romanchuk, G; Flowe, K

    1992-04-01

    Myenteric plexus neurons derived from neonatal guinea pigs, when exposed to serum, demonstrated a characteristic pattern of growth, including a proliferating outgrowth zone of glial cells, peripheral extension of dendritic processes, and progressive dendritic growth. Serum effects upon dendritic growth, measured morphometrically, was strongly dose- and temporally dependent. Dendritic density was increased 10-fold (120 hr) by the addition of 6% serum, while mean dendritic length was increased 3-fold. Development of cholinergic function was reflected by release of [3H]ACh in response to cholecystokinin octapeptide, vasoactive intestinal peptide, substance P, and calcitonin gene-related peptide (10(-10) and 10(-8) M).

  9. Neuroprotective effects of phytochemicals on dopaminergic neuron cultures.

    Science.gov (United States)

    Sandoval-Avila, S; Diaz, N F; Gómez-Pinedo, U; Canales-Aguirre, A A; Gutiérrez-Mercado, Y K; Padilla-Camberos, E; Marquez-Aguirre, A L; Díaz-Martínez, N E

    2016-06-21

    Parkinson's disease is a progressive neurodegenerative disorder characterised by a loss of dopaminergic neurons in the substantia nigra pars compacta, which results in a significant decrease in dopamine levels and consequent functional motor impairment. Although its aetiology is not fully understood, several pathogenic mechanisms, including oxidative stress, have been proposed. Current therapeutic approaches are based on dopamine replacement drugs; these agents, however, are not able to stop or even slow disease progression. Novel therapeutic approaches aimed at acting on the pathways leading to neuronal dysfunction and death are under investigation. In recent years, such natural molecules as polyphenols, alkaloids, and saponins have been shown to have a neuroprotective effect due to their antioxidant and anti-inflammatory properties. The aim of our review is to analyse the most relevant studies worldwide addressing the benefits of some phytochemicals used in in vitro models of Parkinson's disease. Copyright © 2016 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  10. Reactive oxygen species are involved in BMP-induced dendritic growth in cultured rat sympathetic neurons.

    Science.gov (United States)

    Chandrasekaran, Vidya; Lea, Charlotte; Sosa, Jose Carlo; Higgins, Dennis; Lein, Pamela J

    2015-07-01

    Previous studies have shown that bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons; however, the downstream signaling molecules that mediate the dendrite promoting activity of BMPs are not well characterized. Here we test the hypothesis that reactive oxygen species (ROS)-mediated signaling links BMP receptor activation to dendritic growth. In cultured rat sympathetic neurons, exposure to any of the three mechanistically distinct antioxidants, diphenylene iodinium (DPI), nordihydroguaiaretic acid (NGA) or desferroxamine (DFO), blocked de novo BMP-induced dendritic growth. Addition of DPI to cultures previously induced with BMP to extend dendrites caused dendritic retraction while DFO and NGA prevented further growth of dendrites. The inhibition of the dendrite promoting activity of BMPs by antioxidants was concentration-dependent and occurred without altering axonal growth or neuronal cell survival. Antioxidant treatment did not block BMP activation of SMAD 1,5 as determined by nuclear localization of these SMADs. While BMP treatment did not cause a detectable increase in intracellular ROS in cultured sympathetic neurons as assessed using fluorescent indicator dyes, BMP treatment increased the oxygen consumption rate in cultured sympathetic neurons as determined using the Seahorse XF24 Analyzer, suggesting increased mitochondrial activity. In addition, BMPs upregulated expression of NADPH oxidase 2 (NOX2) and either pharmacological inhibition or siRNA knockdown of NOX2 significantly decreased BMP-7 induced dendritic growth. Collectively, these data support the hypothesis that ROS are involved in the downstream signaling events that mediate BMP7-induced dendritic growth in sympathetic neurons, and suggest that ROS-mediated signaling positively modulates dendritic complexity in peripheral neurons. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. The BDNF val-66-met Polymorphism Affects Neuronal Morphology and Synaptic Transmission in Cultured Hippocampal Neurons from Rett Syndrome Mice

    Directory of Open Access Journals (Sweden)

    Xin Xu

    2017-07-01

    Full Text Available Brain-derived neurotrophic factor (Bdnf has been implicated in several neurological disorders including Rett syndrome (RTT, an X-linked neurodevelopmental disorder caused by loss-of-function mutations in the transcriptional modulator methyl-CpG-binding protein 2 (MECP2. The human BDNF gene has a single nucleotide polymorphism (SNP—a methionine (met substitution for valine (val at codon 66—that affects BDNF’s trafficking and activity-dependent release and results in cognitive dysfunction. Humans that are carriers of the met-BDNF allele have subclinical memory deficits and reduced hippocampal volume and activation. It is still unclear whether this BDNF SNP affects the clinical outcome of RTT individuals. To evaluate whether this BDNF SNP contributes to RTT pathophysiology, we examined the consequences of expression of either val-BDNF or met-BDNF on dendrite and dendritic spine morphology, and synaptic function in cultured hippocampal neurons from wildtype (WT and Mecp2 knockout (KO mice. Our findings revealed that met-BDNF does not increase dendritic growth and branching, dendritic spine density and individual spine volume, and the number of excitatory synapses in WT neurons, as val-BDNF does. Furthermore, met-BDNF reduces dendritic complexity, dendritic spine volume and quantal excitatory synaptic transmission in Mecp2 KO neurons. These results suggest that the val-BDNF variant contributes to RTT pathophysiology, and that BDNF-based therapies should take into consideration the BDNF genotype of the RTT individuals.

  12. A primary neuron culture system for the study of herpes simplex virus latency and reactivation.

    Science.gov (United States)

    Kobayashi, Mariko; Kim, Ju-Youn; Camarena, Vladimir; Roehm, Pamela C; Chao, Moses V; Wilson, Angus C; Mohr, Ian

    2012-04-02

    Herpes simplex virus type-1 (HSV-1) establishes a life-long latent infection in peripheral neurons. This latent reservoir is the source of recurrent reactivation events that ensure transmission and contribute to clinical disease. Current antivirals do not impact the latent reservoir and there are no vaccines. While the molecular details of lytic replication are well-characterized, mechanisms controlling latency in neurons remain elusive. Our present understanding of latency is derived from in vivo studies using small animal models, which have been indispensable for defining viral gene requirements and the role of immune responses. However, it is impossible to distinguish specific effects on the virus-neuron relationship from more general consequences of infection mediated by immune or non-neuronal support cells in live animals. In addition, animal experimentation is costly, time-consuming, and limited in terms of available options for manipulating host processes. To overcome these limitations, a neuron-only system is desperately needed that reproduces the in vivo characteristics of latency and reactivation but offers the benefits of tissue culture in terms of homogeneity and accessibility. Here we present an in vitro model utilizing cultured primary sympathetic neurons from rat superior cervical ganglia (SCG) (Figure 1) to study HSV-1 latency and reactivation that fits most if not all of the desired criteria. After eliminating non-neuronal cells, near-homogeneous TrkA(+) neuron cultures are infected with HSV-1 in the presence of acyclovir (ACV) to suppress lytic replication. Following ACV removal, non-productive HSV-1 infections that faithfully exhibit accepted hallmarks of latency are efficiently established. Notably, lytic mRNAs, proteins, and infectious virus become undetectable, even in the absence of selection, but latency-associated transcript (LAT) expression persists in neuronal nuclei. Viral genomes are maintained at an average copy number of 25 per neuron

  13. Controlled adhesion and growth of long term glial and neuronal cultures on Parylene-C.

    Directory of Open Access Journals (Sweden)

    Evangelos Delivopoulos

    Full Text Available This paper explores the long term development of networks of glia and neurons on patterns of Parylene-C on a SiO(2 substrate. We harvested glia and neurons from the Sprague-Dawley (P1-P7 rat hippocampus and utilized an established cell patterning technique in order to investigate cellular migration, over the course of 3 weeks. This work demonstrates that uncontrolled glial mitosis gradually disrupts cellular patterns that are established early during culture. This effect is not attributed to a loss of protein from the Parylene-C surface, as nitrogen levels on the substrate remain stable over 3 weeks. The inclusion of the anti-mitotic cytarabine (Ara-C in the culture medium moderates glial division and thus, adequately preserves initial glial and neuronal conformity to underlying patterns. Neuronal apoptosis, often associated with the use of Ara-C, is mitigated by the addition of brain derived neurotrophic factor (BDNF. We believe that with the right combination of glial inhibitors and neuronal promoters, the Parylene-C based cell patterning method can generate structured, active neural networks that can be sustained and investigated over extended periods of time. To our knowledge this is the first report on the concurrent application of Ara-C and BDNF on patterned cell cultures.

  14. Comparison of gene expression profile in embryonic mesencephalon and neuronal primary cultures.

    Directory of Open Access Journals (Sweden)

    Dario Greco

    Full Text Available In the mammalian central nervous system (CNS an important contingent of dopaminergic neurons are localized in the substantia nigra and in the ventral tegmental area of the ventral midbrain. They constitute an anatomically and functionally heterogeneous group of cells involved in a variety of regulatory mechanisms, from locomotion to emotional/motivational behavior. Midbrain dopaminergic neuron (mDA primary cultures represent a useful tool to study molecular mechanisms involved in their development and maintenance. Considerable information has been gathered on the mDA neurons development and maturation in vivo, as well as on the molecular features of mDA primary cultures. Here we investigated in detail the gene expression differences between the tissue of origin and ventral midbrain primary cultures enriched in mDA neurons, using microarray technique. We integrated the results based on different re-annotations of the microarray probes. By using knowledge-based gene network techniques and promoter sequence analysis, we also uncovered mechanisms that might regulate the expression of CNS genes involved in the definition of the identity of specific cell types in the ventral midbrain. We integrate bioinformatics and functional genomics, together with developmental neurobiology. Moreover, we propose guidelines for the computational analysis of microarray gene expression data. Our findings help to clarify some molecular aspects of the development and differentiation of DA neurons within the midbrain.

  15. Learning in Live Neuronal Cultures: a Training Protocol Evaluated

    NARCIS (Netherlands)

    le Feber, Jakob; Stegenga, J.; Rutten, Wim

    2008-01-01

    We applied a training protocol to cultured cortical networks, adapted from Shahaf and Marom [1]. Like they did, on average we found an improved response to input stimuli. However, not all experiments were successful, and the shapes of our learning curves differed from theirs. Furthermore, we

  16. Novel Nuclear Protein Complexes of Dystrophin 71 Isoforms in Rat Cultured Hippocampal GABAergic and Glutamatergic Neurons.

    Directory of Open Access Journals (Sweden)

    Rafael Rodríguez-Muñoz

    Full Text Available The precise functional role of the dystrophin 71 in neurons is still elusive. Previously, we reported that dystrophin 71d and dystrophin 71f are present in nuclei from cultured neurons. In the present work, we performed a detailed analysis of the intranuclear distribution of dystrophin 71 isoforms (Dp71d and Dp71f, during the temporal course of 7-day postnatal rats hippocampal neurons culture for 1h, 2, 4, 10, 15 and 21 days in vitro (DIV. By immunofluorescence assays, we detected the highest level of nuclear expression of both dystrophin Dp71 isoforms at 10 DIV, during the temporal course of primary culture. Dp71d and Dp71f were detected mainly in bipolar GABAergic (≥60% and multipolar Glutamatergic (≤40% neurons, respectively. We also characterized the existence of two nuclear dystrophin-associated protein complexes (DAPC: dystrophin 71d or dystrophin 71f bound to β-dystroglycan, α1-, β-, α2-dystrobrevins, α-syntrophin, and syntrophin-associated protein nNOS (Dp71d-DAPC or Dp71f-DAPC, respectively, in the hippocampal neurons. Furthermore, both complexes were localized in interchromatin granule cluster structures (nuclear speckles of neuronal nucleoskeleton preparations. The present study evinces that each Dp71's complexes differ slightly in dystrobrevins composition. The results demonstrated that Dp71d-DAPC was mainly localized in bipolar GABAergic and Dp71f-DAPC in multipolar Glutamatergic hippocampal neurons. Taken together, our results show that dystrophin 71d, dystrophin 71f and DAP integrate protein complexes, and both complexes were associated to nuclear speckles structures.

  17. Novel Nuclear Protein Complexes of Dystrophin 71 Isoforms in Rat Cultured Hippocampal GABAergic and Glutamatergic Neurons.

    Science.gov (United States)

    Rodríguez-Muñoz, Rafael; Cárdenas-Aguayo, María Del Carmen; Alemán, Víctor; Osorio, Beatriz; Chávez-González, Oscar; Rendon, Alvaro; Martínez-Rojas, Dalila; Meraz-Ríos, Marco Antonio

    2015-01-01

    The precise functional role of the dystrophin 71 in neurons is still elusive. Previously, we reported that dystrophin 71d and dystrophin 71f are present in nuclei from cultured neurons. In the present work, we performed a detailed analysis of the intranuclear distribution of dystrophin 71 isoforms (Dp71d and Dp71f), during the temporal course of 7-day postnatal rats hippocampal neurons culture for 1h, 2, 4, 10, 15 and 21 days in vitro (DIV). By immunofluorescence assays, we detected the highest level of nuclear expression of both dystrophin Dp71 isoforms at 10 DIV, during the temporal course of primary culture. Dp71d and Dp71f were detected mainly in bipolar GABAergic (≥60%) and multipolar Glutamatergic (≤40%) neurons, respectively. We also characterized the existence of two nuclear dystrophin-associated protein complexes (DAPC): dystrophin 71d or dystrophin 71f bound to β-dystroglycan, α1-, β-, α2-dystrobrevins, α-syntrophin, and syntrophin-associated protein nNOS (Dp71d-DAPC or Dp71f-DAPC, respectively), in the hippocampal neurons. Furthermore, both complexes were localized in interchromatin granule cluster structures (nuclear speckles) of neuronal nucleoskeleton preparations. The present study evinces that each Dp71's complexes differ slightly in dystrobrevins composition. The results demonstrated that Dp71d-DAPC was mainly localized in bipolar GABAergic and Dp71f-DAPC in multipolar Glutamatergic hippocampal neurons. Taken together, our results show that dystrophin 71d, dystrophin 71f and DAP integrate protein complexes, and both complexes were associated to nuclear speckles structures.

  18. Agmatine protects against cell damage induced by NMDA and glutamate in cultured hippocampal neurons.

    Science.gov (United States)

    Wang, Wei-Ping; Iyo, Abiye H; Miguel-Hidalgo, Javier; Regunathan, Soundar; Zhu, Meng-Yang

    2006-04-21

    Agmatine is a polyamine and has been considered as a novel neurotransmitter or neuromodulator in the central nervous system. In the present study, the neuroprotective effect of agmatine against cell damage caused by N-methyl-D-aspartate (NMDA) and glutamate was investigated in cultured rat hippocampal neurons. Lactate dehydrogenase (LDH) activity assay, beta-tubulin III immunocytochemical staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end-labeling (TUNEL) assay were conducted to detect cell damage. Exposure of 12-day neuronal cultures of rat hippocampus to NMDA or glutamate for 1 h caused a concentration-dependent neurotoxicity, as indicated by the significant increase in released LDH activities. Addition of 100 microM agmatine into media ablated the neurotoxicity induced by NMDA or glutamate, an effect also produced by the specific NMDA receptor antagonist dizocilpine hydrogen maleate (MK801). Arcaine, an analog of agmatine with similar structure as agmatine, fully prevented the NMDA- or glutamate-induced neuronal damage. Spermine and putrescine, the endogenous polyamine and metabolic products of agmatine without the guanidine moiety of agmatine, failed to show this effect, indicating a structural relevance for this neuroprotection. Immunocytochemical staining and TUNEL assay confirmed the findings in the LDH measurement. That is, agmatine and MK801 markedly attenuated NMDA-induced neuronal death and significantly reduced TUNEL-positive cell numbers induced by exposure of cultured hippocampal neurons to NMDA. Taken together, these results demonstrate that agmatine can protect cultured hippocampal neurons from NMDA- or glutamate-induced excitotoxicity, through a possible blockade of the NMDA receptor channels or a potential anti-apoptotic property.

  19. Repeated Stimulation of Cultured Networks of Rat Cortical Neurons Induces Parallel Memory Traces

    Science.gov (United States)

    le Feber, Joost; Witteveen, Tim; van Veenendaal, Tamar M.; Dijkstra, Jelle

    2015-01-01

    During systems consolidation, memories are spontaneously replayed favoring information transfer from hippocampus to neocortex. However, at present no empirically supported mechanism to accomplish a transfer of memory from hippocampal to extra-hippocampal sites has been offered. We used cultured neuronal networks on multielectrode arrays and…

  20. Neural stem cells improve neuronal survival in cultured postmortem brain tissue from aged and Alzheimer patients

    NARCIS (Netherlands)

    Wu, L.; Sluiter, A.A.; Guo, Ho Fu; Balesar, R. A.; Swaab, D. F.; Zhou, Jiang Ning; Verwer, R. W H

    Neurodegenerative diseases are progressive and incurable and are becoming ever more prevalent. To study whether neural stem cell can reactivate or rescue functions of impaired neurons in the human aging and neurodegenerating brain, we co-cultured postmortem slices from Alzheimer patients and control

  1. Network bursts in cortical neuronal cultures: 'noise - versus pacemaker'- driven neural network simulations

    NARCIS (Netherlands)

    Gritsun, T.; Stegenga, J.; le Feber, Jakob; Rutten, Wim

    2009-01-01

    In this paper we address the issue of spontaneous bursting activity in cortical neuronal cultures and explain what might cause this collective behavior using computer simulations of two different neural network models. While the common approach to acivate a passive network is done by introducing

  2. Chronic odorant exposure upregulates acquisition of functional properties in cultured embryonic chick olfactory sensory neurons.

    Science.gov (United States)

    O'Neill, Grace; Musto, Christa; Gomez, George

    2017-05-01

    Neuronal development and differentiation is modulated by activity-dependent mechanisms that stimulate endogenous neurogenesis and differentiation to promote adaptive survival of the organism. Studies on bird odor imprinting have shown how sensory stimuli or environmental influences can affect neonatal behavior, presumably by remodeling the developing nervous system. It is unclear whether these changes originate from the sensory neurons themselves or from the brain. Thus, we attempted to address this by using an in vitro system to separate the peripheral neurons from their central connections. Olfactory neurons from embryonic day 17 Gallus domesticus chicks were isolated, cultured, and exposed to 100 µM amyl acetate or phenethyl alcohol in 12-hr bouts, alternated with periods of no-odor exposure. On days 4 and 5 in vitro, cells were immunostained for olfactory marker protein, neuron-specific tubulin, and olfactory GTP-binding protein, and tested for odorant sensitivity using calcium imaging. While odorant exposure did not result in a significant increase in the overall number of neurons, it promoted neuron differentiation: a larger proportion of odorant-exposed cells expressed olfactory marker protein and the olfactory GTP-binding protein. When cell responsiveness was tested using calcium imaging, a greater proportion of odorant-exposed cells responded to stimulation with 100 µM amyl acetate or phenethyl alcohol. Thus, odorant exposure during development modulated the developmental trajectories of individual neurons, resulting in changes in protein expression associated with odorant signaling. This suggests that the neuronal changes in the periphery have an important contribution to the overall long-term functional changes associated with odor imprinting. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Purinergic modulation of adult guinea pig cardiomyocytes in long term cultures and co-cultures with extracardiac or intrinsic cardiac neurones.

    Science.gov (United States)

    Horackova, M; Huang, M H; Armour, J A

    1994-05-01

    To determine the capacity of ATP to modify cardiomyocytes directly or indirectly via peripheral autonomic neurones, the effects of various purinergic agents were studied on long term cultures of adult guinea pig ventricular myocytes and their co-cultures with extracardiac (stellate ganglion) or intrinsic cardiac neurones. Ventricular myocytes and cardiac neurones were enzymatically dissociated and plated together or alone (myocytes only). Myocyte cultures were used for experiments after three to six weeks. The electrical and contractile properties of cultured myocytes and myocyte-neuronal networks were investigated. The spontaneous beating frequency of ventricular myocytes co-cultured with stellate ganglion neurones increased by approximately 140% (p under control conditions, but when beta adrenergic receptors of tetrodotoxin sensitive neural responses were blocked, ATP induced greater augmentation (> 100%). In contrast, ATP induced much smaller effects in non-innervated myocyte cultures (approximately 26%, p UTP > MSATP > beta gamma ATP > alpha beta ATP. Adenosine (10(-4) M) attenuated the beating frequency of myocytes in both types of co-culture, while not significantly affecting non-innervated myocyte cultures. The experimental model used in this study showed that extrinsic and intrinsic cardiac neurones which possess P2 receptors can greatly enhance cardiac myocyte contractile rate when activated by ATP. Since adenosine reduced contractile rate in both types of co-cultures while not affecting non-innervated myocytes, it is concluded that some of these neurones possess P1 receptors.

  4. In vitro differentiation of bone marrow stromal cells into neurons and glial cells and differential protein expression in a two-compartment bone marrow stromal cell/neuron co-culture system.

    Science.gov (United States)

    Qi, Xu; Shao, Ming; Peng, Haisheng; Bi, Zhenggang; Su, Zhiqiang; Li, Hulun

    2010-07-01

    This study was performed to establish a bone marrow stromal cell (BMSC)/neuron two-compartment co-culture model in which differentiation of BMSCs into neurons could occur without direct contact between the two cell types, and to investigate protein expression changes during differentiation of this entirely BMSC-derived population. Cultured BMSCs isolated from Wistar rats were divided into three groups: BMSC culture, BMSC/neuron co-culture and BMSC/neuron two-compartment co-culture. Cells were examined for neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) expression. The electrophysiological behavior of the BMSCs was examined using patch clamping. Proteins that had significantly different expression levels in BMSCs cultured alone and co-cultured with neurons were studied using a protein chip-mass spectroscopy technique. Expression of NSE and GFAP were significantly higher in co-culture cells than in two-compartment co-culture cells, and significantly higher in both co-culture groups than in BMSCs cultured alone. Five proteins showed significant changes in expression during differentiation: TIP39_RAT and CALC_RAT underwent increases, and INSL6_RAT, PNOC_RAT and PCSK1_RAT underwent decreases in expression. We conclude that BMSCs can differentiate into neurons during both contact co-culture with neurons and two-compartment co-culture with neurons. The rate at which BMSCs differentiated into neurons was higher in contact co-culture than in non-contact co-culture.

  5. Omega-3 Polyunsaturated Fatty Acids Enhance Neuronal Differentiation in Cultured Rat Neural Stem Cells

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    Masanori Katakura

    2013-01-01

    Full Text Available Polyunsaturated fatty acids (PUFAs can induce neurogenesis and recovery from brain diseases. However, the exact mechanisms of the beneficial effects of PUFAs have not been conclusively described. We recently reported that docosahexaenoic acid (DHA induced neuronal differentiation by decreasing Hes1 expression and increasing p27kip1 expression, which causes cell cycle arrest in neural stem cells (NSCs. In the present study, we examined the effect of eicosapentaenoic acid (EPA and arachidonic acid (AA on differentiation, expression of basic helix-loop-helix transcription factors (Hes1, Hes6, and NeuroD, and the cell cycle of cultured NSCs. EPA also increased mRNA levels of Hes1, an inhibitor of neuronal differentiation, Hes6, an inhibitor of Hes1, NeuroD, and Map2 mRNA and Tuj-1-positive cells (a neuronal marker, indicating that EPA induced neuronal differentiation. EPA increased the mRNA levels of p21cip1 and p27kip1, a cyclin-dependent kinase inhibitor, which indicated that EPA induced cell cycle arrest. Treatment with AA decreased Hes1 mRNA but did not affect NeuroD and Map2 mRNA levels. Furthermore, AA did not affect the number of Tuj-1-positive cells or cell cycle progression. These results indicated that EPA could be involved in neuronal differentiation by mechanisms alternative to those of DHA, whereas AA did not affect neuronal differentiation in NSCs.

  6. Characterization of synchronized bursts in cultured hippocampal neuronal networks with learning training on microelectrode arrays.

    Science.gov (United States)

    Li, Yanling; Zhou, Wei; Li, Xiangning; Zeng, Shaoqun; Liu, Man; Luo, Qingming

    2007-06-15

    Spontaneous synchronized bursts seem to play a key role in brain functions such as learning and memory. Still controversial is the characterization of spontaneous synchronized bursts in neuronal networks after learning training, whether depression or promotion. By taking advantages of the main features of the microelectrode array (MEA) technology (i.e. multisite recordings, stable and long-term coupling with the biological preparation), we analyzed changes of spontaneous synchronized bursts in cultured hippocampal neuronal networks after learning training. And for this purpose, a learning model at networking level on MEA system was constructed, and analysis of spontaneous synchronized burst activity modulation was presented. Preliminary results show that, the number of burst was increased by 154%, burst duration was increased by 35%, and the number of spikes per burst was increased by 124%, while interburst interval decreased by 44% with learning. In particular, correlation and synchrony of neuronal activities in networks were enhanced by 51% and 36%, respectively, with learning. In contrast, dynamic properties of neuronal networks were not changed much when the network was under "non-learning" condition. These results indicate that firing, association and synchrony of spontaneous bursts in neuronal networks were promoted by learning. Furthermore, from these observations, we are encouraged to think of a more engineered system based on in vitro hippocampal neurons, as a novel sensitive system for electrophysiological evaluations.

  7. Metabolic changes of cultured DRG neurons induced by adenosine using confocal microscopy imaging

    Science.gov (United States)

    Zheng, Liqin; Huang, Yimei; Chen, Jiangxu; Wang, Yuhua; Yang, Hongqin; Zhang, Yanding; Xie, Shusen

    2012-12-01

    Adenosine exerts multiple effects on pain transmission in the peripheral nervous system. This study was performed to use confocal microscopy to evaluate whether adenosine could affect dorsal root ganglia (DRG) neurons in vitro and test which adenosine receptor mediates the effect of adenosine on DRG neurons. After adding adenosine with different concentration, we compared the metabolic changes by the real time imaging of calcium and mitochondria membrane potential using confocal microscopy. The results showed that the effect of 500 μM adenosine on the metabolic changes of DRG neurons was more significant than others. Furthermore, four different adenosine receptor antagonists were used to study which receptor mediated the influences of adenosine on the cultured DRG neurons. All adenosine receptor antagonists especially A1 receptor antagonist (DPCPX) had effect on the Ca2+ and mitochondria membrane potential dynamics of DRG neurons. The above studies demonstrated that the effect of adenosine which may be involved in the signal transmission on the sensory neurons was dose-dependent, and all the four adenosine receptors especially the A1R may mediate the transmission.

  8. Emergence of small-world anatomical networks in self-organizing clustered neuronal cultures.

    Directory of Open Access Journals (Sweden)

    Daniel de Santos-Sierra

    Full Text Available In vitro primary cultures of dissociated invertebrate neurons from locust ganglia are used to experimentally investigate the morphological evolution of assemblies of living neurons, as they self-organize from collections of separated cells into elaborated, clustered, networks. At all the different stages of the culture's development, identification of neurons' and neurites' location by means of a dedicated software allows to ultimately extract an adjacency matrix from each image of the culture. In turn, a systematic statistical analysis of a group of topological observables grants us the possibility of quantifying and tracking the progression of the main network's characteristics during the self-organization process of the culture. Our results point to the existence of a particular state corresponding to a small-world network configuration, in which several relevant graph's micro- and meso-scale properties emerge. Finally, we identify the main physical processes ruling the culture's morphological transformations, and embed them into a simplified growth model qualitatively reproducing the overall set of experimental observations.

  9. Prolonged cannabinoid exposure alters GABAA receptor mediated synaptic function in cultured hippocampal neurons

    Science.gov (United States)

    Deshpande, Laxmikant S.; Blair, Robert. E.; DeLorenzo, Robert. J.

    2011-01-01

    Developing cannabinoid based medication along with marijuana’s recreational use makes it important to investigate molecular adaptations the endocannabinoid system undergoes following prolonged use and withdrawal. Repeated cannabinoid administration results in development of tolerance and produces withdrawal symptoms that may include seizures. Here we employed electrophysiological and immunochemical techniques to investigate the effects of prolonged CB1 receptor agonist exposure on cultured hippocampal neurons. Approximately 60% of CB1 receptors colocalize to GABAergic terminals in hippocampal cultures. Prolonged treatment with the cannabinamimetic WIN 55,212-2 (+WIN, 1μM, 24-h) caused profound CB1 receptor downregulation accompanied by neuronal hyperexcitability. Furthermore, prolonged +WIN treatment resulted in increased GABA release as indicated by increased mIPSC frequency, a diminished GABAergic inhibition as indicated by reduction in mIPSC amplitude and a reduction in GABAA channel number. Additionally, surface staining for the GABAA β2/3 receptor subunits was decreased, while no changes in staining for the presynaptic vesicular GABA transporter were observed, indicating that GABAergic terminals remained intact. These findings demonstrate that agonist-induced downregulation of the CB1 receptor in hippocampal cultures results in neuronal hyperexcitability that may be attributed, in part, to alterations in both presynaptic GABA release mechanisms and postsynaptic GABAA receptor function demonstrating a novel role for cannabinoid-dependent presynaptic control of neuronal transmission. PMID:21324315

  10. Quantitative Analysis of Rat Dorsal Root Ganglion Neurons Cultured on Microelectrode Arrays Based on Fluorescence Microscopy Image Processing.

    Science.gov (United States)

    Mari, João Fernando; Saito, José Hiroki; Neves, Amanda Ferreira; Lotufo, Celina Monteiro da Cruz; Destro-Filho, João-Batista; Nicoletti, Maria do Carmo

    2015-12-01

    Microelectrode Arrays (MEA) are devices for long term electrophysiological recording of extracellular spontaneous or evocated activities on in vitro neuron culture. This work proposes and develops a framework for quantitative and morphological analysis of neuron cultures on MEAs, by processing their corresponding images, acquired by fluorescence microscopy. The neurons are segmented from the fluorescence channel images using a combination of segmentation by thresholding, watershed transform, and object classification. The positioning of microelectrodes is obtained from the transmitted light channel images using the circular Hough transform. The proposed method was applied to images of dissociated culture of rat dorsal root ganglion (DRG) neuronal cells. The morphological and topological quantitative analysis carried out produced information regarding the state of culture, such as population count, neuron-to-neuron and neuron-to-microelectrode distances, soma morphologies, neuron sizes, neuron and microelectrode spatial distributions. Most of the analysis of microscopy images taken from neuronal cultures on MEA only consider simple qualitative analysis. Also, the proposed framework aims to standardize the image processing and to compute quantitative useful measures for integrated image-signal studies and further computational simulations. As results show, the implemented microelectrode identification method is robust and so are the implemented neuron segmentation and classification one (with a correct segmentation rate up to 84%). The quantitative information retrieved by the method is highly relevant to assist the integrated signal-image study of recorded electrophysiological signals as well as the physical aspects of the neuron culture on MEA. Although the experiments deal with DRG cell images, cortical and hippocampal cell images could also be processed with small adjustments in the image processing parameter estimation.

  11. Establishment of a long-term spiral ganglion neuron culture with reduced glial cell number: Effects of AraC on cell composition and neurons.

    Science.gov (United States)

    Schwieger, Jana; Esser, Karl-Heinz; Lenarz, Thomas; Scheper, Verena

    2016-08-01

    Sensorineural deafness is mainly caused by damage to hair cells and degeneration of the spiral ganglion neurons (SGN). Cochlear implants can functionally replace lost hair cells and stimulate the SGN electrically. The benefit from cochlear implantation depends on the number and excitability of these neurons. To identify potential therapies for SGN protection, in vitro tests are carried out on spiral ganglion cells (SGC). A glial cell-reduced and neuron-enhanced culture of neonatal rat SGC under mitotic inhibition (cytarabine (AraC)) for up to seven days is presented. Serum containing and neurotrophin-enriched cultures with and without AraC-addition were analyzed after 4 and 7 days. The total number of cells was significantly reduced, while the proportion of neurons was greatly increased by AraC-treatment. Cell type-specific labeling demonstrated that nearly all fibroblasts and most of the glial cells were removed. Neither the neuronal survival, nor the neurite outgrowth or soma diameter were negatively affected. Additionally neurites remain partly free of surrounding non-neuronal cells. Recent culture conditions allow only for short-term cultivation of neonatal SGC and lack information on the influence of non-neuronal cells on SGN and of direct contact of neurites with test-materials. AraC-addition reduces the number of non-neuronal cells and increases the ratio of SGN in culture, without negative impact on neuronal viability. This treatment allows longer-term cultivation of SGC and provides deeper insight into SGN-glial cell interaction and the attachment of neurites on test-material surfaces. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Study of the protective effects of nootropic agents against neuronal damage induced by amyloid-beta (fragment 25-35) in cultured hippocampal neurons.

    Science.gov (United States)

    Sendrowski, Krzysztof; Sobaniec, Wojciech; Stasiak-Barmuta, Anna; Sobaniec, Piotr; Popko, Janusz

    2015-04-01

    Alzheimer's disease (AD) is a common neurodegenerative disorder, in which progressive neuron loss, mainly in the hippocampus, is observed. The critical events in the pathogenesis of AD are associated with accumulation of β-amyloid (Aβ) peptides in the brain. Deposits of Aβ initiate a neurotoxic "cascade" leading to apoptotic death of neurons. Aim of this study was to assess a putative neuroprotective effects of two nootropic drugs: piracetam (PIR) and levetiracetam (LEV) on Aβ-injured hippocampal neurons in culture. Primary cultures of rat's hippocampal neurons at 7 day in vitro were exposed to Aβ(25-35) in the presence or absence of nootropics in varied concentrations. Flow cytometry with Annexin V/PI staining was used for counting and establishing neurons as viable, necrotic or apoptotic. Additionally, release of lactate dehydrogenase (LDH) to the culture medium, as a marker of cell death, was evaluated. Aβ(25-35) caused concentration-dependent death of about one third number of hippocampal neurons, mainly through an apoptotic pathway. In drugs-containing cultures, number of neurons injured with 20 μM Aβ(25-35) was about one-third lesser for PIR and almost two-fold lesser for LEV. When 40 μM Aβ(25-35) was used, only LEV exerted beneficial neuroprotective action, while PIR was ineffective. Our results suggest the protective potential of both studied nootropics against Aβ-induced death of cultured hippocampal neurons with more powerful neuroprotective effects of LEV. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  13. Synaptotagmin 1 causes phosphatidyl inositol lipid-dependent actin remodeling in cultured non-neuronal and neuronal cells

    International Nuclear Information System (INIS)

    Johnsson, Anna-Karin; Karlsson, Roger

    2012-01-01

    Here we demonstrate that a dramatic actin polymerizing activity caused by ectopic expression of the synaptic vesicle protein synaptotagmin 1 that results in extensive filopodia formation is due to the presence of a lysine rich sequence motif immediately at the cytoplasmic side of the transmembrane domain of the protein. This polybasic sequence interacts with anionic phospholipids in vitro, and, consequently, the actin remodeling caused by this sequence is interfered with by expression of a phosphatidyl inositol (4,5)-bisphosphate (PIP2)-targeted phosphatase, suggesting that it intervenes with the function of PIP2-binding actin control proteins. The activity drastically alters the behavior of a range of cultured cells including the neuroblastoma cell line SH-SY5Y and primary cortical mouse neurons, and, since the sequence is conserved also in synaptotagmin 2, it may reflect an important fine-tuning role for these two proteins during synaptic vesicle fusion and neurotransmitter release.

  14. Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure

    Directory of Open Access Journals (Sweden)

    Atsushi Saito

    2018-03-01

    Full Text Available High-intensity and low frequency (1–100 kHz time-varying electromagnetic fields stimulate the human body through excitation of the nervous system. In power frequency range (50/60 Hz, a frequency-dependent threshold of the external electric field-induced neuronal modulation in cultured neuronal networks was used as one of the biological indicator in international guidelines; however, the threshold of the magnetic field-induced neuronal modulation has not been elucidated. In this study, we exposed rat brain-derived neuronal networks to a high-intensity power frequency magnetic field (hPF-MF, and evaluated the modulation of synchronized bursting activity using a multi-electrode array (MEA-based extracellular recording technique. As a result of short-term hPF-MF exposure (50–400 mT root-mean-square (rms, 50 Hz, sinusoidal wave, 6 s, the synchronized bursting activity was increased in the 400 mT-exposed group. On the other hand, no change was observed in the 50–200 mT-exposed groups. In order to clarify the mechanisms of the 400 mT hPF-MF exposure-induced neuronal response, we evaluated it after blocking inhibitory synapses using bicuculline methiodide (BMI; subsequently, increase in bursting activity was observed with BMI application, and the response of 400 mT hPF-MF exposure disappeared. Therefore, it was suggested that the response of hPF-MF exposure was involved in the inhibitory input. Next, we screened the inhibitory pacemaker-like neuronal activity which showed autonomous 4–10 Hz firing with CNQX and D-AP5 application, and it was confirmed that the activity was reduced after 400 mT hPF-MF exposure. Comparison of these experimental results with estimated values of the induced electric field (E-field in the culture medium revealed that the change in synchronized bursting activity occurred over 0.3 V/m, which was equivalent to the findings of a previous study that used the external electric fields. In addition, the results suggested that

  15. Primary neuron culture for nerve growth and axon guidance studies in zebrafish (Danio rerio.

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    Zheyan Chen

    Full Text Available Zebrafish (Danio rerio is a widely used model organism in genetics and developmental biology research. Genetic screens have proven useful for studying embryonic development of the nervous system in vivo, but in vitro studies utilizing zebrafish have been limited. Here, we introduce a robust zebrafish primary neuron culture system for functional nerve growth and guidance assays. Distinct classes of central nervous system neurons from the spinal cord, hindbrain, forebrain, and retina from wild type zebrafish, and fluorescent motor neurons from transgenic reporter zebrafish lines, were dissociated and plated onto various biological and synthetic substrates to optimize conditions for axon outgrowth. Time-lapse microscopy revealed dynamically moving growth cones at the tips of extending axons. The mean rate of axon extension in vitro was 21.4±1.2 µm hr(-1 s.e.m. for spinal cord neurons, which corresponds to the typical ∼0.5 mm day(-1 growth rate of nerves in vivo. Fluorescence labeling and confocal microscopy demonstrated that bundled microtubules project along axons to the growth cone central domain, with filamentous actin enriched in the growth cone peripheral domain. Importantly, the growth cone surface membrane expresses receptors for chemotropic factors, as detected by immunofluorescence microscopy. Live-cell functional assays of axon extension and directional guidance demonstrated mammalian brain-derived neurotrophic factor (BDNF-dependent stimulation of outgrowth and growth cone chemoattraction, whereas mammalian myelin-associated glycoprotein inhibited outgrowth. High-resolution live-cell Ca(2+-imaging revealed local elevation of cytoplasmic Ca(2+ concentration in the growth cone induced by BDNF application. Moreover, BDNF-induced axon outgrowth, but not basal outgrowth, was blocked by treatments to suppress cytoplasmic Ca(2+ signals. Thus, this primary neuron culture model system may be useful for studies of neuronal development

  16. Temporally coordinated spiking activity of human induced pluripotent stem cell-derived neurons co-cultured with astrocytes.

    Science.gov (United States)

    Kayama, Tasuku; Suzuki, Ikuro; Odawara, Aoi; Sasaki, Takuya; Ikegaya, Yuji

    2018-01-01

    In culture conditions, human induced-pluripotent stem cells (hiPSC)-derived neurons form synaptic connections with other cells and establish neuronal networks, which are expected to be an in vitro model system for drug discovery screening and toxicity testing. While early studies demonstrated effects of co-culture of hiPSC-derived neurons with astroglial cells on survival and maturation of hiPSC-derived neurons, the population spiking patterns of such hiPSC-derived neurons have not been fully characterized. In this study, we analyzed temporal spiking patterns of hiPSC-derived neurons recorded by a multi-electrode array system. We discovered that specific sets of hiPSC-derived neurons co-cultured with astrocytes showed more frequent and highly coherent non-random synchronized spike trains and more dynamic changes in overall spike patterns over time. These temporally coordinated spiking patterns are physiological signs of organized circuits of hiPSC-derived neurons and suggest benefits of co-culture of hiPSC-derived neurons with astrocytes. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Roles and Regulation of Ketogenesis in Cultured Astroglia and Neurons Under Hypoxia and Hypoglycemia

    Directory of Open Access Journals (Sweden)

    Shinichi Takahashi

    2014-09-01

    Full Text Available Exogenous ketone bodies (KBs, acetoacetate (AA, and β-hydroxybutyrate (BHB act as alternative energy substrates in neural cells under starvation. The present study examined the endogenous ketogenic capacity of astroglia under hypoxia with/without glucose and the possible roles of KBs in neuronal energy metabolism. Cultured neurons and astroglia were prepared from Sprague-Dawley rats. Palmitic acid (PAL and l-carnitine (LC were added to the assay medium. The 4- to 24-hr production of AA and BHB was measured using the cyclic thio-NADH method. 14C-labeled acid-soluble products (KBs and 14CO2 produced from [1-14C]PAL were also measured. l-[U-14C]lactic acid ([14C]LAC, [1-14C]pyruvic acid ([14C]PYR, or β-[1-14C]hydroxybutyric acid ([14C]BHB was used to compare the oxidative metabolism of the glycolysis end products with that of the KBs. Some cells were placed in a hypoxic chamber (1% O2. PAL and LC induced a higher production of KBs in astroglia than in neurons, while the CO2 production from PAL was less than 5% of the KB production in both astroglia and neurons. KB production in astroglia was augmented by the AMP-activated protein kinase activators, AICAR and metformin, as well as hypoxia with/without glucose. Neuronal KB production increased under hypoxia in the absence of PAL and LC. In neurons, [14C]LAC and [14C]PYR oxidation decreased after 24 hr of hypoxia, while [14C]BHB oxidation was preserved. Astroglia responds to ischemia in vitro by enhancing KB production, and astroglia-produced KBs derived from fatty acid might serve as a neuronal energy substrate for the tricarboxylic acid cycle instead of lactate, as pyruvate dehydrogenase is susceptible to ischemia.

  18. Insulin receptors mediate growth effects in cultured fetal neurons. I. Rapid stimulation of protein synthesis

    International Nuclear Information System (INIS)

    Heidenreich, K.A.; Toledo, S.P.

    1989-01-01

    In this study we have examined the effects of insulin on protein synthesis in cultured fetal chick neurons. Protein synthesis was monitored by measuring the incorporation of [3H]leucine (3H-leu) into trichloroacetic acid (TCA)-precipitable protein. Upon addition of 3H-leu, there was a 5-min lag before radioactivity occurred in protein. During this period cell-associated radioactivity reached equilibrium and was totally recovered in the TCA-soluble fraction. After 5 min, the incorporation of 3H-leu into protein was linear for 2 h and was inhibited (98%) by the inclusion of 10 micrograms/ml cycloheximide. After 24 h of serum deprivation, insulin increased 3H-leu incorporation into protein by approximately 2-fold. The stimulation of protein synthesis by insulin was dose dependent (ED50 = 70 pM) and seen within 30 min. Proinsulin was approximately 10-fold less potent than insulin on a molar basis in stimulating neuronal protein synthesis. Insulin had no effect on the TCA-soluble fraction of 3H-leu at any time and did not influence the uptake of [3H]aminoisobutyric acid into neurons. The isotope ratio of 3H-leu/14C-leu in the leucyl tRNA pool was the same in control and insulin-treated neurons. Analysis of newly synthesized proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that insulin uniformly increased the incorporation of 14C-leu into all of the resolved neuronal proteins. We conclude from these data that (1) insulin rapidly stimulates overall protein synthesis in fetal neurons independent of amino acid uptake and aminoacyl tRNA precursor pools; (2) stimulation of protein synthesis is mediated by the brain subtype of insulin receptor; and (3) insulin is potentially an important in vivo growth factor for fetal central nervous system neurons

  19. Evaluating the Autonomy of the Drosophila Circadian Clock in Dissociated Neuronal Culture

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    Virginie Sabado

    2017-10-01

    Full Text Available Circadian behavioral rhythms offer an excellent model to study intricate interactions between the molecular and neuronal mechanisms of behavior. In mammals, pacemaker neurons in the suprachiasmatic nucleus (SCN generate rhythms cell-autonomously, which are synchronized by the network interactions within the circadian circuit to drive behavioral rhythms. However, whether this principle is universal to circadian systems in animals remains unanswered. Here, we examined the autonomy of the Drosophila circadian clock by monitoring transcriptional and post-transcriptional rhythms of individual clock neurons in dispersed culture with time-lapse microscopy. Expression patterns of the transcriptional reporter show that CLOCK/CYCLE (CLK/CYC-mediated transcription is constantly active in dissociated clock neurons. In contrast, the expression profile of the post-transcriptional reporter indicates that PERIOD (PER protein levels fluctuate and ~10% of cells display rhythms in PER levels with periods in the circadian range. Nevertheless, PER and TIM are enriched in the cytoplasm and no periodic PER nuclear accumulation was observed. These results suggest that repression of CLK/CYC-mediated transcription by nuclear PER is impaired, and thus the negative feedback loop of the molecular clock is incomplete in isolated clock neurons. We further demonstrate that, by pharmacological assays using the non-amidated form of neuropeptide pigment-dispersing factor (PDF, which could be specifically secreted from larval LNvs and adult s-LNvs, downstream events of the PDF signaling are partly impaired in dissociated larval clock neurons. Although non-amidated PDF is likely to be less active than the amidated one, these results point out the possibility that alteration in PDF downstream signaling may play a role in dampening of molecular rhythms in isolated clock neurons. Taken together, our results suggest that Drosophila clocks are weak oscillators that need to be in the

  20. Three-dimensional micro-electrode array for recording dissociated neuronal cultures.

    Science.gov (United States)

    Musick, Katherine; Khatami, David; Wheeler, Bruce C

    2009-07-21

    This work demonstrates the design, fabrication, packaging, characterization, and functionality of an electrically and fluidically active three-dimensional micro-electrode array (3D MEA) for use with neuronal cell cultures. The successful function of the device implies that this basic concept-construction of a 3D array with a layered approach-can be utilized as the basis for a new family of neural electrode arrays. The 3D MEA prototype consists of a stack of individually patterned thin films that form a cell chamber conducive to maintaining and recording the electrical activity of a long-term three-dimensional network of rat cortical neurons. Silicon electrode layers contain a polymer grid for neural branching, growth, and network formation. Along the walls of these electrode layers lie exposed gold electrodes which permit recording and stimulation of the neuronal electrical activity. Silicone elastomer micro-fluidic layers provide a means for loading dissociated neurons into the structure and serve as the artificial vasculature for nutrient supply and aeration. The fluidic layers also serve as insulation for the micro-electrodes. Cells have been shown to survive in the 3D MEA for up to 28 days, with spontaneous and evoked electrical recordings performed in that time. The micro-fluidic capability was demonstrated by flowing in the drug tetrotodoxin to influence the activity of the culture.

  1. Fabrication of biocompatible free-standing nanopatterned films for primary neuronal cultures

    KAUST Repository

    Cesca, F.

    2014-09-10

    Devising and constructing biocompatible devices for nervous system regeneration is an extremely challenging task. Besides tackling the issue of biocompatibility, biomaterials for neuroscience applications should mimic the complex environment of the extracellular matrix, which in vivo provides neurons with a series of cues and signals to guide cells towards their appropriate targets. In this work, a novel nanopatterned biocompatible poly-ε-caprolactone (PCL) film is realized to assist the attachment and growth of primary hippocampal neurons. Costly and time-consuming processes can be avoided using plasma-surface nanotexturing obtained by a mixed gas SF6/Ar at −5 °C. The intrinsic composition and line topography of nanopatterned PCL ensure healthy development of the neuronal network, as shown by confocal microscopy, by analysing the expression of a range of neuronal markers typical of mature cultures, as well as by scanning electron microscopy. In addition, we show that surface nanopatterning improves differentiation of neurons compared to flat PCL films, while no neural growth was observed on either flat or nanopatterned substrates in the absence of a poly-D-lysine coating. Thus, we successfully optimized a nanofabrication protocol to obtain nanostructured PCL layers endowed with several mechanical and structural characteristics that make them a promising, versatile tool for future tissue engineering studies aimed at neural tissue regeneration.

  2. Difference of acute dissociation and 1-day culture on the electrophysiological properties of rat dorsal root ganglion neurons.

    Science.gov (United States)

    Song, Yuanlong; Zhang, Miaomiao; Tao, Xiaoqing; Xu, Zifen; Zheng, Yunjie; Zhu, Minjie; Zhang, Liangpin; Qiao, Jinhan; Gao, Linlin

    2018-01-19

    The dissociated dorsal root ganglion (DRG) neurons with or without culture were widely used for investigation of their electrophysiological properties. The culture procedures, however, may alter the properties of these neurons and the effects are not clear. In the present study, we recorded the action potentials (AP) and the voltage-gated Na + , K + , and Ca 2+ currents with patch clamp technique and measured the mRNA of Nav1.6-1.9 and Cav2.1-2.2 with real-time PCR technique from acutely dissociated and 1-day (1-d) cultured DRG neurons. The effects of the nerve growth factor (NGF) on the expression of Nav1.6-1.9 and Cav2.1-2.2 were evaluated. The neurons were classified as small (DRG-S), medium (DRG-M), and large (DRG-L), according to their size frequency distribution pattern. We found 1-d culture increased the AP size but reduced the excitability, and reduced the voltage-gated Na + and Ca 2+ currents and their corresponding mRNA expression in all types of neurons. The lack of NGF in the culture medium may contribute to the reduced Na + and Ca 2+ current, as the application of NGF recovered some of the reduced transcripts (Nav1.9, Cav2.1, and Cav2.2). 1-d culture showed neuron-type specific effects on some of the AP properties: it increased the maximum AP depolarizing rate (MDR) and hyperpolarized the resting membrane potential (RP) in DRG-M and DRG-L neurons, but slowed the maximum AP repolarizing rate (MRR) in DRG-S neurons. In conclusion, the 1-d cultured neurons had different properties with those of the acutely dissociated neurons, and lack of NGF may contribute to some of these differences.

  3. Parallel expression of synaptophysin and evoked neurotransmitter release during development of cultured neurons

    DEFF Research Database (Denmark)

    Ehrhart-Bornstein, M; Treiman, M; Hansen, Gert Helge

    1991-01-01

    by quantitative immunoblotting and light microscope immunocytochemistry, respectively. In both cell types, a close parallelism was found between the temporal pattern of development in synaptophysin expression and neurotransmitter release. This temporal pattern differed between the two types of neurons......Primary cultures of GABAergic cerebral cortex neurons and glutamatergic cerebellar granule cells were used to study the expression of synaptophysin, a synaptic vesicle marker protein, along with the ability of each cell type to release neurotransmitter upon stimulation. The synaptophysin expression...... and neurotransmitter release were measured in each of the culture types as a function of development for up to 8 days in vitro, using the same batch of cells for both sets of measurements to obtain optimal comparisons. The content and the distribution of synaptophysin in the developing cells were assessed...

  4. Parallel expression of synaptophysin and evoked neurotransmitter release during development of cultured neurons

    DEFF Research Database (Denmark)

    Ehrhart-Bornstein, M; Treiman, M; Hansen, Gert Helge

    1991-01-01

    Primary cultures of GABAergic cerebral cortex neurons and glutamatergic cerebellar granule cells were used to study the expression of synaptophysin, a synaptic vesicle marker protein, along with the ability of each cell type to release neurotransmitter upon stimulation. The synaptophysin expression...... and neurotransmitter release were measured in each of the culture types as a function of development for up to 8 days in vitro, using the same batch of cells for both sets of measurements to obtain optimal comparisons. The content and the distribution of synaptophysin in the developing cells were assessed...... by quantitative immunoblotting and light microscope immunocytochemistry, respectively. In both cell types, a close parallelism was found between the temporal pattern of development in synaptophysin expression and neurotransmitter release. This temporal pattern differed between the two types of neurons...

  5. Metabolic differences between primary cultures of astrocytes and neurons from cerebellum and cerebral cortex. Effects of fluorocitrate.

    Science.gov (United States)

    Hassel, B; Westergaard, N; Schousboe, A; Fonnum, F

    1995-04-01

    Astrocytes and neurons cultured from mouse cerebellum and cerebral cortex were analyzed with respect to content and synthesis of amino acids as well as export of metabolites to the culture medium and the response to fluorocitrate, an inhibitor of aconitase. The intracellular levels of amino acids were similar in the two astrocytic populations. The release of citrate, lactate and glutamine, however, was markedly higher from cerebellar than from cortical astrocytes. Neurons contained higher levels of glutamate, aspartate and GABA than astrocytic cultures. Cortical neurons were especially high in GABA and aspartate, and the level of aspartate increased specifically when the extracellular level of glutamine was elevated. Fluorocitrate inhibited the TCA cycle in the astrocytes, but was less effective in cerebellar neurons. Whereas neurons responded to fluorocitrate with an increase in the formation of lactate, reflecting glycolysis, astrocytes decreased the formation of lactate in the presence of fluorocitrate, indicating that astrocytes to a high degree synthesize pyruvate and hence lactate from TCA cycle intermediates.

  6. Effect of acute stretch injury on action potential and network activity of rat neocortical neurons in culture.

    Science.gov (United States)

    Magou, George C; Pfister, Bryan J; Berlin, Joshua R

    2015-10-22

    The basis for acute seizures following traumatic brain injury (TBI) remains unclear. Animal models of TBI have revealed acute hyperexcitablility in cortical neurons that could underlie seizure activity, but studying initiating events causing hyperexcitability is difficult in these models. In vitro models of stretch injury with cultured cortical neurons, a surrogate for TBI, allow facile investigation of cellular changes after injury but they have only demonstrated post-injury hypoexcitability. The goal of this study was to determine if neuronal hyperexcitability could be triggered by in vitro stretch injury. Controlled uniaxial stretch injury was delivered to a spatially delimited region of a spontaneously active network of cultured rat cortical neurons, yielding a region of stretch-injured neurons and adjacent regions of non-stretched neurons that did not directly experience stretch injury. Spontaneous electrical activity was measured in non-stretched and stretch-injured neurons, and in control neuronal networks not subjected to stretch injury. Non-stretched neurons in stretch-injured cultures displayed a three-fold increase in action potential firing rate and bursting activity 30-60 min post-injury. Stretch-injured neurons, however, displayed dramatically lower rates of action potential firing and bursting. These results demonstrate that acute hyperexcitability can be observed in non-stretched neurons located in regions adjacent to the site of stretch injury, consistent with reports that seizure activity can arise from regions surrounding the site of localized brain injury. Thus, this in vitro procedure for localized neuronal stretch injury may provide a model to study the earliest cellular changes in neuronal function associated with acute post-traumatic seizures. Copyright © 2015. Published by Elsevier B.V.

  7. Neuron-oligodendrocyte myelination co-culture derived from embryonic rat spinal cord and cerebral cortex.

    Science.gov (United States)

    Pang, Yi; Zheng, Baoying; Kimberly, Simpson L; Cai, Zhengwei; Rhodes, Philip G; Lin, Rick C S

    2012-01-01

    An in vitro myelination model derived from rat central nervous system (CNS) remains to be established. Here, we describe a simple and reproducible myelination culture method using dissociated neuron-oligodendrocyte (OL) co-cultures from either the embryonic day 16 (E16) rat spinal cord or cerebral cortex. The dissociated cells are plated directly on poly-L-lysine-coated cover slips and maintained in a modified myelination medium that supports both OL and neuron differentiation. The spinal cord derived OL progenitor cells develop quickly into myelin basic protein (MBP)+ mature OLs and start to myelinate axons around 17 days in vitro (DIV17). Myelination reaches its peak around six weeks (DIV40) and the typical nodes of Ranvier are revealed by paranodal proteins Caspr and juxaparanodal protein Kv1.2 immunoreactivity. Electron microscopy (EM) shows typical myelination cytoarchitecture and synaptic organization. In contrast, the cortical-derived co-culture requires triiodothyronine (T3) in the culture medium for myelination. Finally, either hypomyelination and/or demyelination can be induced by exposing proinflammatory cytokines or demyelinating agents to the co-culture, suggesting the feasibility of this modified in vitro myelination model for myelin-deficit investigation.

  8. Neonicotinoid Insecticides Alter the Gene Expression Profile of Neuron-Enriched Cultures from Neonatal Rat Cerebellum

    Directory of Open Access Journals (Sweden)

    Junko Kimura-Kuroda

    2016-10-01

    Full Text Available Neonicotinoids are considered safe because of their low affinities to mammalian nicotinic acetylcholine receptors (nAChRs relative to insect nAChRs. However, because of importance of nAChRs in mammalian brain development, there remains a need to establish the safety of chronic neonicotinoid exposures with regards to children’s health. Here we examined the effects of longterm (14 days and low dose (1 μM exposure of neuron-enriched cultures from neonatal rat cerebellum to nicotine and two neonicotinoids: acetamiprid and imidacloprid. Immunocytochemistry revealed no differences in the number or morphology of immature neurons or glial cells in any group versus untreated control cultures. However, a slight disturbance in Purkinje cell dendritic arborization was observed in the exposed cultures. Next we performed transcriptome analysis on total RNAs using microarrays, and identified significant differential expression (p < 0.05, q < 0.05, ≥1.5 fold between control cultures versus nicotine-, acetamiprid-, or imidacloprid-exposed cultures in 34, 48, and 67 genes, respectively. Common to all exposed groups were nine genes essential for neurodevelopment, suggesting that chronic neonicotinoid exposure alters the transcriptome of the developing mammalian brain in a similar way to nicotine exposure. Our results highlight the need for further careful investigations into the effects of neonicotinoids in the developing mammalian brain.

  9. Extracellular matrix-associated gene expression in adult sensory neuron populations cultured on a laminin substrate.

    Science.gov (United States)

    Fudge, Neva J; Mearow, Karen M

    2013-01-30

    In our previous investigations of the role of the extracellular matrix (ECM) in promoting neurite growth we have observed that a permissive laminin (LN) substrate stimulates differential growth responses in subpopulations of mature dorsal root ganglion (DRG) neurons. DRG neurons expressing Trk and p75 receptors grow neurites on a LN substrate in the absence of neurotrophins, while isolectin B4-binding neurons (IB4+) do not display significant growth under the same conditions. We set out to determine whether there was an expression signature of the LN-induced neurite growth phenotype. Using a lectin binding protocol IB4+ neurons were isolated from dissociated DRG neurons, creating two groups - IB4+ and IB4-. A small-scale microarray approach was employed to screen the expression of a panel of ECM-associated genes following dissociation (t=0) and after 24 hr culture on LN (t=24LN). This was followed by qRT-PCR and immunocytochemistry of selected genes. The microarray screen showed that 36 of the 144 genes on the arrays were consistently expressed by the neurons. The array analyses showed that six genes had lower expression in the IB4+ neurons compared to the IB4- cells at t=0 (CTSH, Icam1, Itgβ1, Lamb1, Plat, Spp1), and one gene was expressed at higher levels in the IB4+ cells (Plaur). qRT-PCR was carried out as an independent assessment of the array results. There were discrepancies between the two methods, with qRT-PCR confirming the differences in Lamb1, Plat and Plaur, and showing decreased expression of AdamTs1, FN, and Icam in the IB4+ cells at t=0. After 24 hr culture on LN, there were no significant differences detected by qRT-PCR between the IB4+ and IB4- cells. However, both groups showed upregulation of Itgβ1 and Plaur after 24 hr on LN, the IB4+ group also had increased Plat, and the IB4- cells showed decreased Lamb1, Icam1 and AdamTs1. Further, the array screen also detected a number of genes (not subjected to qRT-PCR) expressed similarly by both

  10. Neuron-specific enolase is a useful maker of neuroendocrine origin in pheochromocytoma cell culture

    International Nuclear Information System (INIS)

    Abelin, N.; Dahia, P.L.M.; Martin, R.; Kato, S.; Toledo, S.P.A.

    1994-01-01

    Neuron-specific enolase (NSE) has been used as a marker for neuroendocrine tumors either in immunocytochemical studies or in serum measurements. In this paper NSE levels were determined in cultured pheochromocytoma cells to test whether it is also a useful marker in cell culture of tumors derived from neuroendocrine system. Cultured pheochromocytoma cells came from a primary explant and were grown in RPMI supplemented with 20% fetal calf serum, 100 μg/mL ampicillin and 100 μ/mL streptomycin. NSE was measured in culture medium and cell homogenates. Samples from different pheochromocytoma cultures were analyzed and compared to normal cultured fibroblast cells derived from human skin. NSE was measured by a commercially available radioimmunoassay kit. NSE levels were higher in cell homogenates as compared to those in culture medium, reaching levels as high as 6-fold in the former in TE cell line (26.46 ng/mL and 4.39 ng/mL, respectively). Serial measurements in culture medium from TE cell line evidenced decreasing values in subsequential subcultures (from 9.24 ng/mL during primary explant to 1.7 ng/mL in the tenth subculture). In cultured normal fibroblasts, NSE levels in cultured media were definitely lower than those obtained from pheochromocytoma cultures. These preliminary data suggest that NSE may be a useful marker of neuroendocrine derived tumors, such as pheochromocytoma, in culture. Thus, the simplicity and availability of NSE radioimmunoassay provides an alternative to catecholamine measurement to better characterize pheochromocytoma cell lines in culture, with the advantage of faster result at lower costs. (author). 18 refs, 2 tabs

  11. Co-cultures with stem cell-derived human sensory neurons reveal regulators of peripheral myelination.

    Science.gov (United States)

    Clark, Alex J; Kaller, Malte S; Galino, Jorge; Willison, Hugh J; Rinaldi, Simon; Bennett, David L H

    2017-04-01

    See Saporta and Shy (doi:10.1093/awx048) for a scientific commentary on this article.Effective bidirectional signalling between axons and Schwann cells is essential for both the development and maintenance of peripheral nerve function. We have established conditions by which human induced pluripotent stem cell-derived sensory neurons can be cultured with rat Schwann cells, and have produced for the first time long-term and stable myelinating co-cultures with human neurons. These cultures contain the specialized domains formed by axonal interaction with myelinating Schwann cells, such as clustered voltage-gated sodium channels at the node of Ranvier and Shaker-type potassium channel (Kv1.2) at the juxtaparanode. Expression of type III neuregulin-1 (TIIINRG1) in induced pluripotent stem cell-derived sensory neurons strongly enhances myelination, while conversely pharmacological blockade of the NRG1-ErbB pathway prevents myelination, providing direct evidence for the ability of this pathway to promote the myelination of human sensory axons. The β-secretase, BACE1 is a protease needed to generate active NRG1 from the full-length form. Due to the fact that it also cleaves amyloid precursor protein, BACE1 is a therapeutic target in Alzheimer's disease, however, consistent with its role in NRG1 processing we find that BACE1 inhibition significantly impairs myelination in our co-culture system. In order to exploit co-cultures to address other clinically relevant problems, they were exposed to anti-disialosyl ganglioside antibodies, including those derived from a patient with a sensory predominant, inflammatory neuropathy with mixed axonal and demyelinating electrophysiology. The co-cultures reveal that both mouse and human disialosyl antibodies target the nodal axolemma, induce acute axonal degeneration in the presence of complement, and impair myelination. The human, neuropathy-associated IgM antibody is also shown to induce complement-independent demyelination

  12. Evolution of triiodothyronine nuclear binding sites in hypothalamic serum-free cultures: evidence for their presence in neurons and astrocytes

    International Nuclear Information System (INIS)

    Puymirat, J.; Faivre-Bauman, A.

    1986-01-01

    ( 125 I)Triiodothyronine (T 3 ) nuclear binding was studied in hypothalamic cultures from fetal mouse grown in serum-free medium. In enriched neuronal cultures, the apparent dissociation constant of the binding does not change with time in vitro (7 x 10 -11 M), but the maximum binding capacity (MBC) doubles between day 7 and day 14 in vitro. We show here for the first time that homologous astrocyte cell cultures, devoid of neurons as checked by tetanus toxin binding, also display T 3 nuclear binding, with the same affinity as neuronal cultures. However, their MBC is 3 times lower than that of neurons after a week in vitro, and increases more quickly thereafter (Author)

  13. Endogenous cholinergic tone modulates spontaneous network level neuronal activity in primary cortical cultures grown on multi-electrode arrays

    OpenAIRE

    Hammond, Mark W; Xydas, Dimitris; Downes, Julia H; Bucci, Giovanna; Becerra, Victor; Warwick, Kevin; Constanti, Andrew; Nasuto, Slawomir J; Whalley, Benjamin J

    2013-01-01

    Background\\ud Cortical cultures grown long-term on multi-electrode arrays (MEAs) are frequently and extensively used as models of cortical networks in studies of neuronal firing activity, neuropharmacology, toxicology and mechanisms underlying synaptic plasticity. However, in contrast to the predominantly asynchronous neuronal firing activity exhibited by intact cortex, electrophysiological activity of mature cortical cultures is dominated by spontaneous epileptiform-like global burst events ...

  14. Characterization of ex vivo cultured neuronal- and glial- like cells from human idiopathic epiretinal membranes.

    Science.gov (United States)

    Andjelić, Sofija; Lumi, Xhevat; Yan, Xiaohe; Graw, Jochen; Moe, Morten C; Facskó, Andrea; Hawlina, Marko; Petrovski, Goran

    2014-12-23

    Characterization of the neuro-glial profile of cells growing out of human idiopathic epiretinal membranes (iERMs) and testing their proliferative and pluripotent properties ex vivo is needed to better understand the pathogenesis of their formation. iERMs obtained during uneventful vitrectomies were cultivated ex vivo under adherent conditions and assessed by standard morphological and immunocytochemical methods. The intracellular calcium dynamics of the outgrowing cells was assessed by fluorescent dye Fura-2 in response to acetylcholine (ACh)- or mechano- stimulation. The cells from the iERMs formed sphere-like structures when cultured ex vivo. The diameter of the spheres increased by 5% at day 6 and kept an increasing tendency over a month time. The outgrowing cells from the iERM spheres had mainly glial- and some neuronal- like morphology. ACh- or mechano- stimulation of these cells induced intracellular calcium propagation in both cell types; in the neuronal-like cells resembling action potential from the soma to the dendrites. Immunocytochemistry confirmed presence of glial- and neuronal cell phenotype (GFAP and Nestin-1 positivity, respectively) in the iERMs, as well as presence of pluripotency marker (Sox2). iERMs contain cells of neuronal- and glial- like origin which have proliferative and pluripotent potential, show functionality reflected through calcium dynamics upon ACh and mechano- stimulation, and a corresponding molecular phenotype.

  15. Activation of 5-HT2A/2C receptors reduces the excitability of cultured cortical neurons.

    Science.gov (United States)

    Hu, Lingli; Liu, Chunhua; Dang, Minyan; Luo, Bin; Guo, Yiping; Wang, Haitao

    2016-10-06

    The abundant forebrain serotonergic projections are believed to modulate the activities of cortical neurons. 5-HT2 receptor among multiple subtypes of serotonin receptors contributes to the modulation of excitability, synaptic transmissions and plasticity. In the present study, whole-cell patch-clamp recording was adopted to examine whether activation of 5-HT2A/2C receptors would have any impact on the excitability of cultured cortical neurons. We found that 2,5-Dimethoxy-4-iodoamphetamine (DOI), a selective 5-HT2A/2C receptor agonist, rapidly and reversibly depressed spontaneous action potentials mimicking the effect of serotonin. The decreased excitability was also observed for current-evoked firing. Additionally DOI increased neuronal input resistance. Hyperpolarization-activated cyclic nucleotide-gated cationic channels (HCN) did not account for the inhibition of spontaneous firing. The synaptic contribution was ruled out in that DOI augmented excitation and attenuated inhibition to actually favor an increase in the excitability. Our findings revealed that activation of 5-HT2A/2C receptors reduces neuronal excitability, which would deepen our understanding of serotonergic modulation of cortical activities. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Cultured Cortical Neurons Can Perform Blind Source Separation According to the Free-Energy Principle.

    Directory of Open Access Journals (Sweden)

    Takuya Isomura

    2015-12-01

    Full Text Available Blind source separation is the computation underlying the cocktail party effect--a partygoer can distinguish a particular talker's voice from the ambient noise. Early studies indicated that the brain might use blind source separation as a signal processing strategy for sensory perception and numerous mathematical models have been proposed; however, it remains unclear how the neural networks extract particular sources from a complex mixture of inputs. We discovered that neurons in cultures of dissociated rat cortical cells could learn to represent particular sources while filtering out other signals. Specifically, the distinct classes of neurons in the culture learned to respond to the distinct sources after repeating training stimulation. Moreover, the neural network structures changed to reduce free energy, as predicted by the free-energy principle, a candidate unified theory of learning and memory, and by Jaynes' principle of maximum entropy. This implicit learning can only be explained by some form of Hebbian plasticity. These results are the first in vitro (as opposed to in silico demonstration of neural networks performing blind source separation, and the first formal demonstration of neuronal self-organization under the free energy principle.

  17. GDNF family ligands display distinct action profiles on cultured GABAergic and serotonergic neurons of rat ventral mesencephalon

    DEFF Research Database (Denmark)

    Ducray, Angélique; Krebs, Sandra H:; Schaller, Benoft

    2006-01-01

    the effects of GFLs on other neuronal populations in the VM is essential for their potential application as therapeutic molecules for Parkinson's disease. Hence, in a comparative study, we investigated the effects of GFLs on cell densities and morphological differentiation of gamma-aminobutyric acid......Glial-cell-line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN) and persephin (PSPN), known as the GDNF family ligands (GFLs), influence the development, survival and differentiation of cultured dopaminergic neurons from ventral mesencephalon (VM). Detailed knowledge about......-immunoreactive (GABA-ir) and serotonin-ir (5-HT-ir) neurons in primary cultures of E14 rat VM. We observed that all GFLs [10 ng/ml] significantly increased GABA-ir cell densities (1.6-fold) as well as neurite length/neuron. However, only GDNF significantly increased the number of primary neurites/neuron, and none...

  18. High Content Analysis of Hippocampal Neuron-Astrocyte Co-cultures Shows a Positive Effect of Fortasyn Connect on Neuronal Survival and Postsynaptic Maturation

    Directory of Open Access Journals (Sweden)

    Anne-Lieke F. van Deijk

    2017-08-01

    Full Text Available Neuronal and synaptic membranes are composed of a phospholipid bilayer. Supplementation with dietary precursors for phospholipid synthesis –docosahexaenoic acid (DHA, uridine and choline– has been shown to increase neurite outgrowth and synaptogenesis both in vivo and in vitro. A role for multi-nutrient intervention with specific precursors and cofactors has recently emerged in early Alzheimer's disease, which is characterized by decreased synapse numbers in the hippocampus. Moreover, the medical food Souvenaid, containing the specific nutrient combination Fortasyn Connect (FC, improves memory performance in early Alzheimer's disease patients, possibly via maintaining brain connectivity. This suggests an effect of FC on synapses, but the underlying cellular mechanism is not fully understood. Therefore, we investigated the effect of FC (consisting of DHA, eicosapentaenoic acid (EPA, uridine, choline, phospholipids, folic acid, vitamins B12, B6, C and E, and selenium, on synaptogenesis by supplementing it to primary neuron-astrocyte co-cultures, a cellular model that mimics metabolic dependencies in the brain. We measured neuronal developmental processes using high content screening in an automated manner, including neuronal survival, neurite morphology, as well as the formation and maturation of synapses. Here, we show that FC supplementation resulted in increased numbers of neurons without affecting astrocyte number. Furthermore, FC increased postsynaptic PSD95 levels in both immature and mature synapses. These findings suggest that supplementation with FC to neuron-astrocyte co-cultures increased both neuronal survival and the maturation of postsynaptic terminals, which might aid the functional interpretation of FC-based intervention strategies in neurological diseases characterized by neuronal loss and impaired synaptic functioning.

  19. Surface plasmon-enhanced optical trapping of quantum-dot-conjugated surface molecules on neurons cultured on a plasmonic chip

    Science.gov (United States)

    Miyauchi, Kohei; Tawa, Keiko; Kudoh, Suguru N.; Taguchi, Takahisa; Hosokawa, Chie

    2016-06-01

    Living neurons in a complex neuronal network communicate with each other through synaptic connections. The molecular dynamics of cell surface molecules localized at synaptic terminals is essential for functional connections via synaptic plasticity in the neuronal network. Here, we demonstrate surface-plasmon-resonance-based optical trapping using a plasmonic chip toward realizing effective manipulation of molecules on the surface of neurons. Surface-plasmon-enhanced optical trapping was evaluated by the fluorescence analysis of nanoparticles suspended in water and neural cell adhesion molecules (NCAMs) labeled with quantum dots (Q-dots) on rat hippocampal neurons. The motion of nanoparticles in water and the molecular dynamics of NCAMs on neuronal cells cultured on a plasmonic chip were constrained at the laser focus more effectively than those on a glass substrate because of the surface plasmon resonance effect.

  20. Accumulating microglia phagocytose injured neurons in hippocampal slice cultures: involvement of p38 MAP kinase.

    Directory of Open Access Journals (Sweden)

    Takahiro Katayama

    Full Text Available In this study, microglial migration and phagocytosis were examined in mouse organotypic hippocampal slice cultures, which were treated with N-methyl-D-aspartate (NMDA to selectively injure neuronal cells. Microglial cells were visualized by the expression of enhanced green fluorescent protein. Daily observation revealed microglial accumulation in the pyramidal cell layer, which peaked 5 to 6 days after NMDA treatment. Time-lapse imaging showed that microglia migrated to the pyramidal cell layer from adjacent and/or remote areas. There was no difference in the number of proliferating microglia between control and NMDA-treated slices in both the pyramidal cell layer and stratum radiatum, suggesting that microglial accumulation in the injured areas is mainly due to microglial migration, not to proliferation. Time-lapse imaging also showed that the injured neurons, which were visualized by propidium iodide (PI, disappeared just after being surrounded by microglia. Daily observation revealed that the intensity of PI fluorescence gradually attenuated, and this attenuation was suppressed by pretreatment with clodronate, a microglia toxin. These findings suggest that accumulating microglia phagocytosed injured neurons, and that PI fluorescence could be a useful indicator for microglial phagocytosis. Using this advantage to examine microglial phagocytosis in living slice cultures, we investigated the involvements of mitogen-activated protein (MAP kinases in microglial accumulation and phagocytosis. p38 MAP kinase inhibitor SB203580, but not MAP kinase/extracellular signal-regulated kinase inhibitor PD98059 or c-Jun N-terminal kinase inhibitor SP600125, suppressed the attenuation of PI fluorescence. On the other hand, microglial accumulation in the injured areas was not inhibited by any of these inhibitors. These data suggest that p38 MAP kinase plays an important role in microglial phagocytosis of injured neurons.

  1. PCB 136 Atropselectively Alters Morphometric and Functional Parameters of Neuronal Connectivity in Cultured Rat Hippocampal Neurons via Ryanodine Receptor-Dependent Mechanisms

    Science.gov (United States)

    Yang, Dongren; Kania-Korwel, Izabela; Ghogha, Atefeh; Chen, Hao; Stamou, Marianna; Bose, Diptiman D.; Pessah, Isaac N.; Lehmler, Hans-Joachim; Lein, Pamela J.

    2014-01-01

    We recently demonstrated that polychlorinated biphenyl (PCB) congeners with multiple ortho chlorine substitutions sensitize ryanodine receptors (RyRs), and this activity promotes Ca2+-dependent dendritic growth in cultured neurons. Many ortho-substituted congeners display axial chirality, and we previously reported that the chiral congener PCB 136 (2,2′,3,3′,6,6′-hexachlorobiphenyl) atropselectively sensitizes RyRs. Here, we test the hypothesis that PCB 136 atropisomers differentially alter dendritic growth and other parameters of neuronal connectivity influenced by RyR activity. (−)-PCB 136, which potently sensitizes RyRs, enhances dendritic growth in primary cultures of rat hippocampal neurons, whereas (+)-PCB 136, which lacks RyR activity, has no effect on dendritic growth. The dendrite-promoting activity of (−)-PCB 136 is observed at concentrations ranging from 0.1 to 100nM and is blocked by pharmacologic RyR antagonism. Neither atropisomer alters axonal growth or cell viability. Quantification of PCB 136 atropisomers in hippocampal cultures indicates that atropselective effects on dendritic growth are not due to differential partitioning of atropisomers into cultured cells. Imaging of hippocampal neurons loaded with Ca2+-sensitive dye demonstrates that (−)-PCB 136 but not (+)-PCB 136 increases the frequency of spontaneous Ca2+ oscillations. Similarly, (−)-PCB 136 but not (+)-PCB 136 increases the activity of hippocampal neurons plated on microelectrode arrays. These data support the hypothesis that atropselective effects on RyR activity translate into atropselective effects of PCB 136 atropisomers on neuronal connectivity, and suggest that the variable atropisomeric enrichment of chiral PCBs observed in the human population may be a significant determinant of individual susceptibility for adverse neurodevelopmental outcomes following PCB exposure. PMID:24385416

  2. Oligomeric forms of the metastasis-related Mts1 (S100A4) protein stimulate neuronal differentiation in cultures of rat hippocampal neurons

    DEFF Research Database (Denmark)

    Novitskaya, V; Grigorian, M; Kriajevska, M

    2000-01-01

    protein family. The oligomeric but not the dimeric form of Mts1 strongly induces differentiation of cultured hippocampal neurons. A mutant with a single Y75F amino acid substitution, which stabilizes the dimeric form of Mts1, is unable to promote neurite extension. Disulfide bonds do not play an essential...

  3. Distinct Effects of Abelson Kinase Mutations on Myocytes and Neurons in Dissociated Drosophila Embryonic Cultures: Mimicking of High Temperature

    Science.gov (United States)

    Liu, Lijuan; Wu, Chun-Fang

    2014-01-01

    Abelson tyrosine kinase (Abl) is known to regulate axon guidance, muscle development, and cell-cell interaction in vivo. The Drosophila primary culture system offers advantages in exploring the cellular mechanisms mediated by Abl with utilizing various experimental manipulations. Here we demonstrate that single-embryo cultures exhibit stage-dependent characteristics of cellular differentiation and developmental progression in neurons and myocytes, as well as nerve-muscle contacts. In particular, muscle development critically depends on the stage of dissociated embryos. In wild-type (WT) cultures derived from embryos before stage 12, muscle cells remained within cell clusters and were rarely detected. Interestingly, abundant myocytes were spotted in Abl mutant cultures, exhibiting enhanced myocyte movement and fusion, as well as neuron-muscle contacts even in cultures dissociated from younger, stage 10 embryos. Notably, Abl myocytes frequently displayed well-expanded lamellipodia. Conversely, Abl neurons were characterized with fewer large veil-like lamellipodia, but instead had increased numbers of filopodia and darker nodes along neurites. These distinct phenotypes were equally evident in both homo- and hetero-zygous cultures (Abl/Abl vs. Abl/+) of different alleles (Abl1 and Abl4) indicating dominant mutational effects. Strikingly, in WT cultures derived from stage 10 embryos, high temperature (HT) incubation promoted muscle migration and fusion, partially mimicking the advanced muscle development typical of Abl cultures. However, HT enhanced neuronal growth with increased numbers of enlarged lamellipodia, distinct from the characteristic Abl neuronal morphology. Intriguingly, HT incubation also promoted Abl lamellipodia expansion, with a much greater effect on nerve cells than muscle. Our results suggest that Abl is an essential regulator for myocyte and neuron development and that high-temperature incubation partially mimics the faster muscle development

  4. Roles and regulation of ketogenesis in cultured astroglia and neurons under hypoxia and hypoglycemia.

    Science.gov (United States)

    Takahashi, Shinichi; Iizumi, Takuya; Mashima, Kyoko; Abe, Takato; Suzuki, Norihiro

    2014-09-11

    Exogenous ketone bodies (KBs), acetoacetate (AA), and β-hydroxybutyrate (BHB) act as alternative energy substrates in neural cells under starvation. The present study examined the endogenous ketogenic capacity of astroglia under hypoxia with/without glucose and the possible roles of KBs in neuronal energy metabolism. Cultured neurons and astroglia were prepared from Sprague-Dawley rats. Palmitic acid (PAL) and l-carnitine (LC) were added to the assay medium. The 4- to 24-hr production of AA and BHB was measured using the cyclic thio-NADH method. (14)C-labeled acid-soluble products (KBs) and (14)CO2 produced from [1-(14)C]PAL were also measured. l-[U-(14)C]lactic acid ([(14)C]LAC), [1-(14)C]pyruvic acid ([(14)C]PYR), or β-[1-(14)C]hydroxybutyric acid ([(14)C]BHB) was used to compare the oxidative metabolism of the glycolysis end products with that of the KBs. Some cells were placed in a hypoxic chamber (1% O2). PAL and LC induced a higher production of KBs in astroglia than in neurons, while the CO2 production from PAL was less than 5% of the KB production in both astroglia and neurons. KB production in astroglia was augmented by the AMP-activated protein kinase activators, AICAR and metformin, as well as hypoxia with/without glucose. Neuronal KB production increased under hypoxia in the absence of PAL and LC. In neurons, [(14)C]LAC and [(14)C]PYR oxidation decreased after 24 hr of hypoxia, while [(14)C]BHB oxidation was preserved. Astroglia responds to ischemia in vitro by enhancing KB production, and astroglia-produced KBs derived from fatty acid might serve as a neuronal energy substrate for the tricarboxylic acid cycle instead of lactate, as pyruvate dehydrogenase is susceptible to ischemia. © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav.

  5. Neonicotinoid Insecticides Alter the Gene Expression Profile of Neuron-Enriched Cultures from Neonatal Rat Cerebellum.

    Science.gov (United States)

    Kimura-Kuroda, Junko; Nishito, Yasumasa; Yanagisawa, Hiroko; Kuroda, Yoichiro; Komuta, Yukari; Kawano, Hitoshi; Hayashi, Masaharu

    2016-10-04

    Neonicotinoids are considered safe because of their low affinities to mammalian nicotinic acetylcholine receptors (nAChRs) relative to insect nAChRs. However, because of importance of nAChRs in mammalian brain development, there remains a need to establish the safety of chronic neonicotinoid exposures with regards to children's health. Here we examined the effects of longterm (14 days) and low dose (1 μM) exposure of neuron-enriched cultures from neonatal rat cerebellum to nicotine and two neonicotinoids: acetamiprid and imidacloprid. Immunocytochemistry revealed no differences in the number or morphology of immature neurons or glial cells in any group versus untreated control cultures. However, a slight disturbance in Purkinje cell dendritic arborization was observed in the exposed cultures. Next we performed transcriptome analysis on total RNAs using microarrays, and identified significant differential expression (p neonicotinoid exposure alters the transcriptome of the developing mammalian brain in a similar way to nicotine exposure. Our results highlight the need for further careful investigations into the effects of neonicotinoids in the developing mammalian brain.

  6. Localized Induced Current Stimulation to Neuronal Culture Using Soft Magnetic Material

    Science.gov (United States)

    Saito, Atsushi; Saito, Aki; Moriguchi, Hiroyuki; Kotani, Kiyoshi; Jimbo, Yasuhiko

    To establish precisely focused magnetic stimulation, we developed a Mu-meal based low-frequency localized induced current (LIC) stimulation system with micro-fabricated dual cell-culture chamber. The dual cell-culture chamber was arranged in a concentric circle manner. Between the inner and outer chambers, 4 or 8 connecting micro-channels were fabricated using polydimethylsiloxane (PDMS). Rat cortical neurons were separately cultured in outer and inner chambers. Through the micro-channels, functional synaptic connections were formed. Mu-metal that has very high magnetic permeability was aligned along the outer circle, which allowed us of LIC stimulation to the cells in the outer chamber. Applying low-frequency magnetic fields to the Mu-metal, induced currents were generated and the electrical activity of the cells in the outer chamber was modified depending on the stimulation intensity. Following the modified activity in the outer circles, the cells in the inner chamber also showed slightly depressed activity patterns. These results suggested that our system would be promising for localized stimulation of neuronal networks and highly regulation of network activities.

  7. Culturing of primary rat neurons and glia on ultra-thin parylene-C

    International Nuclear Information System (INIS)

    Unsworth, C.P.; Delivopoulos, E.; Murray, A.F.

    2010-01-01

    Full text: In this article, we will describe how we have successfully cultured dissociated embryonic cortical neurons and glia from the postnatal rat hippocampus on extremely thin layers (up to 10 nm) of Parylene-C on a silicon dioxide substrate. Silicon wafers were oxidised, deposited with the biomaterial, Parylene-C, photo-lithographically patterned and plasma etched to produce chips that consisted of lines of Paryl ene-C with varying widths, thickness and lengths. The chips produced were then immersed in Horse Serum and plated with the cells. Ratios of Neurons; Glia; Cell Body were measured on, adjacent to and away from the Parylene-C. Our initial results show how these ratios remained roughly constant for ultra-thin Parylene-C thicknesses of 10 nm as compared to a benchmark thickness of 100 nm (where such cells are known to grow well). Thus, our findings demonstrate that it is possible to culture primary rat neurons and glia to practically cell membrane thicknesses of Parylene-C. Being able to culture cells on such ultra thin levels of Parylene-C will open up the possibility to develop Multi-Electrode Arrays (MEA) that can capacitively couple embedded electrodes through the parylene to the cells on its surface. Thus, providing a neat, insulated passive electrode. Only the ultra-thin thicknesses of Parylene demonstrated here would allow for the rea isation of such a technology. Hence, the outcome of this work, will be of great interest to the Neuroengineering and the Multi-Electrode Array (MEA) community, as an alternative material for the fabric tion of passive electrodes, used in capacitive coupling mode.

  8. Simple and Inexpensive Paper-Based Astrocyte Co-culture to Improve Survival of Low-Density Neuronal Networks.

    Science.gov (United States)

    Aebersold, Mathias J; Thompson-Steckel, Greta; Joutang, Adriane; Schneider, Moritz; Burchert, Conrad; Forró, Csaba; Weydert, Serge; Han, Hana; Vörös, János

    2018-01-01

    Bottom-up neuroscience aims to engineer well-defined networks of neurons to investigate the functions of the brain. By reducing the complexity of the brain to achievable target questions, such in vitro bioassays better control experimental variables and can serve as a versatile tool for fundamental and pharmacological research. Astrocytes are a cell type critical to neuronal function, and the addition of astrocytes to neuron cultures can improve the quality of in vitro assays. Here, we present cellulose as an astrocyte culture substrate. Astrocytes cultured on the cellulose fiber matrix thrived and formed a dense 3D network. We devised a novel co-culture platform by suspending the easy-to-handle astrocytic paper cultures above neuronal networks of low densities typically needed for bottom-up neuroscience. There was significant improvement in neuronal viability after 5 days in vitro at densities ranging from 50,000 cells/cm 2 down to isolated cells at 1,000 cells/cm 2 . Cultures exhibited spontaneous spiking even at the very low densities, with a significantly greater spike frequency per cell compared to control mono-cultures. Applying the co-culture platform to an engineered network of neurons on a patterned substrate resulted in significantly improved viability and almost doubled the density of live cells. Lastly, the shape of the cellulose substrate can easily be customized to a wide range of culture vessels, making the platform versatile for different applications that will further enable research in bottom-up neuroscience and drug development.

  9. Simple and Inexpensive Paper-Based Astrocyte Co-culture to Improve Survival of Low-Density Neuronal Networks

    Directory of Open Access Journals (Sweden)

    Mathias J. Aebersold

    2018-02-01

    Full Text Available Bottom-up neuroscience aims to engineer well-defined networks of neurons to investigate the functions of the brain. By reducing the complexity of the brain to achievable target questions, such in vitro bioassays better control experimental variables and can serve as a versatile tool for fundamental and pharmacological research. Astrocytes are a cell type critical to neuronal function, and the addition of astrocytes to neuron cultures can improve the quality of in vitro assays. Here, we present cellulose as an astrocyte culture substrate. Astrocytes cultured on the cellulose fiber matrix thrived and formed a dense 3D network. We devised a novel co-culture platform by suspending the easy-to-handle astrocytic paper cultures above neuronal networks of low densities typically needed for bottom-up neuroscience. There was significant improvement in neuronal viability after 5 days in vitro at densities ranging from 50,000 cells/cm2 down to isolated cells at 1,000 cells/cm2. Cultures exhibited spontaneous spiking even at the very low densities, with a significantly greater spike frequency per cell compared to control mono-cultures. Applying the co-culture platform to an engineered network of neurons on a patterned substrate resulted in significantly improved viability and almost doubled the density of live cells. Lastly, the shape of the cellulose substrate can easily be customized to a wide range of culture vessels, making the platform versatile for different applications that will further enable research in bottom-up neuroscience and drug development.

  10. Concentration-dependent effects of fullerenol on cultured hippocampal neuron viability

    Directory of Open Access Journals (Sweden)

    Zha YY

    2012-06-01

    Full Text Available Ying-ying Zha,1 Bo Yang,1 Ming-liang Tang,2 Qiu-chen Guo,1 Ju-tao Chen,1 Long-ping Wen,3 Ming Wang11CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, 2Suzhou Institute of NanoTech and NanoBionics, Chinese Academy of Sciences, Suzhou, 3Laboratory of Nano-biology, School of Life Sciences, University of Science and Technology of China, Hefei, People's Republic of ChinaBackground: Recent studies have shown that the biological actions and toxicity of the water-soluble compound, polyhydroxyfullerene (fullerenol, are related to the concentrations present at a particular site of action. This study investigated the effects of different concentrations of fullerenol on cultured rat hippocampal neurons.Methods and results: Fullerenol at low concentrations significantly enhanced hippocampal neuron viability as tested by MTT assay and Hoechst 33342/propidium iodide double stain detection. At high concentrations, fullerenol induced apoptosis confirmed by Comet assay and assessment of caspase proteins.Conclusion: These findings suggest that fullerenol promotes cell death and protects against cell damage, depending on the concentration present. The concentration-dependent effects of fullerenol were mainly due to its influence on the reduction-oxidation pathway.Keywords: fullerenol, nanomaterial, neurotoxicity, neuroprotection, hippocampal neuron

  11. Humanin rescues cultured rat cortical neurons from NMDA-induced toxicity not by NMDA receptor.

    Science.gov (United States)

    Cui, Ai-Ling; Li, Jian-Zhong; Feng, Zhi-Bo; Ma, Guo-Lin; Gong, Liang; Li, Chun-Ling; Zhang, Ce; Li, Kefeng

    2014-01-01

    Excitatory neurotoxicity has been implicated in many pathological situations and there is no effective treatment available. Humanin is a 24-aa peptide cloned from the brain of patients with Alzheimer's disease (AD). In the present study, excitatory toxicity was induced by N-methyl-D-aspartate (NMDA) in primarily cultured rat cortical neurons. MTT assessment, lactate dehydrogenase (LDH) release, and calcein staining were employed to evaluate the protective activity of humanin on NMDA induced toxicity. The results suggested that NMDA (100 μmol/L, 2.5 hr) triggered neuronal morphological changes, lactate dehydrogenase (LDH) release (166% of the control), reduction of cell viability (about 50% of the control), and the decrease of living cell density (about 50% of the control). When pretreated with humanin, the toxicity was suppressed. The living cells' density of humanin treated group was similar to that of control. The cell viability was attenuated dose-dependently (IC50 = 0.132 nmol/L). The LDH release was also neutralized in a dose-dependent manner. In addition, the intracellular Ca(2+) overloading triggered by NMDA reverted quickly and humanin could not inhibit it. These findings indicate that humanin can rescue cortical neurons from NMDA-induced toxicity in rat but not through interfering with NMDA receptor directly.

  12. Humanin Rescues Cultured Rat Cortical Neurons from NMDA-Induced Toxicity Not by NMDA Receptor

    Directory of Open Access Journals (Sweden)

    Ai-Ling Cui

    2014-01-01

    Full Text Available Excitatory neurotoxicity has been implicated in many pathological situations and there is no effective treatment available. Humanin is a 24-aa peptide cloned from the brain of patients with Alzheimer’s disease (AD. In the present study, excitatory toxicity was induced by N-methyl-D-aspartate (NMDA in primarily cultured rat cortical neurons. MTT assessment, lactate dehydrogenase (LDH release, and calcein staining were employed to evaluate the protective activity of humanin on NMDA induced toxicity. The results suggested that NMDA (100 μmol/L, 2.5 hr triggered neuronal morphological changes, lactate dehydrogenase (LDH release (166% of the control, reduction of cell viability (about 50% of the control, and the decrease of living cell density (about 50% of the control. When pretreated with humanin, the toxicity was suppressed. The living cells’ density of humanin treated group was similar to that of control. The cell viability was attenuated dose-dependently (IC50 = 0.132 nmol/L. The LDH release was also neutralized in a dose-dependent manner. In addition, the intracellular Ca2+ overloading triggered by NMDA reverted quickly and humanin could not inhibit it. These findings indicate that humanin can rescue cortical neurons from NMDA-induced toxicity in rat but not through interfering with NMDA receptor directly.

  13. Cultured subventricular zone progenitor cells transduced with neurogenin-2 become mature glutamatergic neurons and integrate into the dentate gyrus.

    Directory of Open Access Journals (Sweden)

    Xia Chen

    Full Text Available We have previously shown that transplantation of immature DCX+/NeuN+/Prox1+ neurons (found in the neonatal DG, but not undifferentiated neuronal progenitor cells (NPCs from ventral subventricular zone (SVZ, results in neuronal maturation in vivo within the dentate niche. Here we investigated whether we could enhance the integration of SVZ NPCs by forced expression of the proneural gene Neurogenin 2 (NEUROG2. NPCs cultured from neonatal GFP-transgenic rat SVZ for 7 days in a non-differentiating medium were transduced with a retrovirus encoding NEUROG2 and DsRed or the DsRed reporter gene alone (control. By 3 days post-transduction, the NEUROG2-transduced cells maintained in culture contained mostly immature neurons (91% DCX+; 76% NeuN+, whereas the control virus-transduced cells remained largely undifferentiated (30% DCX+; <1% NeuN+. At 6 weeks following transplantation into the DG of adult male rats, there were no neurons among the transplanted cells treated with the control virus but the majority of the NEUROG2-transduced DsRed+ SVZ cells became mature neurons (92% NeuN+; DCX-negative. Although the NEUROG2-transduced SVZ cells did not express the dentate granule neuron marker Prox1, most of the NEUROG2-transduced SVZ cells (78% expressed the glutamatergic marker Tbr1, suggesting the acquisition of a glutamatergic phenotype. Moreover, some neurons extended dendrites into the molecular layer, grew axons containing Ankyrin G+ axonal initial segments, and projected into the CA3 region, thus resembling mature DG granule neurons. A proportion of NEUROG2 transduced cells also expressed c-Fos and P-CREB, two markers of neuronal activation. We conclude that NEUROG2-transduction is sufficient to promote neuronal maturation and integration of transplanted NPCs from SVZ into the DG.

  14. Inhibition of β-amyloid1-42 internalization attenuates neuronal death by stabilizing the endosomal-lysosomal system in rat cortical cultured neurons.

    Science.gov (United States)

    Song, M S; Baker, G B; Todd, K G; Kar, S

    2011-03-31

    A number of recent studies have indicated that accumulation of β amyloid (Aβ) peptides within neurons is an early event which may trigger degeneration of neurons and subsequent development of Alzheimer's disease (AD) pathology. However, very little is known about the internalization and/or subcellular sites involved in trafficking of Aβ peptides into the neurons that are vulnerable in AD pathology. To address this issue we evaluated internalization of fluoroscein conjugated Aβ1-42 (FAβ1-42) and subsequent alteration of endosomal-lysosomal (EL) markers such as cathepsin D, Rab5 and Rab7 in rat cortical cultured neurons. It is evident from our results that internalization of FAβ1-42, which occurred in a dose- and time-dependent manner, triggered degeneration of neurons along with increased levels and/or altered distribution of cathepsin D, Rab5 and Rab7. Our results further revealed that FAβ1-42 internalization was attenuated by phenylarsine oxide (a general inhibitor of endocytosis) and sucrose (an inhibitor of clathrin-mediated endocytosis) but not by antagonists of N-methyl-d-aspartate (NMDA) glutamate receptors. Additionally, inhibition of FAβ1-42 endocytosis not only protected neurons against toxicity but also reversed the altered levels/distributions of EL markers. These results, taken together, suggest that internalization of exogenous Aβ1-42, which is partly mediated via a clathrin-dependent process, can lead to degeneration of neurons, possibly by activating the EL system. Inhibition of FAβ endocytosis attenuated toxicity, thus suggesting a potential strategy for preventing loss of neurons in AD pathology. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Astrocyte-neuron co-culture on microchips based on the model of SOD mutation to mimic ALS.

    Science.gov (United States)

    Kunze, Anja; Lengacher, Sylvain; Dirren, Elisabeth; Aebischer, Patrick; Magistretti, Pierre J; Renaud, Philippe

    2013-07-24

    Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. ALS is believed to be a non-cell autonomous condition, as other cell types, including astrocytes, have been implicated in disease pathogenesis. Hence, to facilitate the development of therapeutics against ALS, it is crucial to better understand the interactions between astrocytes and neural cells. Furthermore, cell culture assays are needed that mimic the complexity of cell to cell communication at the same time as they provide control over the different microenvironmental parameters. Here, we aim to validate a previously developed microfluidic system for an astrocyte-neuron cell culture platform, in which astrocytes have been genetically modified to overexpress either a human wild-type (WT) or a mutated form of the super oxide dismutase enzyme 1 (SOD1). Cortical neural cells were co-cultured with infected astrocytes and studied for up to two weeks. Using our microfluidic device that prevents direct cell to cell contact, we could evaluate neural cell response in the vicinity of astrocytes. We showed that neuronal cell density was reduced by about 45% when neurons were co-cultured with SOD-mutant astrocytes. Moreover, we demonstrated that SOD-WT overexpressing astrocytes reduced oxidative stress on cortical neurons that were in close metabolic contact. In contrast, cortical neurons in metabolic contact with SOD-mutant astrocytes lost their synapsin protein expression after severe glutamate treatment, an indication of the toxicity potentiating effect of the SOD-mutant enzyme.

  16. Preparation of gene gun bullets and biolistic transfection of neurons in slice culture.

    Science.gov (United States)

    Woods, Georgia; Zito, Karen

    2008-02-13

    Biolistic transfection is a physical means of transfecting cells by bombarding tissue with high velocity DNA coated particles. We provide a detailed protocol for biolistic transfection of rat hippocampal slices, from the initial preparation of DNA coated bullets to the final shooting of the organotypic slice cultures using a gene gun. Gene gun transfection is an efficient and easy means of transfecting neurons and is especially useful for fluorescently labeling a small subset of cells in tissue slice. In this video, we first outline the steps required to coat gold particles with DNA. We next demonstrate how to line the inside of plastic tubing with the gold/DNA bullets, and how to cut this tubing to obtain the plastic cartridges for loading into the gene gun. Finally, we perform biolistic transfection of rat hippocampal slice cultures, demonstrating handling of the Bio-Rad Helios gene gun, and offering trouble shooting advice to obtain healthy and optimally transfected tissue slices.

  17. Additivity of Pyrethroid Actions on Sodium Influx in Cerebrocortical Neurons in Primary Culture

    Science.gov (United States)

    Cao, Zhengyu; Shafer, Timothy J.; Crofton, Kevin M.; Gennings, Chris

    2011-01-01

    Background: Pyrethroid insecticides bind to voltage-gated sodium channels and modify their gating kinetics, thereby disrupting neuronal function. Although previous work has tested the additivity of pyrethroids in vivo, this has not been assessed directly at the primary molecular target using a functional measure. Objectives: We investigated the potency and efficacy of 11 structurally diverse food-use pyrethroids to evoke sodium (Na+) influx in neurons and tested the hypothesis of dose additivity for a mixture of these same 11 compounds. Methods: We determined pyrethroid-induced increases in Na+ influx in primary cultures of cerebrocortical neurons using the Na+-sensitive dye sodium-binding benzofuran isophthalate (SBFI). Concentration-dependent responses for 11 pyrethroids were determined, and the response to dilutions of a mixture of all 11 compounds at an equimolar mixing ratio was assessed. Additivity was tested assuming a dose-additive model. Results: Seven pyrethroids produced concentration-dependent, tetrodotoxin-sensitive Na+ influx. The rank order of potency was deltamethrin > S-bioallethrin > β-cyfluthrin > λ-cyhalothrin > esfenvalerate > tefluthrin > fenpropathrin. Cypermethrin and bifenthrin produced modest increases in Na+ influx, whereas permethrin and resmethrin were inactive. When all 11 pyrethroids were present at an equimolar mixing ratio, their actions on Na+ influx were consistent with a dose-additive model. Conclusions: These data provide in vitro relative potency and efficacy measurements for 7 pyrethroid compounds in intact mammalian neurons. Despite differences in individual compound potencies, we found the action of a mixture of all 11 pyrethroids to be additive when we used an appropriate statistical model. These results are consistent with a previous report of the additivity of pyrethroids in vivo. PMID:21665567

  18. Rapid regulation of tonic GABA currents in cultured rat hippocampal neurons.

    Science.gov (United States)

    Ransom, Christopher B; Tao, Wucheng; Wu, Yuanming; Spain, William J; Richerson, George B

    2013-02-01

    Subacute and chronic changes in tonic GABAergic inhibition occur in human and experimental epilepsy. Less is known about how tonic inhibition is modulated over shorter time frames (seconds). We measured endogenous tonic GABA currents from cultured rat hippocampal neurons to evaluate how they are affected by 1) transient increases in extracellular GABA concentration ([GABA]), 2) transient postsynaptic depolarization, and 3) depolarization of presynaptic cells. Transient increases in [GABA] (1 μM) reduced tonic currents; this reduction resulted from GABA-induced shifts in the reversal potential for GABA currents (E(GABA)). Transient depolarization of postsynaptic neurons reversed the effects of exogenous GABA and potentiated tonic currents. The voltage-dependent potentiation of tonic GABA currents was independent of E(GABA) shifts and represented postdepolarization potentiation (PDP), an intrinsic GABA(A) receptor property (Ransom CB, Wu Y, Richerson GB. J Neurosci 30: 7672-7684, 2010). Inhibition of vesicular GABA release with concanamycin A (ConA) did not affect tonic currents. In ConA-treated cells, transient application of 12 mM K(+) to depolarize presynaptic neurons and glia produced a persistent increase in tonic current amplitude. The K(+)-induced increase in tonic current was reversibly inhibited by SKF89976a (40 μM), indicating that this was caused by nonvesicular GABA release from GABA transporter type 1 (GAT1). Nonvesicular GABA release due to GAT1 reversal also occurred in acute hippocampal brain slices. Our results indicate that tonic GABA currents are rapidly regulated by GABA-induced changes in intracellular Cl(-) concentration, PDP of extrasynaptic GABA(A) receptors, and nonvesicular GABA release. These mechanisms may influence tonic inhibition during seizures when neurons are robustly depolarized and extracellular GABA and K(+) concentrations are elevated.

  19. Chlorpyrifos exerts opposing effects on axonal and dendritic growth in primary neuronal cultures

    International Nuclear Information System (INIS)

    Howard, Angela S.; Bucelli, Robert; Jett, David A.; Bruun, Donald; Yang, Dongren; Lein, Pamela J.

    2005-01-01

    Evidence that children are widely exposed to organophosphorus pesticides (OPs) and that OPs cause developmental neurotoxicity in animal models raises significant concerns about the risks these compounds pose to the developing human nervous system. Critical to assessing this risk is identifying specific neurodevelopmental events targeted by OPs. Observations that OPs alter brain morphometry in developing rodents and inhibit neurite outgrowth in neural cell lines suggest that OPs perturb neuronal morphogenesis. However, an important question yet to be answered is whether the dysmorphogenic effect of OPs reflects perturbation of axonal or dendritic growth. We addressed this question by quantifying axonal and dendritic growth in primary cultures of embryonic rat sympathetic neurons derived from superior cervical ganglia (SCG) following in vitro exposure to chlorpyrifos (CPF) or its metabolites CPF-oxon (CPFO) and trichloropyridinol (TCP). Axon outgrowth was significantly inhibited by CPF or CPFO, but not TCP, at concentrations ≥0.001 μM or 0.001 nM, respectively. In contrast, all three compounds enhanced BMP-induced dendritic growth. Acetylcholinesterase was inhibited only by the highest concentrations of CPF (≥1 μM) and CPFO (≥1 nM); TCP had no effect on this parameter. In summary, these compounds perturb neuronal morphogenesis via opposing effects on axonal and dendritic growth, and both effects are independent of acetylcholinesterase inhibition. These findings have important implications for current risk assessment practices of using acetylcholinesterase inhibition as a biomarker of OP neurotoxicity and suggest that OPs may disrupt normal patterns of neuronal connectivity in the developing nervous system

  20. Multiple pathways of sigma(1) receptor ligand uptakes into primary cultured neuronal cells.

    Science.gov (United States)

    Yamamoto, H; Karasawa, J; Sagi, N; Takahashi, S; Horikomi, K; Okuyama, S; Nukada, T; Sora, I; Yamamoto, T

    2001-08-03

    Although many antipsychotics have affinities for sigma receptors, the transportation pathway of exogenous sigma(1) receptor ligands to intracellular type-1 sigma receptors are not fully understood. In this study, sigma(1) receptor ligand uptakes were studied using primary cultured neuronal cells. [(3)H](+)-pentazocine and [(3)H](R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate (MS-377), used as a selective sigma(1) receptor ligands, were taken up in a time-, energy- and temperature-dependent manner, suggesting that active transport mechanisms were involved in their uptakes. sigma(1) receptor ligands taken up into primary cultured neuronal cells were not restricted to agonists, but also concerned antagonists. The uptakes of these ligands were mainly Na(+)-independent. Kinetic analysis of [(3)H](+)-pentazocine and [(3)H]MS-377 uptake showed K(m) values (microM) of 0.27 and 0.32, and V(max) values (pmol/mg protein/min) of 17.4 and 9.4, respectively. Although both ligands were incorporated, the pharmacological properties of these two ligands were different. Uptake of [(3)H](+)-pentazocine was inhibited in the range 0.4-7.1 microM by all the sigma(1) receptor ligands used, including N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]ethylamine monohydrochloride (NE-100), a selective sigma(1) receptor ligand. In contrast, the inhibition of [(3)H]MS-377 uptake was potently inhibited by haloperidol, characterized by supersensitivity (IC(50), approximately 2 nM) and was inhibited by NE-100 with low sensitivity (IC(50), 4.5 microM). Moreover, kinetic analysis revealed that NE-100 inhibited [(3)H]MS-377 uptake in a noncompetitive manner, suggesting that NE-100 acted at a site different from the uptake sites of [(3)H]MS-377. These findings suggest that there are at least two uptake pathways for sigma(1) receptor ligands in primary cultured neuronal cells (i.e. a haloperidol-sensitive pathway and another, unclear, pathway). In

  1. Tissue plasminogen activator inhibits NMDA-receptor-mediated increases in calcium levels in cultured hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Samuel D Robinson

    2015-10-01

    Full Text Available NMDA receptors (NMDARs play a critical role in neurotransmission, acting as essential mediators of many forms of synaptic plasticity, and also modulating aspects of development, synaptic transmission and cell death. NMDAR-induced responses are dependent on a range of factors including subunit composition and receptor location. Tissue-type plasminogen activator (tPA is a serine protease that has been reported to interact with NMDARs and modulate NMDAR activity. In this study we report that tPA inhibits NMDAR-mediated changes in intracellular calcium levels in cultures of primary hippocampal neurons stimulated by low (5 μM but not high (50 μM concentrations of NMDA. tPA also inhibited changes in calcium levels stimulated by presynaptic release of glutamate following treatment with bicucculine/4-AP. Inhibition was dependent on the proteolytic activity of tPA but was unaffected by α2-antiplasmin, an inhibitor of the tPA substrate plasmin, and RAP, a pan-ligand blocker of the low-density lipoprotein receptor, two proteins previously reported to modulate NMDAR activity. These findings suggest that tPA can modulate changes in intracellular calcium levels in a subset of NMDARs expressed in cultured embryonic hippocampal neurons through a mechanism that involves the proteolytic activity of tPA and synaptic NMDARs.

  2. Neuroprotective effect of the endogenous neural peptide apelin in cultured mouse cortical neurons

    International Nuclear Information System (INIS)

    Zeng, Xiang Jun; Yu, Shan Ping; Zhang, Like; Wei, Ling

    2010-01-01

    The adipocytokine apelin and its G protein-coupled APJ receptor were initially isolated from a bovine stomach and have been detected in the brain and cardiovascular system. Recent studies suggest that apelin can protect cardiomyocytes from ischemic injury. Here, we investigated the effect of apelin on apoptosis in mouse primary cultures of cortical neurons. Exposure of the cortical cultures to a serum-free medium for 24 h induced nuclear fragmentation and apoptotic death; apelin-13 (1.0-5.0 nM) markedly prevented the neuronal apoptosis. Apelin neuroprotective effects were mediated by multiple mechanisms. Apelin-13 reduced serum deprivation (SD)-induced ROS generation, mitochondria depolarization, cytochrome c release and activation of caspase-3. Apelin-13 prevented SD-induced changes in phosphorylation status of Akt and ERK1/2. In addition, apelin-13 attenuated NMDA-induced intracellular Ca 2+ accumulation. These results indicate that apelin is an endogenous neuroprotective adipocytokine that may block apoptosis and excitotoxic death via cellular and molecular mechanisms. It is suggested that apelins may be further explored as a potential neuroprotective reagent for ischemia-induced brain damage.

  3. Neuroprotective effect of the endogenous neural peptide apelin in cultured mouse cortical neurons

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xiang Jun [Department of Pathophysiology, Capital Medical University, Beijing 100069 (China); Department of Anesthesiology, 101 Woodruff Circle, Suite 617, Emory University School of Medicine, Atlanta, GA 30322 (United States); Yu, Shan Ping [Department of Anesthesiology, 101 Woodruff Circle, Suite 617, Emory University School of Medicine, Atlanta, GA 30322 (United States); Zhang, Like [Department of Pathophysiology, Capital Medical University, Beijing 100069 (China); Wei, Ling, E-mail: lwei7@emory.edu [Department of Anesthesiology, 101 Woodruff Circle, Suite 617, Emory University School of Medicine, Atlanta, GA 30322 (United States)

    2010-07-01

    The adipocytokine apelin and its G protein-coupled APJ receptor were initially isolated from a bovine stomach and have been detected in the brain and cardiovascular system. Recent studies suggest that apelin can protect cardiomyocytes from ischemic injury. Here, we investigated the effect of apelin on apoptosis in mouse primary cultures of cortical neurons. Exposure of the cortical cultures to a serum-free medium for 24 h induced nuclear fragmentation and apoptotic death; apelin-13 (1.0-5.0 nM) markedly prevented the neuronal apoptosis. Apelin neuroprotective effects were mediated by multiple mechanisms. Apelin-13 reduced serum deprivation (SD)-induced ROS generation, mitochondria depolarization, cytochrome c release and activation of caspase-3. Apelin-13 prevented SD-induced changes in phosphorylation status of Akt and ERK1/2. In addition, apelin-13 attenuated NMDA-induced intracellular Ca{sup 2+} accumulation. These results indicate that apelin is an endogenous neuroprotective adipocytokine that may block apoptosis and excitotoxic death via cellular and molecular mechanisms. It is suggested that apelins may be further explored as a potential neuroprotective reagent for ischemia-induced brain damage.

  4. Time-dependent Increase in the Network Response to the Stimulation of Neuronal Cell Cultures on Micro-electrode Arrays.

    Science.gov (United States)

    Gertz, Monica L; Baker, Zachary; Jose, Sharon; Peixoto, Nathalia

    2017-05-29

    Micro-electrode arrays (MEAs) can be used to investigate drug toxicity, design paradigms for next-generation personalized medicine, and study network dynamics in neuronal cultures. In contrast with more traditional methods, such as patch-clamping, which can only record activity from a single cell, MEAs can record simultaneously from multiple sites in a network, without requiring the arduous task of placing each electrode individually. Moreover, numerous control and stimulation configurations can be easily applied within the same experimental setup, allowing for a broad range of dynamics to be explored. One of the key dynamics of interest in these in vitro studies has been the extent to which cultured networks display properties indicative of learning. Mouse neuronal cells cultured on MEAs display an increase in response following training induced by electrical stimulation. This protocol demonstrates how to culture neuronal cells on MEAs; successfully record from over 95% of the plated dishes; establish a protocol to train the networks to respond to patterns of stimulation; and sort, plot, and interpret the results from such experiments. The use of a proprietary system for stimulating and recording neuronal cultures is demonstrated. Software packages are also used to sort neuronal units. A custom-designed graphical user interface is used to visualize post-stimulus time histograms, inter-burst intervals, and burst duration, as well as to compare the cellular response to stimulation before and after a training protocol. Finally, representative results and future directions of this research effort are discussed.

  5. Immunocytochemistry and fluorescence imaging efficiently identify individual neurons with CRISPR/Cas9-mediated gene disruption in primary cortical cultures.

    Science.gov (United States)

    Tsunematsu, Hiroto; Uyeda, Akiko; Yamamoto, Nobuhiko; Sugo, Noriyuki

    2017-08-01

    CRISPR/Cas9 system is a powerful method to investigate the role of genes by introducing a mutation selectively and efficiently to specific genome positions in cell and animal lines. However, in primary neuron cultures, this method is affected by the issue that the effectiveness of CRISPR/Cas9 is different in each neuron. Here, we report an easy, quick and reliable method to identify mutants induced by the CRISPR/Cas9 system at a single neuron level, using immunocytochemistry (ICC) and fluorescence imaging. Dissociated cortical cells were transfected with CRISPR/Cas9 plasmids targeting the transcription factor cAMP-response element binding protein (CREB). Fluorescence ICC with CREB antibody and quantitative analysis of fluorescence intensity demonstrated that CREB expression disappeared in a fraction of the transfected neurons. The downstream FOS expression was also decreased in accordance with suppressed CREB expression. Moreover, dendritic arborization was decreased in the transfected neurons which lacked CREB immunoreactivity. Detection of protein expression is efficient to identify individual postmitotic neurons with CRISPR/Cas9-mediated gene disruption in primary cortical cultures. The present method composed of CRISPR/Cas9 system, ICC and fluorescence imaging is applicable to study the function of various genes at a single-neuron level.

  6. Ginsenoside Rg1 protects against neurodegeneration by inducing neurite outgrowth in cultured hippocampal neurons.

    Science.gov (United States)

    Huang, Liang; Liu, Li-Feng; Liu, Juan; Dou, Ling; Wang, Ge-Ying; Liu, Xiao-Qing; Yuan, Qiong-Lan

    2016-02-01

    Ginsenoside Rg1 (Rg1) has anti-aging and anti-neurodegenerative effects. However, the mechanisms underlying these actions remain unclear. The aim of the present study was to determine whether Rg1 affects hippocampal survival and neurite outgrowth in vitro after exposure to amyloid-beta peptide fragment 25-35 (Aβ25-35), and to explore whether the extracellular signal-regulated kinase (ERK) and Akt signaling pathways are involved in these biological processes. We cultured hippocampal neurons from newborn rats for 24 hours, then added Rg1 to the medium for another 24 hours, with or without pharmacological inhibitors of the mitogen-activated protein kinase (MAPK) family or Akt signaling pathways for a further 24 hours. We then immunostained the neurons for growth associated protein-43, and measured neurite length. In a separate experiment, we exposed cultured hippocampal neurons to Aβ25-35 for 30 minutes, before adding Rg1 for 48 hours, with or without Akt or MAPK inhibitors, and assessed neuronal survival using Hoechst 33258 staining, and phosphorylation of ERK1/2 and Akt by western blot analysis. Rg1 induced neurite outgrowth, and this effect was blocked by API-2 (Akt inhibitor) and PD98059 (MAPK/ERK kinase inhibitor), but not by SP600125 or SB203580 (inhibitors of c-Jun N-terminal kinase and p38 MAPK, respectively). Consistent with this effect, Rg1 upregulated the phosphorylation of Akt and ERK1/2; these effects were reversed by API-2 and PD98059, respectively. In addition, Rg1 significantly reversed Aβ25-35-induced apoptosis; this effect was blocked by API-2 and PD98059, but not by SP600125 or SB203580. Finally, Rg1 significantly reversed the Aβ25-35-induced decrease in Akt and ERK1/2 phosphorylation, but API-2 prevented this reversal. Our results indicate that Rg1 enhances neurite outgrowth and protects against Aβ25-35-induced damage, and that its mechanism may involve the activation of Akt and ERK1/2 signaling.

  7. Dexamethasone enhances glutamine synthetase activity and reduces N-methyl-D-aspartate neurotoxicity in mixed cultures of neurons and astrocytes

    Directory of Open Access Journals (Sweden)

    Edith Debroas

    2015-05-01

    Full Text Available Astrocytes are claimed to protect neurons against excitotoxicity by clearing glutamate from the extracellular space and rapidly converting it into glutamine. Glutamine, is then released into the extracellular medium, taken up by neurons and transformed back into glutamate which is then stored into synaptic vesicles. Glutamine synthetase (GS, the key enzyme that governs this glutamate/glutamine cycle, is known to be upregulated by glucocorticoids. In the present work we have thus studied in parallel the effects of dexamethasone on glutamine synthetase activity and NMDA-induced neuronal death in cultures derived from the brain cortex of murine embryos. We showed that dexamethasone was able to markedly enhance GS activity in cultures of astrocytes but not in near pure neuronal cultures. The pharmacological characteristics of the dexamethasone action strongly suggest that it corresponds to a typical receptor-mediated effect. We also observed that long lasting incubation (72 h of mixed astrocyte-neuron cultures in the presence of 100 nM dexamethasone significantly reduced the toxicity of NMDA treatment. Furthermore we demonstrated that methionine sulfoximine, a selective inhibitor of GS, abolished the dexamethasone-induced increase in GS activity and also markedly potentiated NMDA toxicity. Altogether these results suggest that dexamethasone may promote neuroprotection through a stimulation of astrocyte glutamine synthetase.

  8. Protein fingerprints of cultured CA3-CA1 hippocampal neurons: comparative analysis of the distribution of synaptosomal and cytosolic proteins

    Directory of Open Access Journals (Sweden)

    Cerutti Sergio

    2008-04-01

    Full Text Available Abstract Background All studies aimed at understanding complex molecular changes occurring at synapses face the problem of how a complete view of the synaptic proteome and of its changes can be efficiently met. This is highly desirable when synaptic plasticity processes are analyzed since the structure and the biochemistry of neurons and synapses get completely reshaped. Because most molecular studies of synapses are nowadays mainly or at least in part based on protein extracts from neuronal cultures, this is not a feasible option: these simplified versions of the brain tissue on one hand provide an homogeneous pure population of neurons but on the other yield only tiny amounts of proteins, many orders of magnitude smaller than conventional brain tissue. As a way to overcome this limitation and to find a simple way to screen for protein changes at cultured synapses, we have produced and characterized two dimensional electrophoresis (2DE maps of the synaptic proteome of CA3-CA1 hippocampal neurons in culture. Results To obtain 2D maps, hippocampal cultures were mass produced and after synaptic maturation, proteins were extracted following subfractionation procedures and separated by 2D gel electrophoresis. Similar maps were obtained for the crude cytosol of cultured neurons and for synaptosomes purified from CA3-CA1 hippocampal tissue. To efficiently compare these different maps some clearly identifiable reference points were molecularly identified by mass spectrometry and immunolabeling methods. This information was used to run a differential analysis and establish homologies and dissimilarities in these 2D protein profiles. Conclusion Because reproducible fingerprints of cultured synapses were clearly obtained, we believe that our mapping effort could represent a simple tool to screen for protein expression and/or protein localization changes in CA3-CA1 hippocampal neurons following plasticity.

  9. Design, Surface Treatment, Cellular Plating, and Culturing of Modular Neuronal Networks Composed of Functionally Inter-connected Circuits.

    Science.gov (United States)

    Kanner, Sivan; Bisio, Marta; Cohen, Gilad; Goldin, Miri; Tedesco, Marieteresa; Hanein, Yael; Ben-Jacob, Eshel; Barzilai, Ari; Chiappalone, Michela; Bonifazi, Paolo

    2015-04-15

    The brain operates through the coordinated activation and the dynamic communication of neuronal assemblies. A major open question is how a vast repertoire of dynamical motifs, which underlie most diverse brain functions, can emerge out of a fixed topological and modular organization of brain circuits. Compared to in vivo studies of neuronal circuits which present intrinsic experimental difficulties, in vitro preparations offer a much larger possibility to manipulate and probe the structural, dynamical and chemical properties of experimental neuronal systems. This work describes an in vitro experimental methodology which allows growing of modular networks composed by spatially distinct, functionally interconnected neuronal assemblies. The protocol allows controlling the two-dimensional (2D) architecture of the neuronal network at different levels of topological complexity. A desired network patterning can be achieved both on regular cover slips and substrate embedded micro electrode arrays. Micromachined structures are embossed on a silicon wafer and used to create biocompatible polymeric stencils, which incorporate the negative features of the desired network architecture. The stencils are placed on the culturing substrates during the surface coating procedure with a molecular layer for promoting cellular adhesion. After removal of the stencils, neurons are plated and they spontaneously redirected to the coated areas. By decreasing the inter-compartment distance, it is possible to obtain either isolated or interconnected neuronal circuits. To promote cell survival, cells are co-cultured with a supporting neuronal network which is located at the periphery of the culture dish. Electrophysiological and optical recordings of the activity of modular networks obtained respectively by using substrate embedded micro electrode arrays and calcium imaging are presented. While each module shows spontaneous global synchronizations, the occurrence of inter-module synchronization

  10. Neuroprotective effect of adenoviral catalase gene transfer in cortical neuronal cultures.

    Science.gov (United States)

    Gáspár, Tamás; Domoki, Ferenc; Lenti, Laura; Institoris, Adám; Snipes, James A; Bari, Ferenc; Busija, David W

    2009-05-13

    Reduced availability of reactive oxygen species is a key component of neuroprotection against various toxic stimuli. Recently we showed that the hydrogen peroxide scavenger catalase plays a central role in delayed preconditioning induced by the mitochondrial ATP-sensitive potassium channel opener BMS-191095. The purpose of the experiments discussed here was to investigate the neuroprotective effect of catalase in vitro using a recombinant adenoviral catalase gene transfer protocol. To induce catalase overexpression, cultured rat cortical neurons were infected with the adenoviral vector Ad5CMVcatalase and control cells were incubated with Ad5CMVntLacZ for 24 h. Gene transfer effectively increased catalase protein levels and activity, but did not influence other antioxidants tested. Ad5CMVcatalase, with up to 10 plaque forming units (pfu) per neuron, did not affect cell viability under control conditions and did not protect against glutamate excitotoxicity or oxygen-glucose deprivation. In contrast, catalase overexpression conferred a dose-dependent protection against exposure to hydrogen peroxide (viability: control, 33.02+/-1.09%; LacZ 10 pfu/cell, 32.85+/-1.51%; catalase 1 pfu/cell, 62.09+/-4.17%*; catalase 2 pfu/cell, 98.71+/-3.35%*; catalase 10 pfu/cell, 99.68+/-1.99%*; *pcatalase inhibitor 3-aminotriazole. Our results support the view that enhancing cellular antioxidant capacity may play a crucial role in neuroprotective strategies.

  11. Phenolic Compounds Protect Cultured Hippocampal Neurons against Ethanol-Withdrawal Induced Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Marianna E. Jung

    2009-04-01

    Full Text Available Ethanol withdrawal is linked to elevated oxidative damage to neurons. Here we report our findings on the contribution of phenolic antioxidants (17β-estradiol, p-octyl-phenol and 2,6-di-tert-butyl-4-methylphenol to counterbalance sudden ethanol withdrawal-initiated oxidative events in hippocampus-derived cultured HT-22 cells. We showed that ethanol withdrawal for 4 h after 24-h ethanol treatment provoked greater levels of oxidative damage than the preceding ethanol exposure. Phenolic antioxidant treatment either during ethanol exposure or ethanol withdrawal only, however, dose-dependently reversed cellular oxidative damage, as demonstrated by the significantly enhanced cell viability, reduced malondialdehyde production and protein carbonylation, compared to untreated cells. Interestingly, the antioxidant treatment schedule had no significant impact on the observed neuroprotection. In addition, the efficacy of the three phenolic compounds was practically equipotent in protecting HT-22 cells in spite of predictions based on an in silico study and a cell free assay of lipid peroxidation. This finding implies that free-radical scavenging may not be the sole factor responsible for the observed neuroprotection and warrants further studies to establish, whether the HT-22 line is indeed a suitable model for in vitro screening of antioxidants against EW-related neuronal damage.

  12. Localization and pharmacological characterization of voltage dependent calcium channels in cultured neocortical neurons

    DEFF Research Database (Denmark)

    Timmermann, D B; Lund, Trine Meldgaard; Belhage, B

    2001-01-01

    The physiological significance and subcellular distribution of voltage dependent calcium channels was defined using calcium channel blockers to inhibit potassium induced rises in cytosolic calcium concentration in cultured mouse neocortical neurons. The cytosolic calcium concentration was measured...... channels were differentially distributed in somata, neurites and nerve terminals. omega-conotoxin MVIIC (omega-CgTx MVIIC) inhibited approximately 40% of the Ca(2+)-rise in both somata and neurites and 60% of the potassium induced [3H]GABA release, indicating that the Q-type channel is the quantitatively...... using the fluorescent calcium chelator fura-2. The types of calcium channels present at the synaptic terminal were determined by the inhibitory action of calcium channel blockers on potassium-induced [3H]GABA release in the same cell preparation. L-, N-, P-, Q- and R-/T-type voltage dependent calcium...

  13. Glutamate stimulates the formation of N-acylphosphatidylethanolamine in cortical neurons in culture

    DEFF Research Database (Denmark)

    Hansen, Harald S.; Lauritzen, L.; Strand, A.M.

    1995-01-01

    The formation of anandamide (N-arachidonoylethanolamine), N-acylethanolamine, and N-acylphosphatidylethanolamine was studied in primary cultures of rat cortical neurons. The cells were incubated for 22 h with [C]ethanolamine, [U-C]arachidonic acid, [H]arachidonic acid, [P]phosphate, [C]stearic acid......-acylethanolamine. Compound I could be labelled with [C]stearic acid and [H]myristic acid, but not with [H]- or [C]arachidonic acid. Exogenous [H]anandamide was metabolised with a t( 1/2 ) of 2.6 h. The labelling of the two compounds identified as N-acylethanolamine and N-acylphosphatidylethanolamine were more pronounced......, or [H]myristic acid. The lipids from the cells and media were separated by thin layer chromatography. [C]Ethanolamine labelling revealed two compounds (I and II), which on different thin layer chromatography systems migrated as N-acylethanolamine (0.06-0.55% of total radioactivity) and N...

  14. Novel cell separation method for molecular analysis of neuron-astrocyte co-cultures

    OpenAIRE

    Goudriaan, Andrea; Camargo, Nutabi; Carney, Karen E.; Oliet, Stéphane H. R.; Smit, August B.; Verheijen, Mark H. G.

    2014-01-01

    Over the last decade, the importance of astrocyte-neuron communication in neuronal development and synaptic plasticity has become increasingly clear. Since neuron-astrocyte interactions represent highly dynamic and reciprocal processes, we hypothesized that many astrocyte genes may be regulated as a consequence of their interactions with maturing neurons. In order to identify such neuron-responsive astrocyte genes in vitro, we sought to establish an expedited technique for separation of neuro...

  15. Neurotoxicity of coral snake phospholipases A2 in cultured rat hippocampal neurons.

    Science.gov (United States)

    de Carvalho, Nathalia Delazeri; Garcia, Raphael CaioTamborelli; Ferreira, Adilson Kleber; Batista, Daniel Rodrigo; Cassola, Antonio Carlos; Maria, Durvanei; Lebrun, Ivo; Carneiro, Sylvia Mendes; Afeche, Solange Castro; Marcourakis, Tania; Sandoval, Maria Regina Lopes

    2014-03-13

    The neurotoxicity of two secreted Phospholipases A2 from Brazilian coral snake venom in rat primary hippocampal cell culture was investigated. Following exposure to Mlx-8 or Mlx-9 toxins, an increase in free cytosolic Ca(2+) and a reduction in mitochondrial transmembrane potential (ΔΨm) became evident and occurred prior to the morphological changes and cytotoxicity. Exposure of hippocampal neurons to Mlx-8 or Mlx-9 caused a decrease in the cell viability as assessed by MTT and LDH assays. Inspection using fluorescent images and ultrastructural analysis by scanning and transmission electron microscopy showed that multiphase injury is characterized by overlapping cell death phenotypes. Shrinkage, membrane blebbing, chromatin condensation, nucleosomal DNA fragmentation and the formation of apoptotic bodies were observed. The most striking alteration observed in the electron microscopy was the fragmentation and rarefaction of the neuron processes network. Degenerated terminal synapses, cell debris and apoptotic bodies were observed among the fragmented fibers. Numerous large vacuoles as well as swollen mitochondria and dilated Golgi were noted. Necrotic signs such as a large amount of cellular debris and membrane fragmentation were observed mainly when the cells were exposed to highest concentration of the PLA2-neurotoxins. PLA2s exposed cultures showed cytoplasmic vacuoles filled with cell debris, clusters of mitochondria presented mitophagy-like structures that are in accordance to patterns of programmed cell death by autophagy. Finally, we demonstrated that the sPLA2s, Mlx-8 and Mlx-9, isolated from the Micrurus lemniscatus snake venom induce a hybrid cell death with apoptotic, autophagic and necrotic features. Furthermore, this study suggests that the augment in free cytosolic Ca(2+) and mitochondrial dysfunction are involved in the neurotoxicity of Elapid coral snake venom sPLA2s. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Full Length Bid is sufficient to induce apoptosis of cultured rat hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Ward Manus W

    2007-02-01

    Full Text Available Abstract Background Bcl-2 homology domain (BH 3-only proteins are pro-apoptotic proteins of the Bcl-2 family that couple stress signals to the mitochondrial cell death pathways. The BH3-only protein Bid can be activated in response to death receptor activation via caspase 8-mediated cleavage into a truncated protein (tBid, which subsequently translocates to mitochondria and induces the release of cytochrome-C. Using a single-cell imaging approach of Bid cleavage and translocation during apoptosis, we have recently demonstrated that, in contrast to death receptor-induced apoptosis, caspase-independent excitotoxic apoptosis involves a translocation of full length Bid (FL-Bid from the cytosol to mitochondria. We induced a delayed excitotoxic cell death in cultured rat hippocampal neurons by a 5-min exposure to the glutamate receptor agonist N-methyl-D-aspartate (NMDA; 300 μM. Results Western blot experiments confirmed a translocation of FL-Bid to the mitochondria during excitotoxic apoptosis that was associated with the release of cytochrome-C from mitochondria. These results were confirmed by immunofluorescence analysis of Bid translocation during excitotoxic cell death using an antibody raised against the amino acids 1–58 of mouse Bid that is not able to detect tBid. Finally, inducible overexpression of FL-Bid or a Bid mutant that can not be cleaved by caspase-8 was sufficient to induce apoptosis in the hippocampal neuron cultures. Conclusion Our data suggest that translocation of FL-Bid is sufficient for the activation of mitochondrial cell death pathways in response to glutamate receptor overactivation.

  17. DIDS prevents ischemic membrane degradation in cultured hippocampal neurons by inhibiting matrix metalloproteinase release.

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    Matthew E Pamenter

    Full Text Available During stroke, cells in the infarct core exhibit rapid failure of their permeability barriers, which releases ions and inflammatory molecules that are deleterious to nearby tissue (the penumbra. Plasma membrane degradation is key to penumbral spread and is mediated by matrix metalloproteinases (MMPs, which are released via vesicular exocytosis into the extracellular fluid in response to stress. DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid preserves membrane integrity in neurons challenged with an in vitro ischemic penumbral mimic (ischemic solution: IS and we asked whether this action was mediated via inhibition of MMP activity. In cultured murine hippocampal neurons challenged with IS, intracellular proMMP-2 and -9 expression increased 4-10 fold and extracellular latent and active MMP isoform expression increased 2-22 fold. MMP-mediated extracellular gelatinolytic activity increased ∼20-50 fold, causing detachment of 32.1±4.5% of cells from the matrix and extensive plasma membrane degradation (>60% of cells took up vital dyes and >60% of plasma membranes were fragmented or blebbed. DIDS abolished cellular detachment and membrane degradation in neurons and the pathology-induced extracellular expression of latent and active MMPs. DIDS similarly inhibited extracellular MMP expression and cellular detachment induced by the pro-apoptotic agent staurosporine or the general proteinase agonist 4-aminophenylmercuric acetate (APMA. Conversely, DIDS-treatment did not impair stress-induced intracellular proMMP production, nor the intracellular cleavage of proMMP-2 to the active form, suggesting DIDS interferes with the vesicular extrusion of MMPs rather than directly inhibiting proteinase expression or activation. In support of this hypothesis, an antagonist of the V-type vesicular ATPase also inhibited extracellular MMP expression to a similar degree as DIDS. In addition, in a proteinase-independent model of vesicular exocytosis, DIDS

  18. Green Tea Polyphenols Attenuated Glutamate Excitotoxicity via Antioxidative and Antiapoptotic Pathway in the Primary Cultured Cortical Neurons.

    Science.gov (United States)

    Cong, Lin; Cao, Chang; Cheng, Yong; Qin, Xiao-Yan

    2016-01-01

    Green tea polyphenols are a natural product which has antioxidative and antiapoptotic effects. It has been shown that glutamate excitotoxicity induced oxidative stress is linked to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In this study we explored the neuroprotective effect of green teen polyphenols against glutamate excitotoxicity in the primary cultured cortical neurons. We found that green tea polyphenols protected against glutamate induced neurotoxicity in the cortical neurons as measured by MTT and TUNEL assays. Green tea polyphenols were then showed to inhibit the glutamate induced ROS release and SOD activity reduction in the neurons. Furthermore, our results demonstrated that green tea polyphenols restored the dysfunction of mitochondrial pro- or antiapoptotic proteins Bax, Bcl-2, and caspase-3 caused by glutamate. Interestingly, the neuroprotective effect of green tea polyphenols was abrogated when the neurons were incubated with siBcl-2. Taken together, these results demonstrated that green tea polyphenols protected against glutamate excitotoxicity through antioxidative and antiapoptotic pathways.

  19. Generation of Otic Sensory Neurons from Mouse Embryonic Stem Cells in 3D Culture

    Directory of Open Access Journals (Sweden)

    Michael Perny

    2017-12-01

    Full Text Available The peripheral hearing process taking place in the cochlea mainly depends on two distinct sensory cell types: the mechanosensitive hair cells and the spiral ganglion neurons (SGNs. The first respond to the mechanical stimulation exerted by sound pressure waves on their hair bundles by releasing neurotransmitters and thereby activating the latter. Loss of these sensorineural cells is associated with permanent hearing loss. Stem cell-based approaches aiming at cell replacement or in vitro drug testing to identify potential ototoxic, otoprotective, or regenerative compounds have lately gained attention as putative therapeutic strategies for hearing loss. Nevertheless, they rely on efficient and reliable protocols for the in vitro generation of cochlear sensory cells for their implementation. To this end, we have developed a differentiation protocol based on organoid culture systems, which mimics the most important steps of in vivo otic development, robustly guiding mouse embryonic stem cells (mESCs toward otic sensory neurons (OSNs. The stepwise differentiation of mESCs toward ectoderm was initiated using a quick aggregation method in presence of Matrigel in serum-free conditions. Non-neural ectoderm was induced via activation of bone morphogenetic protein (BMP signaling and concomitant inhibition of transforming growth factor beta (TGFβ signaling to prevent mesendoderm induction. Preplacodal and otic placode ectoderm was further induced by inhibition of BMP signaling and addition of fibroblast growth factor 2 (FGF2. Delamination and differentiation of SGNs was initiated by plating of the organoids on a 2D Matrigel-coated substrate. Supplementation with brain-derived neurotrophic factor (BDNF and neurotrophin-3 (NT-3 was used for further maturation until 15 days of in vitro differentiation. A large population of neurons with a clear bipolar morphology and functional excitability was derived from these cultures. Immunostaining and gene expression

  20. A Non-Destructive Culturing and Cell Sorting Method for Cardiomyocytes and Neurons Using a Double Alginate Layer

    Science.gov (United States)

    Terazono, Hideyuki; Kim, Hyonchol; Hayashi, Masahito; Hattori, Akihiro; Nomura, Fumimasa; Kaneko, Tomoyuki; Yasuda, Kenji

    2012-01-01

    A non-destructive method of collecting cultured cells after identifying their in situ functional characteristics is proposed. In this method, cells are cultivated on an alginate layer in a culture dish and released by spot application of a calcium chelate buffer that locally melts the alginate layer and enables the collection of cultured cells at the single-cell level. Primary hippocampal neurons, beating human embryonic stem (hES) cell-derived cardiomyocytes, and beating hES cell-derived cardiomyocyte clusters cultivated on an alginate layer were successfully released and collected with a micropipette. The collected cells were recultured while maintaining their physiological function, including beating, and elongated neurites. These results suggest that the proposed method may eventually facilitate the transplantation of ES- or iPS-derived cardiomyocytes and neurons differentiated in culture. PMID:22870332

  1. A non-destructive culturing and cell sorting method for cardiomyocytes and neurons using a double alginate layer.

    Directory of Open Access Journals (Sweden)

    Hideyuki Terazono

    Full Text Available A non-destructive method of collecting cultured cells after identifying their in situ functional characteristics is proposed. In this method, cells are cultivated on an alginate layer in a culture dish and released by spot application of a calcium chelate buffer that locally melts the alginate layer and enables the collection of cultured cells at the single-cell level. Primary hippocampal neurons, beating human embryonic stem (hES cell-derived cardiomyocytes, and beating hES cell-derived cardiomyocyte clusters cultivated on an alginate layer were successfully released and collected with a micropipette. The collected cells were recultured while maintaining their physiological function, including beating, and elongated neurites. These results suggest that the proposed method may eventually facilitate the transplantation of ES- or iPS-derived cardiomyocytes and neurons differentiated in culture.

  2. Biosynthesis of the D2 cell adhesion molecule: pulse-chase studies in cultured fetal rat neuronal cells

    DEFF Research Database (Denmark)

    Lyles, J M; Norrild, B; Bock, E

    1984-01-01

    D2 is a membrane glycoprotein that is believed to function as a cell adhesion molecule (CAM) in neural cells. We have examined its biosynthesis in cultured fetal rat brain neurones. We found D2-CAM to be synthesized initially as two polypeptides: Mr 186,000 (A) and Mr 136,000 (B). With increasing...

  3. 125I-labelled tetanus toxin as a neuronal marker in tissue cultures derived from embryonic CNS

    International Nuclear Information System (INIS)

    Dimpfel, W.; Neale, J.H.; Habermann, E.; National Inst. of Child Health and Human Development, Bethesda, Md.

    1975-01-01

    Primary cultures derived from embryonic mouse brain and spinal cord were exposed to 125 I-labelled tetanus toxin and subjected to autoradioraphy. Cells with neuronal, bur not glial, morphology selectively accumulated the toxin. The distribution of the grains over these cells and their processes was not uniform, discrete processes showing heavier labelling. (orig.) [de

  4. EFFECTS OF THALLIUM SALTS ON NEURONAL MITOCHONDRIA IN ORGANOTYPIC CORD-GANGLIA-MUSCLE COMBINATION CULTURES

    Science.gov (United States)

    Spencer, Peter S.; Peterson, Edith R.; Madrid A., Ricardo; Raine, Cedric S.

    1973-01-01

    A functionally coupled organotypic complex of cultured dorsal root ganglia, spinal cord peripheral nerve, and muscle has been employed in an experimental approach to the investigation of the neurotoxic effects of thallium. Selected cultures, grown for up to 12 wk in vitro, were exposed to thallous salts for periods ranging up to 4 days. Cytopathic effects were first detected after 2 h of exposure with the appearance of considerably enlarged mitochondria in axons of peripheral nerve fibers. With time, the matrix space of these mitochondria became progressively swollen, transforming the organelle into an axonal vacuole bounded by the original outer mitochondrial membrane. Coalescence of adjacent axonal vacuoles produced massive internal axon compartments, the membranes of which were shown by electron microprobe mass spectrometry to have an affinity for thallium. Other axoplasmic components were displaced within a distended but intact axolemma. The resultant fiber swelling caused myelin retraction from nodes of Ranvier but no degeneration. Impulses could still propagate along the nerve fibers throughout the time course of the experiment. Comparable, but less severe changes were seen in dorsal root ganglion neurons and in central nerve fibers. Other cell types showed no mitochondrial change. It is uncertain how these findings relate to the neurotoxic effects of thallium in vivo, but a sensitivity of the nerve cell and especially its axon to thallous salts is indicated. PMID:4125375

  5. Intracellular recording, sensory field mapping, and culturing identified neurons in the leech, Hirudo medicinalis.

    Science.gov (United States)

    Titlow, Josh; Majeed, Zana R; Nicholls, John G; Cooper, Robin L

    2013-11-04

    The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of neurophysiology, neuroethology, and developmental biology. The goal of this report is to consolidate experimental techniques from the leech system into a single article that will be of use to physiologists with expertise in other nervous system preparations, or to biology students with little or no electrophysiology experience. We demonstrate how to dissect the leech for recording intracellularly from identified neural circuits in the ganglion. Next we show how individual cells of known function can be removed from the ganglion to be cultured in a Petri dish, and how to record from those neurons in culture. Then we demonstrate how to prepare a patch of innervated skin to be used for mapping sensory or motor fields. These leech preparations are still widely used to address basic electrical properties of neural networks, behavior, synaptogenesis, and development. They are also an appropriate training module for neuroscience or physiology teaching laboratories.

  6. Phase transition approach to bursting in neuronal cultures: quorum percolation models

    Science.gov (United States)

    Monceau, P.; Renault, R.; Métens, S.; Bottani, S.; Fardet, T.

    2017-10-01

    The Quorum Percolation model has been designed in the context of neurobiology to describe bursts of activity occurring in neuronal cultures from the point of view of statistical physics rather than from a dynamical synchronization approach. It is based upon information propagation on a directed graph with a threshold activation rule; this leads to a phase diagram which exhibits a giant percolation cluster below some critical value mC of the excitability. We describe the main characteristics of the original model and derive extensions according to additional relevant biological features. Firstly, we investigate the effects of an excitability variability on the phase diagram and show that the percolation transition can be destroyed by a sufficient amount of such a disorder; we stress the weakly averaging character of the order parameter and show that connectivity and excitability can be seen as two overlapping aspects of the same reality. Secondly, we elaborate a discrete time stochastic model taking into account the decay originating from ionic leakage through the membrane of neurons and synaptic depression; we give evidence that the decay softens and shifts the transition, and conjecture than decay destroys the transition in the thermodynamical limit. We were able to develop mean-field theories associated with each of the two effects; we discuss the framework of their agreement with Monte Carlo simulations. It turns out that the the critical point mC from which information on the connectivity of the network can be inferred is affected by each of these additional effects. Lastly, we show how dynamical simulations of bursts with an adaptive exponential integrateand- fire model can be interpreted in terms of Quorum Percolation. Moreover, the usefulness of the percolation model including the set of sophistication we investigated can be extended to many scientific fields involving information propagation, such as the spread of rumors in sociology, ethology, ecology.

  7. Barbed channels enhance unidirectional connectivity between neuronal networks cultured on multi electrode arrays

    Science.gov (United States)

    le Feber, Joost; Postma, Wybren; de Weerd, Eddy; Weusthof, Marcel; Rutten, Wim L. C.

    2015-01-01

    Cultured neurons on multi electrode arrays (MEAs) have been widely used to study various aspects of neuronal (network) functioning. A possible drawback of this approach is the lack of structure in these networks. At the single cell level, several solutions have been proposed to enable directed connectivity, and promising results were obtained. At the level of connected sub-populations, a few attempts have been made with promising results. First assessment of the designs' functionality, however, suggested room for further improvement. We designed a two chamber MEA aiming to create a unidirectional connection between the networks in both chambers (“emitting” and “receiving”). To achieve this unidirectionality, all interconnecting channels contained barbs that hindered axon growth in the opposite direction (from receiving to emitting chamber). Visual inspection showed that axons predominantly grew through the channels in the promoted direction. This observation was confirmed by spontaneous activity recordings. Cross-correlation between the signals from two electrodes inside the channels suggested signal propagation at ≈2 m/s from emitting to receiving chamber. Cross-correlation between the firing patterns in both chambers indicated that most correlated activity was initiated in the emitting chamber, which was also reflected by a significantly lower fraction of partial bursts (i.e., a one-chamber-only burst) in the emitting chamber. Finally, electrical stimulation in the emitting chamber induced a fast response in that chamber, and a slower response in the receiving chamber. Stimulation in the receiving chamber evoked a fast response in that chamber, but no response in the emitting chamber. These results confirm the predominantly unidirectional nature of the connecting channels from emitting to receiving chamber. PMID:26578869

  8. Barbed channels enhance unidirectional connectivity between neuronal networks cultured on multi electrode arrays.

    Directory of Open Access Journals (Sweden)

    Joost eLe Feber

    2015-11-01

    Full Text Available Cultured neurons on multi electrode arrays (MEAs have been widely used to study various as-pects of neuronal (network functioning. A possible drawback of this approach is the lack of structure in these networks. At the single cell level, several solutions have been proposed to ena-ble directed connectivity, and promising results were obtained. At the level of connected sub-populations, a few attempts have been made with promising results. First assessment of the de-signs’ functionality, however, suggested room for further improvement.We designed a two chamber MEA aiming to create a unidirectional connection between the net-works in both chambers (‘emitting’ and ‘receiving’. To achieve this unidirectionality, all inter-connecting channels contained barbs that hindered axon growth in the opposite direction (from receiving to emitting chamber. Visual inspection showed that axons predominantly grew through the channels in the promoted direction . This observation was confirmed by spontaneous activity recordings. Cross-correlation between the signals from two electrodes inside the channels suggested signal propagation at ≈2 m/s from emitting to receiving chamber. Cross-correlation between the firing patterns in both chambers indicated that most correlated activity was initiated in the emitting chamber, which was also reflected by a significantly lower fraction of partial bursts (e. a one-chamber-only burst in the emitting chamber. Finally, electrical stimulation in the emitting chamber induced a fast response in that chamber, and a slower response in the receiving chamber. Stimulation in the receiving chamber evoked a fast response in that chamber, but no response in the emitting chamber. These results confirm the predominantly unidirectional nature of the connecting channels from emitting to receiving chamber.

  9. Hexane extract from Polygonum multiflorum attenuates glutamate-induced apoptosis in primary cultured cortical neurons.

    Science.gov (United States)

    Jang, Ji Yeon; Kim, Ha Neui; Kim, Yu Ri; Choi, Young Whan; Choi, Yung Hyun; Lee, Jun Hyuk; Shin, Hwa Kyoung; Choi, Byung Tae

    2013-01-09

    Polygonum multiflorum has traditionally had wide use as an anti-aging treatment in East Asian countries. We investigated the neuroprotective effects of Polygonum multiflorum against glutamate-induced neurotoxicity with a focus on the anti-apoptotic mechanism in primary cultured cortical neurons. Cell viability, cytotoxicity, morphological, flow cytometry, Western blot, and caspase activity assays were performed for examination of the neuroprotective effects of active hexane extract from Polygonum multiflorum (HEPM). Pretreatment with HEPM resulted in significantly decreased glutamate-induced neurotoxicity in a concentration-dependent manner and also resulted in drastically inhibited glutamate-induced apoptosis. Treatment with HEPM resulted in decreased expression of glutamate-induced death receptor (DR)4, and enhanced expression of glutamate-attenuated anti-apoptotic proteins, including Bcl-2, XIAP, and cIAP-1, and slightly reduced glutamate-induced cleavage of Bid. In addition, treatment with HEPM resulted in suppressed glutamate-induced activation of caspase-8, caspase-9, and caspase-3, and, subsequently, decreased degradation of poly(ADP-ribose) polymerase, β-catenin, and phospholipase Cγ1 protein, which are downstream targets of activated caspase-3. The results of this study demonstrated that HEPM exerts a neuroprotective effect against glutamate-induced neurotoxicity via inhibition of apoptosis. This protection may be mediated through suppression of DR4 and up-regulation of Bcl-2, XIAP, and cIAP-1, as well as inhibition of caspase activation, resulting in prevention of apoptosis of cortical neurons. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Novel cell separation method for molecular analysis of neuron-astrocyte co-cultures

    NARCIS (Netherlands)

    Goudriaan, A.; Camargo, N.K.; Carney, K.E.; Oliet, S.H.R.; Smit, A.B.; Verheijen, M.H.G.

    2014-01-01

    Over the last decade, the importance of astrocyte-neuron communication in neuronal development and synaptic plasticity has become increasingly clear. Since neuron-astrocyte interactions represent highly dynamic and reciprocal processes, we hypothesized that many astrocyte genes may be regulated as a

  11. Contrasting effects of cerebrospinal fluid from motor neuron disease patients on the survival of primary motor neurons cultured with or without glia.

    Science.gov (United States)

    Barber, Siân C; Wood-Allum, Clare A; Sargsyan, Siranush A; Walsh, Theresa; Cox, Laura E; Monk, Peter N; Shaw, Pamela J

    2011-07-01

    Motor neuronal (MN) degeneration in motor neuron disease (MND) often starts focally before spreading to neighbouring MN populations, suggesting soluble factors may contribute to disease propagation. Whether cerebrospinal fluid (CSF) from MND patients contains such factors has been difficult to prove. We aimed to determine the effect of glia on the response of MNs to CSF from MND patients. Primary rat spinal MNs grown in mono-culture or cocultured with glia were exposed to CSF from patients (MND-CSF) or controls (Con-CSF) and survival measured by cell counting. In mono-culture both MND-CSF and Con-CSF reduced MN survival with MND-CSF reducing MN survival by less than Con-CSF. In coculture MN survival was unchanged by exposure to MND-CSF while exposure to Con-CSF improved MN survival. In separate experiments, murine MNs grown in mono-culture and stressed by growth factor withdrawal were partially rescued by the application of monocyte chemoattractant protein-1 (MCP-1), a trophic factor previously found to be elevated in MND-CSF. Our results suggest that MND-CSF may contain factors harmful to MNs as well as factors protective of MNs, the interplay of which is altered by the presence of glial cells. These preliminary results further emphasize the importance of MN environment to MN health.

  12. Neuronal differentiation of hair-follicle-bulge-derived stem cells co-cultured with mouse cochlear modiolus explants.

    Directory of Open Access Journals (Sweden)

    Timo Schomann

    Full Text Available Stem-cell-based repair of auditory neurons may represent an attractive therapeutic option to restore sensorineural hearing loss. Hair-follicle-bulge-derived stem cells (HFBSCs are promising candidates for this type of therapy, because they (1 have migratory properties, enabling migration after transplantation, (2 can differentiate into sensory neurons and glial cells, and (3 can easily be harvested in relatively high numbers. However, HFBSCs have never been used for this purpose. We hypothesized that HFBSCs can be used for cell-based repair of the auditory nerve and we have examined their migration and incorporation into cochlear modiolus explants and their subsequent differentiation. Modiolus explants obtained from adult wild-type mice were cultured in the presence of EF1α-copGFP-transduced HFBSCs, constitutively expressing copepod green fluorescent protein (copGFP. Also, modiolus explants without hair cells were co-cultured with DCX-copGFP-transduced HFBSCs, which demonstrate copGFP upon doublecortin expression during neuronal differentiation. Velocity of HFBSC migration towards modiolus explants was calculated, and after two weeks, co-cultures were fixed and processed for immunohistochemical staining. EF1α-copGFP HFBSC migration velocity was fast: 80.5 ± 6.1 μm/h. After arrival in the explant, the cells formed a fascicular pattern and changed their phenotype into an ATOH1-positive neuronal cell type. DCX-copGFP HFBSCs became green-fluorescent after integration into the explants, confirming neuronal differentiation of the cells. These results show that HFBSC-derived neuronal progenitors are migratory and can integrate into cochlear modiolus explants, while adapting their phenotype depending on this micro-environment. Thus, HFBSCs show potential to be employed in cell-based therapies for auditory nerve repair.

  13. APE1, the DNA base excision repair protein, regulates the removal of platinum adducts in sensory neuronal cultures by NER

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Suk [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States); Guo, Chunlu; Thompson, Eric L. [Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Jiang, Yanlin [Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Kelley, Mark R. [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States); Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Vasko, Michael R. [Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Lee, Suk-Hee, E-mail: slee@iu.edu [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States)

    2015-09-15

    Peripheral neuropathy is one of the major side effects of treatment with the anticancer drug, cisplatin. One proposed mechanism for this neurotoxicity is the formation of platinum adducts in sensory neurons that could contribute to DNA damage. Although this damage is largely repaired by nuclear excision repair (NER), our previous findings suggest that augmenting the base excision repair pathway (BER) by overexpressing the repair protein APE1 protects sensory neurons from cisplatin-induced neurotoxicity. The question remains whether APE1 contributes to the ability of the NER pathway to repair platinum-damage in neuronal cells. To examine this, we manipulated APE1 expression in sensory neuronal cultures and measured Pt-removal after exposure to cisplatin. When neuronal cultures were treated with increasing concentrations of cisplatin for two or three hours, there was a concentration-dependent increase in Pt-damage that peaked at four hours and returned to near baseline levels after 24 h. In cultures where APE1 expression was reduced by ∼80% using siRNA directed at APE1, there was a significant inhibition of Pt-removal over eight hours which was reversed by overexpressing APE1 using a lentiviral construct for human wtAPE1. Overexpressing a mutant APE1 (C65 APE1), which only has DNA repair activity, but not its other significant redox-signaling function, mimicked the effects of wtAPE1. Overexpressing DNA repair activity mutant APE1 (226 + 177APE1), with only redox activity was ineffective suggesting it is the DNA repair function of APE1 and not its redox-signaling, that restores the Pt-damage removal. Together, these data provide the first evidence that a critical BER enzyme, APE1, helps regulate the NER pathway in the repair of cisplatin damage in sensory neurons.

  14. APE1, the DNA base excision repair protein, regulates the removal of platinum adducts in sensory neuronal cultures by NER

    International Nuclear Information System (INIS)

    Kim, Hyun-Suk; Guo, Chunlu; Thompson, Eric L.; Jiang, Yanlin; Kelley, Mark R.; Vasko, Michael R.; Lee, Suk-Hee

    2015-01-01

    Peripheral neuropathy is one of the major side effects of treatment with the anticancer drug, cisplatin. One proposed mechanism for this neurotoxicity is the formation of platinum adducts in sensory neurons that could contribute to DNA damage. Although this damage is largely repaired by nuclear excision repair (NER), our previous findings suggest that augmenting the base excision repair pathway (BER) by overexpressing the repair protein APE1 protects sensory neurons from cisplatin-induced neurotoxicity. The question remains whether APE1 contributes to the ability of the NER pathway to repair platinum-damage in neuronal cells. To examine this, we manipulated APE1 expression in sensory neuronal cultures and measured Pt-removal after exposure to cisplatin. When neuronal cultures were treated with increasing concentrations of cisplatin for two or three hours, there was a concentration-dependent increase in Pt-damage that peaked at four hours and returned to near baseline levels after 24 h. In cultures where APE1 expression was reduced by ∼80% using siRNA directed at APE1, there was a significant inhibition of Pt-removal over eight hours which was reversed by overexpressing APE1 using a lentiviral construct for human wtAPE1. Overexpressing a mutant APE1 (C65 APE1), which only has DNA repair activity, but not its other significant redox-signaling function, mimicked the effects of wtAPE1. Overexpressing DNA repair activity mutant APE1 (226 + 177APE1), with only redox activity was ineffective suggesting it is the DNA repair function of APE1 and not its redox-signaling, that restores the Pt-damage removal. Together, these data provide the first evidence that a critical BER enzyme, APE1, helps regulate the NER pathway in the repair of cisplatin damage in sensory neurons

  15. Secondary Ion Mass Spectrometry Imaging of Molecular Distributions in Cultured Neurons and Their Processes: Comparative Analysis of Sample Preparation

    Science.gov (United States)

    Tucker, Kevin R.; Li, Zhen; Rubakhin, Stanislav S.; Sweedler, Jonathan V.

    2012-11-01

    Neurons often exhibit a complex chemical distribution and topography; therefore, sample preparation protocols that preserve structures ranging from relatively large cell somata to small neurites and growth cones are important factors in secondary ion mass spectrometry (SIMS) imaging studies. Here, SIMS was used to investigate the subcellular localization of lipids and lipophilic species in neurons from Aplysia californica. Using individual neurons cultured on silicon wafers, we compared and optimized several SIMS sampling approaches. After an initial step to remove the high salt culturing media, formaldehyde, paraformaldehyde, and glycerol, and various combinations thereof, were tested for their ability to achieve cell stabilization during and after the removal of extracellular media. These treatments improved the preservation of cellular morphology as visualized with SIMS imaging. For analytes >250 Da, coating the cell surface with a 3.2 nm-thick gold layer increased the ion intensity; multiple analytes previously not observed or observed at low abundance were detected, including intact cholesterol and vitamin E molecular ions. However, once a sample was coated, many of the lower molecular mass (SIMS imaging of processes of individual cultured neurons over a broad mass range with enhanced image contrast.

  16. Human neural stem cell-derived cultures in three-dimensional substrates form spontaneously functional neuronal networks.

    Science.gov (United States)

    Smith, Imogen; Silveirinha, Vasco; Stein, Jason L; de la Torre-Ubieta, Luis; Farrimond, Jonathan A; Williamson, Elizabeth M; Whalley, Benjamin J

    2017-04-01

    Differentiated human neural stem cells were cultured in an inert three-dimensional (3D) scaffold and, unlike two-dimensional (2D) but otherwise comparable monolayer cultures, formed spontaneously active, functional neuronal networks that responded reproducibly and predictably to conventional pharmacological treatments to reveal functional, glutamatergic synapses. Immunocytochemical and electron microscopy analysis revealed a neuronal and glial population, where markers of neuronal maturity were observed in the former. Oligonucleotide microarray analysis revealed substantial differences in gene expression conferred by culturing in a 3D vs a 2D environment. Notable and numerous differences were seen in genes coding for neuronal function, the extracellular matrix and cytoskeleton. In addition to producing functional networks, differentiated human neural stem cells grown in inert scaffolds offer several significant advantages over conventional 2D monolayers. These advantages include cost savings and improved physiological relevance, which make them better suited for use in the pharmacological and toxicological assays required for development of stem cell-based treatments and the reduction of animal use in medical research. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  17. Prototypical antipsychotic drugs protect hippocampal neuronal cultures against cell death induced by growth medium deprivation

    Directory of Open Access Journals (Sweden)

    Williams Sylvain

    2006-03-01

    Full Text Available Abstract Background Several clinical studies suggested that antipsychotic-based medications could ameliorate cognitive functions impaired in certain schizophrenic patients. Accordingly, we investigated the effects of various dopaminergic receptor antagonists – including atypical antipsychotics that are prescribed for the treatment of schizophrenia – in a model of toxicity using cultured hippocampal neurons, the hippocampus being a region of particular relevance to cognition. Results Hippocampal cell death induced by deprivation of growth medium constituents was strongly blocked by drugs including antipsychotics (10-10-10-6 M that display nM affinities for D2 and/or D4 receptors (clozapine, haloperidol, (±-sulpiride, domperidone, clozapine, risperidone, chlorpromazine, (+-butaclamol and L-741,742. These effects were shared by some caspases inhibitors and were not accompanied by inhibition of reactive oxygen species. In contrast, (--raclopride and remoxipride, two drugs that preferentially bind D2 over D4 receptors were ineffective, as well as the selective D3 receptor antagonist U 99194. Interestingly, (--raclopride (10-6 M was able to block the neuroprotective effect of the atypical antipsychotic clozapine (10-6 M. Conclusion Taken together, these data suggest that D2-like receptors, particularly the D4 subtype, mediate the neuroprotective effects of antipsychotic drugs possibly through a ROS-independent, caspase-dependent mechanism.

  18. Experimental investigation of magnetic nanotubes in PC-12 neuron cells culturing

    Science.gov (United States)

    Chen, Linfeng; Xie, Jining; Yancey, J.; Srivatsan, Malathi; Varadan, Vijay K.

    2007-04-01

    This report discusses the effects of magnetic nanotubes on the differentiation and growth of neurons. The magnetic nanotubes used in this study are hematite nanotubes synthesized using template method, and their structural and magnetic properties have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). PC-12 cells are differentiated into neurons in the presence of magnetic nanotubes to confirm the biocompatibility and cytotoxic effects of magnetic nanotubes during the processes of neuron differentiation and neuronal growth. The morphological changes and synapse formation of neurons are investigated, and the contact effects of magnetic nanotubes on neurite (axon and dendrites) outgrowth are explored. This research allows us to understand the interaction between magnetic nanomaterials and neurons, and pave the way towards developing potential treatments using the magnetic nano tubes for neurodegenerative disorders and injuries to the nervous system in the future.

  19. Mangiferin Upregulates Glyoxalase 1 Through Activation of Nrf2/ARE Signaling in Central Neurons Cultured with High Glucose.

    Science.gov (United States)

    Liu, Yao-Wu; Cheng, Ya-Qin; Liu, Xiao-Li; Hao, Yun-Chao; Li, Yu; Zhu, Xia; Zhang, Fan; Yin, Xiao-Xing

    2017-08-01

    Mangiferin, a natural C-glucoside xanthone, has anti-inflammatory, anti-oxidative, neuroprotective actions. Our previous study showed that mangiferin could attenuate diabetes-associated cognitive impairment of rats by enhancing the function of glyoxalase 1 (Glo-1) in brain. The aim of this study was to investigate whether Glo-1 upregulation by mangiferin in central neurons exposed to chronic high glucose may be related to activation of Nrf2/ARE pathway. Compared with normal glucose (25 mmol/L) culture, Glo-1 protein, mRNA, and activity levels were markedly decreased in primary hippocampal and cerebral cortical neurons cultured with high glucose (50 mmol/L) for 72 h, accompanied by the declined Nrf2 nuclear translocation and protein expression of Nrf2 in cell nucleus, as well as protein expression and mRNA level of γ-glutamylcysteine synthetase (γ-GCS) and superoxide dismutase activity, target genes of Nrf2/ARE signaling. Nonetheless, high glucose cotreating with mangiferin or sulforaphane, a typical inducer of Nrf2 activation, attenuated the above changes in both central neurons. In addition, mangiferin and sulforaphane significantly prevented the formation of advanced glycation end-products (AGEs) reflecting Glo-1 activity, while elevated the level of glutathione, a cofactor of Glo-1 activity and production of γ-GCS, in high glucose cultured central neurons. These findings demonstrated that Glo-1 was greatly downregulated in central neurons exposed to chronic high glucose, which is expected to lead the formation of AGEs and oxidative stress damages. We also proved that mangiferin enhanced the function of Glo-1 under high glucose condition by inducing activation of Nrf2/ARE signaling pathway.

  20. Role of laser fluence in protein synthesis of cultured DRG neurons following low-level laser irradiation

    Science.gov (United States)

    Zheng, Liqin; Qiu, Caimin; Wang, Yuhua; Zeng, Yixiu; Yang, Hongqin; Zhang, Yanding; Xie, Shusen

    2014-11-01

    Low-level lasers have been used to relieve pain in clinical for many years. But the mechanism is not fully clear. In animal models, nitric oxide (NO) has been reported involving in the transmission and modulation of nociceptive signals. So the objective of this study was to establish whether low-level laser with different fluence could stimulate the production of nitric oxide synthese (NOS), which produces NO in cultured primary dorsal root ganglion neurons (DRG neurons). The primary DRG neurons were isolated from healthy Sprague Dawley rats (8-12 weeks of age) and spread on 35 mm culture dishes specially used for confocal microscopy. 24 hours after spreading, cells were irradiated with 658 nm laser for two consecutive days at the energy density of 20, 40, 60 and 80 mJ·cm-2 respectively. Control groups were not exposed to the laser, but were kept under the same conditions as the irradiated ones. The synthesis of NOS after laser irradiation was detected by immunofluorescence assay, and the changes of NOS were evaluated using confocal microscopy and Image J software. The results showed that all the laser fluence could promote the production of NOS in DRG neurons, especially the 60 mJ·cm-2 . These results demonstrated that low-level laser irradiation could modify protein synthesis in a dose- or fluence- dependent manner, and indicated that low-level laser irradiation might achieve the analgesic effect through modulation of NO production.

  1. Long-Term Culture of Rat Hippocampal Neurons at Low Density in Serum-Free Medium: Combination of the Sandwich Culture Technique with the Three-Dimensional Nanofibrous Hydrogel PuraMatrix

    OpenAIRE

    Kaneko, Ai; Sankai, Yoshiyuki

    2014-01-01

    The primary culture of neuronal cells plays an important role in neuroscience. There has long been a need for methods enabling the long-term culture of primary neurons at low density, in defined serum-free medium. However, the lower the cell density, the more difficult it is to maintain the cells in culture. Therefore, we aimed to develop a method for long-term culture of neurons at low density, in serum-free medium, without the need for a glial feeder layer. Here, we describe the work leadin...

  2. Human induced pluripotent stem cell (hiPSC)-derived neurons respond to convulsant drugs when co-cultured with hiPSC-derived astrocytes.

    Science.gov (United States)

    Ishii, Misawa Niki; Yamamoto, Koji; Shoji, Masanobu; Asami, Asano; Kawamata, Yuji

    2017-08-15

    Accurate risk assessment for drug-induced seizure is expected to be performed before entering clinical studies because of its severity and fatal damage to drug development. Induced pluripotent stem cell (iPSC) technology has allowed the use of human neurons and glial cells in toxicology studies. Recently, several studies showed the advantage of co-culture system of human iPSC (hiPSC)-derived neurons with rodent/human primary astrocytes regarding neuronal functions. However, the application of hiPSC-derived neurons for seizure risk assessment has not yet been fully addressed, and not at all when co-cultured with hiPSC-derived astrocytes. Here, we characterized hiPSC-derived neurons co-cultured with hiPSC-derived astrocytes to discuss how hiPSC-derived neurons are useful to assess seizure risk of drugs. First, we detected the frequency of spikes and synchronized bursts hiPSC-derived neurons when co-cultured with hiPSC-derived astrocytes for 8 weeks. This synchronized burst was suppressed by the treatment with 6-cyano-7-nitroquinoxaline-2,3-dione, α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor antagonist, and D-(-)-2-amino-5-phosphonopentanoic acid, an N-Methyl-d-aspartate (NMDA) receptor antagonist. These data suggested that co-cultured hiPSC-derived neurons formed synaptic connections mediated by AMPA and NMDA receptors. We also demonstrated that co-cultured hiPSC-derived neurons showed epileptiform activity upon treatment with gabazine or kaliotoxin. Finally, we performed single-cell transcriptome analysis in hiPSC-derived neurons and found that hiPSC-derived astrocytes activated the pathways involved in the activities of AMPA and NMDA receptor functions, neuronal polarity, and axon guidance in hiPSC-derived neurons. These data suggested that hiPSC-derived astrocytes promoted the development of action potential, synaptic functions, and neuronal networks in hiPSC-derived neurons, and then these functional alterations result in the epileptiform

  3. Glial cell line-derived neurotrophic factor promotes the development of adrenergic neurons in mouse neural crest cultures

    Science.gov (United States)

    Maxwell, Gerald D.; Reid, Kate; Elefanty, Andrew; Bartlett, Perry F.; Murphy, Mark

    1996-01-01

    Growth of mouse neural crest cultures in the presence of glial cell line-derived neurotrophic factor (GDNF) resulted in a dramatic dose-dependent increase in the number of tyrosine hydroxylase (TH)-positive cells that developed when 5% chicken embryo extract was present in the medium. In contrast, growth in the presence of bone morphogenetic protein (BMP)-2, BMP-4, BMP-6, transforming growth factor (TGF) β1, TGF-β2, and TGF-β3 elicited no increase in the number of TH-positive cells. The TH-positive cells that developed in the presence of GDNF had neuronal morphology and contained the middle and low molecular weight neurofilament proteins. Numerous TH-negative cells with the morphology of neurons also were observed in GDNF-treated cultures. Analysis revealed that the period from 6 to 12 days in vitro was the critical time for exposure to GDNF to generate the increase in TH-positive cell number. The growth factors neurotrophin-3 and fibroblast growth factor-2 elicited increases in the number of TH-positive cells similar to that seen in response to GDNF. In contrast, nerve growth factor was unable to substitute for GDNF. These findings extend the previously reported biological activities of GDNF by showing that it can act on mouse neural crest cultures to promote the development of neurons. PMID:8917581

  4. Effect of acute ethanol on beta-endorphin secretion from rat fetal hypothalamic neurons in primary cultures

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, D.K.; Minami, S. (Washington State Univ., Pullman (USA))

    1990-01-01

    To characterize the effect of ethanol on the hypothalamic {beta}-endorphin-containing neurons, rat fetal hypothalamic neurons were maintained in primary culture, and the secretion of {beta}-endorphin ({beta}-EP) was determined after ethanol challenges. Constant exposure to ethanol at doses of 6-50 mM produced a dose-dependent increase in basal secretion of {beta}-EP from these cultured cells. These doses of ethanol did not produce any significant effect on cell viability, DNA or protein content. The stimulated secretion of {beta}-EP following constant ethanol exposure is short-lasting. However, intermittent ethanol exposures maintained the ethanol stimulatory action on {beta}-EP secretion for a longer time. The magnitude of the {beta}-EP response to 50 mM ethanol is similar to that of the {beta}-EP response to 56 mM of potassium. Ethanol-stimulated {beta}-EP secretion required extracellular calcium and was blocked by a calcium channel blocker; a sodium channel blocker did not affect ethanol-stimulated secretion. These results suggest that the neuron culture system is a useful model for studying the cellular mechanisms involved in the ethanol-regulated hypothalamic opioid secretion.

  5. Cultured neurons as model systems for biochemical and pharmacological studies on receptors for neurotransmitter amino acids

    DEFF Research Database (Denmark)

    Schousboe, A; Drejer, J; Hansen, Gert Helge

    1985-01-01

    , which mediate an L-glutamate-induced transmitter release. The pharmacological properties of these glutamate receptors are, however, distinctly different for the 2 types of neurons. While cerebral cortex neurons express both quisqualate-, N-methyl-D-aspartate- and kainate-receptors, the cerebellar...

  6. Target recognition and synapse formation by ciliary-ganglion neurons in tissue culture

    NARCIS (Netherlands)

    Stevens, W.F.; Slaaf, D.W.; Hooisma, J.; Magchielse, T.; Meeter, E.

    1978-01-01

    A less complicated source of neurons suitable for this type of studies is the parasympathetic ciliary ganglion. In the pigeon and in the chick this ganglion is known to contain only two classes of neurons, both of which are cholinoceptive and cholinergic and that innervate the muscle fibres of the

  7. Cultured neurons as model systems for biochemical and pharmacological studies on receptors for neurotransmitter amino acids

    DEFF Research Database (Denmark)

    Schousboe, A; Drejer, J; Hansen, Gert Helge

    1985-01-01

    action of GABA on evoked release of glutamate, which is the neurotransmitter in cerebellar granule cells. Also glutamate receptors have been studied with regard to the 2 types of neurons. Both cerebral cortex neurons (GABAergic) and cerebellar granule cells (glutamatergic) possess glutamate receptors...

  8. Live-cell imaging of post-golgi transport vesicles in cultured hippocampal neurons

    DEFF Research Database (Denmark)

    Jensen, Camilla Stampe; Misonou, Hiroaki

    2015-01-01

    compartments of neurons. In the past two decades, the establishment and advancement of fluorescent protein technology have provided us with opportunities to study how proteins are trafficked in living cells. However, live imaging of trafficking processes in neurons necessitate imaging tools to distinguish......The subcellular localization of neuronal membrane signaling molecules such as receptors and ion channels depends on intracellular trafficking mechanisms. Essentially, vesicular trafficking mechanisms ensure that a large number of membrane proteins are correctly targeted to different subcellular...... the several different routes that neurons use for protein trafficking. Here we provide a novel protocol to selectively visualize post-Golgi transport vesicles carrying fluorescent-labeled ion channel proteins in living neurons. Further, we provide a number of analytical tools we developed to quantify...

  9. Neonatal mouse cortical but not isogenic human astrocyte feeder layers enhance the functional maturation of induced pluripotent stem cell-derived neurons in culture.

    Science.gov (United States)

    Lischka, Fritz W; Efthymiou, Anastasia; Zhou, Qiong; Nieves, Michael D; McCormack, Nikki M; Wilkerson, Matthew D; Sukumar, Gauthaman; Dalgard, Clifton L; Doughty, Martin L

    2018-04-01

    Human induced pluripotent stem (iPS) cell-derived neurons and astrocytes are attractive cellular tools for nervous system disease modeling and drug screening. Optimal utilization of these tools requires differentiation protocols that efficiently generate functional cell phenotypes in vitro. As nervous system function is dependent on networked neuronal activity involving both neuronal and astrocytic synaptic functions, we examined astrocyte effects on the functional maturation of neurons from human iPS cell-derived neural stem cells (NSCs). We first demonstrate human iPS cell-derived NSCs can be rapidly differentiated in culture to either neurons or astrocytes with characteristic cellular, molecular and physiological features. Although differentiated neurons were capable of firing multiple action potentials (APs), few cells developed spontaneous electrical activity in culture. We show spontaneous electrical activity was significantly increased by neuronal differentiation of human NSCs on feeder layers of neonatal mouse cortical astrocytes. In contrast, co-culture on feeder layers of isogenic human iPS cell-derived astrocytes had no positive effect on spontaneous neuronal activity. Spontaneous electrical activity was dependent on glutamate receptor-channel function and occurred without changes in I Na , I K , V m , and AP properties of iPS cell-derived neurons. These data demonstrate co-culture with neonatal mouse cortical astrocytes but not human isogenic iPS cell-derived astrocytes stimulates glutamatergic synaptic transmission between iPS cell-derived neurons in culture. We present RNA-sequencing data for an immature, fetal-like status of our human iPS cell-derived astrocytes as one possible explanation for their failure to enhance synaptic activity in our co-culture system. © 2017 Wiley Periodicals, Inc.

  10. Effects of 17beta-estradiol and xenoestrogens on the neuronal survival in an organotypic hippocampal culture.

    Science.gov (United States)

    Sato, Kaoru; Matsuki, Norio; Ohno, Yasuo; Nakazawa, Ken

    2002-10-01

    Xenoestrogens are man-made compounds that mimic the actions of estrogens through interactions with estrogen receptors (ERs). Although xenoestrogens have received a great deal of attention as possible causes of brain disfunctions, little information concerning the effects of xenoestrogens on the central nervous system is available. In this study, we investigated the effects of 17beta-estradiol (E(2)) and four xenoestrogens (17alpha-ethynylestradiol, diethylstilbestrol, p-nonylphenol and bisphenol A (BPA)) on the neuronal survival using organotypic hippocampal slice cultures. When the cultured hippocampal slices were exposed to glutamate (1 mM, 15 min), the CA1-selective neuronal damage was induced. Pretreatment with E(2) and the xenoestrogens (24 h) selectively exacerbated the CA3 neuronal damage caused by glutamate. In spite of the marked difference of binding affinities to ERs, all compounds revealed maximal effects at 1 nM. ER antagonists, tamoxifen and ICI 182,780, did not affect responses to E(2) and the xenoestrogens, indicating that these effects are mediated through mechanisms other than ERs. In spite of the fact that BPA has little interaction with ERs at 1 nM, E(2) and BPA equally increased the expression of N-methyl-D-aspartate receptor in CA3 and upregulated the spine density of the apical portion of CA3 dendrites at 1 nM. These compounds also enhanced the sprouting of mossy fibers to CA3 neurons. These results suggest that exposure to E(2) and xenoestrogens during the developmental stage results in a marked influence on synaptogenesis and neuronal vulnerability through mechanisms other than ERs. Copyright 2002 S. Karger AG, Basel

  11. Altered NMDA receptor function in primary cultures of hippocampal neurons from mice lacking the Homer2 gene.

    Science.gov (United States)

    Smothers, C Thetford; Szumlinski, Karen K; Worley, Paul F; Woodward, John J

    2016-01-01

    N-Methyl-D-Aspartate (NMDA) receptors are inhibited during acute exposure to ethanol and are involved in changes in neuronal plasticity following repeated ethanol exposure. The postsynaptic scaffolding protein Homer2 can regulate the cell surface expression of NMDA receptors in vivo, and mice with a null mutation of the Homer2 gene exhibit an alcohol-avoiding and -intolerant phenotype that is accompanied by a lack of ethanol-induced glutamate sensitization. Thus, Homer2 deletion may perturb the function or acute ethanol sensitivity of the NMDA receptor. In this study, the function and ethanol sensitivity of glutamate receptors in cultured hippocampal neurons from wild-type (WT) and Homer2 knock-out (KO) mice were examined at 7 and 14 days in vitro (DIV) using standard whole-cell voltage-clamp electrophysiology. As compared with wild-type controls, NMDA receptor current density was reduced in cultured hippocampal neurons from Homer2 KO mice at 14 DIV, but not at 7 DIV. There were no genotype-dependent changes in whole-cell capacitance or in currents evoked by kainic acid. The GluN2B-selective antagonist ifenprodil inhibited NMDA-evoked currents to a similar extent in both wild-type and Homer2 KO neurons and inhibition was greater at 7 versus 14 DIV. NMDA receptor currents from both WT and KO mice were inhibited by ethanol (10-100 mM) and the degree of inhibition did not differ as a function of genotype. In conclusion, NMDA receptor function, but not ethanol sensitivity, is reduced in hippocampal neurons lacking the Homer2 gene. © 2015 Wiley Periodicals, Inc.

  12. Embryonic Cell Grafts in a Culture Model of Spinal Cord Lesion: Neuronal Relay Formation is Essential for Functional Regeneration

    Directory of Open Access Journals (Sweden)

    Anne Tscherter

    2016-09-01

    Full Text Available Presently there exists no cure for spinal cord injury. However, transplantation of embryonic tissue into spinal cord lesions resulted in axon outgrowth across the lesion site and some functional recovery, fostering hope for future stem cell therapies. Although in vivo evidence for functional recovery is given, the exact cellular mechanism of the graft support remains elusive: either the grafted cells provide a permissive environment for the host tissue to regenerate itself or the grafts actually integrate functionally into the host neuronal network reconnecting the separated spinal cord circuits. We tested the two hypotheses in an in vitro spinal cord lesion model that is based on propagation of activity between two rat organotypic spinal cord slices in culture. Transplantation of dissociated cells from E14 rat spinal cord or forebrain re-established the relay of activity over the lesion site and, thus, provoked functional regeneration. Combining patch-clamp recordings from transplanted cells with network activity measurements from the host tissue on multi-electrode arrays we here show that neurons differentiate from the grafted cells and integrate into the host circuits. Optogenetic silencing of neurons developed from transplanted embryonic mouse forebrain cells provides clear evidence that they replace the lost neuronal connections to relay and synchronize activity between the separated spinal cord circuits. In contrast, transplantation of neurospheres induced neither the differentiation of mature neurons from the grafts nor an improvement of functional regeneration. Together these findings suggest, that the formation of neuronal relays from grafted embryonic cells is essential to re-connect segregated spinal cord circuits.

  13. Comparative pharmacology of cholecystokinin induced activation of cultured vagal afferent neurons from rats and mice.

    Directory of Open Access Journals (Sweden)

    Dallas C Kinch

    Full Text Available Cholecystokinin (CCK facilitates the process of satiation via activation of vagal afferent neurons innervating the upper gastrointestinal tract. Recent findings indicate CCK acts on these neurons via a ruthenium red (RuR sensitive pathway that involves members of the vanilloid (V subfamily of transient receptor potential (TRP channels. To further test this mechanism, the mouse provides an ideal model in which genetic tools could be applied. However, whether CCK acts by similar mechanism(s in mice has not been determined. In the present study we explored the actions of CCK on nodose neurons isolated from Sprague Dawley (SD rat and two strains of mice; C57BL/6 and BalbC using fluorescence-based calcium imaging. With minor exceptions nodose neurons isolated from all species/strains behaved similarly. They all respond to brief depolarization with a large calcium transient. A significant subset of neurons responded to capsaicin (CAP, a TRPV1 agonist, although neurons from C57BL/6 were 10-fold more sensitive to CAP than SD rats or BalbC mice, and a significantly smaller fraction of neurons from BalbC mice responded to CAP. CCK-8 dose-dependently activated a subpopulation of neurons with similar dose dependency, percent responders, and overlap between CCK and CAP responsiveness. In all species/strains CCK-8 induced activation was significantly attenuated (but not completely blocked by pretreatment with the TRPV channel blocker RuR. Surprisingly, the CCK analogue JMV-180, which is reported to have pure antagonistic properties in rat but mixed agonist/antagonist properties in mice, behaved as a pure antagonist to CCK in both rat and mouse neurons. The pure antagonistic action of JMV-180 in this in vitro preparation suggests that prior reported differential effects of JMV-180 on satiation in rats versus mouse must be mediated by a site other than vagal afferent activation.

  14. Differential induction of heme oxygenase and other stress proteins in cultured hippocampal astrocytes and neurons by inorganic lead

    International Nuclear Information System (INIS)

    Cabell, Leigh; Ferguson, Charles; Luginbill, Deana; Kern, Marcey; Weingart, Adam; Audesirk, Gerald

    2004-01-01

    We examined the effects of exposure to inorganic lead (Pb 2+ ) on the induction of stress proteins in cultured hippocampal neurons and astrocytes, with particular emphasis on the induction of heme oxygenase-1 (HO-1). In radiolabeled neuronal cultures, Pb 2+ exposure had no significant effect on the synthesis of any protein at any concentration (up to 250 μM) or duration of exposure (up to 4 days). In radiolabeled astrocyte cultures, however, Pb 2+ exposure (100 nM to 100 μM; 1-4 days) increased synthesis of proteins with approximate molecular weights of 23, 32, 45, 57, 72, and 90 kDa. Immunoblot experiments showed that Pb 2+ exposure (100 nM to 10 μM, 1-14 days) induces HO-1 synthesis in astrocytes, but not in neurons; this is probably the 32-kDa protein. The other heme oxygenase isoform, HO-2, is present in both neurons and astrocytes, but is not inducible by Pb 2+ at concentrations up to 100 μM. HO-1 can be induced by a variety of stimuli. We found that HO-1 induction in astrocytes is increased by combined exposure to Pb 2+ and many other stresses, including heat, nitric oxide, H 2 O 2 , and superoxide. One of the stimuli that may induce HO-1 is oxidative stress. Lead exposure causes oxidative stress in many cell types, including astrocytes. Induction of HO-1 by Pb 2+ is reduced by the hydroxyl radical scavengers dimethylthiourea (DMTU) and mannitol, but not by inhibitors of calmodulin, calmodulin-dependent protein kinases, protein kinase C, or extracellular signal-regulated kinases (ERK). Therefore, we conclude that oxidative stress is an important mechanism by which Pb 2+ induces HO-1 synthesis in astrocytes

  15. Demonstration of extensive GABA synthesis in the small population of GAD positive neurons in cerebellar cultures by the use of pharmacological tools

    DEFF Research Database (Denmark)

    Sonnewald, Ursula; Kortner, Trond M; Qu, Hong

    2006-01-01

    by labeling from [U-(13)C]glutamine added on day 7. Altogether the findings show continuous GABA synthesis and degradation throughout the culture period in the cerebellar neurons. At 10 microM AOAA, GABA synthesis from [U-(13)C]glutamine was not affected, indicating that transaminases are not involved in GABA...... that GABA synthesis is taking place via GAD in a subpopulation of the cerebellar neurons, throughout the culture period....

  16. Formation and spreading of TDP-43 aggregates in cultured neuronal and glial cells demonstrated by time-lapse imaging.

    Directory of Open Access Journals (Sweden)

    Tomohiro Ishii

    Full Text Available TAR DNA-binding protein 43 (TDP-43 is a main constituent of cytoplasmic aggregates in neuronal and glial cells in cases of amyotrophic lateral sclerosis and frontotemporal lobar degeneration. We have previously demonstrated that adenovirus-transduced artificial TDP-43 cytoplasmic aggregates formation is enhanced by proteasome inhibition in vitro and in vivo. However, the relationship between cytoplasmic aggregate formation and cell death remains unclear. In the present study, rat neural stem cell lines stably transfected with EGFP- or Sirius-expression vectors under the control of tubulin beta III, glial fibrillary acidic protein, or 2',3'-cyclic nucleotide 3'-phosphodiesterase promoter were differentiated into neurons, astrocytes, and oligodendrocytes, respectively, in the presence of retinoic acid. The differentiated cells were then transduced with adenoviruses expressing DsRed-tagged human wild type and C-terminal fragment TDP-43 under the condition of proteasome inhibition. Time-lapse imaging analyses revealed growing cytoplasmic aggregates in the transduced neuronal and glial cells, followed by collapse of the cell. The aggregates remained insoluble in culture media, consisted of sarkosyl-insoluble granular materials, and contained phosphorylated TDP-43. Moreover, the released aggregates were incorporated into neighboring neuronal cells, suggesting cell-to-cell spreading. The present study provides a novel tool for analyzing the detailed molecular mechanisms of TDP-43 proteinopathy in vitro.

  17. Formation and spreading of TDP-43 aggregates in cultured neuronal and glial cells demonstrated by time-lapse imaging.

    Science.gov (United States)

    Ishii, Tomohiro; Kawakami, Emiko; Endo, Kentaro; Misawa, Hidemi; Watabe, Kazuhiko

    2017-01-01

    TAR DNA-binding protein 43 (TDP-43) is a main constituent of cytoplasmic aggregates in neuronal and glial cells in cases of amyotrophic lateral sclerosis and frontotemporal lobar degeneration. We have previously demonstrated that adenovirus-transduced artificial TDP-43 cytoplasmic aggregates formation is enhanced by proteasome inhibition in vitro and in vivo. However, the relationship between cytoplasmic aggregate formation and cell death remains unclear. In the present study, rat neural stem cell lines stably transfected with EGFP- or Sirius-expression vectors under the control of tubulin beta III, glial fibrillary acidic protein, or 2',3'-cyclic nucleotide 3'-phosphodiesterase promoter were differentiated into neurons, astrocytes, and oligodendrocytes, respectively, in the presence of retinoic acid. The differentiated cells were then transduced with adenoviruses expressing DsRed-tagged human wild type and C-terminal fragment TDP-43 under the condition of proteasome inhibition. Time-lapse imaging analyses revealed growing cytoplasmic aggregates in the transduced neuronal and glial cells, followed by collapse of the cell. The aggregates remained insoluble in culture media, consisted of sarkosyl-insoluble granular materials, and contained phosphorylated TDP-43. Moreover, the released aggregates were incorporated into neighboring neuronal cells, suggesting cell-to-cell spreading. The present study provides a novel tool for analyzing the detailed molecular mechanisms of TDP-43 proteinopathy in vitro.

  18. Humanin rescues cultured rat cortical neurons from NMDA-induced toxicity through the alleviation of mitochondrial dysfunction.

    Science.gov (United States)

    Cui, Ai-Ling; Zhang, Ying-Hua; Li, Jian-Zhong; Song, Tianbin; Liu, Xue-Min; Wang, Hui; Zhang, Ce; Ma, Guo-Lin; Zhang, Hui; Li, Kefeng

    2017-01-01

    N -methyl-D-aspartate (NDMA) receptor-mediated excitotoxicity has been implicated in a variety of pathological situations such as Alzheimer's disease (AD) and Parkinson's disease. However, no effective treatments for the same have been developed so far. Humanin (HN) is a 24-amino acid peptide originally cloned from the brain of patients with AD and it prevents stress-induced cell death in many cells/tissues. In our previous study, HN was found to effectively rescue rat cortical neurons. It is still not clear whether HN protects the neurons through the attenuation of mitochondrial dysfunction. In this study, excitatory toxicity was induced by NMDA, which binds the NMDA receptor in primarily cultured rat cortical neurons. We found that NMDA (100 μmol/L) dramatically induced the decrease of cell viability and caused mitochondrial dysfunction. Pretreatment of the neurons with HN (1 μmol/L) led to significant increases of mitochondrial succinate dehydrogenase (SDH) activity and membrane potential. In addition, HN pretreatment significantly reduced the excessive production of both reactive oxygen species (ROS) and nitric oxide (NO). Thus, HN could attenuate the excitotoxicity caused by the overactivation of the NMDA receptor through the alleviation of mitochondrial dysfunction.

  19. Nano-Ampere Stimulation Window for Cultured Neurons on Micro-Electrode Arrays

    National Research Council Canada - National Science Library

    Buitenweg, J

    2001-01-01

    From experiments, it appears to be possible to stimulate a neuron by depolarization of the lower membrane patch, the sealing part of the membrane, using a nano-ampere current through the extracellular...

  20. Inhibitory synaptic transmission in isolated patches of membrane from cultured rat spinal cord and medullary neurons.

    Science.gov (United States)

    Lewis, C A; Faber, D S

    1996-07-01

    1. To quantify the variability in the characteristics of inhibitory glycinergic and GABAergic currents at single synaptic connections between cultured rat embryonic spinal cord or medullary neurons, we have used patch-clamp techniques to record miniature inhibitory postsynaptic currents (mIPSCs) in cell-attached patches. Experiments were performed with the patch pipette containing either a low-calcium internal saline to allow comparison with subsequent whole cell recordings or external saline with tetrodotoxin, DL-2-amino-5-phosphonovaleric acid, and 6-cyano-7-nitroquinoxaline-2,3-dione, a solution that is more appropriate for bathing a nerve terminal. 2. The mIPSCs recorded from the synapses restricted to the cell-attached patches were characterized by their times to peak, amplitudes, and time constants of decay. The degree of variability in these characteristics was quantified with the use of the following model-independent parameters: the coefficient of variation, skewness, and kurtosis. The distribution of time to peak values has a mean value of 5.6 +/- 0.5 (SE) ms, has the lowest coefficient of variation (0.33 +/- 0.01), is fairly symmetrical, and has a Gaussian shape with respect to peakedness. On the other hand, both the amplitude and decay time constant distributions are highly skewed and more peaked than Gaussian distributions. The mean amplitude is -6.6 +/- 0.6 pA with a coefficient of variation of 0.60 +/- 0.05, whereas the mean decay time constant is 22.8 +/- 1.0 ms with a coefficient of variation of 0.81 +/- 0.03. 3. The amplitude distributions for spontaneous inhibitory currents recorded from cell-attached patches are best fitted by the sum of multiple Gaussians. The coefficient of variation for the first Gaussian peak fitted to the amplitude distributions is 0.290 +/- 0.028. 4. Decay time distributions were consistently best fitted by the sum of four Gaussians with decay constants as follows: D1 = 5.7 +/- 0.2 ms (n = 12), D2 = 11.2 +/- 0.7 ms (n = 11

  1. Ctip2-, Satb2-, Prox1-, and GAD65-Expressing Neurons in Rat Cultures: Preponderance of Single- and Double-Positive Cells, and Cell Type-Specific Expression of Neuron-Specific Gene Family Members, Nsg-1 (NEEP21) and Nsg-2 (P19).

    Science.gov (United States)

    Digilio, Laura; Yap, Chan Choo; Winckler, Bettina

    2015-01-01

    The brain consists of many distinct neuronal cell types, but which cell types are present in widely used primary cultures of embryonic rodent brain is often not known. We characterized how abundantly four cell type markers (Ctip2, Satb2, Prox1, GAD65) were represented in cultured rat neurons, how easily neurons expressing different markers can be transfected with commonly used plasmids, and whether neuronal-enriched endosomal proteins Nsg-1 (NEEP21) and Nsg-2 (P19) are ubiquitously expressed in all types of cultured neurons. We found that cultured neurons stably maintain cell type identities that are reflective of cell types in vivo. This includes neurons maintaining simultaneous expression of two transcription factors, such as Ctip2+/Satb2+ or Prox1+/Ctip2+ double-positive cells, which have also been described in vivo. Secondly, we established the superior efficiency of CAG promoters for both Lipofectamine-mediated transfection as well as for electroporation. Thirdly, we discovered that Nsg-1 and Nsg-2 were not expressed equally in all neurons: whereas high levels of both Nsg-1 and Nsg-2 were found in Satb2-, Ctip2-, and GAD65-positive neurons, Prox1-positive neurons in hippocampal cultures expressed low levels of both. Our findings thus highlight the importance of identifying neuronal cell types for doing cell biology in cultured neurons: Keeping track of neuronal cell type might uncover effects in assays that might otherwise be masked by the mixture of responsive and non-responsive neurons in the dish.

  2. DIRECT VISUALIZATION OF THE DOPAMINE TRANSPORTER IN CULTURED NEWBORN RAT MIDBRAIN NEURONS USING THE FLUORESCENT COCAINE ANALOGUE JHC 1-64

    DEFF Research Database (Denmark)

    Rasmussen, Søren; Vægter, Christian Bjerggaard; Cha, J

    In this study we have established methods for visualization and tracking of the dopamine transporter (DAT) in cultured dopaminergic neurons in real time using a fluorescent cocaine analogue JHC 1-64 and confocal fluorescence microscopy. The initial binding experiments in HEK 293 cells stably......-DAT was internalized, corroborating the usefulness of this cocaine analogue as a tool for monitoring DAT trafficking. In the cultured neurons JHC 1-64 labeled the surface of almost the entire dopaminergic neurons including the cell body, although not as strongly as some of the neuronal extensions. This labeling by JHC...... 1-64 was prevented by excess concentrations of dopamine, cocaine, mazindol, or RTI-55, whereas the norepinephrine and/or serotonin transporter specific inhibitors desmethylimipramine and citalopram did not affect fluorescent labeling of the neurons. This strongly supports that JHC 1-64 specifically...

  3. A subpopulation of dopaminergic neurons co-expresses serotonin in ventral mesencephalic cultures but not after intrastriatal transplantation in a rat model of Parkinsons disease

    DEFF Research Database (Denmark)

    Di Santo, Stefano; Seiler, Stefanie; Ducray, Angélique

    2017-01-01

    of a mixed neuronal population and its heterogeneity likely contributes to the inconsistent outcome observed in clinical trials. Detailed knowledge about the neuronal subpopulations in the VM seems, hence, essential for successful cell transplantation. Interestingly, it has been reported that some tyrosine...... 30% of the dopaminergic neurons in the donor tissue co-expressed serotonin, no co-localization could be detected in grafts one month after intrastriatal transplantation into hemi-parkinsonian rats. In conclusion, a significant and susceptible sub-population of dopaminergic neurons in fetal VM tissues...... hydroxylase (TH) positive neurons in the VM of adult rats and in cultured midbrain-derived neuroblasts co-express additional neurotransmitters. Thus, the present study investigated by means of co-localization analyses for the possible expression of GABA or serotonin in TH positive neurons. For that purpose...

  4. Activity of the lactate-alanine shuttle is independent of glutamate-glutamine cycle activity in cerebellar neuronal-astrocytic cultures

    DEFF Research Database (Denmark)

    Bak, Lasse K; Sickmann, Helle M; Schousboe, Arne

    2004-01-01

    The glutamate-glutamine cycle describes the neuronal release of glutamate into the synaptic cleft, astrocytic uptake, and conversion into glutamine, followed by release for use as a neuronal glutamate precursor. This only explains the fate of the carbon atoms, however, and not that of the ammonia....... Recently, a role for alanine has been proposed in transfer of ammonia between glutamatergic neurons and astrocytes, denoted the lactate-alanine shuttle (Waagepetersen et al. [ 2000] J. Neurochem. 75:471-479). The role of alanine in this context has been studied further using cerebellar neuronal cultures...... and corresponding neuronal-astrocytic cocultures. A superfusion paradigm was used to induce repetitively vesicular glutamate release by N-methyl-D-aspartate (NMDA) in the neurons, allowing the relative activity dependency of the lactate-alanine shuttle to be assessed. [(15)N]Alanine (0.2 mM), [2-(15)N]/[5-(15)N...

  5. Imaging of mitochondrial and non-mitochondrial responses in cultured rat hippocampal neurons exposed to micromolar concentrations of TMRM.

    Directory of Open Access Journals (Sweden)

    Andrew Monteith

    Full Text Available Tetramethylrhodamine methyl ester (TMRM is a fluorescent dye used to study mitochondrial function in living cells. Previously, we reported that TMRM effectively labeled mitochondria of neurons deep within mouse brain slices. Use of micromolar concentration of dye, which was required to get sufficient staining for two-photon imaging, resulted in typical fluctuations of TMRM. With prolonged exposure, we recorded additional responses in some neurons that included slow oscillations and propagating waves of fluorescence. (Note: We use the terms "fluctuation" to refer to a change in the fluorescent state of an individual mitochondrion, "oscillation" to refer to a localized change in fluorescence in the cytosol, and "wave" to refer to a change in cytosolic fluorescence that propagated within a cell. Use of these terms does not imply any underlying periodicity. In this report we describe similar results using cultured rat hippocampal neurons. Prolonged exposure of cultures to 2.5 µM TMRM produced a spontaneous increase in fluorescence in some neurons, but not glial cells, after 45-60 minutes that was followed by slow oscillations, waves, and eventually apoptosis. Spontaneous increases in fluorescence were insensitive to high concentrations of FCCP (100 µM and thapsigargin (10 µM indicating that they originated, at least in part, from regions outside of mitochondria. The oscillations did not correlate with changes in intracellular Ca(2+, but did correlate with differences in fluorescence lifetime of the dye. Fluorescence lifetime and one-photon ratiometric imaging of TMRM suggested that the spontaneous increase and subsequent oscillations were due to movement of dye between quenched (hydrophobic and unquenched (hydrophilic compartments. We propose that these movements may be correlates of intracellular events involved in early stages of apoptosis.

  6. Isolation and Culture of Pig Spermatogonial Stem Cells and Their in Vitro Differentiation into Neuron-Like Cells and Adipocytes

    Directory of Open Access Journals (Sweden)

    Xiaoyan Wang

    2015-11-01

    Full Text Available Spermatogonial stem cells (SSCs renew themselves throughout the life of an organism and also differentiate into sperm in the adult. They are multipopent and therefore, can be induced to differentiate into many cells types in vitro. SSCs from pigs, considered an ideal animal model, are used in studies of male infertility, regenerative medicine, and preparation of transgenic animals. Here, we report on a culture system for porcine SSCs and the differentiation of these cells into neuron-like cells and adipocytes. SSCs and Sertoli cells were isolated from neonatal piglet testis by differential adhesion and SSCs were cultured on a feeder layer of Sertoli cells. Third-generation SSCs were induced to differentiate into neuron-like cells by addition of retinoic acid, β-mercaptoethanol, and 3-isobutyl-1-methylxanthine (IBMX to the induction media and into adipocytes by the addition of hexadecadrol, insulin, and IBMX to the induction media. The differentiated cells were characterized by biochemical staining, qRT-PCR, and immunocytochemistry. The cells were positive for SSC markers, including alkaline phosphatase and SSC-specific genes, consistent with the cells being undifferentiated. The isolated SSCs survived on the Sertoli cells for 15 generations. Karyotyping confirmed that the chromosomal number of the SSCs were normal for pig (2n = 38, n = 19. Pig SSCs were successfully induced into neuron-like cells eight days after induction and into adipocytes 22 days after induction as determined by biochemical and immunocytochemical staining. qPCR results also support this conclusion. The nervous tissue markers genes, Nestin and β-tubulin, were expressed in the neuron-like cells and the adipocyte marker genes, PPARγ and C/EBPα, were expressed in the adipocytes.

  7. Micro fluidic System for Culturing and Monitoring of Neuronal Cells and Tissue

    DEFF Research Database (Denmark)

    Bakmand, Tanya; Waagepetersen, Helle S.

    The aim of this Ph.D. project was to combine experience within cell and tissue culturing, electrochemistry and microfabrication in order to develop an in vivo-like fluidic culturing platform, challenging the traditional culturing methods. The first goal was to develope a fluidic system for cultur...

  8. Folate and S-adenosylmethionine modulate synaptic activity in cultured cortical neurons: acute differential impact on normal and apolipoprotein-deficient mice

    International Nuclear Information System (INIS)

    Serra, Michael; Chan, Amy; Dubey, Maya; Shea, Thomas B; Gilman, Vladimir

    2008-01-01

    Folate deficiency is accompanied by a decline in the cognitive neurotransmitter acetylcholine and a decline in cognitive performance in mice lacking apolipoprotein E (ApoE−/− mice), a low-density lipoprotein that regulates aspects of lipid metabolism. One direct consequence of folate deficiency is a decline in S-adenosylmethionine (SAM). Since dietary SAM supplementation maintains acetylcholine levels and cognitive performance in the absence of folate, we examined herein the impact of folate and SAM on neuronal synaptic activity. Embryonic cortical neurons from mice expressing or lacking ApoE (ApoE+/+ or −/−, respectively) were cultured for 1 month on multi-electrode arrays, and signaling was recorded. ApoE+/+ cultures displayed significantly more frequent spontaneous signals than ApoE−/− cultures. Supplementation with 166 µm SAM (not normally present in culture medium) increased signal frequency and decreased signal amplitude in ApoE+/+ cultures. SAM also increased the frequency of tightly clustered signal bursts. Folate deprivation reversibly reduced signal frequency in ApoE+/+ cultures; SAM supplementation maintained signal frequency despite folate deprivation. These findings support the importance of dietary supplementation with folate and SAM on neuronal health. Supplementation with 166 µm SAM did not alter signaling in ApoE−/− cultures, which may be a reflection of the reduced SAM levels in ApoE−/− mice. The differential impact of SAM on ApoE+/+ and −/− neurons underscores the combined impact of nutritional and genetic deficiencies on neuronal homeostasis. (communication)

  9. Protective effects of humanin on okadaic Acid-induced neurotoxicities in cultured cortical neurons.

    Science.gov (United States)

    Zhao, Jinfeng; Wang, Dan; Li, Lingmin; Zhao, Wenhui; Zhang, Ce

    2014-11-01

    Neurofibrillary tangles are pathological hallmarks of Alzheimer's disease (AD), which are mostly composed of hyperphosphorylated tau and directly correlate with dementia in AD patients. Okadaic acid (OA), a toxin extracted from marine life, can specifically inhibit protein phosphatases (PPs), including PP1 and Protein phosphatase 2A (PP2A), resulting in tau hyperphosphorylation. Humanin (HN), a peptide of 24 amino acids, was initially reported to protect neurons from AD-related cell toxicities. The present study was designed to test if HN could attenuate OA-induced neurotoxicities, including neural insults, apoptosis, autophagy, and tau hyperphosphorylation. We found that administration of OA for 24 h induced neuronal insults, including lactate dehydrogenase released, decreased of cell viability and numbers of living cells, neuronal apoptosis, cells autophagy and tau protein hyperphosphorylation. Pretreatment of cells with HN produced significant protective effects against OA-induced neural insults, apoptosis, autophagy and tau hyperphosphorylation. We also found that OA treatment inhibited PP2A activity and HN pretreatment significantly attenuated the inhibitory effects of OA. This study demonstrated for the first time that HN protected cortical neurons against OA-induced neurotoxicities, including neuronal insults, apoptosis, autophagy, and tau hyperphosphorylation. The mechanisms underlying the protections of HN may involve restoration of PP2A activity.

  10. Long-term culture of rat hippocampal neurons at low density in serum-free medium: combination of the sandwich culture technique with the three-dimensional nanofibrous hydrogel PuraMatrix.

    Science.gov (United States)

    Kaneko, Ai; Sankai, Yoshiyuki

    2014-01-01

    The primary culture of neuronal cells plays an important role in neuroscience. There has long been a need for methods enabling the long-term culture of primary neurons at low density, in defined serum-free medium. However, the lower the cell density, the more difficult it is to maintain the cells in culture. Therefore, we aimed to develop a method for long-term culture of neurons at low density, in serum-free medium, without the need for a glial feeder layer. Here, we describe the work leading to our determination of a protocol for long-term (>2 months) primary culture of rat hippocampal neurons in serum-free medium at the low density of 3×10(4) cells/mL (8.9×10(3) cells/cm2) without a glial feeder layer. Neurons were cultured on a three-dimensional nanofibrous hydrogel, PuraMatrix, and sandwiched under a coverslip to reproduce the in vivo environment, including the three-dimensional extracellular matrix, low-oxygen conditions, and exposure to concentrated paracrine factors. We examined the effects of varying PuraMatrix concentrations, the timing and presence or absence of a coverslip, the timing of neuronal isolation from embryos, cell density at plating, medium components, and changing the medium or not on parameters such as developmental pattern, cell viability, neuronal ratio, and neurite length. Using our method of combining the sandwich culture technique with PuraMatrix in Neurobasal medium/B27/L-glutamine for primary neuron culture, we achieved longer neurites (≥3,000 µm), greater cell viability (≥30%) for 2 months, and uniform culture across the wells. We also achieved an average neuronal ratio of 97%, showing a nearly pure culture of neurons without astrocytes. Our method is considerably better than techniques for the primary culture of neurons, and eliminates the need for a glial feeder layer. It also exhibits continued support for axonal elongation and synaptic activity for long periods (>6 weeks).

  11. Glucose is necessary to maintain neurotransmitter homeostasis during synaptic activity in cultured glutamatergic neurons

    DEFF Research Database (Denmark)

    Bak, Lasse K; Schousboe, Arne; Sonnewald, Ursula

    2006-01-01

    Glucose is the primary energy substrate for the adult mammalian brain. However, lactate produced within the brain might be able to serve this purpose in neurons. In the present study, the relative significance of glucose and lactate as substrates to maintain neurotransmitter homeostasis was inves...

  12. Exogenous α-synuclein hinders synaptic communication in cultured cortical primary rat neurons

    NARCIS (Netherlands)

    Hassink, G. C.; Raiss, C. C.; Segers-Nolten, I. M.J.; Van Wezel, R. J.A.; Subramaniam, V.; Le Feber, J.; Claessens, M. M.A.E.

    2018-01-01

    Amyloid aggregates of the protein a-synuclein (aS) called Lewy Bodies (LB) and Lewy Neurites (LN) are the pathological hallmark of Parkinson's disease (PD) and other synucleinopathies. We have previously shown that high extracellular αS concentrations can be toxic to cells and that neurons take up

  13. Reciprocal influences of nigral cells and striatal patch neurons in dissociated co-cultures

    NARCIS (Netherlands)

    Aronica, E.; Costantini, L. C.; Snyder-Keller, A.

    1996-01-01

    Our previous work has shown that the functional efficacy of nigral tissue transplants into dopamine (DA)-depleted rats is increased when embryonic striatal tissue is included (Costantini et al.: Exp Neurol 127:219-231, 1994). To examine further the influence of striatal patch neurons in this regard,

  14. Nano-ampère stimulation window for cultured neurons on micro-electrode arrays

    NARCIS (Netherlands)

    Buitenweg, Jan R.; Rutten, Wim; Marani, Enrico

    2001-01-01

    From experiments, it appears to be possible to stimulate a neuron by depolarisation of the lower membrane patch, the sealing part of the membrane, using a nano-ampere current through the extracellular electrode. Also, a stimulation window is observed. These findings can be explained by a finite

  15. Elevated potassium prevents neuronal death but inhibits network formation in neocortical cultures

    NARCIS (Netherlands)

    Baker, R. E.; Ruijter, J. M.; Bingmann, D.

    1991-01-01

    Chronic depolarization is inimical to neuronal growth and synaptogenesis so that spontaneous action potential generation appears to be required for the normal cytomorphological maturation of neocortical networks. The efficacy of 25 mM K in suppressing spontaneous bioelectric activity was monitored

  16. Orexin-A expression in dissociated neuronal cultures of the newborn rat cortex

    NARCIS (Netherlands)

    Stoyanova, Irina; le Feber, Jakob; Wiertz, Remy; Rutten, Wim

    2009-01-01

    Orexin A is a neuropeptide isolated from a small group of neurons in the hypothalamus, which orchestrates many different brain functions. Despite the extensive information about orexin A expression and function in the nervous system of adults, data about the formation and maturation of the orexin

  17. Role of IFN-gamma and LPS on Neuron/Glial Co-Cultures Infected by Neospora caninum

    Directory of Open Access Journals (Sweden)

    Erica Etelvina Viana De Jesus

    2014-10-01

    Full Text Available Neospora caninum causes cattle abortion and neurological symptoms in dogs. Although infection is usually asymptomatic, classical neurological symptoms of neosporosis may be associated with encephalitis. This parasite can grow in brain endothelial cells without markedly damages, but it can modulate the cellular environment to promote its survival in the brain. In previous studies, we described that IFN-γ decreased the parasite proliferation and down regulated nitric oxide production in astrocyte/microglia cultures. However, it remains unclear how glial cells respond to N. caninum in the presence of neurons. Therefore, we evaluated the effect of 300 IU/mL IFN-γ or 1.0 μg/mL of LPS on infected rat neuron/glial co-cultures. After 72 hours of infection, LPS did not affect the mitochondrial dehydrogenase activity. However, IFN-γ decreased this parameter by 15.5 and 12.0% in uninfected and infected cells, respectively. The number of tachyzoites decreased 54.1 and 44.3% in cells stimulated with IFN-γ and LPS, respectively. Infection or LPS treatment did not change NO production. On the other hand, IFN-γ induced increased nitrite release in 55.7%, but the infection reverted this induction. IL-10 levels increased only in infected cultures (treated or not, meanwhile PGE2 release was improved in IFN-γ/infected or LPS/infected cells. Although IFN-γ significantly reduced the neurite length in uninfected cultures (42.64%; p < 0.001, this inflammatory cytokine reverted the impairment of neurite outgrowth induced by the infection (81.39%. The results suggest a neuroprotective potential response of glia to N. caninum infection under IFN-γ stimulus. This observation contributes to understand the immune mediated mechanisms of neosporosis in CNS

  18. Neuron cell positioning on polystyrene in culture by silver-negative ion implantation and region control of neural outgrowth

    International Nuclear Information System (INIS)

    Tsuji, Hiroshi; Sato, Hiroko; Baba, Takahiro; Ikemura, Shin'ichi; Gotoh, Yasuhito; Ishikawa, Junzo

    2000-01-01

    A new method to control the position of neuron cell attachment and extension region of neural outgrowth has been developed by using a pattering ion implantation with silver-negative ions into polystyrene dishes. This technique offers a promising method to form an artificially designed neural network in cell culture in vitro. Silver-negative ions were implanted into non-treated polystyrene dishes (NTPS) at conditions of 20 keV and 3x10 15 ions/cm 2 through a pattering mask, which had as many as 67 slits of 60 μm in width and 4 mm in length with a spacing of 60 μm. For cell culture in vitro, nerve cells of PC-12h (rat adrenal phechromocytoma) were used because they respond to a nerve growth factor (NGF). In the first 2 days in culture without NGF, we observed a selective cell attachment only to the ion-implanted region in patterning Ag - implanted polystyrene sample (p-Ag/NTPS). In another 2 days in culture with NGF, the nerve cells expanded neurites only over the ion-implanted region. For collagen-coated p-Ag/NTPS sample of which collagen was coated after the ion implantation (Collagen/p-Ag/NTPS), most nerve cells were also attached on the ion-implanted region. However, neurites expanded in both ion-implanted and unimplanted regions. The contact angle of NTPS decreased after the ion implantation from 86 deg. to 74 deg. . The region selectivity of neuron attachment and neurite extension is considered to be due to contact angle lowering by the ion implantation as radiation effect on the surface

  19. Characterization of spiral ganglion neurons cultured on silicon micro-pillar substrates for new auditory neuro-electronic interfaces

    Science.gov (United States)

    Mattotti, M.; Micholt, L.; Braeken, D.; Kovačić, D.

    2015-04-01

    Objective. One of the strategies to improve cochlear implant technology is to increase the number of electrodes in the neuro-electronic interface. The objective was to characterize in vitro cultures of spiral ganglion neurons (SGN) cultured on surfaces of novel silicon micro-pillar substrates (MPS). Approach. SGN from P5 rat pups were cultured on MPS with different micro-pillar widths (1-5.6 μm) and spacings (0.6-15 μm) and were compared with control SGN cultures on glass coverslips by immunocytochemistry and scanning electron microscopy (SEM). Main results. Overall, MPS support SGN growth equally well as the control glass surfaces. Micro-pillars of a particular size-range (1.2-2.4 μm) were optimal in promoting SGN presence, neurite growth and alignment. On this specific micro-pillar size, more SGN were present, and neurites were longer and more aligned. SEM pictures highlight how cells on micro-pillars with smaller spacings grow directly on top of pillars, while at wider spacings (from 3.2 to 15 μm) they grow on the bottom of the surface, losing contact guidance. Further, we found that MPS encourage more monopolar and bipolar SGN morphologies compared to the control condition. Finally, MPS induce longest neurite growth with minimal interaction of S100+ glial cells. Significance. These results indicate that silicon micro-pillar substrates create a permissive environment for the growth of primary auditory neurons promoting neurite sprouting and are a promising technology for future high-density three-dimensional CMOS-based auditory neuro-electronic interfaces.

  20. Comparison of P2X and TRPV1 receptors in ganglia or primary culture of trigeminal neurons and their modulation by NGF or serotonin

    Directory of Open Access Journals (Sweden)

    Giniatullin Rashid

    2006-03-01

    Full Text Available Abstract Background Cultured sensory neurons are a common experimental model to elucidate the molecular mechanisms of pain transduction typically involving activation of ATP-sensitive P2X or capsaicin-sensitive TRPV1 receptors. This applies also to trigeminal ganglion neurons that convey pain inputs from head tissues. Little is, however, known about the plasticity of these receptors on trigeminal neurons in culture, grown without adding the neurotrophin NGF which per se is a powerful algogen. The characteristics of such receptors after short-term culture were compared with those of ganglia. Furthermore, their modulation by chronically-applied serotonin or NGF was investigated. Results Rat or mouse neurons in culture mainly belonged to small and medium diameter neurons as observed in sections of trigeminal ganglia. Real time RT-PCR, Western blot analysis and immunocytochemistry showed upregulation of P2X3 and TRPV1 receptors after 1–4 days in culture (together with their more frequent co-localization, while P2X2 ones were unchanged. TRPV1 immunoreactivity was, however, lower in mouse ganglia and cultures. Intracellular Ca2+ imaging and whole-cell patch clamping showed functional P2X and TRPV1 receptors. Neurons exhibited a range of responses to the P2X agonist α, β-methylene-adenosine-5'-triphosphate indicating the presence of homomeric P2X3 receptors (selectively antagonized by A-317491 and heteromeric P2X2/3 receptors. The latter were observed in 16 % mouse neurons only. Despite upregulation of receptors in culture, neurons retained the potential for further enhancement of P2X3 receptors by 24 h NGF treatment. At this time point TRPV1 receptors had lost the facilitation observed after acute NGF application. Conversely, chronically-applied serotonin selectively upregulated TRPV1 receptors rather than P2X3 receptors. Conclusion Comparing ganglia and cultures offered the advantage of understanding early adaptive changes of nociception

  1. Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats.

    Science.gov (United States)

    Jayaraman, Anusha; Christensen, Amy; Moser, V Alexandra; Vest, Rebekah S; Miller, Chris P; Hattersley, Gary; Pike, Christian J

    2014-04-01

    The decline in testosterone levels in men during normal aging increases risks of dysfunction and disease in androgen-responsive tissues, including brain. The use of testosterone therapy has the potential to increase the risks for developing prostate cancer and or accelerating its progression. To overcome this limitation, novel compounds termed "selective androgen receptor modulators" (SARMs) have been developed that lack significant androgen action in prostate but exert agonist effects in select androgen-responsive tissues. The efficacy of SARMs in brain is largely unknown. In this study, we investigate the SARM RAD140 in cultured rat neurons and male rat brain for its ability to provide neuroprotection, an important neural action of endogenous androgens that is relevant to neural health and resilience to neurodegenerative diseases. In cultured hippocampal neurons, RAD140 was as effective as testosterone in reducing cell death induced by apoptotic insults. Mechanistically, RAD140 neuroprotection was dependent upon MAPK signaling, as evidenced by elevation of ERK phosphorylation and inhibition of protection by the MAPK kinase inhibitor U0126. Importantly, RAD140 was also neuroprotective in vivo using the rat kainate lesion model. In experiments with gonadectomized, adult male rats, RAD140 was shown to exhibit peripheral tissue-specific androgen action that largely spared prostate, neural efficacy as demonstrated by activation of androgenic gene regulation effects, and neuroprotection of hippocampal neurons against cell death caused by systemic administration of the excitotoxin kainate. These novel findings demonstrate initial preclinical efficacy of a SARM in neuroprotective actions relevant to Alzheimer's disease and related neurodegenerative diseases.

  2. Dependence of synchronized bursting activity on medium stirring and the perfusion rate in a cultured network of neurons

    Science.gov (United States)

    Heo, Ryoun; Kim, Hyun; Lee, Kyoung J.

    2016-05-01

    A cultured network of neurons coupled with a multi-electrode-array (MEA) recording system has been a useful platform for investigating various issues in neuroscience and engineering. The neural activity supported by the system can be sensitive to environmental fluctuations, for example, in the medium's nutrient composition, ph, and temperature, and to mechanical disturbances, yet this issue has not been the subject. Especially, a normal practice in maintaining neuronal cell cultures involves an intermittent sequence of medium exchanges, typically at a time interval of a few days, and one such sudden medium exchange is unavoidably accompanied by many unintended disturbances. Here, based on a quantitative time-series analysis of synchronized bursting events, we explicitly demonstrate that such a medium exchange can, indeed, bring a huge change in the existing neural activity. Subsequently, we develop a medium perfusion-stirring system and an ideal protocol that can be used in conjunction with a MEA recording system, providing long-term stability. Specifically, we systematically evaluate the effects of medium stirring and perfusion rates. Unexpectedly, even some vigorous mechanical agitations do not have any impacts on neural activity. On the other hand, too much replenishment ( e.g., 1.8 ml/day for a 1.8-ml dish) of neurobasal medium results in an excitotoxicity.

  3. Huntington's disease modeling and treatment: from primary neuronal cultures to rodents

    OpenAIRE

    Zala, Diana; Aebischer, Patrick; Déglon, Nicole

    2007-01-01

    Huntington's disease (HD) is a mid-life-onset neurodegenerative disorder characterized by involuntary movements, personality changes and dementia. It progresses to death within 10-20 years after onset. There is currently no cure to treat this fatal disease. In HD patients, the protein huntingtin contains an abnormal expansion of a polyglutamine tract, which leads to the selective death of striatal neurons. The functions of huntingtin, as well as the dysfunctions induced by the mutation are st...

  4. Crambescidin 816 induces calcium influx though glutamate receptors in primary cultures of cortical neurons

    Directory of Open Access Journals (Sweden)

    Víctor Martín Vázquez

    2014-06-01

    In summary, our data suggest that the cytotoxic effect of 10 μM Cramb816 in cortical neurons may be related to an increase in the cytosolic calcium concentration elicited by the toxin, which is shown to be mediated by glutamate receptor activation. Further studies analyzing the effect of glutamate receptor blockers on the cytotoxic effect of Cramb816 are needed to confirm this hypothesis.

  5. Nonyloxytryptamine Mimics Polysialic Acid and Modulates Neuronal and Glial Functions in Cell Culture

    Science.gov (United States)

    2014-01-01

    outgrowth from NCAM-deficient neurons. Data repre- sent mean values of neurite lengths per cell SEM as compared with PLL only from three independent...around 800 lm in the cell layer (gap width 100%). Recolonization of the wounded areas (closure of the gap) was studied using an inverted phase -contrast...lengths per cell were determined from 50 cells in each of two wells per experiment. At least three independent experiments were performed per condition

  6. Effects of Trace Metal Profiles Characteristic for Autism on Synapses in Cultured Neurons

    OpenAIRE

    Hagmeyer, Simone; Mangus, Katharina; Boeckers, Tobias M.; Grabrucker, Andreas M.

    2015-01-01

    Various recent studies revealed that biometal dyshomeostasis plays a crucial role in the pathogenesis of neurological disorders such as autism spectrum disorders (ASD). Substantial evidence indicates that disrupted neuronal homeostasis of different metal ions such as Fe, Cu, Pb, Hg, Se, and Zn may mediate synaptic dysfunction and impair synapse formation and maturation. Here, we performed in vitro studies investigating the consequences of an imbalance of transition metals on glutamatergic syn...

  7. Involvement of cyclin D1/CDK4 and pRb mediated by PI3K/AKT pathway activation in Pb2+-induced neuronal death in cultured hippocampal neurons

    International Nuclear Information System (INIS)

    Li Chenchen; Xing Tairan; Tang Mingliang; Yong Wu; Yan Dan; Deng Hongmin; Wang Huili; Wang Ming; Chen Jutao; Ruan Diyun

    2008-01-01

    Lead (Pb) is widely recognized as a neurotoxicant. One of the suggested mechanisms of lead neurotoxicity is apoptotic cell death. And the mechanism by which Pb 2+ causes neuronal death is not well understood. The present study sought to examine the obligate nature of cyclin D1/cyclin-dependent kinase 4 (CDK4), phosphorylation of its substrate retinoblastoma protein (pRb) and its select upstream signal phosphoinositide 3-kinase (PI3K)/AKT pathway in the death of primary cultured rat hippocampal neurons evoked by Pb 2+ . Our data showed that lead treatment of primary hippocampal cultures results in dose-dependent cell death. Inhibition of CDK4 prevented Pb 2+ -induced neuronal death significantly but was incomplete. In addition, we demonstrated that the levels of cyclin D1 and pRb/p107 were increased during Pb 2+ treatment. These elevated expression persisted up to 48 h, returning to control levels after 72 h. We also presented pharmacological and morphological evidences that cyclin D1/CDK4 and pRb/p107 were required for such kind of neuronal death. Addition of the PI3K inhibitor LY294002 (30 μM) or wortmannin (100 nM) significantly rescued the cultured hippocampal neurons from death caused by Pb 2+ . And that Pb 2+ -elicited phospho-AKT (Ser473) participated in the induction of cyclin D1 and partial pRb/p107 expression. These results provide evidences that cell cycle elements play a required role in the death of neurons evoked by Pb 2+ and suggest that certain signaling elements upstream of cyclin D1/CDK4 are modified and/or required for this form of neuronal death

  8. Ciliary neurotrophic factor reverses aberrant mitochondrial bioenergetics through the JAK/STAT pathway in cultured sensory neurons derived from streptozotocin-induced diabetic rodents.

    Science.gov (United States)

    Chowdhury, Subir Roy; Saleh, Ali; Akude, Eli; Smith, Darrell R; Morrow, Dwane; Tessler, Lori; Calcutt, Nigel A; Fernyhough, Paul

    2014-07-01

    Mitochondrial dysfunction occurs in sensory neurons and contributes to diabetic neuropathy. Ciliary neurotrophic factor (CNTF) stimulates axon regeneration in type 1 diabetic rodents and prevents deficits in axonal caliber, nerve conduction, and thermal sensation. We tested the hypothesis that CNTF enhances sensory neuron function in diabetes through JAK/STAT (Janus kinase/signal transducers and activators of transcription) signaling to normalize impaired mitochondrial bioenergetics. The effect of CNTF on gene expression and neurite outgrowth of cultured adult dorsal root ganglia (DRG) sensory neurons derived from control and streptozotocin (STZ)-induced diabetic rodents was quantified. Polarization status and bioenergetics profile of mitochondria from cultured sensory neurons were determined. CNTF treatment prevented reduced STAT3 phosphorylation (Tyr 705) in DRG of STZ-diabetic mice and also enhanced STAT3 phosphorylation in rat DRG cultures. CNTF normalized polarization status of the mitochondrial inner membrane and corrected the aberrant oligomycin-induced mitochondrial hyperpolarization in axons of diabetic neurons. The mitochondrial bioenergetics profile demonstrated that spare respiratory capacity and respiratory control ratio were significantly depressed in sensory neurons cultured from STZ-diabetic rats and were corrected by acute CNTF treatment. The positive effects of CNTF on neuronal mitochondrial function were significantly inhibited by the specific JAK inhibitor, AG490. Neurite outgrowth of sensory neurons from age-matched control and STZ-induced diabetic rats was elevated by CNTF and blocked by AG490. We propose that CNTF's ability to enhance axon regeneration and protect from fiber degeneration in diabetes is associated with its targeting of mitochondrial function and improvement of cellular bioenergetics, in part, through JAK/STAT signaling.

  9. Culturing of PC12 Cells, Neuronal Cells, Astrocytes Cultures and Brain Slices in an Open Microfluidic System

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya; Rømer Sørensen, Ane

    and electrochemical sensor system that enables real time detection of metabolites, e.g. dopamine from cell cultures and brain slices. In summary we present results on culturing of brain slices and cells in the microfluidic system as well as on the incorporation of an electrochemical sensor system for characterization......The brain is the center of the nervous system, where serious neurodegenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s are products of functional loss in the neural cells (1). Typical techniques used to investigate these diseases lack precise control of the cellular surroundings......, in addition to isolating the neural tissue from nutrient delivery and to creating unwanted gradients (2). This means that typical techniques used to investigate neurodegenerative diseases cannot mimic in vivo conditions, as closely as desired. We have developed a novel microfluidic system for culturing PC12...

  10. Using FRAP or FRAPA to Visualize the Movement of Fluorescently Labeled Proteins or Cellular Organelles in Live Cultured Neurons Transformed with Adeno-Associated Viruses.

    Science.gov (United States)

    Tevet, Yaara; Gitler, Daniel

    2016-01-01

    Fluorescence recovery after photobleaching (FRAP) and fluorescence redistribution after photoactivation (FRAPA) are complementary methods used to gauge the movement of proteins or sub-resolution organelles within cells. Using these methods we can determine the nature of the movement of labeled particles, whether it is random, constrained, or active, the coefficient of diffusion if applicable, binding and unbinding constants, and the direction of active transport. These two techniques have been extensively utilized to probe the cell biology of neurons. A practical outline of FRAP and FRAPA in cultured neurons is presented, including the preparation of the neurons and their infection with adeno-associated viral vectors. Considerations in planning such experiments are provided.

  11. Cellular changes in motor neuron cell culture produced by cytotoxic cerebrospinal fluid from patients with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Gomez-Pinedo, U; Yáñez, M; Matías-Guiu, J; Galán, L; Guerrero-Sola, A; Benito-Martin, M S; Vela, A; Arranz-Tagarro, J A; García, A G

    2014-01-01

    The neurotoxic effects of cerebrospinal fluid (CSF) from patients with amyotrophic lateral sclerosis (ALS) have been reported by various authors who have attributed this neurotoxicity to the glutamate in CSF-ALS. Cultures of rat embryonic cortical neurons were exposed to CSF from ALS patients during an incubation period of 24 hours. Optical microscopy was used to compare cellular changes to those elicited by exposure to 100μm glutamate, and confocal microscopy was used to evaluate immunohistochemistry for caspase-3, TNFα, and peripherin. In the culture exposed to CSF-ALS, we observed cells with nuclear fragmentation and scarce or null structural modifications to the cytoplasmic organelles or to plasma membrane maintenance. This did not occur in the culture exposed to glutamate. The culture exposed to CSF-ALS also demonstrated increases in caspase-3, TNFα, and in peripherin co-locating with caspase-3, but not with TNFα, suggesting that TNFα may play an early role in the process of apoptosis. CFS-ALS cytotoxicity is not related to glutamate. It initially affects the nucleus without altering the cytoplasmic membrane. It causes cytoplasmic apoptosis that involves an increase in caspase-3 co-located with peripherin, which is also overexpressed. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  12. The development of the action potential mechanism of amphibian neurons isolated in culture.

    Science.gov (United States)

    Spitzer, N C; Lamborghini, J E

    1976-05-01

    Nerve and muscle cells differentiated morphologically, in cultures of dissociated cells prepared from amphibian neural plate and underlying mesoderm (Xenopus laevis, Nieuwkoop and Faber stage 15). Cultures were grown in a defined medium containing sterile Steinberg's salt solution and 0.1% bovine serum albumin, and maintained for periods up to 5 days.

  13. Protective effects of plant seed extracts against amyloid β-induced neurotoxicity in cultured hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Yoshinori Okada

    2013-01-01

    Full Text Available Aim: Alzheimer′s disease (AD is characterized by large deposits of amyloid β (Aβ peptide. Aβ is known to increase reactive oxygen species (ROS production in neurons, leading to cell death. In this study, we screened 15 plant seeds′ aqueous extracts (PSAE for inhibitory effects on Aβ (25-35-induced cell death using hippocampus neurons (HIPN. Materials and Methods: Fifteen chosen plants were nine medical herbs (Japanese honeywort, luffa, rapeseed, Chinese colza, potherb mustard, Japanese radish, bitter melon, red shiso, corn, and kaiware radish and six general commercial plants (common bean, komatsuna, Qing geng cai, bell pepper, kale, and lettuce. PSAE were measured for total phenolic content (TPC with the Folin-Ciocalteu method, and the 2-diphenyl-1-picryl-hydrazyl (DPPH radical scavenging effect of each seed extract was measured. To find a protectant against Aβ-induced oxidative stress, we screened 15 PSAE using a 2′, 7′-dichlorofluorescein diacetate assay. To further unravel the anti-inflammatory effects of PSAE on Aβ-induced inflammation, PSAE were added to HIPN. The neuroprotective effects of the PSAE were evaluated by Cell Counting Kit-8 assay, measuring the cell viability in Aβ-induced HIPN. Results: TPC of 15 PSAE was in the range of 0.024-1.96 mg of chlorogenic acid equivalents/gram. The aqueous extracts showed antioxidant activities. Furthermore, intracellular ROS accumulation resulting from Aβ treatment was reduced when cells were treated with some PSAE. Kale, bitter melon, kaiware radish, red shiso, and corn inhibited tumor necrosis factor-alpha secretion by the Aβ-stimulated neurons and all samples except Japanese honeywort showed enhancement of cell survival. Conclusion: From these results, we suggest that some plant seed extracts offer protection against Aβ-mediated cell death.

  14. Recording Spikes Activity in Cultured Hippocampal Neurons Using Flexible or Transparent Graphene Transistors

    Directory of Open Access Journals (Sweden)

    Farida Veliev

    2017-08-01

    Full Text Available The emergence of nanoelectronics applied to neural interfaces has started few decades ago, and aims to provide new tools for replacing or restoring disabled functions of the nervous systems as well as further understanding the evolution of such complex organization. As the same time, graphene and other 2D materials have offered new possibilities for integrating micro and nano-devices on flexible, transparent, and biocompatible substrates, promising for bio and neuro-electronics. In addition to many bio-suitable features of graphene interface, such as, chemical inertness and anti-corrosive properties, its optical transparency enables multimodal approach of neuronal based systems, the electrical layer being compatible with additional microfluidics and optical manipulation ports. The convergence of these fields will provide a next generation of neural interfaces for the reliable detection of single spike and record with high fidelity activity patterns of neural networks. Here, we report on the fabrication of graphene field effect transistors (G-FETs on various substrates (silicon, sapphire, glass coverslips, and polyimide deposited onto Si/SiO2 substrates, exhibiting high sensitivity (4 mS/V, close to the Dirac point at VLG < VD and low noise level (10−22 A2/Hz, at VLG = 0 V. We demonstrate the in vitro detection of the spontaneous activity of hippocampal neurons in-situ-grown on top of the graphene sensors during several weeks in a millimeter size PDMS fluidics chamber (8 mm wide. These results provide an advance toward the realization of biocompatible devices for reliable and high spatio-temporal sensing of neuronal activity for both in vitro and in vivo applications.

  15. Differential effects of ciguatoxin and maitotoxin in primary cultures of cortical neurons.

    Science.gov (United States)

    Martin, Victor; Vale, Carmen; Antelo, Alvaro; Hirama, Masahiro; Yamashita, Shuji; Vieytes, Mercedes R; Botana, Luis M

    2014-08-18

    Ciguatoxins (CTXs) and maitotoxins (MTXs) are polyether ladder shaped toxins derived from the dinoflagellate Gambierdiscus toxicus. Despite the fact that MTXs are 3 times larger than CTXs, part of the structure of MTXs resembles that of CTXs. To date, the synthetic ciguatoxin, CTX 3C has been reported to activate voltage-gated sodium channels, whereas the main effect of MTX is inducing calcium influx into the cell leading to cell death. However, there is a lack of information regarding the effects of these toxins in a common cellular model. Here, in order to have an overview of the main effects of these toxins in mice cortical neurons, we examined the effects of MTX and the synthetic ciguatoxin CTX 3C on the main voltage dependent ion channels in neurons, sodium, potassium, and calcium channels as well as on membrane potential, cytosolic calcium concentration ([Ca(2+)]c), intracellular pH (pHi), and neuronal viability. Regarding voltage-gated ion channels, neither CTX 3C nor MTX affected voltage-gated calcium or potassium channels, but while CTX 3C had a large effect on voltage-gated sodium channels (VGSC) by shifting the activation and inactivation curves to more hyperpolarized potentials and decreasing peak sodium channel amplitude, MTX, at 5 nM, had no effect on VGSC activation and inactivation but decreased peak sodium current amplitude. Other major differences between both toxins were the massive calcium influx and intracellular acidification produced by MTX but not by CTX 3C. Indeed, the novel finding that MTX produces acidosis supports a pathway recently described in which MTX produces calcium influx via the sodium-hydrogen exchanger (NHX). For the first time, we found that VGSC blockers partially blocked the MTX-induced calcium influx, intracellular acidification, and protected against the short-term MTX-induced cytotoxicity. The results presented here provide the first report that shows the comparative effects of two prototypical ciguatera toxins, CTX 3C

  16. Simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell cultures and in sub-regions of guinea pig brain

    DEFF Research Database (Denmark)

    Schou-Pedersen, Anne Marie Voigt; Hansen, Stine Normann; Tveden-Nyborg, Pernille

    2016-01-01

    In the present paper, we describe a validated chromatographic method for the simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell culture and in sub-regions of the guinea pig brain. Electrochemical...... of intracellular and extracellular amounts of monoamine neurotransmitters and their metabolites in guinea pig frontal cortex and hippocampal primary neuronal cell cultures. Noradrenaline, dopamine and serotonin were found to be in a range from 0.31 to 1.7 pmol per 2 million cells intracellularly, but only...

  17. Long-lasting changes in DNA methylation following short-term hypoxic exposure in primary hippocampal neuronal cultures.

    Directory of Open Access Journals (Sweden)

    Iain Hartley

    Full Text Available While the effects of hypoxia on gene expression have been investigated in the CNS to some extent, we currently do not know what role epigenetics plays in the transcription of many genes during such hypoxic stress. To start understanding the role of epigenetic changes during hypoxia, we investigated the long-term effect of hypoxia on gene expression and DNA methylation in hippocampal neuronal cells. Primary murine hippocampal neuronal cells were cultured for 7 days. Hypoxic stress of 1% O2, 5% CO2 for 24 hours was applied on Day 3, conditions we found to maximize cellular hypoxic stress response without inducing cell death. Cells were returned to normoxia for 4 days following the period of hypoxic stress. On Day 7, Methyl-Sensitive Cut Counting (MSCC was used to identify a genome-wide methylation profile of the hippocampal cell lines to assess methylation changes resulting from hypoxia. RNA-Seq was also done on Day 7 to analyze changes in gene transcription. Phenotypic analysis showed that neuronal processes were significantly shorter after 1 day of hypoxia, but there was a catch-up growth of these processes after return to normoxia. Transcriptome profiling using RNA-Seq revealed 369 differentially expressed genes with 225 being upregulated, many of which form networks shown to affect CNS development and function. Importantly, the expression level of 59 genes could be correlated to the changes in DNA methylation in their promoter regions. CpG islands, in particular, had a strong tendency to remain hypomethylated long after hypoxic stress was removed. From this study, we conclude that short-term, sub-lethal hypoxia results in long-lasting changes to genome wide DNA methylation status and that some of these changes can be highly correlated with transcriptional modulation in a number of genes involved in functional pathways that have been previously implicated in neural growth and development.

  18. Mastoparan-7 rescues botulinum toxin-A poisoned neurons in a mouse spinal cord cell culture model.

    Science.gov (United States)

    Zhang, Peng; Ray, Radharaman; Singh, Bal Ram; Ray, Prabhati

    2013-12-15

    Botulinum neurotoxin serotype A (BoNT/A) is the most potent poison of biological origin known to mankind. The toxicity of BoNT/A is due to the inhibition of neurotransmission at cholinergic synapses; this is responsible for the symptom of flaccid paralysis at peripheral neuromuscular junctions. At a molecular level, the BoNT/A effect is due to its inhibition of stimulated acetylcholine (ACh) release from presynaptic nerve terminals. Currently, there is no antidote available to rescue BoNT/A-poisoned synapses. Here, we report an example of rescuing botulinum-poisoned cultured mouse spinal cord neurons by treatment with Mastoparan-7 (Mas-7), which is known to be a phospholipase A2 activator compound. Mas-7, a naturally occurring bee venom peptide, was delivered to botulinum-poisoned neurons via a drug delivery vehicle (DDV) construct prepared using the recombinant non-toxic heavy chain (HC) fragment of BoNT/A itself. In this method, the BoNT/A HC component in the DDV served as a neuron specific drug targeting molecule. We found that Mas-7 delivered into BoNT/A intoxicated spinal cord cells restored over 40% their property of stimulated neurotransmitter release. Rescue from cell poisoning did not occur from inhibition of the endopeptidase activity of BoNT/A light chain (LC) against its well-known substrate, SNAP-25 that is mechanistically involved in the cholinergic neuroexocytosis process. Rather, Mas-7 induced a physiological host response apparently unrelated to SNAP-25, but linked to the phospholipase-mediated signal transduction pathway. Published by Elsevier Ltd.

  19. Autophagy activation is involved in 3,4-methylenedioxymethamphetamine ('ecstasy'--induced neurotoxicity in cultured cortical neurons.

    Directory of Open Access Journals (Sweden)

    I-Hsun Li

    Full Text Available Autophagic (type II cell death, characterized by the massive accumulation of autophagic vacuoles in the cytoplasm of cells, has been suggested to play pathogenetic roles in cerebral ischemia, brain trauma, and neurodegenerative disorders. 3,4-Methylenedioxymethamphetamine (MDMA or ecstasy is an illicit drug causing long-term neurotoxicity in the brain. Apoptotic (type I and necrotic (type III cell death have been implicated in MDMA-induced neurotoxicity, while the role of autophagy in MDMA-elicited neurotoxicity has not been investigated. The present study aimed to evaluate the occurrence and contribution of autophagy to neurotoxicity in cultured rat cortical neurons challenged with MDMA. Autophagy activation was monitored by expression of microtubule-associated protein 1 light chain 3 (LC3; an autophagic marker using immunofluorescence and western blot analysis. Here, we demonstrate that MDMA exposure induced monodansylcadaverine (MDC- and LC3B-densely stained autophagosome formation and increased conversion of LC3B-I to LC3B-II, coinciding with the neurodegenerative phase of MDMA challenge. Autophagy inhibitor 3-methyladenine (3-MA pretreatment significantly attenuated MDMA-induced autophagosome accumulation, LC3B-II expression, and ameliorated MDMA-triggered neurite damage and neuronal death. In contrast, enhanced autophagy flux by rapamycin or impaired autophagosome clearance by bafilomycin A1 led to more autophagosome accumulation in neurons and aggravated neurite degeneration, indicating that excessive autophagosome accumulation contributes to MDMA-induced neurotoxicity. Furthermore, MDMA induced phosphorylation of AMP-activated protein kinase (AMPK and its downstream unc-51-like kinase 1 (ULK1, suggesting the AMPK/ULK1 signaling pathway might be involved in MDMA-induced autophagy activation.

  20. Effects of Trace Metal Profiles Characteristic for Autism on Synapses in Cultured Neurons

    Directory of Open Access Journals (Sweden)

    Simone Hagmeyer

    2015-01-01

    Full Text Available Various recent studies revealed that biometal dyshomeostasis plays a crucial role in the pathogenesis of neurological disorders such as autism spectrum disorders (ASD. Substantial evidence indicates that disrupted neuronal homeostasis of different metal ions such as Fe, Cu, Pb, Hg, Se, and Zn may mediate synaptic dysfunction and impair synapse formation and maturation. Here, we performed in vitro studies investigating the consequences of an imbalance of transition metals on glutamatergic synapses of hippocampal neurons. We analyzed whether an imbalance of any one metal ion alters cell health and synapse numbers. Moreover, we evaluated whether a biometal profile characteristic for ASD patients influences synapse formation, maturation, and composition regarding NMDA receptor subunits and Shank proteins. Our results show that an ASD like biometal profile leads to a reduction of NMDAR (NR/Grin/GluN subunit 1 and 2a, as well as Shank gene expression along with a reduction of synapse density. Additionally, synaptic protein levels of GluN2a and Shanks are reduced. Although Zn supplementation is able to rescue the aforementioned alterations, Zn deficiency is not solely responsible as causative factor. Thus, we conclude that balancing Zn levels in ASD might be a prime target to normalize synaptic alterations caused by biometal dyshomeostasis.

  1. Untargeted metabolomics of neuronal cell culture: A model system for the toxicity testing of insecticide chemical exposure.

    Science.gov (United States)

    Hayton, Sarah; Maker, Garth L; Mullaney, Ian; Trengove, Robert D

    2017-12-01

    Toxicity testing is essential for the protection of human health from exposure to toxic environmental chemicals. As traditional toxicity testing is carried out using animal models, mammalian cell culture models are becoming an increasingly attractive alternative to animal testing. Combining the use of mammalian cell culture models with screening-style molecular profiling technologies, such as metabolomics, can uncover previously unknown biochemical bases of toxicity. We have used a mass spectrometry-based untargeted metabolomics approach to characterize for the first time the changes in the metabolome of the B50 cell line, an immortalised rat neuronal cell line, following acute exposure to two known neurotoxic chemicals that are common environmental contaminants; the pyrethroid insecticide permethrin and the organophosphate insecticide malathion. B50 cells were exposed to either the dosing vehicle (methanol) or an acute dose of either permethrin or malathion for 6 and 24 hours. Intracellular metabolites were profiled by gas chromatography-mass spectrometry. Using principal components analysis, we selected the key metabolites whose abundance was altered by chemical exposure. By considering the major fold changes in abundance (>2.0 or culture metabolomics to detect finer metabolic effects of acute exposure to known toxic chemicals, and validate the need for further development of this process in the application of trace-level dose and chronic toxicity studies, and toxicity testing of unknown chemicals. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Protective Effects of Testosterone on Presynaptic Terminals against Oligomeric β-Amyloid Peptide in Primary Culture of Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Chi-Fai Lau

    2014-01-01

    Full Text Available Increasing lines of evidence support that testosterone may have neuroprotective effects. While observational studies reported an association between higher bioavailable testosterone or brain testosterone levels and reduced risk of Alzheimer’s disease (AD, there is limited understanding of the underlying neuroprotective mechanisms. Previous studies demonstrated that testosterone could alleviate neurotoxicity induced by β-amyloid (Aβ, but these findings mainly focused on neuronal apoptosis. Since synaptic dysfunction and degeneration are early events during the pathogenesis of AD, we aim to investigate the effects of testosterone on oligomeric Aβ-induced synaptic changes. Our data suggested that exposure of primary cultured hippocampal neurons to oligomeric Aβ could reduce the length of neurites and decrease the expression of presynaptic proteins including synaptophysin, synaptotagmin, and synapsin-1. Aβ also disrupted synaptic vesicle recycling and protein folding machinery. Testosterone preserved the integrity of neurites and the expression of presynaptic proteins. It also attenuated Aβ-induced impairment of synaptic exocytosis. By using letrozole as an aromatase antagonist, we further demonstrated that the effects of testosterone on exocytosis were unlikely to be mediated through the estrogen receptor pathway. Furthermore, we showed that testosterone could attenuate Aβ-induced reduction of HSP70, which suggests a novel mechanism that links testosterone and its protective function on Aβ-induced synaptic damage. Taken together, our data provide further evidence on the beneficial effects of testosterone, which may be useful for future drug development for AD.

  3. Characterization of glutamate-induced formation of N- acylphosphatidylethanolamine and N-acylethanolamine in cultured neocortical neurons

    DEFF Research Database (Denmark)

    Hansen, Harald S.; Lauritzen, L.; Strand, A.M.

    1997-01-01

    receptors as seen by the inhibitory action of the NMDA-selective receptor antagonists D(-)-2-amino-5-phosphonovalerate and N- (1-(2-thienyl)-cyclohexyl)piperidine and the lack of effect of the a-amino- 3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate-receptor antagonist 6-cyano-7-nitro......-quinoxaline-2,3-dione (CNQX). In 6-day-old cultures, exposure to NMDA (100 µM for 24 h) induced a linear increase in the formation of NAPE and NAE as well as a 40-50% neuronal death, as measured by a decrease in cellular formazan formation [3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT......) assay). The increase in NAPE and NAE could be detected earlier than the neuronal death. Neither cyclic AMP, cyclic GMP, nitric oxide, protein kinase C, nor peroxidation appears to be involved in the formation of NAPE and NAE, as assessed by the use of different pharmacological agents. Exposure to 5 m...

  4. Gabapentin Inhibits Protein Kinase C Epsilon Translocation in Cultured Sensory Neurons with Additive Effects When Coapplied with Paracetamol (Acetaminophen

    Directory of Open Access Journals (Sweden)

    Vittorio Vellani

    2017-01-01

    Full Text Available Gabapentin is a well-established anticonvulsant drug which is also effective for the treatment of neuropathic pain. Although the exact mechanism leading to relief of allodynia and hyperalgesia caused by neuropathy is not known, the blocking effect of gabapentin on voltage-dependent calcium channels has been proposed to be involved. In order to further evaluate its analgesic mechanisms, we tested the efficacy of gabapentin on protein kinase C epsilon (PKCε translocation in cultured peripheral neurons isolated from rat dorsal root ganglia (DRGs. We found that gabapentin significantly reduced PKCε translocation induced by the pronociceptive peptides bradykinin and prokineticin 2, involved in both inflammatory and chronic pain. We recently showed that paracetamol (acetaminophen, a very commonly used analgesic drug, also produces inhibition of PKCε. We tested the effect of the combined use of paracetamol and gabapentin, and we found that the inhibition of translocation adds up. Our study provides a novel mechanism of action for gabapentin in sensory neurons and suggests a mechanism of action for the combined use of paracetamol and gabapentin, which has recently been shown to be effective, with a cumulative behavior, in the control of postoperative pain in human patients.

  5. Insulin receptors mediate growth effects in cultured fetal neurons. II. Activation of a protein kinase that phosphorylates ribosomal protein S6

    International Nuclear Information System (INIS)

    Heidenreich, K.A.; Toledo, S.P.

    1989-01-01

    As an initial attempt to identify early steps in insulin action that may be involved in the growth responses of neurons to insulin, we investigated whether insulin receptor activation increases the phosphorylation of ribosomal protein S6 in cultured fetal neurons and whether activation of a protein kinase is involved in this process. When neurons were incubated for 2 h with 32Pi, the addition of insulin (100 ng/ml) for the final 30 min increased the incorporation of 32Pi into a 32K microsomal protein. The incorporation of 32Pi into the majority of other neuronal proteins was unaltered by the 30-min exposure to insulin. Cytosolic extracts from insulin-treated neurons incubated in the presence of exogenous rat liver 40S ribosomes and [gamma-32P]ATP displayed a 3- to 8-fold increase in the phosphorylation of ribosomal protein S6 compared to extracts from untreated cells. Inclusion of cycloheximide during exposure of the neurons to insulin did not inhibit the increased cytosolic kinase activity. Activation of S6 kinase activity by insulin was dose dependent (seen at insulin concentration as low as 0.1 ng/ml) and reached a maximum after 20 min of incubation. Addition of phosphatidylserine, diolein, and Ca2+ to the in vitro kinase reaction had no effect on the phosphorylation of ribosomal protein S6. Likewise, treatment of neurons with (Bu)2cAMP did not alter the phosphorylation of ribosomal protein S6 by neuronal cytosolic extracts. We conclude that insulin activates a cytosolic protein kinase that phosphorylates ribosomal S6 in neurons and is distinct from protein kinase-C and cAMP-dependent protein kinase. Stimulation of this kinase may play a role in insulin signal transduction in neurons

  6. Reduced Hyperpolarization-Activated Current Contributes to Enhanced Intrinsic Excitability in Cultured Neonatal Hippocampal Neurons from PrP−/− Mice

    Directory of Open Access Journals (Sweden)

    Jing eFan

    2016-03-01

    Full Text Available Genetic ablation of cellular prion protein (PrPC has been linked to increased neuronal excitability and synaptic activity in the hippocampus. We have previously shown that synaptic activity in hippocampi of PrP-null mice is increased due to enhanced N-methyl-D-aspartate receptor (NMDAR function. Here, we focused on the effect of PRNP gene knock-out (KO on intrinsic neuronal excitability, and in particular, the underlying ionic mechanism in hippocampal neurons cultured from P0 mouse pups. We found that the absence of PrPC profoundly affected the firing properties of cultured hippocampal neurons in the presence of synaptic blockers. The membrane impedance was greater in PrP-null neurons, and this difference was abolished by the hyperpolarization-activated cyclic nucleotide-gated (HCN channel blocker ZD7288 (100 µM. HCN channel activity appeared to be functionally regulated by PrPC. The amplitude of voltage sag, a characteristic of activating HCN channel current (Ih, was decreased in null mice. Moreover, Ih peak current was reduced, along with a hyperpolarizing shift in activation gating and slower kinetics. However, neither HCN1 nor HCN2 formed a biochemical complex with PrPC. These results suggest that the absence of PrP downregulates the activity of HCN channels through activation of a cell signaling pathway rather than through direct interactions. This in turn contributes to an increase in membrane impedance to potentiate neuronal excitability.

  7. Ethanol Exposure RegulatesGabra1Expression via Histone Deacetylation at the Promoter in Cultured Cortical Neurons.

    Science.gov (United States)

    Bohnsack, John Peyton; Patel, Vraj K; Morrow, A Leslie

    2017-10-01

    γ -Aminobutyric acid A receptors (GABA A -Rs) mediate the majority of inhibitory neurotransmission in the adult brain. The α 1-containing GABA A -Rs are the most prominent subtype in the adult brain and are important in both homeostatic function and several disease pathologies including alcohol dependence, epilepsy, and stress. Ethanol exposure causes a decrease of α 1 transcription and peptide expression both in vivo and in vitro, but the mechanism that controls the transcriptional regulation is unknown. Because ethanol is known to activate epigenetic regulation of gene expression, we tested the hypothesis that ethanol regulates α 1 expression through histone modifications in cerebral cortical cultured neurons. We found that class I histone deacetylases (HDACs) regulate ethanol-induced changes in α 1 gene and protein expression as pharmacologic inhibition or knockdown of HDAC1-3 prevents the effects of ethanol exposure. Targeted histone acetylation associated with the Gabra1 promoter using CRISPR (clustered regularly interspaced palindromic repeat) dCas9-P300 (a nuclease-null Cas9 fused with a histone acetyltransferase) increases histone acetylation and prevents the decrease of Gabra1 expression. In contrast, there was no effect of a mutant histone acetyltransferase or generic transcriptional activator or targeting P300 to a distant exon. Conversely, using a dCas9-KRAB construct that increases repressive methylation (H3K9me3) does not interfere with ethanol-induced histone deacetylation. Overall our results indicate that ethanol deacetylates histones associated with the Gabra1 promoter through class I HDACs and that pharmacologic, genetic, or epigenetic intervention prevents decreases in α 1 expression in cultured cortical neurons. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  8. sigma receptor ligands attenuate N-methyl-D-aspartate cytotoxicity in dopaminergic neurons of mesencephalic slice cultures.

    Science.gov (United States)

    Shimazu, S; Katsuki, H; Takenaka, C; Tomita, M; Kume, T; Kaneko, S; Akaike, A

    2000-01-28

    We investigated the potential neuroprotective effects of several sigma receptor ligands in organotypic midbrain slice cultures as an excitotoxicity model system. When challenged with 100-microM N-methyl-D-aspartate (NMDA) for 24 h, dopaminergic neurons in midbrain slice cultures degenerated, and this was prevented by (5R, 10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,b]-cyclohepten-5, 10-imine (MK-801; 1-10 microM). Concomitant application of ifenprodil (1-10 microM) or haloperidol (1-10 microM), both of which are high-affinity sigma receptor ligands, significantly attenuated the neurotoxicity of 100 microM NMDA. The sigma(1) receptor-selective ligand (+)-N-allylnormetazocine ((+)-SKF 10047; 1-10 microM) was also effective in attenuating the toxicity of NMDA. The effect of R(-)-N-(3-phenyl-1-propyl)-1-phenyl-2-aminopropane hydrochloride ((-)-PPAP), a sigma receptor ligand with negligible affinity for the phencyclidine site of NMDA receptors, was also examined. (-)-PPAP (3-100 microM) caused a concentration-dependent reduction of NMDA cytotoxicity, with significant protection at concentrations of 30 and 100 microM. In contrast, (+)-SKF 10047 (10 microM) and (-)-PPAP (100 microM) showed no protective effects against cell death induced by the Ca(2+) ionophore ionomycin (1-3 microM). These results indicate that sigma receptor ligands attenuate the cytotoxic effects of NMDA on midbrain dopaminergic neurons, possibly via inhibition of NMDA receptor functions.

  9. N-cadherin induces partial differentiation of cholinergic presynaptic terminals in heterologous cultures of brainstem neurons and CHO cells

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    Richard J Flannery

    2012-12-01

    Full Text Available N-cadherin is a calcium-sensitive cell adhesion molecule commonly expressed at synaptic junctions and contributes to formation and maturation of synaptic contacts. This study used heterologous cell cultures of brainstem cholinergic neurons and transfected Chinese Hamster Ovary (CHO cells to examine whether N-cadherin is sufficient to induce differentiation of cholinergic presynaptic terminals. Brainstem nuclei isolated from transgenic mice expressing EGFP under the control of choline acetyltransferase transcriptional regulatory elements (ChATBACEGFP were cultured as tissue explants for five days and cocultured with transfected CHO cells for an additional two days. Immunostaining for synaptic vesicle proteins SV2 and synapsin I revealed a ~3-fold increase in the area of SV2 immunolabeling over N-cadherin expressing CHO cells, and this effect was enhanced by coexpression of p120-catenin. Synapsin I immunolabeling per axon length was also increased on N-cadherin expressing CHO cells but required coexpression of p120-catenin. To determine whether N-cadherin induces formation of neurotransmitter release sites, whole-cell voltage-clamp recordings of CHO cells expressing alpha-3 and beta-4 nicotinic acetylcholine receptor (nAChR subunits in contact with cholinergic axons were used to monitor excitatory postsynaptic potentials (EPSPs and miniature EPSPs (mEPSPs. EPSPs and mEPSPs were not detected in both, control and in N-cadherin expressing CHO cells in the absence or presence of tetrodotoxin. These results indicate that expression of N-cadherin in non-neuronal cells is sufficient to initiate differentiation of presynaptic cholinergic terminals by inducing accumulation of synaptic vesicles; however, development of readily detectable mature cholinergic release sites and/or clustering of postsynaptic nAChR may require expression of additional synaptogenic proteins.

  10. Humanin rescues cultured rat cortical neurons from NMDA-induced toxicity through the alleviation of mitochondrial dysfunction

    Directory of Open Access Journals (Sweden)

    Cui A

    2017-04-01

    Full Text Available Ai-Ling Cui,1 Ying-Hua Zhang,2 Jian-Zhong Li,3 Tianbin Song,4 Xue-Min Liu,1 Hui Wang,2 Ce Zhang,5 Guo-Lin Ma,6 Hui Zhang,7 Kefeng Li8 1Anatomy Department, Changzhi Medical College, Changzhi, Shanxi, 2Key Laboratory of Tissue Regeneration of Henan Province, Xinxiang Medical University, Xinxiang, Henan, 3Clinical Laboratory of Heji Hospital Affiliated to Changzhi Medical College, Changzhi, Shanxi, 4Department of Nuclear Medicine, Xuanwu Hospital, Capital Medical University, Beijing, 5Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, 6Department of Radiology, China-Japan Friendship Hospital, Beijing, 7Department of Radiology, First Clinical Medical College, Shanxi Medical University, Taiyuan, Shanxi, People’s Republic of China; 8School of Medicine, University of California – San Diego, San Diego, CA, USA Abstract: N-methyl-D-aspartate (NDMA receptor-mediated excitotoxicity has been implicated in a variety of pathological situations such as Alzheimer’s disease (AD and Parkinson’s disease. However, no effective treatments for the same have been developed so far. Humanin (HN is a 24-amino acid peptide originally cloned from the brain of patients with AD and it prevents stress-induced cell death in many cells/tissues. In our previous study, HN was found to effectively rescue rat cortical neurons. It is still not clear whether HN protects the neurons through the attenuation of mitochondrial dysfunction. In this study, excitatory toxicity was induced by NMDA, which binds the NMDA receptor in primarily cultured rat cortical neurons. We found that NMDA (100 µmol/L dramatically induced the decrease of cell viability and caused mitochondrial dysfunction. Pretreatment of the neurons with HN (1 µmol/L led to significant increases of mitochondrial succinate dehydrogenase (SDH activity and membrane potential. In addition, HN pretreatment significantly reduced the excessive production of both reactive oxygen species (ROS and nitric

  11. The effect of training of culture neuronal networks, can they learn

    NARCIS (Netherlands)

    van Staveren, G.W.; Buitenweg, Jan R.; Marani, Enrico; Rutten, Wim

    2005-01-01

    Dissociated 1 or 2 days old postnatal rat cortical cells were cultured onto multi electrode arrays (MEA’s) with 61 electrode sites. They were trained with two protocols, i.e. the tetanic stimulation method from the report by Jimbo et al. (1998) and the selective adaptation protocol (report Shahaf

  12. Zinc, a neurotoxin to cultured neurons, contaminates cycad flour prepared by traditional guamanian methods.

    Science.gov (United States)

    Duncan, M W; Marini, A M; Watters, R; Kopin, I J; Markey, S P

    1992-04-01

    We have used cultured ventral mesencephalic and cerebellar granule cells to test the toxicity of extracts of cycad seeds (genus Cycas) and cycad-derived flours traditionally prepared in Guam. There was no significant difference in the toxicity of extracts prepared from the female gametophyte tissue of C. circinalis, C. revoluta, and C. media, common wheat flour, and 13 of 17 cycad flour samples. However, extracts prepared from 4 of 17 Guamanian flour samples exhibited marked dose-dependent neurotoxicity to mesencephalic and granule cell cultures. There was no correlation between toxicity and 2-amino-3-(methylamino)-propanoic acid (BMAA) content, and the concentration of BMAA in the medium arising from these extracts was far below that required to be neurotoxic. Toxicity of extracts was not blocked by the NMDA receptor antagonist MK-801 or the non-NMDA receptor antagonist 6-cyano-7-dinitroquinoxaline-2,3-dione, indicating that toxicity was not mediated by excitatory amino acid receptors. Analysis of the four toxic processed flour samples indicated high zinc content. Zinc produced a concentration-dependent neurotoxic response in mesencephalic and granule cell cultures that paralleled the calculated concentrations of zinc in the cultures derived from the four toxic flour samples. When sliced C. circinalis gametophyte tissue was "processed" in our laboratory by soaking in a galvanized container, there was a time-dependent increase in zinc content.

  13. Chronic 14-day exposure to insecticides or methylmercury modulates neuronal activity in primary rat cortical cultures

    NARCIS (Netherlands)

    Dingemans, Milou; Schütte, Marijke G; Wiersma, Daphne M M; de Groot, Aart; van Kleef, Gina; Wijnolts, Fiona; Westerink, Remco

    2016-01-01

    There is an increasing demand for in vitro test systems to detect neurotoxicity for use in chemical risk assessment. In this study, we evaluated the applicability of rat primary cortical cultures grown on multi-well micro-electrode arrays (mwMEAs) to detect effects of chronic 14-day exposure to

  14. [The expression of p53, MDM2 and Ref1 gene in cultured retina neurons of SD rats treated with vitamin B1 and/or elevated pressure].

    Science.gov (United States)

    Yang, Zhikuan; Ge, Jian; Yin, Wei; Shen, Huangxuan; Liu, Haiquan; Guo, Yan

    2004-12-01

    To investigate the expression of p53, MDM2 and Ref1 gene in cultured retina neurons of SD rats treated with Vitamin B1 and (or) elevated pressure. The retinal neuron of postnatal SD rats were cultured in vivo, the elevated pressure was produced after 7 days, and the total RNA was extracted after another 2 days, expression of p53, MDM2 and Ref1 gene were analyzed with RT-PCR. The expression level of p53 and MDM2 gene were increased in elevated pressure group, normal with Ref1 gene expression. But the expression of p53 and MDM2 gene were decreased significantly in elevated pressure group treated with vitamine B1 compare to the elevated group. Apoptosis seem to be a mechanism of cell death in retinal neurons of SD rats with elevated pressure.Vitamine B1 have protect effects against elevated pressure.

  15. Long term ex-vivo culturing of Drosophila brain as a method to live image pupal brains: insights into the cellular mechanisms of neuronal remodeling

    Directory of Open Access Journals (Sweden)

    Dana eRabinovich

    2015-08-01

    Full Text Available Holometabolous insects, including Drosophila melanogaster, undergo complete metamorphosis that includes a pupal stage. During metamorphosis, the Drosophila nervous system undergoes massive remodeling and growth, that include cell death and large-scale axon and synapse elimination as well as neurogenesis, developmental axon regrowth and formation of new connections. Neuronal remodeling is an essential step in the development of vertebrate and invertebrate nervous systems. Research on the stereotypic remodeling of Drosophila mushroom body (MB γ neurons has contributed to our knowledge of the molecular mechanisms of remodeling but our knowledge of the cellular mechanisms remain poorly understood. A major hurdle in understanding various dynamic processes that occur during metamorphosis is the lack of time-lapse resolution. The pupal case and opaque fat bodies that enwrap the central nervous system (CNS make live-imaging of the central brain in-vivo impossible. We have established an ex-vivo long-term brain culture system that supports the development and neuronal remodeling of pupal brains. By optimizing culture conditions and dissection protocols, we have observed development in culture at kinetics similar to what occurs in vivo. Using this new method, we have obtained the first time-lapse sequence of MB γ neurons undergoing remodeling in up to a single cell resolution. We found that axon pruning is initiated by blebbing, followed by one-two nicks that seem to initiate a more widely spread axon fragmentation. As such, we have set up some of the tools and methodologies needed for further exploration of the cellular mechanisms of neuronal remodeling, not limited to the MB. The long-term ex-vivo brain culture system that we report here could be used to study dynamic aspects of neurodevelopment of any Drosophila neuron.

  16. Sodium/bicarbonate cotransporter NBCn1/slc4a7 increases cytotoxicity in magnesium depletion in primary cultures of hippocampal neurons

    Science.gov (United States)

    Cooper, Deborah S.; Yang, Han Soo; He, Peijian; Kim, Eunjin; Rajbhandari, Ira; Yun, Chris C.; Choi, Inyeong

    2009-01-01

    Growing evidence suggests that pharmacological inhibition of Na/H exchange and Na/HCO3 transport provides protection against damage or injury in cardiac ischemia. In this study, we examined the contribution of the sodium/bicarbonate cotransporter NBCn1 (slc4a7) to cytotoxicity in cultured hippocampal neurons of rats. In neurons exposed to extracellular pH (pHo) ranging from 6.2 to 8.3, NBCn1 protein expression increased by fivefold at pH < 6.5 compared to the expression at pHo 7.4. At pHo 6.5, the intracellular pH of neurons was ~1 unit lower than that at pH 7.4. Immunochemistry showed a marked increase in NBCn1 immunofluorescence in plasma membranes and cytosol of the soma as well as in dendrites, at pHo 6.5. NBCn1 expression also increased by 40% in a prolonged Mg2+-free incubation at normal pHo. Knockdown of NBCn1 in neurons had negligible effect on cell viability. The effect of NBCn1 knockdown on cytotoxicity was then determined by exposing neurons to 0.5 mM glutamate for 10 min and measuring lactate dehydrogenase (LDH) release from neurons. Compared to normal incubation (pHo 7.2 for 6 h) after glutamate exposure, acidic incubation (pHo 6.3 for 6 h) reduced cytotoxicity by 75% for control neurons and 78% for NBCn1-knockdown neurons. Thus, both controls and knockdown neurons showed acidic protection from cytotoxicity. However, in Mg2+-free incubation after glutamate exposure, NBCn1 knockdown progressively attenuated cytotoxicity. This attenuation was unaffected by acidic preincubation before glutamate exposure. We conclude that NBCn1 has a dynamic upregulation in low pHo and Mg2+ depletion. NBCn1 is not required for acidic protection, but increases cytotoxicity in Mg2+-free conditions. PMID:19170751

  17. Network bursting dynamics in excitatory cortical neuron cultures results from the combination of different adaptive mechanisms.

    Directory of Open Access Journals (Sweden)

    Timothée Masquelier

    Full Text Available In the brain, synchronization among cells of an assembly is a common phenomenon, and thought to be functionally relevant. Here we used an in vitro experimental model of cell assemblies, cortical cultures, combined with numerical simulations of a spiking neural network (SNN to investigate how and why spontaneous synchronization occurs. In order to deal with excitation only, we pharmacologically blocked GABAAergic transmission using bicuculline. Synchronous events in cortical cultures tend to involve almost every cell and to display relatively constant durations. We have thus named these "network spikes" (NS. The inter-NS-intervals (INSIs proved to be a more interesting phenomenon. In most cortical cultures NSs typically come in series or bursts ("bursts of NSs", BNS, with short (~1 s INSIs and separated by long silent intervals (tens of s, which leads to bimodal INSI distributions. This suggests that a facilitating mechanism is at work, presumably short-term synaptic facilitation, as well as two fatigue mechanisms: one with a short timescale, presumably short-term synaptic depression, and another one with a longer timescale, presumably cellular adaptation. We thus incorporated these three mechanisms into the SNN, which, indeed, produced realistic BNSs. Next, we systematically varied the recurrent excitation for various adaptation timescales. Strong excitability led to frequent, quasi-periodic BNSs (CV~0, and weak excitability led to rare BNSs, approaching a Poisson process (CV~1. Experimental cultures appear to operate within an intermediate weakly-synchronized regime (CV~0.5, with an adaptation timescale in the 2-8 s range, and well described by a Poisson-with-refractory-period model. Taken together, our results demonstrate that the INSI statistics are indeed informative: they allowed us to infer the mechanisms at work, and many parameters that we cannot access experimentally.

  18. Single Cell Electroporation Method for Mammalian CNS Neurons in Organotypic Slice Cultures

    Science.gov (United States)

    Uesaka, Naofumi; Hayano, Yasufumi; Yamada, Akito; Yamamoto, Nobuhiko

    Axon tracing is an essential technique to study the projection pattern of neurons in the CNS. Horse radish peroxidase and lectins have contributed to revealing many neural connection patterns in the CNS (Itaya and van Hoesen, 1982; Fabian and Coulter, 1985; Yoshihara, 2002). Moreover, a tracing method with fluorescent dye has enabled the observation of growing axons in living conditions, and demon strated a lot of developmental aspects in axon growth and guidance (Harris et al., 1987; O'Rourke and Fraser, 1990; Kaethner and Stuermer, 1992; Halloran and Kalil, 1994; Yamamoto et al., 1997). More recently, genetically encoded fluores cent proteins can be used as a powerful tool to observe various biological events. Several gene transfer techniques such as microinjection, biolistic gene gun, viral infection, lipofection and transgenic technology have been developed (Feng et al., 2000; Ehrengruber et al., 2001; O'Brien et al., 2001; Ma et al., 2002; Sahly et al., 2003). In particular, the electroporation technique was proved as a valuable tool, since it can be applied to a wide range of tissues and cell types with little toxicity and can be performed with relative technical easiness. Most methods, including a stand ard electroporation technique, are suitable for gene transfer to a large number of cells. However, this is not ideal for axonal tracing, because observation of individ ual axons is occasionally required. To overcome this problem, we have developed an electroporation method using glass micropipettes containing plasmid solutions and small current injection. Here we introduce the method in detail and exemplified results with some example applications and discuss its usefulness.

  19. MDMA (Ecstasy) Decreases the Number of Neurons and Stem Cells in Embryonic Cortical Cultures

    DEFF Research Database (Denmark)

    Kindlundh-Högberg, Anna M S; Pickering, Chris; Wicher, Grzegorz

    2010-01-01

    Ecstasy, 3,4-methylenedioxymetamphetamine (MDMA), is a recreational drug used among adolescents, including young pregnant women. MDMA passes the placental barrier and may therefore influence fetal development. The aim was to investigate the direct effect of MDMA on cortical cells using dissociated...... CNS cortex of rat embryos, E17. The primary culture was exposed to a single dose of MDMA and collected 5 days later. MDMA caused a dramatic, dose-dependent (100 and 400 muM) decrease in nestin-positive stem cell density, as well as a significant reduction (400 muM) in NeuN-positive cells. By q...

  20. Inhibition of the Jak-STAT pathway prevents CNTF-mediated survival of axotomized oxytocinergic magnocellular neurons in organotypic cultures of the rat supraoptic nucleus

    Science.gov (United States)

    Askvig, Jason M.; Lo, David Y.; Sudbeck, Adam W.; Behm, Kathryn E.; Leiphon, Laura J.; Watt, John A.

    2012-01-01

    Previous studies have demonstrated that ciliary neurotrophic factor (CNTF) enhances survival and process outgrowth from magnocellular neurons in the paraventricular (PVN) and the supraoptic (SON) nuclei. However, the mechanisms by which CNTF facilitates these processes remain to be determined. Therefore, the aim of this study was to identify the immediate signal transduction events that occur within the rat SON following administration of exogenous rat recombinant CNTF (rrCNTF) and to determine the contribution of those intracellular signaling pathway(s) to neuronal survival and process outgrowth, respectively. Immunohistochemical and Western blot analysis demonstrated that axonal injury and acute unilateral pressure injection of 100 ng/μl of rrCNTF directly over the rat SON resulted in a rapid and transient increase in phosphorylated-STAT3 (pSTAT3) in astrocytes but not neurons in the SON in vivo. Utilizing rat hypothalamic organotypic explant cultures, we then demonstrated that administration of 25 ng/ml rrCNTF for 14 days significantly increased the survival and process outgrowth of OT magnocellular neurons. In addition, pharmacological inhibition of the Jak-STAT pathway via AG490 and cucurbitacin I significantly reduced the survival of OT magnocellular neurons in the SON and PVN; however, the contribution of the Jak-STAT pathway to CNTF-mediated process outgrowth remains to be determined. Together, these data indicate that CNTF-induced survival of OT magnocellular neurons is mediated indirectly through astrocytes via the Jak-STAT signaling pathway. PMID:23123407

  1. A Highly Efficient Human Pluripotent Stem Cell Microglia Model Displays a Neuronal-Co-culture-Specific Expression Profile and Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Walther Haenseler

    2017-06-01

    Full Text Available Microglia are increasingly implicated in brain pathology, particularly neurodegenerative disease, with many genes implicated in Alzheimer's, Parkinson's, and motor neuron disease expressed in microglia. There is, therefore, a need for authentic, efficient in vitro models to study human microglial pathological mechanisms. Microglia originate from the yolk sac as MYB-independent macrophages, migrating into the developing brain to complete differentiation. Here, we recapitulate microglial ontogeny by highly efficient differentiation of embryonic MYB-independent iPSC-derived macrophages then co-culture them with iPSC-derived cortical neurons. Co-cultures retain neuronal maturity and functionality for many weeks. Co-culture microglia express key microglia-specific markers and neurodegenerative disease-relevant genes, develop highly dynamic ramifications, and are phagocytic. Upon activation they become more ameboid, releasing multiple microglia-relevant cytokines. Importantly, co-culture microglia downregulate pathogen-response pathways, upregulate homeostatic function pathways, and promote a more anti-inflammatory and pro-remodeling cytokine response than corresponding monocultures, demonstrating that co-cultures are preferable for modeling authentic microglial physiology.

  2. Tetrahydrocannabinol-induced neurotoxicity depends on CB1 receptor-mediated c-Jun N-terminal kinase activation in cultured cortical neurons

    Science.gov (United States)

    Downer, Eric J; Fogarty, Marie P; Campbell, Veronica A

    2003-01-01

    Δ9-Tetrahydrocannabinol (THC), the main psychoactive ingredient of marijuana, induces apoptosis in cultured cortical neurons. THC exerts its apoptotic effects in cortical neurons by binding to the CB1 cannabinoid receptor. The CB1 receptor has been shown to couple to the stress-activated protein kinase, c-Jun N-terminal kinase (JNK). However, the involvement of specific JNK isoforms in the neurotoxic properties of THC remains to be established. The present study involved treatment of rat cultured cortical neurons with THC (0.005–50 μM), and combinations of THC with the CB1 receptor antagonist, AM 251 (10 μM) and pertussis toxin (PTX; 200 ng ml−1). Antisense oligonucleotides (AS) were used to deplete neurons of JNK1 and JNK2 in order to elucidate their respective roles in THC signalling. Here we report that THC induces the activation of JNK via the CB1 receptor and its associated G-protein, Gi/o. Treatment of cultured cortical neurons with THC resulted in a differential timeframe of activation of the JNK1 and JNK2 isoforms. Use of specific JNK1 and JNK2 AS identified activation of caspase-3 and DNA fragmentation as downstream consequences of JNK1 and JNK2 activation. The results from this study demonstrate that activation of the CB1 receptor induces JNK and caspase-3 activation, an increase in Bax expression and DNA fragmentation. The data demonstrate that the activation of both JNK1 and JNK2 isoforms is central to the THC-induced activation of the apoptotic pathway in cortical neurons. PMID:14522843

  3. The Neurovirulence of the DA and GDVII Strains of Theiler’s Virus Correlates with Their Ability To Infect Cultured Neurons

    Science.gov (United States)

    Jarousse, Nadine; Syan, Sylvie; Martinat, Cécile; Brahic, Michel

    1998-01-01

    The strains of Theiler’s murine encephalomyelitis virus, a picornavirus, are divided into two groups according to their neurovirulence after intracerebral inoculation. The highly virulent GDVII strain causes an acute, fatal encephalomyelitis, whereas the DA strain causes a mild encephalomyelitis followed by a chronic inflammatory demyelinating disease associated with viral persistence. Studies with recombinant viruses showed that the capsid plays the major role in determining these phenotypes. However, the molecular basis for the effect of the capsid on neurovirulence is still unknown. In this paper, we describe a large difference in the patterns of infection of primary neuron cultures by the GDVII and DA strains. Close to 90% of the neurons were infected 12 h after inoculation with the GDVII strain, and the cytopathic effect was complete 24 h postinoculation. In contrast, with the DA strain, viral antigens were not detected in neurons until 24 h postinoculation. Infected neurons accounted for only 2% of the total number of neurons, even 6 days after inoculation. No cytopathic effect was visible, and the cultures could be kept for the same length of time as the noninfected controls. Because the neurovirulence of the GDVII strain has been mapped to the capsid, we examined the role of the capsid in this difference of phenotype. We showed, using recombinant viruses, that the capsid was indeed responsible for the pattern of infection observed in vitro, most likely through its role in viral entry. Thus, the levels of neurovirulence of the GDVII and DA strains correlate with their abilities to infect cultured neurons, and this ability is controlled by the capsid. PMID:9696815

  4. Neuroprotection of the leaf and stem of Vitis amurensis and their active compounds against ischemic brain damage in rats and excitotoxicity in cultured neurons.

    Science.gov (United States)

    Kim, Joo Youn; Jeong, Ha Yeon; Lee, Hong Kyu; Kim, SeungHwan; Hwang, Bang Yeon; Bae, KiHwan; Seong, Yeon Hee

    2012-01-15

    Vitis amurensis (Vitaceae) has been reported to have anti-oxidant and anti-inflammatory activities. The present study investigated a methanol extract from the leaf and stem of V. amurensis for neuroprotective effects on cerebral ischemic damage in rats and on excitotoxicity induced by glutamate in cultured rat cortical neurons. Transient focal cerebral ischemia was induced by 2h middle cerebral artery occlusion followed by 24h reperfusion (MCAO/reperfusion) in rats. Orally administered V. amurensis (25-100 mg/kg) reduced MCAO/reperfusion-induced infarct and edema formation, neurological deficits, and neuronal death. Depletion of glutathione (GSH) level and lipid peroxidation induced by MCAO/reperfusion was inhibited by administration of V. amurensis. The increase of phosphorylated mitogen-activated protein kinases (MAPKs), cyclooxygenase-2 (COX-2), and pro-apoptotic proteins and the decrease of anti-apoptotic protein in MCAO/reperfusion rats were significantly inhibited by treatment with V. amurensis. Exposure of cultured cortical neurons to 500 μM glutamate for 12h induced neuronal cell death. V. amurensis (1-50 μg/ml) and (+)-ampelopsin A, γ-2-viniferin, and trans-ε-viniferin isolated from the leaf and stem of V. amurensis inhibited glutamate-induced neuronal death, the elevation of intracellular calcium ([Ca(2+)](i)), the generation of reactive oxygen species (ROS), and changes of apoptosis-related proteins in cultured cortical neurons, suggesting that the neuroprotective effect of V. amurensis may be partially attributed to these compounds. These results suggest that the neuroprotective effect of V. amurensis against focal cerebral ischemic injury might be due to its anti-apoptotic effect, resulting from anti-excitotoxic, anti-oxidative, and anti-inflammatory effects and that the leaf and stem of V. amurensis have possible therapeutic roles for preventing neurodegeneration in stroke. Copyright © 2011 Elsevier GmbH. All rights reserved.

  5. Qualitative and quantitative estimation of comprehensive synaptic connectivity in short- and long-term cultured rat hippocampal neurons with new analytical methods inspired by Scatchard and Hill plots

    Energy Technology Data Exchange (ETDEWEB)

    Tanamoto, Ryo; Shindo, Yutaka; Niwano, Mariko [Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University (Japan); Matsumoto, Yoshinori [Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University (Japan); Miki, Norihisa [Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522 (Japan); Hotta, Kohji [Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University (Japan); Oka, Kotaro, E-mail: oka@bio.keio.ac.jp [Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University (Japan)

    2016-03-18

    To investigate comprehensive synaptic connectivity, we examined Ca{sup 2+} responses with quantitative electric current stimulation by indium-tin-oxide (ITO) glass electrode with transparent and high electro-conductivity. The number of neurons with Ca{sup 2+} responses was low during the application of stepwise increase of electric current in short-term cultured neurons (less than 17 days in-vitro (DIV)). The neurons cultured over 17 DIV showed two-type responses: S-shaped (sigmoid) and monotonous saturated responses, and Scatchard plots well illustrated the difference of these two responses. Furthermore, sigmoid like neural network responses over 17 DIV were altered to the monotonous saturated ones by the application of the mixture of AP5 and CNQX, specific blockers of NMDA and AMPA receptors, respectively. This alternation was also characterized by the change of Hill coefficients. These findings indicate that the neural network with sigmoid-like responses has strong synergetic or cooperative synaptic connectivity via excitatory glutamate synapses. - Highlights: • We succeed to evaluate the maturation of neural network by Scathard and Hill Plots. • Long-term cultured neurons showed two-type responses: sigmoid and monotonous. • The sigmoid-like increase indicates the cooperatevity of neural networks. • Excitatory glutamate synapses cause the cooperatevity of neural networks.

  6. Qualitative and quantitative estimation of comprehensive synaptic connectivity in short- and long-term cultured rat hippocampal neurons with new analytical methods inspired by Scatchard and Hill plots

    International Nuclear Information System (INIS)

    Tanamoto, Ryo; Shindo, Yutaka; Niwano, Mariko; Matsumoto, Yoshinori; Miki, Norihisa; Hotta, Kohji; Oka, Kotaro

    2016-01-01

    To investigate comprehensive synaptic connectivity, we examined Ca 2+ responses with quantitative electric current stimulation by indium-tin-oxide (ITO) glass electrode with transparent and high electro-conductivity. The number of neurons with Ca 2+ responses was low during the application of stepwise increase of electric current in short-term cultured neurons (less than 17 days in-vitro (DIV)). The neurons cultured over 17 DIV showed two-type responses: S-shaped (sigmoid) and monotonous saturated responses, and Scatchard plots well illustrated the difference of these two responses. Furthermore, sigmoid like neural network responses over 17 DIV were altered to the monotonous saturated ones by the application of the mixture of AP5 and CNQX, specific blockers of NMDA and AMPA receptors, respectively. This alternation was also characterized by the change of Hill coefficients. These findings indicate that the neural network with sigmoid-like responses has strong synergetic or cooperative synaptic connectivity via excitatory glutamate synapses. - Highlights: • We succeed to evaluate the maturation of neural network by Scathard and Hill Plots. • Long-term cultured neurons showed two-type responses: sigmoid and monotonous. • The sigmoid-like increase indicates the cooperatevity of neural networks. • Excitatory glutamate synapses cause the cooperatevity of neural networks.

  7. Electrical Responses and Spontaneous Activity of Human iPS-Derived Neuronal Networks Characterized for 3-month Culture with 4096-Electrode Arrays.

    Science.gov (United States)

    Amin, Hayder; Maccione, Alessandro; Marinaro, Federica; Zordan, Stefano; Nieus, Thierry; Berdondini, Luca

    2016-01-01

    The recent availability of human induced pluripotent stem cells (hiPSCs) holds great promise as a novel source of human-derived neurons for cell and tissue therapies as well as for in vitro drug screenings that might replace the use of animal models. However, there is still a considerable lack of knowledge on the functional properties of hiPSC-derived neuronal networks, thus limiting their application. Here, upon optimization of cell culture protocols, we demonstrate that both spontaneous and evoked electrical spiking activities of these networks can be characterized on-chip by taking advantage of the resolution provided by CMOS multielectrode arrays (CMOS-MEAs). These devices feature a large and closely-spaced array of 4096 simultaneously recording electrodes and multi-site on-chip electrical stimulation. Our results show that networks of human-derived neurons can respond to electrical stimulation with a physiological repertoire of spike waveforms after 3 months of cell culture, a period of time during which the network undergoes the expression of developing patterns of spontaneous spiking activity. To achieve this, we have investigated the impact on the network formation and on the emerging network-wide functional properties induced by different biochemical substrates, i.e., poly-dl-ornithine (PDLO), poly-l-ornithine (PLO), and polyethylenimine (PEI), that were used as adhesion promoters for the cell culture. Interestingly, we found that neuronal networks grown on PDLO coated substrates show significantly higher spontaneous firing activity, reliable responses to low-frequency electrical stimuli, and an appropriate level of PSD-95 that may denote a physiological neuronal maturation profile and synapse stabilization. However, our results also suggest that even 3-month culture might not be sufficient for human-derived neuronal network maturation. Taken together, our results highlight the tight relationship existing between substrate coatings and emerging network

  8. Diolistic labeling of neuronal cultures and intact tissue using a hand-held gene gun.

    Science.gov (United States)

    O'Brien, John A; Lummis, Sarah C R

    2006-01-01

    Diolistic labeling is a highly efficient method for introducing dyes into cells using biolistic techniques. The use of lipophilic carbocyanine dyes, combined with particle-mediated biolistic delivery using a hand-held gene gun, allows non-toxic labeling of multiple cells in both living and fixed tissue. The technique is rapid (labeled cells can be visualized in minutes) and technically undemanding. Here, we provide a detailed protocol for diolistic labeling of cultured human embryonic kidney 293 cells and whole brain using a hand-held gene gun. There are four major steps: (i) coating gold microcarriers with one or more dyes; (ii) transferring the microcarriers into a cartridge to make a bullet; (iii) preparation of cells or intact tissue; and (iv) firing the microcarriers into cells or tissue. The method can be readily adapted to other cell types and tissues. This protocol can be completed in less than 1 h.

  9. N-Acetyl-L-cysteine in the Presence of Cu2+Induces Oxidative Stress and Death of Granule Neurons in Dissociated Cultures of Rat Cerebellum.

    Science.gov (United States)

    Stelmashook, E V; Genrikhs, E E; Kapkaeva, M R; Zelenova, E A; Isaev, N K

    2017-10-01

    Addition into the culture medium of the antioxidant N-acetylcysteine (NAC, 1 mM) in the presence of Cu2+ (0.0005-0.001 mM) induced intensive death of cultured rat cerebellar granule neurons, which was significantly decreased by the zinc ion chelator TPEN (N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine). However, the combined action of NAC and Zn2+ did not induce destruction of the neurons. Measurement of the relative intracellular concentration of Zn2+ with the fluorescent probe FluoZin-3 AM or of free radical production using a CellROX Green showed that incubation of the culture for 4 h with Cu2+ and NAC induced an intensive increase in the fluorescence of CellROX Green but not of FluoZin-3. Probably, the protective effect of TPEN in this case could be mediated by its ability to chelate Cu2+. Incubation of cultures in a balanced salt solution in the presence of 0.01 mM Cu2+ caused neuronal death already after 1 h if the NAC concentration in the solution was within 0.005-0.05 mM. NAC at higher concentrations (0.1-1 mM) together with 0.01 mM Cu2+ did not cause the death of neurons. These data imply that the antioxidant NAC can be potentially harmful to neurons even in the presence of nanomolar concentrations of variable valence metals.

  10. Role of Cl- -HCO3- exchanger AE3 in intracellular pH homeostasis in cultured murine hippocampal neurons, and in crosstalk to adjacent astrocytes.

    Science.gov (United States)

    Salameh, Ahlam I; Hübner, Christian A; Boron, Walter F

    2017-01-01

    A polymorphism of human AE3 is associated with idiopathic generalized epilepsy. Knockout of AE3 in mice lowers the threshold for triggering epileptic seizures. The explanations for these effects are elusive. Comparisons of cells from wild-type vs. AE3 -/- mice show that AE3 (present in hippocampal neurons, not astrocytes; mediates HCO 3 - efflux) enhances intracellular pH (pH i ) recovery (decrease) from alkali loads in neurons and, surprisingly, adjacent astrocytes. During metabolic acidosis (MAc), AE3 speeds initial acidification, but limits the extent of pH i decrease in neurons and astrocytes. AE3 speeds re-alkalization after removal of MAc in neurons and astrocytes, and speeds neuronal pH i recovery from an ammonium prepulse-induced acid load. We propose that neuronal AE3 indirectly increases acid extrusion in (a) neurons via Cl - loading, and (b) astrocytes by somehow enhancing NBCe1 (major acid extruder). The latter would enhance depolarization-induced alkalinization of astrocytes, and extracellular acidification, and thereby reduce susceptibility to epileptic seizures. The anion exchanger AE3, expressed in hippocampal (HC) neurons but not astrocytes, contributes to intracellular pH (pH i ) regulation by facilitating the exchange of extracellular Cl - for intracellular HCO 3 - . The human AE3 polymorphism A867D is associated with idiopathic generalized epilepsy. Moreover, AE3 knockout (AE3 -/- ) mice are more susceptible to epileptic seizure. The mechanism of these effects has been unclear because the starting pH i in AE3 -/- and wild-type neurons is indistinguishable. The purpose of the present study was to use AE3 -/- mice to investigate the role of AE3 in pH i homeostasis in HC neurons, co-cultured with astrocytes. We find that the presence of AE3 increases the acidification rate constant during pH i recovery from intracellular alkaline loads imposed by reducing [CO 2 ]. The presence of AE3 also speeds intracellular acidification during the early phase of

  11. Effect of extracellular generation of the reactive oxygen species, singlet oxygen (1O2), on the electrophysiological properties of cultured cortical neurons

    DEFF Research Database (Denmark)

    Breitenbach, Thomas; Sinks, Louise, E.; Vionogradov, Sergej A.

    Several models to mimic oxidative stress of cells have been reported. However, these models are often limited to known ROS (e.g. H2O2) or exposure times, which may exceed the pathophysiological stimulation. We have previously investigated neuronal functioning following controlled production of 1O2...... (ABM) were made from cultured rat cortical neurons to provide insight into the events following extracellular generation of 1O2. Membrane resistance (Rm), capacitance (Cm), holding current (Ihold), and firing properties were monitored throughout. The V/I relationship was investigated with 1 s duration...... current steps of 0.1 nA (-0.4 - 1 nA). The PS, dissolved in ABM (10 µM), was administered by local application directly to the neuron monitored. The intensity of the applied light at 455 nm was adjusted by neutral density filters. Phosphorescence at 700 nm proved the presence of the PS, which was absent...

  12. Detoxification of ammonia in mouse cortical GABAergic cell cultures increases neuronal oxidative metabolism and reveals an emerging role for release of glucose-derived alanine

    DEFF Research Database (Denmark)

    Leke, Renata; Bak, Lasse Kristoffer; Anker, Malene

    2011-01-01

    in a mouse neuronal-astrocytic co-culture model of the GABAergic system. We found that 5 mM ammonium chloride affected energy metabolism by increasing the neuronal TCA cycle activity and switching the astrocytic TCA cycle toward synthesis of substrate for glutamine synthesis. Furthermore, ammonia exposure...... enhanced the synthesis and release of alanine. Collectively, our results demonstrate that (1) formation of glutamine is seminal for detoxification of ammonia; (2) neuronal oxidative metabolism is increased in the presence of ammonia; and (3) synthesis and release of alanine is likely to be important......Cerebral hyperammonemia is believed to play a pivotal role in the development of hepatic encephalopathy (HE), a debilitating condition arising due to acute or chronic liver disease. In the brain, ammonia is thought to be detoxified via the activity of glutamine synthetase, an astrocytic enzyme...

  13. Gangliosides in nervous tissue cultures and binding of 125I-labelled tetanus toxin, a neuronal marker

    International Nuclear Information System (INIS)

    Dimpfel, W.; Huang, R.T.C.; Habermann, E.

    1977-01-01

    Continuous cell lines, primary cell cultures derived from embryonic CNS, and homogenates made from adult and embryonic CNS were compared with respect to their lipid pattern and their ability to bind 125 I-labelled tetanus toxin. In parallel experiments de novo synthesis of gangliosides in the cell lines was studied, using [ 14 C] glucosamine as precursor. Of the total lipid only gangliosides were specifically labelled by [ 14 C] glucosamine. The patterns of the de novo synthesized gangliosides corresponded to those present in the respective cells. Pronounced binding of 125 I-labelled toxin was only detectable in tissues containing long-chain gangliosides (ganglioside C which represents GDIb and GTI). Accordingly, hybrid (neuroblastoma x glioma) cells, due to their lack of long-chain gangliosides, bound just-discernible amounts of labelled toxin. When previously exposed to gangliosides, their binding of tetanus toxin tremendously increased. It was concluded that only the long-chain gangliosides in the neuronal cells are functionally involved in the binding of the tetanus toxin and that these acceptors of tetanus toxin can be transplanted. (author)

  14. Inhibitory Activity of Yokukansankachimpihange against Nerve Growth Factor-Induced Neurite Growth in Cultured Rat Dorsal Root Ganglion Neurons

    Directory of Open Access Journals (Sweden)

    Chiaki Murayama

    2015-08-01

    Full Text Available Chronic pruritus is a major and distressing symptom of many cutaneous diseases, however, the treatment remains a challenge in the clinic. The traditional Chinese-Japanese medicine (Kampo medicine is a conservative and increasingly popular approach to treat chronic pruritus for both patients and medical providers. Yokukansankachimpihange (YKH, a Kampo formula has been demonstrated to be effective in the treatment of itching of atopic dermatitis in Japan although its pharmacological mechanism is unknown clearly. In an attempt to clarify its pharmacological actions, in this study, we focused on the inhibitory activity of YKH against neurite growth induced with nerve growth factor (NGF in cultured rat dorsal root ganglion (DRG neurons because epidermal hyperinnervation is deeply related to itch sensitization. YKH showed approximately 200-fold inhibitory activity against NGF-induced neurite growth than that of neurotropin (positive control, a drug used clinically for treatment of chronic pruritus. Moreover, it also found that Uncaria hook, Bupleurum root and their chemical constituents rhynchophylline, hirsutine, and saikosaponin a, d showed inhibitory activities against NGF-induced neurite growth, suggesting they should mainly contribute to the inhibitory activity of YKH. Further study on the effects of YKH against epidermal nerve density in “itch-scratch” animal models is under investigation.

  15. The depolarizing action of GABA in cultured hippocampal neurons is not due to the absence of ketone bodies.

    Directory of Open Access Journals (Sweden)

    Jaylyn Waddell

    Full Text Available Two recent reports propose that the depolarizing action of GABA in the immature brain is an artifact of in vitro preparations in which glucose is the only energy source. The authors argue that this does not mimic the physiological environment because the suckling rats use ketone bodies and pyruvate as major sources of metabolic energy. Here, we show that availability of physiologically relevant levels of ketone bodies has no impact on the excitatory action of GABA in immature cultured hippocampal neurons. Addition of β-hydroxybutyrate (BHB, the primary ketone body in the neonate rat, affected neither intracellular calcium elevation nor membrane depolarizations induced by the GABA-A receptor agonist muscimol, when assessed with calcium imaging or perforated patch-clamp recording, respectively. These results confirm that the addition of ketone bodies to the extracellular environment to mimic conditions in the neonatal brain does not reverse the chloride gradient and therefore render GABA hyperpolarizing. Our data are consistent with the existence of a genuine "developmental switch" mechanism in which GABA goes from having a predominantly excitatory role in immature cells to a predominantly inhibitory one in adults.

  16. Development of calcium-permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors in cultured neocortical neurons visualized by cobalt staining

    DEFF Research Database (Denmark)

    Jensen, J B; Schousboe, A; Pickering, D S

    1998-01-01

    The developmental expression of calcium (Ca2+)-permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate receptors in cultured neocortical neurons was evaluated by using cobalt uptake, a histochemical method that identifies cells expressing Ca2+-permeable, non-N-methyl......The developmental expression of calcium (Ca2+)-permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate receptors in cultured neocortical neurons was evaluated by using cobalt uptake, a histochemical method that identifies cells expressing Ca2+-permeable, non......-N-methyl-D-aspartate (non-NMDA) receptors. At a concentration of 500 microM, AMPA was found to stimulate cobalt uptake only late in development, resulting in staining of 2.7%+/-0.3% of the neurons maintained in culture for 12 days in vitro (DIV). When AMPA receptor desensitization was blocked with 50 microM cyclothiazide......, the developmental profile of cobalt uptake mediated by 25 microM AMPA changed dramatically. The cobalt staining now appeared in young cultures (5 DIV), and the percentage of stained cells increased from 3.4%+/-0.2% at 5 DIV to 21.7%+/-1.6% at 12 DIV. The effect of 200 microM kainate was similar to that seen with 25...

  17. Role of Cl−–HCO3 − exchanger AE3 in intracellular pH homeostasis in cultured murine hippocampal neurons, and in crosstalk to adjacent astrocytes

    Science.gov (United States)

    Salameh, Ahlam I.; Hübner, Christian A.

    2016-01-01

    Key points A polymorphism of human AE3 is associated with idiopathic generalized epilepsy. Knockout of AE3 in mice lowers the threshold for triggering epileptic seizures. The explanations for these effects are elusive.Comparisons of cells from wild‐type vs. AE3–/– mice show that AE3 (present in hippocampal neurons, not astrocytes; mediates HCO3 – efflux) enhances intracellular pH (pHi) recovery (decrease) from alkali loads in neurons and, surprisingly, adjacent astrocytes.During metabolic acidosis (MAc), AE3 speeds initial acidification, but limits the extent of pHi decrease in neurons and astrocytes.AE3 speeds re‐alkalization after removal of MAc in neurons and astrocytes, and speeds neuronal pHi recovery from an ammonium prepulse‐induced acid load.We propose that neuronal AE3 indirectly increases acid extrusion in (a) neurons via Cl– loading, and (b) astrocytes by somehow enhancing NBCe1 (major acid extruder). The latter would enhance depolarization‐induced alkalinization of astrocytes, and extracellular acidification, and thereby reduce susceptibility to epileptic seizures. Abstract The anion exchanger AE3, expressed in hippocampal (HC) neurons but not astrocytes, contributes to intracellular pH (pHi) regulation by facilitating the exchange of extracellular Cl– for intracellular HCO3 –. The human AE3 polymorphism A867D is associated with idiopathic generalized epilepsy. Moreover, AE3 knockout (AE3–/–) mice are more susceptible to epileptic seizure. The mechanism of these effects has been unclear because the starting pHi in AE3–/– and wild‐type neurons is indistinguishable. The purpose of the present study was to use AE3–/– mice to investigate the role of AE3 in pHi homeostasis in HC neurons, co‐cultured with astrocytes. We find that the presence of AE3 increases the acidification rate constant during pHi recovery from intracellular alkaline loads imposed by reducing [CO2]. The presence of AE3 also speeds intracellular

  18. [Nonuniform distribution and contribution of the P- and P/Q-type calcium channels to short-term inhibitory synaptic transmission in cultured hippocampal neurons].

    Science.gov (United States)

    Mizerna, O P; Fedulova, S A; Veselovs'kyĭ, M S

    2010-01-01

    In the present study, we investigated the sensitivity of GABAergic short-term plasticity to the selective P- and P/Q-type calcium channels blocker omega-agatoxin-IVA. To block the P-type channels we used 30 nM of this toxin and 200 nM of the toxin was used to block the P/Q channel types. The evoked inhibitory postsynaptic currents (eIPSC) were studied using patch-clamp technique in whole-cell configuration in postsynaptic neuron and local extracellular stimulation of single presynaptic axon by rectangular pulse. The present data show that the contribution of P- and P/Q-types channels to GABAergic synaptic transmission in cultured hippocampal neurons are 30% and 45%, respectively. It was shown that the mediate contribution of the P- and P/Q-types channels to the amplitudes of eIPSC is different to every discovered neuron. It means that distribution of these channels is non-uniform. To study the short-term plasticity of inhibitory synaptic transmission, axons of presynaptic neurons were paired-pulse stimulated with the interpulse interval of 150 ms. Neurons demonstrated both the depression and facilitation. The application of 30 nM and 200 nM of the blocker decreased the depression and increased facilitation to 8% and 11%, respectively. In addition, we found that the mediate contribution of the P- and P/Q-types channels to realization of synaptic transmission after the second stimuli is 4% less compared to that after the first one. Therefore, blocking of both P- and P/Q-types calcium channels can change the efficiency of synaptic transmission. In this instance it facilitates realization of the transmission via decreased depression or increased facilitation. These results confirm that the P- and P/Q-types calcium channels are involved in regulation of the short-term inhibitory synaptic plasticity in cultured hippocampal neurons.

  19. Neuronal Cell Death Induced by Mechanical Percussion Trauma in Cultured Neurons is not Preceded by Alterations in Glucose, Lactate and Glutamine Metabolism

    DEFF Research Database (Denmark)

    Jayakumar, A R; Bak, L K; Rama Rao, K V

    2016-01-01

    to neurobehavioral and cognitive impairments, that usually develop months to years after single or repetitive episodes of head trauma, are major consequences of chronic TBI. The molecular mechanisms responsible for TBI-induced injury, however, are unclear. Recent studies have suggested that early mitochondrial......Traumatic brain injury (TBI) is a devastating neurological disorder that usually presents in acute and chronic forms. Brain edema and associated increased intracranial pressure in the early phase following TBI are major consequences of acute trauma. On the other hand, neuronal injury, leading...... dysfunction and subsequent energy failure play a role in the pathogenesis of TBI. We therefore examined whether oxidative metabolism of (13)C-labeled glucose, lactate or glutamine is altered early following in vitro mechanical percussion-induced trauma (5 atm) to neurons (4-24 h), and whether such events...

  20. Specific CA3 neurons decode neural information of dentate granule cells evoked by paired-pulse stimulation in co-cultured networks.

    Science.gov (United States)

    Poli, Daniele; DeMarse, Thomas B; Wheeler, Bruce C; Brewer, Gregory J

    2017-07-01

    CA3 and dentate gyrus (DG) neurons are cultured in two-chamber devices on multi-electrode arrays (MEAs) and connected via micro-tunnels. In order to evoke time-locked activity, paired-pulse stimulation is applied to 22 different sites and repeated 25 times in each well in 5 MEA co-cultures and results compared to CA3-CA3 and DG-DG networks homologous controls. In these hippocampal sub-regions, we focus on the mechanisms underpinning a network's ability to decode the identity of site specific stimulation from analysis of evoked network responses using a support vector machine classifier. Our results indicate that a pool of CA3 neurons is able to reliably decode the identity of DG stimulation site information.

  1. Inhibition of glutamine synthesis induces glutamate dehydrogenase-dependent ammonia fixation into alanine in co-cultures of astrocytes and neurons

    DEFF Research Database (Denmark)

    Dadsetan, Sherry; Bak, Lasse Kristoffer; Sørensen, Michael

    2011-01-01

    It has been previously demonstrated that ammonia exposure of neurons and astrocytes in co-culture leads to net synthesis not only of glutamine but also of alanine. The latter process involves the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT). In the present...... study it was investigated if the glutamine synthetase (GS) inhibitor methionine sulfoximine (MSO) would enhance alanine synthesis by blocking the GS-dependent ammonia scavenging process. Hence, co-cultures of neurons and astrocytes were incubated for 2.5h with [U-(13)C]glucose to monitor de novo...... synthesis of alanine and glutamine in the absence and presence of 5.0 mM NH(4)Cl and 10 mM MSO. Ammonia exposure led to increased incorporation of label but not to a significant increase in the amount of these amino acids. However, in the presence of MSO, glutamine synthesis was blocked and synthesis...

  2. Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Midori Kato-Negishi

    2008-03-01

    Full Text Available Midori Kato-Negishi1, Masahiro Kawahara21Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu-shi, Tokyo 183- 8526, Japan; 2Department of Analytical Chemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka-shi, Miyazaki 882-8508, JapanAbstract: The neurotoxicity of β-amyloid protein (AβP is implicated in the etiology of Alzheimer’s disease. We previously have demonstrated that AβP forms Ca2+-permeable pores on neuronal membranes, causes a marked increase in intracellular calcium level, and leads to neuronal death. Here, we investigated in detail the features of AβP-induced changes in intracellular Ca2+ level in primary cultured rat hippocampal neurons using a multisite Ca2+- imaging system with fura-2 as a fluorescent probe. Only a small fraction of short-term cultured hippocampal neurons (ca 1 week in vitro exhibited changes in intracellular Ca2+ level after AβP exposure. However, AβP caused an acute increase in intracellular Ca2+ level in long-term cultured neurons (ca 1 month in vitro. The responses to AβP were highly heterogeneous, and immunohistochemical analysis using an antibody to AβP revealed that AβP is deposited on some but not all neurons. Considering that the disruption of Ca2+ homeostasis is the primary event in AβP neurotoxicity, substances that protect neurons from an AβP-induced intracellular Ca2+ level increase may be candidates as therapeutic drugs for Alzheimer’s disease. In line with the search for such protective substances, we found that the preadministration of neurosteroids including dehydroepiandrosterone, dehydroepiandrosterone sulfate, and pregnenolone significantly inhibits the increase in intracellular calcium level induced by AβP. Our results suggest the possible significance of neurosteroids, whose levels are reduced in the elderly, in preventing AβP neurotoxicity

  3. Activation of 5-HT2A/C receptor reduces glycine receptor-mediated currents in cultured auditory cortical neurons.

    Science.gov (United States)

    Luo, Bin; Hu, Lingli; Liu, Chunhua; Guo, Yiping; Wang, Haitao

    2016-02-01

    Glycine receptors (GlyRs) permeable to chloride only mediate tonic inhibition in the cerebral cortex where glycinergic projection is completely absent. The functional modulation of GlyRs was largely studied in subcortical brain regions with glycinergic transmissions, but the function of cortical GlyRs was rarely addressed. Serotonin could broadly modulate many ion channels through activating 5-HT2 receptor, but whether cortical GlyRs are subjected to serotonergic modulation remains unexplored. The present study adopted patch clamp recordings to examine functional regulation of strychnine-sensitive GlyRs currents in cultured cortical neurons by DOI (2,5-Dimethoxy-4-iodoamphetamine), a 5-HT2A/C receptor agonist. DOI caused a concentration-dependent reduction of GlyR currents with unchanged reversal potential. This reduction was blocked by the selective receptor antagonists (ritanserin and risperidone) and G protein inhibitor (GDP-β-s) demonstrated that the reducing effect of DOI on GlyR current required the activation of 5-HT2A/C receptors. Strychnine-sensitive tonic currents revealed the inhibitory tone mediated by nonsynaptic GlyRs, and DOI similarly reduced the tonic inhibition. The impaired microtube-dependent trafficking or clustering of GlyRs was thought to be involved in that nocodazole as a microtube depolymerizing drug largely blocked the inhibition mediated by 5-HT2A/C receptors. Our results suggested that activation of 5-HT2A/C receptors might suppress cortical tonic inhibition mediated by GlyRs, and the findings would provide important insight into serotonergic modulation of tonic inhibition mediated by GlyRs, and possibly facilitate to develop the therapeutic treatment of neurological diseases such as tinnitus through regulating cortical GlyRs.

  4. Peroxynitrite is Involved in the Apoptotic Death of Cultured Cerebellar Granule Neurons Induced by Staurosporine, but not by Potassium Deprivation.

    Science.gov (United States)

    Olguín-Albuerne, Mauricio; Ramos-Pittol, José Miguel; Coyoy, Angélica; Martínez-Briseño, Carlos Patricio; Domínguez, Guadalupe; Morán, Julio

    2016-02-01

    Nitric oxide (NO) regulates numerous physiological process and is the main source of reactive nitrogen species (RNS). NO promotes cell survival, but it also induces apoptotic death having been involved in the pathogenesis of several neurodegenerative diseases. NO and superoxide anion react to form peroxynitrite, which accounts for most of the deleterious effects of NO. The mechanisms by which these molecules regulate the apoptotic process are not well understood. In this study, we evaluated the role of NO and peroxynitrite in the apoptotic death of cultured cerebellar granule neurons (CGN), which are known to experience apoptosis by staurosporine (St) or potassium deprivation (K5). We found that CGN treated with the peroxynitrite catalyst, FeTTPs were completely rescued from St-induced death, but not from K5-induced death. On the other hand, the inhibition of the inducible nitric oxide synthase partially protected cell viability in CGN treated with K5, but not with St, while the inhibitor L-NAME further reduced the cell viability in St, but it did not affect K5. Finally, an inhibitor of the soluble guanylate cyclase (sGC) diminished the cell viability in K5, but not in St. Altogether, these results shows that NO promotes cell survival in K5 through sGC-cGMP and promotes cell death by other mechanisms, while in St NO promotes cell survival independently of cGMP and peroxynitrite results critical for St-induced death. Our results suggest that RNS are differentially handled by CGN during cell death depending on the death-inducing conditions.

  5. Inhibitor of PI3K/Akt Signaling Pathway Small Molecule Promotes Motor Neuron Differentiation of Human Endometrial Stem Cells Cultured on Electrospun Biocomposite Polycaprolactone/Collagen Scaffolds.

    Science.gov (United States)

    Ebrahimi-Barough, Somayeh; Hoveizi, Elham; Yazdankhah, Meysam; Ai, Jafar; Khakbiz, Mehrdad; Faghihi, Faezeh; Tajerian, Roksana; Bayat, Neda

    2017-05-01

    Small molecules as useful chemical tools can affect cell differentiation and even change cell fate. It is demonstrated that LY294002, a small molecule inhibitor of phosphatidylinositol 3-kinase (PI3K)/Akt signal pathway, can inhibit proliferation and promote neuronal differentiation of mesenchymal stem cells (MSCs). The purpose of this study was to investigate the differentiation effect of Ly294002 small molecule on the human endometrial stem cells (hEnSCs) into motor neuron-like cells on polycaprolactone (PCL)/collagen scaffolds. hEnSCs were cultured in a neurogenic inductive medium containing 1 μM LY294002 on the surface of PCL/collagen electrospun fibrous scaffolds. Cell attachment and viability of cells on scaffolds were characterized by scanning electron microscope (SEM) and 3-(4,5-dimethylthiazoyl-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay. The expression of neuron-specific markers was assayed by real-time PCR and immunocytochemistry analysis after 15 days post induction. Results showed that attachment and differentiation of hEnSCs into motor neuron-like cells on the scaffolds with Ly294002 small molecule were higher than that of the cells on tissue culture plates as control group. In conclusion, PCL/collagen electrospun scaffolds with Ly294002 have potential for being used in neural tissue engineering because of its bioactive and three-dimensional structure which enhances viability and differentiation of hEnSCs into neurons through inhibition of the PI3K/Akt pathway. Thus, manipulation of this pathway by small molecules can enhance neural differentiation.

  6. Fast, Na+ /K+ pump driven, steady-state transcytolemmal water exchange in neuronal tissue: A study of rat brain cortical cultures.

    Science.gov (United States)

    Bai, Ruiliang; Springer, Charles S; Plenz, Dietmar; Basser, Peter J

    2018-06-01

    Water homeostasis and transport play important roles in brain function (e.g., ion homeostasis, neuronal excitability, cell volume regulation, etc.). However, specific mechanisms of water transport across cell membranes in neuronal tissue have not been completely elaborated. The kinetics of transcytolemmal water exchange were measured in neuronal tissue using simultaneous, real-time fluorescence and nuclear magnetic resonance (NMR) measurements of perfused, active brain organotypic cortical cultures. Perfusion with a paramagnetic MRI contrast agent, gadoteridol, allows NMR determination of the unidirectional rate constant for steady-state cellular water efflux (k io ), and the mole fraction of intracellular water ( pi), related to the average cell volume (V). Changes in intracellular calcium concentration [Cai2+] were used as a proxy for neuronal activity and were monitored by fluorescence imaging. The k io value, averaged over all cultures (N = 99) at baseline, was 2.02 (±1.72) s -1 , indicating that on average, the equivalent of the entire intracellular water volume turns over twice each second. To probe possible molecular pathways, the specific Na + -K + -ATPase (NKA) inhibitor, ouabain (1 mM), was transiently introduced into the perfusate. This caused significant transient changes (N = 8): [Cai2+] rose ∼250%, V rose ∼89%, and k io fell ∼45%, with a metabolically active k io contribution probably eliminated by ouabain saturation. These results suggest that transcytolemmal water exchange in neuronal tissue involves mechanisms affected by NKA activity as well as passive pathways. The active pathway may account for half of the basal homeostatic water flux. Magn Reson Med 79:3207-3217, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  7. Lack of insulin results in reduced seladin-1 expression in primary cultured neurons and in cerebral cortex of STZ-induced diabetic rats.

    Science.gov (United States)

    Kazkayasi, Inci; Ismail, Muhammad-Al-Mustafa; Parrado-Fernandez, Cristina; Björkhem, Ingemar; Pekiner, Can; Uma, Serdar; Cedazo-Minguez, Angel; Burul-Bozkurt, Nihan

    2016-10-28

    Several studies demonstrated that Diabetes mellitus (DM) enhances the risk for Alzheimer's disease (AD). Although hyperglycemia and perturbed function of insulin signaling have been proposed to contribute to AD pathogenesis, the molecular mechanisms behind this association is not clear yet. Seladin-1 is an enzyme catalyzing the last step in cholesterol biosynthesis converting desmosterol to cholesterol. The neuroprotective function of seladin-1 has gained interest in AD research recently. Seladin-1 has anti-apoptotic properties and regulates the expression of β-secretase (BACE-1). Here we measured seladin-1 mRNA and protein expressions in rat primary cultured neurons under diabetic conditions and also in the brains of rats with streptozotocine (STZ)-induced diabetes. We show that constant lack of insulin for 5days decreased seladin-1 levels in cultured rat primary neurons. Similarly, a decrease in seladin-1 was found in the brains of rats with STZ-induced diabetes. However, if the lack of insulin and/or high glucose treatment was intermittent, neuronal seladin-1 levels were not affected in vitro. On the other hand, treatment of neurons with metformin resulted in a significant increase in seladin-1. Constant lack of insulin for 5days, as well as high glucose treatment, increased the neuronal expression of BACE-1 in vitro, but not in the in vivo model. Our study defines insulin as a regulator of seladin-1 expression for the first time. The relevance of these findings for the association of DM with AD is discussed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Targeted disruption of the Mast syndrome gene SPG21 in mice impairs hind limb function and alters axon branching in cultured cortical neurons

    Science.gov (United States)

    Soderblom, Cynthia; Stadler, Julia; Jupille, Henri; Blackstone, Craig; Shupliakov, Oleg

    2017-01-01

    Mast syndrome (SPG21) is a childhood-onset, autosomal recessive, complicated form of hereditary spastic paraplegia (HSP) characterized by dementia, thin corpus callosum, white matter abnormalities, and cerebellar and extrapyramidal signs in addition to spastic paraparesis. A nucleotide insertion resulting in premature truncation of the SPG21 gene product maspardin underlies this disorder, likely leading to loss of protein function. In this study, we generated SPG21−/− knockout mice by homologous recombination as a possible animal model for SPG21. Though SPG21−/− mice appeared normal at birth, within several months they developed gradually progressive hind limb dysfunction. Cerebral cortical neurons cultured from SPG21−/− mice exhibited significantly more axonal branching than neurons from wild-type animals, while comprehensive neuropathological analysis of SPG21−/− mice did not reveal definitive abnormalities. Since alterations in axon branching have been seen in neurons derived from animal models of other forms of HSP as well as motor neuron diseases, this may represent a common cellular pathogenic theme. PMID:20661613

  9. A Ground-Based Analog for CNS Exposure to Space Radiation: A System for Integrating Microbeam Technology and Neuronal Culture

    Data.gov (United States)

    National Aeronautics and Space Administration — Problem Statement: The connection between radiation-induced neuronal damage and deficits in behavior and cellular function is still largely unknown. Previous studies...

  10. Long-Term Lithium Treatment Increases cPLA2 and iPLA2 Activity in Cultured Cortical and Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Vanessa de Jesus De-Paula

    2015-11-01

    Full Text Available Background: Experimental evidence supports the neuroprotective properties of lithium, with implications for the treatment and prevention of dementia and other neurodegenerative disorders. Lithium modulates critical intracellular pathways related to neurotrophic support, inflammatory response, autophagy and apoptosis. There is additional evidence indicating that lithium may also affect membrane homeostasis. Objective: To investigate the effect of lithium on cytosolic phospholipase A2 (PLA2 activity, a key player on membrane phospholipid turnover which has been found to be reduced in blood and brain tissue of patients with Alzheimer’s disease (AD. Methods: Primary cultures of cortical and hippocampal neurons were treated for 7 days with different concentrations of lithium chloride (0.02 mM, 0.2 mM and 2 mM. A radio-enzymatic assay was used to determine the total activity of PLA2 and two PLA2 subtypes: cytosolic calcium-dependent (cPLA2; and calcium-independent (iPLA2. Results: cPLA2 activity increased by 82% (0.02 mM; p = 0.05 and 26% (0.2 mM; p = 0.04 in cortical neurons and by 61% (0.2 mM; p = 0.03 and 57% (2 mM; p = 0.04 in hippocampal neurons. iPLA2 activity was increased by 7% (0.2 mM; p = 0.04 and 13% (2 mM; p = 0.05 in cortical neurons and by 141% (0.02 mM; p = 0.0198 in hippocampal neurons. Conclusion: long-term lithium treatment increases membrane phospholipid metabolism in neurons through the activation of total, c- and iPLA2. This effect is more prominent at sub-therapeutic concentrations of lithium, and the activation of distinct cytosolic PLA2 subtypes is tissue specific, i.e., iPLA2 in hippocampal neurons, and cPLA2 in cortical neurons. Because PLA2 activities are reported to be reduced in Alzheimer’s disease (AD and bipolar disorder (BD, the present findings provide a possible mechanism by which long-term lithium treatment may be useful in the prevention of the disease.

  11. Metabotropic glutamate receptor 5 activation enhances tyrosine phosphorylation of the N-methyl-D-aspartate (NMDA) receptor and NMDA-induced cell death in hippocampal cultured neurons.

    Science.gov (United States)

    Takagi, Norio; Besshoh, Shintaro; Marunouchi, Tetsuro; Takeo, Satoshi; Tanonaka, Kouichi

    2012-01-01

    The activation of group I metabotropic glutamate receptors (mGluRs), which are coupled with Gq-protein, initiates a variety physiological responses in different types of cells. While Gq-protein-coupled receptors can upregulate N-methyl-D-aspartate (NMDA) receptor function, group I mGluR-mediated regulations of NMDA receptor function are not fully understood. To determine biochemical roles of group I mGluRs in the regulation of the NMDA receptor, we have investigated changes in tyrosine phosphorylation of NMDA receptor subunits NR2A and NR2B induced by a selective mGluR5 agonist, (RS)-chloro-5-hydroxyphenylglycine (CHPG) in hippocampal neuronal cultures. Activation of mGluR5 by CHPG increased active-forms of Src. CHPG also enhanced tyrosine phosphorylation of NR2A and NR2B in hippocampal neuronal cultures. In addition, NMDA-induced cell death was enhanced by CHPG-induced mGluR5 stimulation at the concentration, which increased tyrosine phosphorylation of Src and NR2A/2B but did not induce cell death. This effect was inhibited by selective mGluR5 antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP). The results suggest that in hippocampal neurons, mGluR5 may regulate NMDA receptor activity, involving tyrosine phosphorylation of NR2A and NR2B and may be involved in NMDA receptor-mediated cell injury.

  12. A functional assay to measure postsynaptic gamma-aminobutyric acidB responses in cultured spinal cord neurons: Heterologous regulation of the same K+ channel

    Energy Technology Data Exchange (ETDEWEB)

    Kamatchi, G.L.; Ticku, M.K. (Univ. of Texas Health Science Center, San Antonio (USA))

    1991-02-01

    The stimulation of postsynaptic gamma-aminobutyric acid (GABA)B receptors leads to slow inhibitory postsynaptic potentials due to the influx of K(+)-ions. This was studied biochemically, in vitro in mammalian cultured spinal cord neurons by using 86Rb as a substitute for K+. (-)-Baclofen, a GABAB receptor agonist, produced a concentration-dependent increase in the 86Rb-influx. This effect was stereospecific and blocked by GABAB receptor antagonists like CGP 35 348 (3-aminopropyl-diethoxymethyl-phosphonic acid) and phaclofen. Apart from the GABAB receptors, both adenosine via adenosine1 receptors and 5-hydroxytryptamine (5-HT) via 5-HT1 alpha agonists also increased the 86Rb-influx. These agonists failed to show any additivity between them when they were combined in their maximal concentration. In addition, their effect was antagonized specifically by their respective antagonists without influencing the others. These findings suggest the presence of GABAB, adenosine1 and 5-HT1 alpha receptors in the cultured spinal cord neurons, which exhibit a heterologous regulation of the same K(+)-channel. The effect of these agonists were antagonized by phorbol 12,13-didecanoate, an activator of protein kinase C, and pretreatment with pertussis toxin. This suggests that these agonists by acting on their own receptors converge on the same K(+)-channel through the Gi/Go proteins. In summary, we have developed a biochemical functional assay for studying and characterizing GABAB synaptic pharmacology in vitro, using spinal cord neurons.

  13. A role for complexes of survival of motor neurons (SMN) protein with gemins and profilin in neurite-like cytoplasmic extensions of cultured nerve cells

    International Nuclear Information System (INIS)

    Sharma, Aarti; Lambrechts, Anja; Le thi Hao; Le, Thanh T.; Sewry, Caroline A.; Ampe, Christophe; Burghes, Arthur H.M.; Morris, Glenn E.

    2005-01-01

    Spinal muscular atrophy (SMA) is caused by reduced levels of SMN (survival of motor neurons protein) and consequent loss of motor neurons. SMN is involved in snRNP transport and nuclear RNA splicing, but axonal transport of SMN has also been shown to occur in motor neurons. SMN also binds to the small actin-binding protein, profilin. We now show that SMN and profilin II co-localise in the cytoplasm of differentiating rat PC12 cells and in neurite-like extensions, especially at their growth cones. Many components of known SMN complexes were also found in these extensions, including gemin2 (SIP-1), gemin6, gemin7 and unrip (unr-interacting protein). Coilin p80 and Sm core protein immunoreactivity, however, were seen only in the nucleus. SMN is known to associate with β-actin mRNA and specific hnRNPs in axons and in neurite extensions of cultured nerve cells, and SMN also stimulates neurite outgrowth in cultures. Our results are therefore consistent with SMN complexes, rather than SMN alone, being involved in the transport of actin mRNPs along the axon as in the transport of snRNPs into the nucleus by similar SMN complexes. Antisense knockdown of profilin I and II isoforms inhibited neurite outgrowth of PC12 cells and caused accumulation of SMN and its associated proteins in cytoplasmic aggregates. BIAcore studies demonstrated a high affinity interaction of SMN with profilin IIa, the isoform present in developing neurons. Pathogenic missense mutations in SMN, or deletion of exons 5 and 7, prevented this interaction. The interaction is functional in that SMN can modulate actin polymerisation in vitro by reducing the inhibitory effect of profilin IIa. This suggests that reduced SMN in SMA might cause axonal pathfinding defects by disturbing the normal regulation of microfilament growth by profilins

  14. Hypoxic Culture Promotes Dopaminergic-Neuronal Differentiation of Nasal Olfactory Mucosa Mesenchymal Stem Cells via Upregulation of Hypoxia-Inducible Factor-1α.

    Science.gov (United States)

    Zhuo, Yi; Wang, Lei; Ge, Lite; Li, Xuan; Duan, Da; Teng, Xiaohua; Jiang, Miao; Liu, Kai; Yuan, Ting; Wu, Pei; Wang, Hao; Deng, Yujia; Xie, Huali; Chen, Ping; Xia, Ying; Lu, Ming

    2017-08-01

    Olfactory mucosa mesenchymal stem cells (OM-MSCs) display significant clonogenic activity and may be easily propagated for Parkinson's disease therapies. Methods of inducing OM-MSCs to differentiate into dopaminergic (DAergic) neurons using olfactory ensheathing cells (OECs) are thus an attractive topic of research. We designed a hypoxic induction protocol to generate DAergic neurons from OM-MSCs using a physiological oxygen (O 2 ) level of 3% and OEC-conditioned medium (OCM; HI group). The normal induction (NI) group was cultured in O 2 at ambient air level (21%). The role of hypoxia-inducible factor-1α (HIF-1α) in the differentiation of OM-MSCs under hypoxia was investigated by treating cells with an HIF-1α inhibitor before induction (HIR group). The proportions of β-tubulin- and tyrosine hydroxylase (TH)-positive cells were significantly increased in the HI group compared with the NI and HIR groups, as shown by immunocytochemistry and Western blotting. Furthermore, the level of dopamine was significantly increased in the HI group. A slow outward potassium current was recorded in differentiated cells after 21 d of induction using whole-cell voltage-clamp tests. A hypoxic environment thus promotes OM-MSCs to differentiate into DAergic neurons by increasing the expression of HIF-1α and by activating downstream target gene TH. This study indicated that OCM under hypoxic conditions could significantly upregulate key transcriptional factors involved in the development of DAergic neurons from OM-MSCs, mediated by HIF-1α. Hypoxia promotes DAergic neuronal differentiation of OM-MSCs, and HIF-1α may play an important role in hypoxia-inducible pathways during DAergic lineage specification and differentiation in vitro.

  15. Comparison of abnormal isoform of prion protein in prion-infected cell lines and primary-cultured neurons by PrPSc-specific immunostaining.

    Science.gov (United States)

    Tanaka, Misaki; Fujiwara, Ai; Suzuki, Akio; Yamasaki, Takeshi; Hasebe, Rie; Masujin, Kentaro; Horiuchi, Motohiro

    2016-08-01

    We established abnormal isoform of prion protein (PrPSc)-specific double immunostaining using mAb 132, which recognizes aa 119-127 of the PrP molecule, and novel PrPSc-specific mAb 8D5, which recognizes the N-terminal region of the PrP molecule. Using the PrPSc-specific double immunostaining, we analysed PrPSc in immortalized neuronal cell lines and primary cerebral-neuronal cultures infected with prions. The PrPSc-specific double immunostaining showed the existence of PrPSc positive for both mAbs 132 and 8D5, as well as those positive only for either mAb 132 or mAb 8D5. This indicated that double immunostaining detects a greater number of PrPSc species than single immunostaining. Double immunostaining revealed cell-type-dependent differences in PrPSc staining patterns. In the 22 L prion strain-infected Neuro2a (N2a)-3 cells, a subclone of N2a neuroblastoma cell line, or GT1-7, a subclone of the GT1 hypothalamic neuronal cell line, granular PrPSc stains were observed at the perinuclear regions and cytoplasm, whereas unique string-like PrPSc stains were predominantly observed on the surface of the 22 L strain-infected primary cerebral neurons. Only 14 % of PrPSc in the 22 L strain-infected N2a-3 cells were positive for mAb 8D5, indicating that most of the PrPSc in N2a-3 lack the N-terminal portion. In contrast, nearly half PrPSc detected in the 22 L strain-infected primary cerebral neurons were positive for mAb 8D5, suggesting the abundance of full-length PrPSc that possesses the N-terminal portion of PrP. Further analysis of prion-infected primary neurons using PrPSc-specific immunostaining will reveal the neuron-specific mechanism for prion propagation.

  16. Neurotoxicity of cerebro-spinal fluid from patients with Parkinson's disease on mesencephalic primary cultures as an in vitro model of dopaminergic neurons.

    Science.gov (United States)

    Kong, Ping; Zhang, Ben-Shu; Lei, Ping; Kong, Xiao-Dong; Zhang, Shi-Shuang; Li, Dai; Zhang, Yun

    2015-08-01

    Parkinson's disease is a degenerative disorder of the central nervous system. In spite of extensive research, neither the cause nor the mechanisms have been firmly established thus far. One assumption is that certain toxic substances may exist in the cerebro-spinal fluid (CSF) of Parkinson's disease patients. To confirm the neurotoxicity of CSF and study the potential correlation between neurotoxicity and the severity of Parkinson's disease, CSF was added to cultured cells. By observation of cell morphology, changes in the levels of lactate dehydrogenase, the ratio of tyrosine hydroxylase-positive cells, and the expression of tyrosine hydroxylase mRNA and protein, the differences between the two groups were shown. The created in vitro model of dopaminergic neurons using primary culture of mouse embryonic mesencephalic tissue is suitable for the study of neurotoxicity. The observations of the present study indicated that CSF from Parkinson's disease patients contains factors that can cause specific injury to cultured dopaminergic neurons. However, no obvious correlation was found between the neurotoxicity of CSF and the severity of Parkinson's disease.

  17. Evaluation of silicon nitride as a substrate for culture of PC12 cells: an interfacial model for functional studies in neurons.

    Directory of Open Access Journals (Sweden)

    Johan Jaime Medina Benavente

    Full Text Available Silicon nitride is a biocompatible material that is currently used as an interfacial surface between cells and large-scale integration devices incorporating ion-sensitive field-effect transistor technology. Here, we investigated whether a poly-L-lysine coated silicon nitride surface is suitable for the culture of PC12 cells, which are widely used as a model for neural differentiation, and we characterized their interaction based on cell behavior when seeded on the tested material. The coated surface was first examined in terms of wettability and topography using contact angle measurements and atomic force microscopy and then, conditioned silicon nitride surface was used as the substrate for the study of PC12 cell culture properties. We found that coating silicon nitride with poly-L-lysine increased surface hydrophilicity and that exposing this coated surface to an extracellular aqueous environment gradually decreased its roughness. When PC12 cells were cultured on a coated silicon nitride surface, adhesion and spreading were facilitated, and the cells showed enhanced morphological differentiation compared to those cultured on a plastic culture dish. A bromodeoxyuridine assay demonstrated that, on the coated silicon nitride surface, higher proportions of cells left the cell cycle, remained in a quiescent state and had longer survival times. Therefore, our study of the interaction of the silicon nitride surface with PC12 cells provides important information for the production of devices that need to have optimal cell culture-supporting properties in order to be used in the study of neuronal functions.

  18. Evaluation of Silicon Nitride as a Substrate for Culture of PC12 Cells: An Interfacial Model for Functional Studies in Neurons

    Science.gov (United States)

    Medina Benavente, Johan Jaime; Mogami, Hideo; Sakurai, Takashi; Sawada, Kazuaki

    2014-01-01

    Silicon nitride is a biocompatible material that is currently used as an interfacial surface between cells and large-scale integration devices incorporating ion-sensitive field-effect transistor technology. Here, we investigated whether a poly-L-lysine coated silicon nitride surface is suitable for the culture of PC12 cells, which are widely used as a model for neural differentiation, and we characterized their interaction based on cell behavior when seeded on the tested material. The coated surface was first examined in terms of wettability and topography using contact angle measurements and atomic force microscopy and then, conditioned silicon nitride surface was used as the substrate for the study of PC12 cell culture properties. We found that coating silicon nitride with poly-L-lysine increased surface hydrophilicity and that exposing this coated surface to an extracellular aqueous environment gradually decreased its roughness. When PC12 cells were cultured on a coated silicon nitride surface, adhesion and spreading were facilitated, and the cells showed enhanced morphological differentiation compared to those cultured on a plastic culture dish. A bromodeoxyuridine assay demonstrated that, on the coated silicon nitride surface, higher proportions of cells left the cell cycle, remained in a quiescent state and had longer survival times. Therefore, our study of the interaction of the silicon nitride surface with PC12 cells provides important information for the production of devices that need to have optimal cell culture-supporting properties in order to be used in the study of neuronal functions. PMID:24587271

  19. The effects of capsaicin and acidity on currents generated by noxious heat in cultured neonatal rat dorsal root ganglion neurones

    Czech Academy of Sciences Publication Activity Database

    Vlachová, Viktorie; Lyfenko, Alla; Orkand, R. K.; Vyklický st., Ladislav

    2001-01-01

    Roč. 533, č. 3 (2001), s. 717-728 ISSN 0022-3751 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Institutional research plan: CEZ:AV0Z5011922 Keywords : capsaicin * dorsal root ganglion neurones * neonatal rat Subject RIV: FH - Neurology Impact factor: 4.476, year: 2001

  20. Valine but not leucine or isoleucine supports neurotransmitter glutamate synthesis during synaptic activity in cultured cerebellar neurons

    DEFF Research Database (Denmark)

    Bak, Lasse Kristoffer; Johansen, Maja L.; Schousboe, Arne

    2012-01-01

    Synthesis of neuronal glutamate from a-ketoglutarate for neurotransmission necessitates an amino group nitrogen donor; however, it is not clear which amino acid(s) serves this role. Thus, the ability of the three branched-chain amino acids (BCAAs), leucine, isoleucine, and valine, to act as amino...

  1. Neuroprotection comparison of chlorogenic acid and its metabolites against mechanistically distinct cell death-inducing agents in cultured cerebellar granule neurons.

    Science.gov (United States)

    Taram, Faten; Winter, Aimee N; Linseman, Daniel A

    2016-10-01

    While the number of patients diagnosed with neurodegenerative disorders like Alzheimer's disease, amyotrophic lateral sclerosis, and Parkinson's disease is increasing, there are currently no effective treatments that significantly limit the neuronal cell death underlying these diseases. Chlorogenic acid (CGA), a polyphenolic compound found in high concentration in coffee, is known to possess antioxidant and free radical scavenging activity. In this study, we investigated the neuroprotective effects of CGA and its major metabolites in primary cultures of rat cerebellar granule neurons. We show that CGA and caffeic acid displayed a dramatic protective effect against the nitric oxide donor, sodium nitroprusside. In marked contrast, ferulic acid and quinic acid had no protective effect against this nitrosative stress. While CGA and quinic acid had no protective effect against glutamate-induced cell death, caffeic acid and ferulic acid significantly protected neurons from excitotoxicity. Finally, caffeic acid was the only compound to display significant protective activity against hydrogen peroxide, proteasome inhibition, caspase-dependent intrinsic apoptosis, and endoplasmic reticulum stress. These results indicate that caffeic acid displays a much broader profile of neuroprotection against a diverse range of stressors than its parent polyphenol, CGA, or the other major metabolites, ferulic acid and quinic acid. We conclude that caffeic acid is a promising candidate for testing in pre-clinical models of neurodegeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Lead decreases cell survival, proliferation, and neuronal differentiation of primary cultured adult neural precursor cells through activation of the JNK and p38 MAP kinases

    Science.gov (United States)

    Engstrom, Anna; Wang, Hao; Xia, Zhengui

    2015-01-01

    Adult hippocampal neurogenesis is the process whereby adult neural precursor cells (aNPCs) in the subgranular zone (SGZ) of the dentate gyrus (DG) generate adult-born, functional neurons in the hippocampus. This process is modulated by various extracellular and intracellular stimuli, and the adult-born neurons have been implicated in hippocampus-dependent learning and memory. However, studies on how neurotoxic agents affect this process and the underlying mechanisms are limited. The goal of this study was to determine whether lead, a heavy metal, directly impairs critical processes in adult neurogenesis and to characterize the underlying signaling pathways using primary cultured SGZ-aNPCs isolated from adult mice. We report here that lead significantly increases apoptosis and inhibits proliferation in SGZ-aNPCs. In addition, lead significantly impairs spontaneous neuronal differentiation and maturation. Furthermore, we found that activation of the c-Jun NH2-terminal kinase (JNK) and p38 mitogen activated protein (MAP) kinase signaling pathways are important for lead cytotoxicity. Our data suggest that lead can directly act on adult neural stem cells and impair critical processes in adult hippocampal neurogenesis, which may contribute to its neurotoxicity and adverse effects on cognition in adults. PMID:25967738

  3. Detoxification of ammonia in mouse cortical GABAergic cell cultures increases neuronal oxidative metabolism and reveals an emerging role for release of glucose-derived alanine.

    Science.gov (United States)

    Leke, Renata; Bak, Lasse K; Anker, Malene; Melø, Torun M; Sørensen, Michael; Keiding, Susanne; Vilstrup, Hendrik; Ott, Peter; Portela, Luis V; Sonnewald, Ursula; Schousboe, Arne; Waagepetersen, Helle S

    2011-04-01

    Cerebral hyperammonemia is believed to play a pivotal role in the development of hepatic encephalopathy (HE), a debilitating condition arising due to acute or chronic liver disease. In the brain, ammonia is thought to be detoxified via the activity of glutamine synthetase, an astrocytic enzyme. Moreover, it has been suggested that cerebral tricarboxylic acid (TCA) cycle metabolism is inhibited and glycolysis enhanced during hyperammonemia. The aim of this study was to characterize the ammonia-detoxifying mechanisms as well as the effects of ammonia on energy-generating metabolic pathways in a mouse neuronal-astrocytic co-culture model of the GABAergic system. We found that 5 mM ammonium chloride affected energy metabolism by increasing the neuronal TCA cycle activity and switching the astrocytic TCA cycle toward synthesis of substrate for glutamine synthesis. Furthermore, ammonia exposure enhanced the synthesis and release of alanine. Collectively, our results demonstrate that (1) formation of glutamine is seminal for detoxification of ammonia; (2) neuronal oxidative metabolism is increased in the presence of ammonia; and (3) synthesis and release of alanine is likely to be important for ammonia detoxification as a supplement to formation of glutamine.

  4. Simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell cultures and in sub-regions of guinea pig brain.

    Science.gov (United States)

    Schou-Pedersen, Anne Marie V; Hansen, Stine N; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-08-15

    In the present paper, we describe a validated chromatographic method for the simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell culture and in sub-regions of the guinea pig brain. Electrochemical detection provided limits of quantifications (LOQs) between 3.6 and 12nM. Within the linear range, obtained recoveries were from 90.9±9.9 to 120±14% and intra-day and inter-day precisions found to be less than 5.5% and 12%, respectively. The analytical method was applicable for quantification of intracellular and extracellular amounts of monoamine neurotransmitters and their metabolites in guinea pig frontal cortex and hippocampal primary neuronal cell cultures. Noradrenaline, dopamine and serotonin were found to be in a range from 0.31 to 1.7pmol per 2 million cells intracellularly, but only the biogenic metabolites could be detected extracellularly. Distinct differences in monoamine concentrations were observed when comparing concentrations in guinea pig frontal cortex and cerebellum tissue with higher amounts of dopamine and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid in frontal cortex, as compared to cerebellum. The chemical turnover in frontal cortex tissue of guinea pig was for serotonin successfully predicted from the turnover observed in the frontal cortex cell culture. In conclusion, the present analytical method shows high precision, accuracy and sensitivity and is broadly applicable to monoamine measurements in cell cultures as well as brain biopsies from animal models used in preclinical neurochemistry. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Clivorine, an otonecine pyrrolizidine alkaloid from Ligularia species, impairs neuronal differentiation via NGF-induced signaling pathway in cultured PC12 cells.

    Science.gov (United States)

    Xiong, Aizhen; Yan, Artemis Lu; Bi, Cathy W C; Lam, Kelly Y C; Chan, Gallant K L; Lau, Kitty K M; Dong, Tina T X; Lin, Huangquan; Yang, Li; Wang, Zhengtao; Tsim, Karl W K

    2016-08-15

    Pyrrolizidine alkaloids (PAs) are commonly found in many plants including those used in medical therapeutics. The hepatotoxicities of PAs have been demonstrated both in vivo and in vitro; however, the neurotoxicities of PAs are rarely mentioned. In this study, we aimed to investigate in vitro neurotoxicities of clivorine, one of the PAs found in various Ligularia species, in cultured PC12 cells. PC12 cell line was employed to first elucidate the neurotoxicity and the underlying mechanism of clivorine, including cell viability and morphology change, neuronal differentiation marker and signaling pathway. PC12 cells were challenged with series concentrations of clivorine and/or nerve growth factor (NGF). The cell lysates were collected for MTT assay, trypan blue staining, immunocytofluorescent staining, qRT-PCR and western blotting. Clivorine inhibited cell proliferation and neuronal differentiation evidenced by MTT assay and dose-dependently reducing neurite outgrowth, respectively. In addition, clivorine decreased the level of mRNAs encoding for neuronal differentiation markers, e.g. neurofilaments and TrkA (NGF receptor). Furthermore, clivorine reduced the NGF-induced the phosphorylations of TrkA, protein kinase B and cAMP response element-binding protein in cultured PC12 cells. Taken together, our results suggest that clivorine might possess neurotoxicities in PC12 cells via down-regulating the NGF/TrkA/Akt signaling pathway. PAs not only damage the liver, but also possess neurotoxicities, which could possibly result in brain disorders, such as depression. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. The Kv2.1 K+ channel targets to the axon initial segment of hippocampal and cortical neurons in culture and in situ

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    Tamkun Michael M

    2008-11-01

    Full Text Available Abstract Background The Kv2.1 delayed-rectifier K+ channel regulates membrane excitability in hippocampal neurons where it targets to dynamic cell surface clusters on the soma and proximal dendrites. In the past, Kv2.1 has been assumed to be absent from the axon initial segment. Results Transfected and endogenous Kv2.1 is now demonstrated to preferentially accumulate within the axon initial segment (AIS over other neurite processes; 87% of 14 DIV hippocampal neurons show endogenous channel concentrated at the AIS relative to the soma and proximal dendrites. In contrast to the localization observed in pyramidal cells, GAD positive inhibitory neurons within the hippocampal cultures did not show AIS targeting. Photoactivable-GFP-Kv2.1-containing clusters at the AIS were stable, moving μm/hr with no channel turnover. Photobleach studies indicated individual channels within the cluster perimeter were highly mobile (FRAP τ = 10.4 ± 4.8 sec, supporting our model that Kv2.1 clusters are formed by the retention of mobile channels behind a diffusion-limiting perimeter. Demonstrating that the AIS targeting is not a tissue culture artifact, Kv2.1 was found in axon initial segments within both the adult rat hippocampal CA1, CA2, and CA3 layers and cortex. Conclusion In summary, Kv2.1 is associated with the axon initial segment both in vitro and in vivo where it may modulate action potential frequency and back propagation. Since transfected Kv2.1 initially localizes to the AIS before appearing on the soma, it is likely multiple mechanisms regulate Kv2.1 trafficking to the cell surface.

  7. Effect of Testosterone on Neuronal Morphology and Neuritic Growth of Fetal Lamb Hypothalamus-Preoptic Area and Cerebral Cortex in Primary Culture.

    Directory of Open Access Journals (Sweden)

    Radhika C Reddy

    Full Text Available Testosterone plays an essential role in sexual differentiation of the male sheep brain. The ovine sexually dimorphic nucleus (oSDN, is 2 to 3 times larger in males than in females, and this sex difference is under the control of testosterone. The effect of testosterone on oSDN volume may result from enhanced expansion of soma areas and/or dendritic fields. To test this hypothesis, cells derived from the hypothalamus-preoptic area (HPOA and cerebral cortex (CTX of lamb fetuses were grown in primary culture to examine the direct morphological effects of testosterone on these cellular components. We found that within two days of plating, neurons derived from both the HPOA and CTX extend neuritic processes and express androgen receptors and aromatase immunoreactivity. Both treated and control neurites continue to grow and branch with increasing time in culture. Treatment with testosterone (10 nM for 3 days significantly (P < 0.05 increased both total neurite outgrowth (35% and soma size (8% in the HPOA and outgrowth (21% and number of branch points (33% in the CTX. These findings indicate that testosterone-induced somal enlargement and neurite outgrowth in fetal lamb neurons may contribute to the development of a fully masculine sheep brain.

  8. Inhibition of glutamine synthesis induces glutamate dehydrogenase-dependent ammonia fixation into alanine in co-cultures of astrocytes and neurons.

    Science.gov (United States)

    Dadsetan, Sherry; Bak, Lasse K; Sørensen, Michael; Keiding, Susanne; Vilstrup, Hendrik; Ott, Peter; Leke, Renata; Schousboe, Arne; Waagepetersen, Helle S

    2011-09-01

    It has been previously demonstrated that ammonia exposure of neurons and astrocytes in co-culture leads to net synthesis not only of glutamine but also of alanine. The latter process involves the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT). In the present study it was investigated if the glutamine synthetase (GS) inhibitor methionine sulfoximine (MSO) would enhance alanine synthesis by blocking the GS-dependent ammonia scavenging process. Hence, co-cultures of neurons and astrocytes were incubated for 2.5h with [U-(13)C]glucose to monitor de novo synthesis of alanine and glutamine in the absence and presence of 5.0 mM NH(4)Cl and 10 mM MSO. Ammonia exposure led to increased incorporation of label but not to a significant increase in the amount of these amino acids. However, in the presence of MSO, glutamine synthesis was blocked and synthesis of alanine increased leading to an elevated content intra- as well as extracellularly of this amino acid. Treatment with MSO led to a dramatic decrease in glutamine content and increased the intracellular contents of glutamate and aspartate. The large increase in alanine during exposure to MSO underlines the importance of the GDH and ALAT biosynthetic pathway for ammonia fixation, and it points to the use of a GS inhibitor to ameliorate the brain toxicity and edema induced by hyperammonemia, events likely related to glutamine synthesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Neurite Outgrowth and Neuroprotective Effects of Quercetin from Caesalpinia mimosoides Lamk. on Cultured P19-Derived Neurons

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    Napat Tangsaengvit

    2013-01-01

    Full Text Available Quercetin has been isolated for the first time from ethyl acetate extract of Caesalpinia mimosoides Lamk. C. mimosoides Lamk. (Fabaceae or Cha rueat (Thai name is an indigenous plant found in mixed deciduous forest in northern and north-eastern parts of Thailand. Thai rural people consume its young shoots and leaves as a fresh vegetable, as well as it is used for medicinal purposes.The antioxidant capacity in terms of radical scavenging activity of quercetin was determined as IC50 of 3.18 ± 0.07 µg/mL, which was higher than that of Trolox and ascorbic acid (12.54 ± 0.89 and 10.52 ± 0.48 µg/mL, resp.. The suppressive effect of quercetin on both purified and cellular acetylcholinesterase (AChE enzymes was investigated as IC50 56.84 ± 2.64 and 36.60 ± 2.78 µg/mL, respectively. In order to further investigate the protective ability of quercetin on neuronal cells, P19-derived neurons were used as a neuronal model in this study. As a result, quercetin at a very low dose of 1 nM enhanced survival and induced neurite outgrowth of P19-derived neurons. Furthermore, this flavonoid also possessed significant protection against oxidative stress induced by serum deprivation. Altogether, these findings suggest that quercetin is a multifunctional compound and promising valuable drugs candidate for the treatment of neurodegenerative disease.

  10. Neuronal protein gene product 9.5 (IEF SSP 6104) is expressed in cultured human MRC-5 fibroblasts of normal origin and is strongly down-regulated in their SV40 transformed counterparts

    DEFF Research Database (Denmark)

    Honoré, B; Rasmussen, H H; Vandekerckhove, J

    1991-01-01

    Neuronal protein gene product 9.5 (PGP 9.5) most likely identical to ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCH-L1) has been reported to be expressed almost exclusively in neuronal and neuroendocrine tissues. By two-dimensional (2D) immunoblotting, comigration and microsequencing...... is expressed at high levels in quiescent and proliferating cultured normal fibroblasts and is strongly down-regulated (about 10 times) in their transformed counterparts. Udgivelsesdato: 1991-Mar-25...

  11. Asarone from Acori Tatarinowii Rhizoma Potentiates the Nerve Growth Factor-Induced Neuronal Differentiation in Cultured PC12 Cells: A Signaling Mediated by Protein Kinase A.

    Directory of Open Access Journals (Sweden)

    Kelly Y C Lam

    Full Text Available Acori Tatarinowii Rhizoma (ATR, the rhizome of Acorus tatarinowii Schott, is being used clinically to treat neurological disorders. The volatile oil of ATR is being considered as an active ingredient. Here, α-asarone and β-asarone, accounting about 95% of ATR oil, were evaluated for its function in stimulating neurogenesis. In cultured PC12 cells, application of ATR volatile oil, α-asarone or β-asarone, stimulated the expression of neurofilaments, a bio-marker for neurite outgrowth, in a concentration-dependent manner. The co-treatment of ATR volatile oil, α-asarone or β-asarone, with low concentration of nerve growth factor (NGF potentiated the NGF-induced neuronal differentiation in cultured PC12 cells. In addition, application of protein kinase A inhibitors, H89 and KT5720, in cultures blocked the ATR-induced neurofilament expression, as well as the phosphorylation of cAMP-responsive element binding protein (CREB. In the potentiation of NGF-induced signaling in cultured PC12 cells, α-asarone and β-asarone showed synergistic effects. These results proposed the neurite-promoting asarone, or ATR volatile oil, could be useful in finding potential drugs for treating various neurodegenerative diseases, in which neurotrophin deficiency is normally involved.

  12. Functional innervation of human induced pluripotent stem cell-derived cardiomyocytes by co-culture with sympathetic neurons developed using a microtunnel technique.

    Science.gov (United States)

    Sakai, Koji; Shimba, Kenta; Ishizuka, Kazuma; Yang, Zhuonan; Oiwa, Kosuke; Takeuchi, Akimasa; Kotani, Kiyoshi; Jimbo, Yasuhiko

    2017-12-09

    Microelectrode array (MEA) based-drug screening with human induced pluripotent stem cell-derived cardiomyocytes (hiPSCM) is a potent pre-clinical assay for efficiently assessing proarrhythmic risks in new candidates. Furthermore, predicting sympathetic modulation of the proarrhythmic side-effects is an important issue. Although we have previously developed an MEA-based co-culture system of rat primary cardiomyocyte and sympathetic neurons (rSNs), it is unclear if this co-culture approach is applicable to develop and investigate sympathetic innervation of hiPSCMs. In this study, we developed a co-culture of rSNs and hiPSCMs on MEA substrate, and assessed functional connections. The inter-beat interval of hiPSCM was significantly shortened by stimulation in SNs depending on frequency and pulse number, indicating functional connections between rSNs and hiPSCM and the dependency of chronotropic effects on rSN activity pattern. These results suggest that our co-culture approach can evaluate sympathetic effects on hiPSCMs and would be a useful tool for assessing sympathetic modulated-cardiotoxicity in human cardiac tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Neuroprotective effects of orientin on oxygen-glucose deprivation/reperfusion-induced cell injury in primary culture of rat cortical neurons.

    Science.gov (United States)

    Tian, Tian; Zeng, Junan; Zhao, Guangyu; Zhao, Wenjing; Gao, Songyi; Liu, Li

    2018-01-01

    Orientin (luteolin-8-C-glucoside) is a phenolic compound found abundantly in millet, juice, and peel of passion fruit and has been shown to have antioxidant properties. In the present study, we explored the effects of orientin on oxygen-glucose deprivation/reperfusion (OGD/RP)-induced cell injury in primary culture of rat cortical neurons using an in vitro model of neonatal ischemic brain injury. The reduced cell viability and elevated lactate dehydrogenase leakage were observed after OGD/RP exposure, which were then reversed by orientin (10, 20, and 30 µM) pretreatment in a dose-dependent manner. Additionally, OGD/RP treatment resulted in significant oxidative stress, accompanied by enhanced intracellular reactive oxygen species (ROS) generation, and obvious depletion in the activities of intracellular Mn-superoxide dismutase, catalase, and glutathione peroxidase antioxidases. However, these effects were dose dependently restored by orientin pretreatment. We also found that orientin pretreatment dose dependently suppressed [Ca 2+ ] i increase and mitochondrial membrane potential dissipation caused by OGD/RP in primary culture of rat cortical neurons. Western blot analysis showed that OGD/RP exposure induced a distinct decrease of Bcl-2 protein and a marked elevation of Bax, caspase-3, and cleaved caspase-3 proteins; whereas these effects were dose dependently reversed by orientin incubation. Both the caspase-3 activity and the apoptosis rate were increased under OGD/RP treatment, but was then dose dependently down-regulated by orientin (10, 20, and 30 µM) incubation. Moreover, orientin pretreatment dose dependently inhibited OGD/RP-induced phosphorylation of JNK and ERK1/2. Notably, JNK inhibitor SP600125 and ERK1/2 inhibitor PD98059 also dramatically attenuated OGD/RP-induced cell viability loss and ROS generation, and further, orientin failed to protect cortical neurons with the interference of JNK activator anisomycin or ERK1/2 activator FGF-2. Taken

  14. Cadmium-induced apoptosis in primary rat cerebral cortical neurons culture is mediated by a calcium signaling pathway.

    Directory of Open Access Journals (Sweden)

    Yan Yuan

    Full Text Available Cadmium (Cd is an extremely toxic metal, capable of severely damaging several organs, including the brain. Studies have shown that Cd disrupts intracellular free calcium ([Ca(2+]i homeostasis, leading to apoptosis in a variety of cells including primary murine neurons. Calcium is a ubiquitous intracellular ion which acts as a signaling mediator in numerous cellular processes including cell proliferation, differentiation, and survival/death. However, little is known about the role of calcium signaling in Cd-induced apoptosis in neuronal cells. Thus we investigated the role of calcium signaling in Cd-induced apoptosis in primary rat cerebral cortical neurons. Consistent with known toxic properties of Cd, exposure of cerebral cortical neurons to Cd caused morphological changes indicative of apoptosis and cell death. It also induced elevation of [Ca(2+]i and inhibition of Na(+/K(+-ATPase and Ca(2+/Mg(2+-ATPase activities. This Cd-induced elevation of [Ca(2+]i was suppressed by an IP3R inhibitor, 2-APB, suggesting that ER-regulated Ca(2+ is involved. In addition, we observed elevation of reactive oxygen species (ROS levels, dysfunction of cytochrome oxidase subunits (COX-I/II/III, depletion of mitochondrial membrane potential (ΔΨm, and cleavage of caspase-9, caspase-3 and poly (ADP-ribose polymerase (PARP during Cd exposure. Z-VAD-fmk, a pan caspase inhibitor, partially prevented Cd-induced apoptosis and cell death. Interestingly, apoptosis, cell death and these cellular events induced by Cd were blocked by BAPTA-AM, a specific intracellular Ca(2+ chelator. Furthermore, western blot analysis revealed an up-regulated expression of Bcl-2 and down-regulated expression of Bax. However, these were not blocked by BAPTA-AM. Thus Cd toxicity is in part due to its disruption of intracellular Ca(2+ homeostasis, by compromising ATPases activities and ER-regulated Ca(2+, and this elevation in Ca(2+ triggers the activation of the Ca(2+-mitochondria apoptotic

  15. Differentiation of human bone marrow precursor cells into neuronal-like cells after transplantation into canine spinal cord organotypic slice cultures.

    Science.gov (United States)

    Fei, Zhi-qiang; Xiong, Jian-yi; Chen, Lei; Shen, Hui-yong; Stephanie, Ngo; Jeffrey, Wang; Wang, Da-ping

    2012-11-01

    Treatments to regenerate different tissue involving the transplantation of bone marrow derived mesenchymal precursor cells are anticipated. Using an alternative methods, in vitro organotypic slice culture method, would be useful to transplant cells and assessing the effects. This study was to determine the possibility of differentiating human bone marrow precursor cells into cells of the neuronal lineage by transplanting into canine spinal cord organotypic slice cultures. Bone marrow aspirates were obtained from posterior superior iliac spine (PSIS) of patients that had undergone spinal fusion due to a degenerative spinal disorder. For cell imaging, mesenchymal precursor cells (MPCs) were pre-stained with PKH-26 just before transplantation to canine spinal cord slices. Canine spinal cord tissues were obtained from three adult beagle dogs. Spinal cords were cut into transverse slices of 1 mm using tissue chopper. Two slices were transferred into 6-well plate containing 3 ml DMEM with antibiotics. Prepared MPCs (1×10(4)) were transplanted into spinal cord slices. On days 0, 3, 7, 14, MPCs were observed for morphological changes and expression of neuronal markers through immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). The morphological study showed: spherical cells in the control and experiment groups on day 0; and on day 3, cells in the control group had one or two thick, short processes and ones in the experiment group had three or four thin, long processes. On day 7, these variously-sized processes contacted each other in the experiment group, but showed typical spindle-shaped cells in the control group. Immunofluorescence showed that PKH-26(+) MPCs stained positive for NeuN(+) and GFAP(+) in experimental group only. Also RT-PCR showed weak expression of β-tubulin III and GFAP. Human bone marrow mesenchymal precursor cells (hMPCs) have the potential to differentiate into the neuronal like cells in this canine spinal cord

  16. Ca2+ Handling in Isolated Brain Mitochondria and Cultured Neurons Derived from the YAC128 Mouse Model of Huntington’s Disease

    Science.gov (United States)

    Pellman, Jessica J.; Hamilton, James; Brustovetsky, Tatiana; Brustovetsky, Nickolay

    2015-01-01

    We investigated Ca2+ handling in isolated brain synaptic and nonsynaptic mitochondria and in cultured striatal neurons from the YAC128 mouse model of Huntington’s disease (HD). Both synaptic and nonsynaptic mitochondria from 2- and 12-month-old YAC128 mice had larger Ca2+ uptake capacity than mitochondria from YAC18 and wild-type FVB/NJ mice. Synaptic mitochondria from 12-month-old YAC128 mice had further augmented Ca2+ capacity compared with mitochondria from 2-month-old YAC128 mice and age-matched YAC18 and FVB/NJ mice. This increase in Ca2+ uptake capacity correlated with an increase in the amount of mutant huntingtin protein (mHtt) associated with mitochondria from 12-month-old YAC128 mice. We speculate that this may happen due to mHtt-mediated sequestration of free fatty acids thereby increasing resistance of mitochondria to Ca2+-induced damage. In experiments with striatal neurons from YAC128 and FVB/NJ mice, brief exposure to 25 or 100μM glutamate produced transient elevations in cytosolic Ca2+ followed by recovery to near resting levels. Following recovery of cytosolic Ca2+, mitochondrial depolarization with FCCP produced comparable elevations in cytosolic Ca2+, suggesting similar Ca2+ release and, consequently, Ca2+ loads in neuronal mitochondria from YAC128 and FVB/NJ mice. Together, our data argue against a detrimental effect of mHtt on Ca2+ handling in brain mitochondria of YAC128 mice. PMID:25963273

  17. Dual effect of serotonin on the dendritic growth of cultured hippocampal neurons: Involvement of 5-HT1A and 5-HT7 receptors.

    Science.gov (United States)

    Rojas, P S; Aguayo, F; Neira, D; Tejos, M; Aliaga, E; Muñoz, J P; Parra, C S; Fiedler, J L

    2017-12-01

    Serotonin acts through its receptors (5-HTRs) to shape brain networks during development and modulates essential functions in mature brain. The 5-HT 1A R is mainly located at soma of hippocampal neurons early during brain development and its expression gradually shifts to dendrites during postnatal development. The 5-HT 7 R expressed early during hippocampus development, shows a progressive reduction in its expression postnatally. Considering these changes during development, we evaluated in cultured hippocampal neurons whether the 5-HT 1A R and 5-HT 7 R change their expression, modulate dendritic growth, and activate signaling pathways such as ERK1/2, AKT/GSK3β and LIMK/cofilin, which may sustain dendrite outgrowth by controlling cytoskeleton dynamics. We show that mRNA levels of both receptors increase between 2 and 7 DIV; however only protein levels of 5-HT 7 R increase significantly at 7 DIV. The 5-HT 1A R is preferentially distributed in the soma, while 5-HT 7 R displays a somato-dendritic localization at 7 DIV. Through stimulation with 5-HT at 7 DIV during 24h and using specific antagonists, we determined that 5-HT 1A R decreases the number of primary and secondary dendrites and restricts the growth of primary dendrites. The activation of 5-HT 1A R and 5-HT 7 R promotes the growth of short secondary dendrites and triggers ERK1/2 and AKT phosphorylation through MEK and PI3K activation respectively; without changes in the phosphorylation of LIMK and cofilin. We conclude that 5-HT 1A R restricts dendritogenesis and outgrowth of primary dendrites, but that both 5-HT 1A R and 5-HT 7 R promote secondary dendrite outgrowth. These data support the role of 5-HT in neuronal outgrowth during development and provide insight into cellular basis of neurodevelopmental disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. A deficit in zinc availability can cause alterations in tubulin thiol redox status in cultured neurons and in the developing fetal rat brain.

    Science.gov (United States)

    Mackenzie, Gerardo G; Salvador, Gabriela A; Romero, Carolina; Keen, Carl L; Oteiza, Patricia I

    2011-07-15

    Zinc (Zn) deficiency during early development can result in multiple brain abnormalities and altered neuronal functions. In rats, a gestational deficit of Zn can affect the fetal brain cytoskeleton and signaling cascades involved in cellular processes that are central to brain development. In this paper, we tested the hypothesis that oxidative stress is involved in Zn deficiency-induced altered tubulin dynamics and the associated dysregulation of transcription factor NF-κB. For this purpose, we used two cell culture models (rat cortical neurons, human IMR-32 neuroblastoma cells) and an animal model of Zn deficiency. A low rate of in vitro tubulin polymerization, an increase in tubulin oligomers, and a higher protein cysteine oxidation were observed in the Zn-deficient neuronal cells and in gestation day 19 fetal brains obtained from dams fed marginal-Zn diets throughout pregnancy. These alterations could be prevented by treating the Zn-deficient cells with the reducing agent tris(2-carboxyethyl)phosphine or by the presence of N-acetylcysteine (NAC) and α-lipoic acid (LA). Consistent with the above, Zn deficiency-induced tubulin-mediated alterations in transcription factor NF-κB nuclear translocation were prevented by treating IMR-32 cells with LA and NAC. Binding of the NF-κB protein p50, dynein, and karyopherin α (components of the NF-κB transport complex) to β-tubulin as well as the expression of NF-κB-dependent genes (Bcl-2, cyclin D1, and c-myc) was also restored by the addition of LA and NAC to Zn-deficient cells. In conclusion, a deficit in Zn viability could affect early brain development through: (1) an induction of oxidative stress, (2) tubulin oxidation, (3) altered tubulin dynamics, and (4) deregulation of signals (e.g., NF-κB) involved in critical developmental events. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    International Nuclear Information System (INIS)

    Onoda, Mitsuyoshi; Abe, Yayoi; Tada, Kazuya

    2009-01-01

    Poly(vinyl alcohol), PVA, produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to those of polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion rate of the electrolyte across the PVA film to the indium tin oxide (ITO) electrode. In particular, a solvent with a hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method of forming an electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using the conducting polymer, PPy. Then, by applying a similar technique, we fabricated poly(3,4-ethylenedioxythiophene), PEDOT/PVA, composite films and investigated their basic electrochemical properties. Moreover, in this study, in order to develop a novel cell-culture system which makes it possible to communicate with cultured cells, fibroblasts were cultured on PPy- and PEDOT-coated ITO conductive glass plates for 7 days. The result reveals that the PPy and PEDOT films support the secretory functions of the cells cultured on its surface. The PPy- and PEDOT-coated electrodes may be useful to culture the cells on.

  20. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Mitsuyoshi, E-mail: onoda@eng.u-hyogo.ac.j [Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Himwji Shosha Campus, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Abe, Yayoi; Tada, Kazuya [Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Himwji Shosha Campus, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan)

    2009-11-30

    Poly(vinyl alcohol), PVA, produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to those of polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion rate of the electrolyte across the PVA film to the indium tin oxide (ITO) electrode. In particular, a solvent with a hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method of forming an electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using the conducting polymer, PPy. Then, by applying a similar technique, we fabricated poly(3,4-ethylenedioxythiophene), PEDOT/PVA, composite films and investigated their basic electrochemical properties. Moreover, in this study, in order to develop a novel cell-culture system which makes it possible to communicate with cultured cells, fibroblasts were cultured on PPy- and PEDOT-coated ITO conductive glass plates for 7 days. The result reveals that the PPy and PEDOT films support the secretory functions of the cells cultured on its surface. The PPy- and PEDOT-coated electrodes may be useful to culture the cells on.

  1. Derivation, Expansion, and Motor Neuron Differentiation of Human-Induced Pluripotent Stem Cells with Non-Integrating Episomal Vectors and a Defined Xenogeneic-free Culture System.

    Science.gov (United States)

    Hu, Wentao; He, Yongpei; Xiong, Yongjie; Lu, Hong; Chen, Hong; Hou, Limin; Qiu, Zhandong; Fang, Yu; Zhang, Suming

    2016-04-01

    Induced pluripotent stem cells (iPSCs) generated from patient-derived somatic cells provides the opportunity for model development in order to study patient-specific disease states with the potential for drug discovery. However, use of lentivirus and exposure of iPSCs to animal-derived products limit their therapeutic utility and affect lineage differentiation and subsequent downstream functionality of iPSC derivatives. Within the context of this study, we describe a simple and practical protocol enabling the efficient reprogramming of terminally differentiated adult fibroblasts into integration-free human iPSCs (hiPSCs) using a combination of episomal plasmids with small molecules (SMs). Using this approach, there was a 10-fold increase in reprogramming efficiency over single plasmid vector-based methods. We obtained approximately 100 iPSCs colonies from 1 × 10(5) human adult dermal fibroblasts (HADFs) and achieved approximately 0.1% reprogramming efficiencies. Concurrently, we developed a highly conducive culture system using xeno-free media and human vitronectin. The resulting hiPSCs were free of DNA integration and had completely lost episomal vectors, maintained long-term self-renewal, featured a normal karyotype, expressed pluripotent stem cell markers, and possessed the capability of differentiating into components of all three germ layers in vivo. Finally, we demonstrate that the integration-free hiPSCs could be differentiated into motor neurons under xeno-free culture conditions. This induction method will promote the derivation of patient-specific integration-free and xeno-free iPSCs and improve the strategy for motor neuron derivation. Our approach provides a useful tool for human disease models, drug screen, and clinical applications.

  2. Modulation of the nicotinic alpha-bungarotoxin site in chromaffin cells in culture by a factor(s) endogenous to neuronal tissue.

    Science.gov (United States)

    Quik, M; Fournier, S; Trifaró, J M

    1986-04-30

    An endogenous factor(s) which affects the in vitro binding of (alpha-BGT) to rat brain membranes has previously been found in brain supernatant. This fraction, as well as a partially purified preparation of this material from bovine brain, is here shown to affect the binding of alpha-BGT to chromaffin cell membranes. To study possible long term effects, the supernatant extract was added to adrenal medullary chromaffin cells in culture. The cells were incubated for several days and at the end of this time, the medium bathing the cells, which contained the endogenous factor(s), was removed and alpha-BGT binding to the cells measured. Binding to control cultures had shown that alpha-BGT bound to the chromaffin cells in a saturable manner, with high affinity (Kd = 1.5 nM) and the specificity of a nicotinic receptor ligand. After incubation of the cells with supernatant factor, a marked decline in the number of alpha-BGT binding sites was observed with no change in affinity. This does not appear to be due to a detrimental effect on the cells as cell number did not appear to be decreased in the cultures preincubated with the supernatant extract and the DNA and protein content were similar in the control and treated cultures. The possibility that there was some non-specific detrimental effect to the chromaffin cell membrane was considered; however, the stimulated release of noradrenaline from the cells was not affected by treatment of the cultures in the presence of the supernatant fractions. In addition, tyrosine hydroxylase activity was significantly increased in the treated cultures. D-Tubo-curarine, an antagonist at the acetylcholine receptor, caused an increase in alpha-BGT binding after 7 days of treatment, while the agonist nicotine and choline had no effect. These results suggest that in brain supernatant there may exist an endogenous factor(s), which may function in the regulation of the nicotinic-like alpha-BGT receptors in neuronal cell.

  3. Developmental disorders of the brain can be caused by PCBs; low doses of hydroxy-PCBs disrupt thyroid hormone-dependent dendrite formation from Purkinje neurons in culture

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Y.; Kimura-Kuroda, J. [Tokyo Metropol. Inst. for Neuroscience, Tokyo (Japan); Nagata, I. [CREST/ JST, Tokyo (Japan)

    2004-09-15

    Exposure to some environmental chemicals during the perinatal period causes developmental disorders of the brain. Cognitive impairment and hyperactivity in infants were reported in Taiwan, known as Yu-cheng incidents caused by the accidental contamination of polychlorinated biphenyls (PCBs). Together with recent experimental data, Kuroda proposes a hypothesis that spatio-temporal disruptions of developing neuronal circuits by PCB exposure can cause the comobidity of learning disorders (LD), attention deficit hyperactivity disorder (ADHD) and autsm with the co-exposure to other environmental chemicals. PCBs and hydroxylated PCBs (OH-PCBs) have similar chemical structures to thyroid hormones (TH), thyroxine (T4) and triiodothyronine (T3). TH deficiency in the perinatal period causes cretinism children with severe cognitive and mental retardation. In primate model, Rice demonstrates that postnatal exposure to PCBs can dramatically influence later behavioral function. Epidemiological studies also indicate the possible developmental neurotoxicity of PCBs accumulated in human bodies. However, the precise underlying mechanisms and which types of PCB or OH-PCB with such effects have yet to be elucidated. It is important to establish a simple, reproducible, and sensitive in vitro assay for determining the effects of PCBs and OH-PCBs on the development of the central nervous system. Recently Iwasaki et al. established a reporter assay system and disclosed that low doses of PCBs potentially interfere TH-dependent gene expressions. This is the first demonstration that PCBs and OH-PCBs directly affect TH-receptor (TR)-mediated gene expressions crucial to the brain development, through unique mechanism. We also have demonstrated TH-dependent development of Purkinje neurons in vitro using a serum-free chemically defined medium. The degree of dendritic development of Purkinje cells is TH dose-dependent and exhibits high sensitivity in the pM order. Therefore, in the present study

  4. Curcumin Pretreatment Induces Nrf2 and an Antioxidant Response and Prevents Hemin-Induced Toxicity in Primary Cultures of Cerebellar Granule Neurons of Rats

    Directory of Open Access Journals (Sweden)

    Susana González-Reyes

    2013-01-01

    Full Text Available Curcumin is a bifunctional antioxidant derived from Curcuma longa. This study identifies curcumin as a neuroprotectant against hemin-induced damage in primary cultures of cerebellar granule neurons (CGNs of rats. Hemin, the oxidized form of heme, is a highly reactive compound that induces cellular injury. Pretreatment of CGNs with 5–30 μM curcumin effectively increased by 2.3–4.9 fold heme oxygenase-1 (HO-1 expression and by 5.6–14.3-fold glutathione (GSH levels. Moreover, 15 μM curcumin attenuated by 55% the increase in reactive oxygen species (ROS production, by 94% the reduction of GSH/glutathione disulfide (GSSG ratio, and by 49% the cell death induced by hemin. The inhibition of heme oxygenase system or GSH synthesis with tin mesoporphyrin and buthionine sulfoximine, respectively, suppressed the protective effect of curcumin against hemin-induced toxicity. These data strongly suggest that HO-1 and GSH play a major role in the protective effect of curcumin. Furthermore, it was found that 24 h of incubation with curcumin increases by 1.4-, 2.3-, and 5.2-fold the activity of glutathione reductase, glutathione S-transferase and superoxide dismutase, respectively. Additionally, it was found that curcumin was capable of inducing nuclear factor (erythroid-derived 2-like 2 (Nrf2 translocation into the nucleus. These data suggest that the pretreatment with curcumin induces Nrf2 and an antioxidant response that may play an important role in the protective effect of this antioxidant against hemin-induced neuronal death.

  5. Frequency-dependent depression of excitatory synaptic transmission is independent of activation of MCPG-sensitive presynaptic metabotropic glutamate receptors in cultured hippocampal neurons.

    Science.gov (United States)

    Maki, R; Cummings, D D; Dichter, M A

    1995-10-01

    1. A paired-pulse paradigm, and a high-frequency train followed by a test pulse, were used to investigate the possible role of presynaptic metabotropic glutamate receptors (mGluRs) in frequency-dependent modulation of the amplitude of excitatory post-synaptic currents (EPSCs). Paired whole cell patch-clamp recordings from monosynaptically connected hippocampal neurons maintained in very low-density cultures were performed, using the mGluR antagonist (RS)-alpha-methyl-4-carboxyphenylglycine (MCPG, 500 microM) and the mGluR agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid [(1S,3R)-ACPD, 100 microM]. 2. Paired-pulse depression (PPD) was observed in all the excitatory pairs recorded. The average PPD ratio (amplitude of the 2nd EPSC divided by the amplitude of the 1st EPSC) was 0.80 +/- 0.1 (SD) (n = 8). Application of the mGluR antagonist MCPG had no effect on the amplitude of the EPSCs and did not affect the ratio of the two EPSCs (PPD ratio 0.79 +/- 0.2). 3. The amplitudes of 10 successive EPSCs stimulated at a high frequency (20 Hz) decremented on average in both 4 mM extracellular Ca2+ (n = 5) and in 1 mM extracellular Ca2+ (n = 6). In all pairs tested, posttetanic depression (PTD) was observed (PTD ratio 0.7 +/- 0.2). Bath application of MCPG (500 microM) did not affect the amplitudes of the EPSCs during the train; MCPG also did not affect PTD. 4. The mGluR agonist (1S,3R)-ACPD depressed the amplitudes of the EPSCs in both the paired-pulse (1st EPSC, 35 +/- 9%; 2nd EPSC, 36 +/- 10%) and posttetanic pulse (1 and 4 mM extracellular Ca2+) paradigms. The amount of depression observed, both PPD and PTD, remained unaffected by application of (1S,3R)-ACPD. Coapplication of the antagonist MCPG (500 microM) blocked the effects of (1S,3R)-ACPD (100 microM). 5. We conclude that frequency-dependent depression of EPSC amplitudes occurs independent of endogenous activation of MCPG-sensitive mGluRs in cultured hippocampal neurons. Moreover, we demonstrate that exogenous

  6. Brain alanine formation as an ammonia-scavenging pathway during hyperammonemia: effects of glutamine synthetase inhibition in rats and astrocyte–neuron co-cultures

    Science.gov (United States)

    Dadsetan, Sherry; Kukolj, Eva; Bak, Lasse K; Sørensen, Michael; Ott, Peter; Vilstrup, Hendrik; Schousboe, Arne; Keiding, Susanne; Waagepetersen, Helle S

    2013-01-01

    Hyperammonemia is a major etiological toxic factor in the development of hepatic encephalopathy. Brain ammonia detoxification occurs primarily in astrocytes by glutamine synthetase (GS), and it has been proposed that elevated glutamine levels during hyperammonemia lead to astrocyte swelling and cerebral edema. However, ammonia may also be detoxified by the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT) leading to trapping of ammonia in alanine, which in vivo likely leaves the brain. Our aim was to investigate whether the GS inhibitor methionine sulfoximine (MSO) enhances incorporation of 15NH4+ in alanine during acute hyperammonemia. We observed a fourfold increased amount of 15NH4 incorporation in brain alanine in rats treated with MSO. Furthermore, co-cultures of neurons and astrocytes exposed to 15NH4Cl in the absence or presence of MSO demonstrated a dose-dependent incorporation of 15NH4 into alanine together with increased 15N incorporation in glutamate. These findings provide evidence that ammonia is detoxified by the concerted action of GDH and ALAT both in vivo and in vitro, a mechanism that is accelerated in the presence of MSO thereby reducing the glutamine level in brain. Thus, GS could be a potential drug target in the treatment of hyperammonemia in patients with hepatic encephalopathy. PMID:23673435

  7. Brain alanine formation as an ammonia-scavenging pathway during hyperammonemia: effects of glutamine synthetase inhibition in rats and astrocyte-neuron co-cultures.

    Science.gov (United States)

    Dadsetan, Sherry; Kukolj, Eva; Bak, Lasse K; Sørensen, Michael; Ott, Peter; Vilstrup, Hendrik; Schousboe, Arne; Keiding, Susanne; Waagepetersen, Helle S

    2013-08-01

    Hyperammonemia is a major etiological toxic factor in the development of hepatic encephalopathy. Brain ammonia detoxification occurs primarily in astrocytes by glutamine synthetase (GS), and it has been proposed that elevated glutamine levels during hyperammonemia lead to astrocyte swelling and cerebral edema. However, ammonia may also be detoxified by the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT) leading to trapping of ammonia in alanine, which in vivo likely leaves the brain. Our aim was to investigate whether the GS inhibitor methionine sulfoximine (MSO) enhances incorporation of (15)NH4(+) in alanine during acute hyperammonemia. We observed a fourfold increased amount of (15)NH4 incorporation in brain alanine in rats treated with MSO. Furthermore, co-cultures of neurons and astrocytes exposed to (15)NH4Cl in the absence or presence of MSO demonstrated a dose-dependent incorporation of (15)NH4 into alanine together with increased (15)N incorporation in glutamate. These findings provide evidence that ammonia is detoxified by the concerted action of GDH and ALAT both in vivo and in vitro, a mechanism that is accelerated in the presence of MSO thereby reducing the glutamine level in brain. Thus, GS could be a potential drug target in the treatment of hyperammonemia in patients with hepatic encephalopathy.

  8. Differential regulation of synaptic and extrasynaptic α4 GABA(A) receptor populations by protein kinase A and protein kinase C in cultured cortical neurons.

    Science.gov (United States)

    Bohnsack, John Peyton; Carlson, Stephen L; Morrow, A Leslie

    2016-06-01

    The GABAA α4 subunit exists in two distinct populations of GABAA receptors. Synaptic GABAA α4 receptors are localized at the synapse and mediate phasic inhibitory neurotransmission, while extrasynaptic GABAA receptors are located outside of the synapse and mediate tonic inhibitory transmission. These receptors have distinct pharmacological and biophysical properties that contribute to interest in how these different subtypes are regulated under physiological and pathological states. We utilized subcellular fractionation procedures to separate these populations of receptors in order to investigate their regulation by protein kinases in cortical cultured neurons. Protein kinase A (PKA) activation decreases synaptic α4 expression while protein kinase C (PKC) activation increases α4 subunit expression, and these effects are associated with increased β3 S408/409 or γ2 S327 phosphorylation respectively. In contrast, PKA activation increases extrasynaptic α4 and δ subunit expression, while PKC activation has no effect. Our findings suggest synaptic and extrasynaptic GABAA α4 subunit expression can be modulated by PKA to inform the development of more specific therapeutics for neurological diseases that involve deficits in GABAergic transmission. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Low-cost production and sealing procedure of mechanical parts of a versatile 3D-printed perfusion chamber for digital holographic microscopy of primary neurons in culture

    Science.gov (United States)

    Bélanger, Erik; Lévesque, Sébastien A.; Anctil, Gabriel; Poulin-Girard, Anne-Sophie; Marquet, Pierre

    2017-02-01

    We have developed a prototype of a low-cost and versatile 3D-printed perfusion chamber for digital holographic microscopy (DHM) of primary neurons in culture. The imaging chamber is 3D-printed in biocompatible plastic. It is easily convertible between a closed configuration, for refractive index - cellular thickness decoupling, and an open configuration, for electrophysiology. In the closed arrangement, the imaging volume is small, allowing a rapid laminar flow with a fast turnover for an optimal implementation of the decoupling procedure. This paper highlights especially the challenges faced while designing and prototyping the 3D-printed closed perfusion chamber with a small imaging volume for DHM. As all 3D-printed mechanical parts were initially leaking because of internal porosities, we developed a simple sealing protocol using acetone vapors to smooth surfaces. Using this protocol, almost all mechanical parts were successfully sealed. Therefore, the production process of the actual prototype, i.e. the 3D printing and the sealing method, is satisfactory for our target application in the field of microfluidics.

  10. DNA Damage Induced Neuronal Death

    National Research Council Canada - National Science Library

    Kisby, Glen

    1999-01-01

    ... (nitrogen mustard or HN2) and the neurotoxic DNA-damaging agent methylazoxymethanol (MAM) using neuronal and astrocyte cell cultures from different brain regions of mice with perturbed DNA repair...

  11. Potential environmental neurotoxins related to 1-methyl-4-phenylpyridinium: Selective toxicity of 1-methyl-4-(4'-acetamidophenyl)-pyridinium and 1-methyl-4-cyclohexylpyridinium for dopaminergic neurons in culture

    International Nuclear Information System (INIS)

    Michel, P.P.; Dandapani, B.K.; Efange, S.M.; Hefti, F.

    1990-01-01

    Mesencephalic cells in culture were exposed to various compounds which we hypothesized to be selective toxins for dopaminergic neurons. The culture system was previously shown suitable for assessing selective dopaminergic neurotoxicity, since 1-methyl-4-phenyl-pyridinium (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinium, destroyed dopaminergic neurons without affecting other cells. Some compounds tested were selected to fulfill two criteria believed to underly the selective dopaminergic neurotoxicity of MPP+, i.e., to be a potential substrate for the uptake carrier for dopamine and to possess a strong delocalized positive charge to inhibit the mitochondrial respiratory system. Other compounds were chosen on the basis of clinical or anecdotal evidence linking them to Parkinson's disease. Among the tested compounds two pyridinium analogs, 1-methyl-4-(4'-acetamidophenyl)pyridinium (MACPP+) and 1-methyl-4-cyclohexylpyridinium (MCP+) were found to be selectively toxic toward dopaminergic neurons. Incubation of cultures with both MACPP+ and MCP+ produced a dramatic reduction in the number of tyrosine hydroxylase-positive cells and the uptake of [3H]dopamine without reducing the number of cells visualized by phase-contrast microscopy or the uptake of [3H]aminobutyric acid. Besides MACPP+ and MCP+ none of the tested compounds exhibited any selective dopaminergic neurotoxicity. Together with earlier findings, these data suggest that the structural requirements are rather strict for a chemical to be a selective dopaminergic neurotoxin and make it unlikely that there is a wide spectrum of environmental dopaminergic toxins

  12. Combined treatment with diazepam and allopregnanolone reverses tetramethylenedisulfotetramine (TETS)-induced calcium dysregulation in cultured neurons and protects TETS-intoxicated mice against lethal seizures.

    Science.gov (United States)

    Bruun, Donald A; Cao, Zhengyu; Inceoglu, Bora; Vito, Stephen T; Austin, Adam T; Hulsizer, Susan; Hammock, Bruce D; Tancredi, Daniel J; Rogawski, Michael A; Pessah, Isaac N; Lein, Pamela J

    2015-08-01

    Tetramethylenedisulfotetramine (TETS) is a potent convulsant GABAA receptor blocker. Mice receiving a lethal dose of TETS (0.15 mg/kg i.p.) are rescued from death by a high dose of diazepam (5 mg/kg i.p.) administered shortly after the second clonic seizure (∼20 min post-TETS). However, this high dose of diazepam significantly impairs blood pressure and mobility, and does not prevent TETS-induced neuroinflammation in the brain. We previously demonstrated that TETS alters synchronous Ca(2+) oscillations in primary mouse hippocampal neuronal cell cultures and that pretreatment with the combination of diazepam and allopregnanolone at concentrations having negligible effects individually prevents TETS effects on intracellular Ca(2+) dynamics. Here, we show that treatment with diazepam and allopregnanolone (0.1 μM) 20 min after TETS challenge normalizes synchronous Ca(2+) oscillations when added in combination but not when added singly. Similarly, doses (0.03-0.1 mg/kg i.p.) of diazepam and allopregnanolone that provide minimal protection when administered singly to TETS intoxicated mice increase survival from 10% to 90% when given in combination either 10 min prior to TETS or following the second clonic seizure. This therapeutic combination has negligible effects on blood pressure or mobility. Combined treatment with diazepam and allopregnanolone also decreases TETS-induced microglial activation. Diazepam and allopregnanolone have distinct actions as positive allosteric modulators of GABAA receptors that in combination enhance survival and mitigate neuropathology following TETS intoxication without the adverse side effects associated with high dose benzodiazepines. Combination therapy with a benzodiazepine and neurosteroid represents a novel neurotherapeutic strategy with potentially broad application. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Indole and synthetic derivative activate chaperone expression to reduce polyQ aggregation in SCA17 neuronal cell and slice culture models

    Directory of Open Access Journals (Sweden)

    Kung PJ

    2014-10-01

    Full Text Available Pin-Jui Kung,1,* Yu-Chen Tao,1,* Ho-Chiang Hsu,1 Wan-Ling Chen,1 Te-Hsien Lin,1 Donala Janreddy,2 Ching-Fa Yao,2 Kuo-Hsuan Chang,3 Jung-Yaw Lin,1 Ming-Tsan Su,1 Chung-Hsin Wu,1 Guey-Jen Lee-Chen,1 Hsiu-Mei Hsieh-Li1 1Department of Life Science, 2Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan; 3Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan *These authors contributed equally to this work Abstract: In spinocerebellar ataxia type 17 (SCA17, the expansion of a translated CAG repeat in the TATA box binding protein (TBP gene results in a long polyglutamine (polyQ tract in the TBP protein, leading to intracellular accumulation of aggregated TBP and cell death. The molecular chaperones act in preventing protein aggregation to ameliorate downstream harmful events. In this study, we used Tet-On SH-SY5Y cells with inducible SCA17 TBP/Q79-green fluorescent protein (GFP expression to test indole and synthetic derivative NC001-8 for neuroprotection. We found that indole and NC001-8 up-regulated chaperone expression to reduce polyQ aggregation in neuronal differentiated TBP/Q79 cells. The effects on promoting neurite outgrowth and on reduction of aggregation on Purkinje cells were also confirmed with cerebellar primary and slice cultures of SCA17 transgenic mice. Our results demonstrate how indole and derivative NC001-8 reduce polyQ aggregation to support their therapeutic potentials in SCA17 treatment. Keywords: spinocerebellar ataxia type 17, TATA box binding protein, polyQ aggregation, indole and derivative, therapeutics

  14. Noisy Neurons

    Indian Academy of Sciences (India)

    IAS Admin

    Nerves are fibres that conduct electrical signals and hence pass on information from and to the brain. Nerves are made of nerve cells called neurons (Figure 1). Instructions in our body are sent via electrical signals that present themselves as variations in the potential across neuronal membranes. These potential differences ...

  15. Cultural

    Science.gov (United States)

    Wilbur F. LaPage

    1971-01-01

    A critical look at outdoor recreation research and some underlying premises. The author focuses on the concept of culture as communication and how it influences our perception of problems and our search for solutions. Both outdoor recreation and science are viewed as subcultures that have their own bodies of mythology, making recreation problems more difficult to...

  16. cultural

    Directory of Open Access Journals (Sweden)

    Irene Kreutz

    2006-01-01

    Full Text Available Es un estudio cualitativo que adoptó como referencial teorico-motodológico la antropología y la etnografía. Presenta las experiencias vivenciadas por mujeres de una comunidad en el proceso salud-enfermedad, con el objetivo de comprender los determinantes sócio-culturales e históricos de las prácticas de prevención y tratamiento adoptados por el grupo cultural por medio de la entrevista semi-estructurada. Los temas que emergieron fueron: la relación entre la alimentación y lo proceso salud-enfermedad, las relaciones con el sistema de salud oficial y el proceso salud-enfermedad y lo sobrenatural. Los dados revelaron que los moradores de la comunidad investigada tienen un modo particular de explicar sus procedimientos terapéuticos. Consideramos que es papel de los profesionales de la salud en sus prácticas, la adopción de abordajes o enfoques que consideren al individuo en su dimensión sócio-cultural e histórica, considerando la enorme diversidad cultural en nuestro país.

  17. Depolarization by K*O+ and glutamate activates different neurotransmitter release mechanisms in gabaergic neurons: vesicular versus non-vesicular release of gaba

    DEFF Research Database (Denmark)

    Belhage, Bo; Hansen, G.H.; Schousboe, Arne

    1993-01-01

    Neurotransmitter release, gaba release, membrane transporter, vesicles, intracellular CA*OH, neuron cultures......Neurotransmitter release, gaba release, membrane transporter, vesicles, intracellular CA*OH, neuron cultures...

  18. Spatially selective photoconductive stimulation of live neurons

    Directory of Open Access Journals (Sweden)

    Jacob eCampbell

    2014-05-01

    Full Text Available Synaptic activity is intimately linked to neuronal structure and function. Stimulation of live cultured primary neurons, coupled with fluorescent indicator imaging, is a powerful technique to assess the impact of synaptic activity on neuronal protein trafficking and function. Current technology for neuronal stimulation in culture include chemical techniques or microelectrode or optogenetic based techniques. While technically powerful, chemical stimulation has limited spatial resolution and microelectrode and optogenetic techniques require specialized equipment and expertise. We report an optimized and improved technique for laser based photoconductive stimulation of live neurons using an inverted confocal microscope that overcomes these limitations. The advantages of this approach include its non-invasive nature and adaptability to temporal and spatial manipulation. We demonstrate that the technique can be manipulated to achieve spatially selective stimulation of live neurons. Coupled with live imaging of fluorescent indicators, this simple and efficient technique should allow for significant advances in neuronal cell biology.

  19. Reducing the Levels of Akt Activation by PDK1 Knock-in Mutation Protects Neuronal Cultures against Synthetic Amyloid-Beta Peptides

    Directory of Open Access Journals (Sweden)

    Shaobin Yang

    2018-01-01

    Full Text Available The Akt kinase has been widely assumed for years as a key downstream effector of the PI3K signaling pathway in promoting neuronal survival. This notion was however challenged by the finding that neuronal survival responses were still preserved in mice with reduced Akt activity. Moreover, here we show that the Akt signaling is elevated in the aged brain of two different mice models of Alzheimer Disease. We manipulate the rate of Akt stimulation by employing knock-in mice expressing a mutant form of PDK1 (phosphoinositide-dependent protein kinase 1 with reduced, but not abolished, ability to activate Akt. We found increased membrane localization and activity of the TACE/ADAM17 α-secretase in the brain of the PDK1 mutant mice with concomitant TNFR1 processing, which provided neurons with resistance against TNFα-induced neurotoxicity. Opposite to the Alzheimer Disease transgenic mice, the PDK1 knock-in mice exhibited an age-dependent attenuation of the unfolding protein response, which protected the mutant neurons against endoplasmic reticulum stressors. Moreover, these two mechanisms cooperatively provide the mutant neurons with resistance against amyloid-beta oligomers, and might singularly also contribute to protect these mice against amyloid-beta pathology.

  20. Determination of the phospholipid precursor of anandamide and other N- acylethanolamine phospholipids before and after sodium azide-induced toxicity in cultured neocortical neurons

    DEFF Research Database (Denmark)

    Hansen, H.H.; Schousboe, A.; Hansen, Harald S.

    2000-01-01

    subjected to sodium azide-induced cell injury. We here extend the information on the NAPE response, reporting on the composition of N-acyl species of NAPE, employing a new methodological approach of HPLC-coupled electrospray ionization mass spectrometry. Exposure to sodium azide (5 mM) increased the total...... method, neuronal NAPE species can be identified and quantified with respect to N-acyl composition, including a trans-isomer of the anandamide precursor. The anandamide precursor is up-regulated to the same extent as other NAPEs upon neuronal injury....

  1. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct.

  2. An insert-based enzymatic cell culture system to rapidly and reversibly induce hypoxia: investigations of hypoxia-induced cell damage, protein expression and phosphorylation in neuronal IMR-32 cells

    Directory of Open Access Journals (Sweden)

    Ying Huang

    2013-11-01

    Ischemia-reperfusion injury and tissue hypoxia are of high clinical relevance because they are associated with various pathophysiological conditions such as myocardial infarction and stroke. Nevertheless, the underlying mechanisms causing cell damage are still not fully understood, which is at least partially due to the lack of cell culture systems for the induction of rapid and transient hypoxic conditions. The aim of the study was to establish a model that is suitable for the investigation of cellular and molecular effects associated with transient and long-term hypoxia and to gain insights into hypoxia-mediated mechanisms employing a neuronal culture system. A semipermeable membrane insert system in combination with the hypoxia-inducing enzymes glucose oxidase and catalase was employed to rapidly and reversibly generate hypoxic conditions in the culture medium. Hydrogen peroxide assays, glucose measurements and western blotting were performed to validate the system and to evaluate the effects of the generated hypoxia on neuronal IMR-32 cells. Using the insert-based two-enzyme model, hypoxic conditions were rapidly induced in the culture medium. Glucose concentrations gradually decreased, whereas levels of hydrogen peroxide were not altered. Moreover, a rapid and reversible (onoff generation of hypoxia could be performed by the addition and subsequent removal of the enzyme-containing inserts. Employing neuronal IMR-32 cells, we showed that 3 hours of hypoxia led to morphological signs of cellular damage and significantly increased levels of lactate dehydrogenase (a biochemical marker of cell damage. Hypoxic conditions also increased the amounts of cellular procaspase-3 and catalase as well as phosphorylation of the pro-survival kinase Akt, but not Erk1/2 or STAT5. In summary, we present a novel framework for investigating hypoxia-mediated mechanisms at the cellular level. We claim that the model, the first of its kind, enables researchers to rapidly and

  3. Noisy Neurons

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 1. Noisy Neurons: Hodgkin-Huxley Model and Stochastic Variants. Shurti Paranjape. General Article Volume 20 Issue 1 January 2015 pp 34-43. Fulltext. Click here to view fulltext PDF. Permanent link:

  4. Long term ex vivo culturing of Drosophila brain as a method to live image pupal brains: insights into the cellular mechanisms of neuronal remodeling

    OpenAIRE

    Rabinovich, Dana; Mayseless, Oded; Schuldiner, Oren

    2015-01-01

    Holometabolous insects, including Drosophila melanogaster, undergo complete metamorphosis that includes a pupal stage. During metamorphosis, the Drosophila nervous system undergoes massive remodeling and growth, that include cell death and large-scale axon and synapse elimination as well as neurogenesis, developmental axon regrowth, and formation of new connections. Neuronal remodeling is an essential step in the development of vertebrate and invertebrate nervous systems. Research on the ster...

  5. Sodium Para-aminosalicylic Acid Protected Primary Cultured Basal Ganglia Neurons of Rat from Manganese-Induced Oxidative Impairment and Changes of Amino Acid Neurotransmitters.

    Science.gov (United States)

    Li, Shao-Jun; Li, Yong; Chen, Jing-Wen; Yuan, Zong-Xiang; Mo, Yu-Huan; Lu, Guo-Dong; Jiang, Yue-Ming; Ou, Chao-Yan; Wang, Fang; Huang, Xiao-Wei; Luo, Yi-Ni; Ou, Shi-Yan; Huang, Yan-Ni

    2016-04-01

    Manganese (Mn), an essential trace metal for protein synthesis and particularly neurotransmitter metabolism, preferentially accumulates in basal ganglia. However, excessive Mn accumulation may cause neurotoxicity referred to as manganism. Sodium para-aminosalicylic acid (PAS-Na) has been used to treat manganism with unclear molecular mechanisms. Thus, we aim to explore whether PAS-Na can inhibit Mn-induced neuronal injury in basal ganglia in vitro. We exposed basal ganglia neurons with 50 μM manganese chloride (MnCl2) for 24 h and then replaced with 50, 150, and 450 μM PAS-Na treatment for another 24 h. MnCl2 significantly decreased cell viability but increased leakage rate of lactate dehydrogenase and DNA damage (as shown by increasing percentage of DNA tail and Olive tail moment). Mechanically, Mn reduced glutathione peroxidase and catalase activity and interrupted amino acid neurotransmitter balance. However, PAS-Na treatment reversed the aforementioned Mn-induced toxic effects. Taken together, these results showed that PAS-Na could protect basal ganglia neurons from Mn-induced neurotoxicity.

  6. Essential roles of mitochondrial depolarization in neuron loss through microglial activation and attraction toward neurons.

    Science.gov (United States)

    Nam, Min-Kyung; Shin, Hyun-Ah; Han, Ji-Hye; Park, Dae-Wook; Rhim, Hyangshuk

    2013-04-10

    As life spans increased, neurodegenerative disorders that affect aging populations have also increased. Progressive neuronal loss in specific brain regions is the most common cause of neurodegenerative disease; however, key determinants mediating neuron loss are not fully understood. Using a model of mitochondrial membrane potential (ΔΨm) loss, we found only 25% cell loss in SH-SY5Y (SH) neuronal mono-cultures, but interestingly, 85% neuronal loss occurred when neurons were co-cultured with BV2 microglia. SH neurons overexpressing uncoupling protein 2 exhibited an increase in neuron-microglia interactions, which represent an early step in microglial phagocytosis of neurons. This result indicates that ΔΨm loss in SH neurons is an important contributor to recruitment of BV2 microglia. Notably, we show that ΔΨm loss in BV2 microglia plays a crucial role in microglial activation and phagocytosis of damaged SH neurons. Thus, our study demonstrates that ΔΨm loss in both neurons and microglia is a critical determinant of neuron loss. These findings also offer new insights into neuroimmunological and bioenergetical aspects of neurodegenerative disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Orexin-A promotes Glu uptake by OX1R/PKCα/ERK1/2/GLT-1 pathway in astrocytes and protects co-cultured astrocytes and neurons against apoptosis in anoxia/hypoglycemic injury in vitro.

    Science.gov (United States)

    Shu, Qing; Zhang, Jianhuai; Ma, Wei; Lei, Youying; Zhou, Dan

    2017-01-01

    Orexin-A, which is an endogenous neuropeptide, is reported to have a protective role in ischemic stroke. High-concentration glutamic acid (Glu) induced by hypoxia injury in ischemic stroke can be inhibited by glial glutamate transporter GLT-1 which is only expressed in astroglia cells. A previous study reported that Orexin-A may regulate GLT-1 expression. However, the role of orexin-A in the regulation of GLT-1 in ischemic stroke still remains unclear. In this study, we aimed to investigate the effect and the underlying mechanism of orexin-A on Glu uptake in astrocytes in vitro and this effect on protecting the neurons from anoxia/hypoglycemic injury. The expression of GLT-1 significantly increased in the astrocytes with orexin-A treatment under anoxia/hypoglycemic conditions, promoting the uptake of Glu and inhibiting the apoptosis of co-cultured cells of astrocytes and neurons. However, these effects were significantly weakened by treatment with orexin-A receptor 1 (OX1R) antagonist. Orexin-A significantly up-regulated the expressions of PKCα and ERK1/2 under anoxia/hypoglycemic conditions in astrocytes, whereas the OX1R antagonist markedly reversed the effect. Furthermore, PKCα or ERK1/2 inhibitor significantly constrained the GLT-1 expression in astrocytes and facilitated the apoptosis of co-cultured cells, and GLT-1 overexpression could reverse those effects of PKCα or ERK1/2 inhibitor. Taken together, orexin-A promoted the GLT-1 expression via OX1R/PKCα/ERK1/2 pathway in astrocytes and protected co-cultured cells against anoxia/hypoglycemic injury.

  8. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... properties of this facility in the path from synaptic sites to the motor axon is reviewed with emphasis on voltage sensitive ion channels and regulatory metabotropic transmitter pathways. The catalog of the intrinsic response properties, their underlying mechanisms, and regulation obtained from motoneurons...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  9. Inducing huntingtin inclusion formation in primary neuronal cell culture and in vivo by high-capacity adenoviral vectors expressing truncated and full-length huntingtin with polyglutamine expansion.

    Science.gov (United States)

    Huang, Bin; Schiefer, Johannes; Sass, Christian; Kosinski, Christoph M; Kochanek, Stefan

    2008-03-01

    Huntington's disease (HD) is an inherited autosomal dominant neurodegenerative disease caused by the expansion of a CAG trinucleotide repeat in exon 1 of the huntingtin (htt) gene. Vector-mediated delivery of N-terminal fragments of mutant htt has been used to study htt function in vitro and to establish HD models in rats. Due to the large size of the htt cDNA vector-mediated delivery of full-length htt has not been achieved so far. High-capacity adenoviral (HC-Ad) vectors were generated expressing mutant and wild-type versions of N-terminal truncated and full-length htt either in vitro in primary neuronal cells or in the striatum of mice. In vitro these vectors were used for transduction of primary neuronal cells isolated from E17 mouse embryos. Expression of mutant htt resulted in the formation of htt inclusions, a surrogate marker of the HD pathology. Kinetics of generation and localization of htt inclusions differed between truncated and full-length htt carrying identical mutations. Following injection into the striatum vector-mediated expression of mutant truncated htt led to prominent accumulation of htt inclusions in cell nuclei, while inclusions formed upon expression of mutant full-length htt localized to the cytoplasm. These results indicate that HC-Ad vector-mediated in vitro and in vivo delivery of truncated and full-length mutant htt results in prominent inclusion formation in neuronal cells but in different cell compartments. These vectors will be useful tools for studying HD and may be used to generate large animal HD models. Copyright (c) 2007 John Wiley & Sons, Ltd.

  10. Neurons other than motor neurons in motor neuron disease.

    Science.gov (United States)

    Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

    2017-11-01

    Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

  11. A novel enteric neuron-glia coculture system reveals the role of glia in neuronal development.

    Science.gov (United States)

    Le Berre-Scoul, Catherine; Chevalier, Julien; Oleynikova, Elena; Cossais, François; Talon, Sophie; Neunlist, Michel; Boudin, Hélène

    2017-01-15

    Unlike astrocytes in the brain, the potential role of enteric glial cells (EGCs) in the formation of the enteric neuronal circuit is currently unknown. To examine the role of EGCs in the formation of the neuronal network, we developed a novel neuron-enriched culture model from embryonic rat intestine grown in indirect coculture with EGCs. We found that EGCs shape axonal complexity and synapse density in enteric neurons, through purinergic- and glial cell line-derived neurotrophic factor-dependent pathways. Using a novel and valuable culture model to study enteric neuron-glia interactions, our study identified EGCs as a key cellular actor regulating neuronal network maturation. In the nervous system, the formation of neuronal circuitry results from a complex and coordinated action of intrinsic and extrinsic factors. In the CNS, extrinsic mediators derived from astrocytes have been shown to play a key role in neuronal maturation, including dendritic shaping, axon guidance and synaptogenesis. In the enteric nervous system (ENS), the potential role of enteric glial cells (EGCs) in the maturation of developing enteric neuronal circuit is currently unknown. A major obstacle in addressing this question is the difficulty in obtaining a valuable experimental model in which enteric neurons could be isolated and maintained without EGCs. We adapted a cell culture method previously developed for CNS neurons to establish a neuron-enriched primary culture from embryonic rat intestine which was cultured in indirect coculture with EGCs. We demonstrated that enteric neurons grown in such conditions showed several structural, phenotypic and functional hallmarks of proper development and maturation. However, when neurons were grown without EGCs, the complexity of the axonal arbour and the density of synapses were markedly reduced, suggesting that glial-derived factors contribute strongly to the formation of the neuronal circuitry. We found that these effects played by EGCs were

  12. BID Mediates Oxygen-Glucose Deprivation-Induced Neuronal Injury in Organotypic Hippocampal Slice Cultures and Modulates Tissue Inflammation in a Transient Focal Cerebral Ischemia Model without Changing Lesion Volume

    DEFF Research Database (Denmark)

    Martin, Nellie Anne; Bonner, Helena; Elkjær, Maria Louise

    2016-01-01

    The BH3 interacting-domain death agonist (BID) is a pro-apoptotic protein involved in death receptor-induced and mitochondria-mediated apoptosis. Recently, it has also been suggested that BID is involved in the regulation of inflammatory responses in the central nervous system. We found that BID...... deficiency protected organotypic hippocampal slice cultures in vitro from neuronal injury induced by oxygen-glucose deprivation. In vivo, BID-knockout (KO) mice and wild type (WT) mice were subjected to 60 min of transient middle cerebral artery occlusion (tMCAO) to induce focal cerebral ischemia...... between BID-KO and WT mice. The inflammatory response was reduced by BID deficiency as indicated by a change in microglial/leukocyte response. In conclusion, our data suggest that BID deficiency is neuroprotective in an in vitro model and modulates the inflammatory response to focal cerebral ischemia...

  13. Effects of tris(1,3-dichloro-2-propyl) phosphate and tris(1-chloropropyl) phosphate on cytotoxicity and mRNA expression in primary cultures of avian hepatocytes and neuronal cells.

    Science.gov (United States)

    Crump, Doug; Chiu, Suzanne; Kennedy, Sean W

    2012-03-01

    Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and tris(1-chloropropyl) phosphate (TCPP) belong to a group of chemicals collectively known as triester organophosphate flame retardants (OPFRs). OPFRs are used in a wide range of consumer products and have been detected in biota, including free-living avian species; however, data on toxicological and molecular effects of exposure are limited. An in vitro screening approach was used to compare concentration-dependent effects of TDCPP and TCPP on cytotoxicity and messenger RNA (mRNA) expression in cultured hepatocytes and neuronal cells derived from embryonic chickens. TDCPP was toxic to hepatocytes (LC₅₀ = 60.3 ± 45.8μM) and neuronal cells (LC₅₀ = 28.7 ± 19.1μM), whereas TCPP did not affect viability in either cell type up to the highest concentration administered, 300μM. Real-time reverse transcription-PCR revealed alterations in mRNA abundance of genes associated with phase I and II metabolism, the thyroid hormone (TH) pathway, lipid regulation, and growth in hepatocytes. None of the transcripts measured in neuronal cells (D2, D3, RC3, and Oct-1) varied in response to TDCPP or TCPP exposure. Exposure to ≥ 10μM TDCPP and TCPP resulted in significant upregulation of CYP2H1 (4- to 8-fold), CYP3A37 (13- to 127-fold), and UGT1A9 (3.5- to 7-fold) mRNA levels. Transthyretin was significantly downregulated more than twofold by TCPP at 100μM; however, TDCPP did not alter its expression. Liver fatty acid-binding protein, TH-responsive spot 14-α, and insulin-like growth factor-1 were all downregulated (up to 10-fold) in hepatocytes exposed to ≥ 0.01μM TDCPP and TCPP. Taken together, our results indicate that genes associated with xenobiotic metabolism, the TH pathway, lipid regulation, and growth are vulnerable to TDCPP and TCPP administration in cultured avian hepatocytes. The mRNA expression data were similar to those from a previous study with hexabromocyclododecane.

  14. Isorhamnetin, A Flavonol Aglycone from Ginkgo biloba L., Induces Neuronal Differentiation of Cultured PC12 Cells: Potentiating the Effect of Nerve Growth Factor

    Directory of Open Access Journals (Sweden)

    Sherry L. Xu

    2012-01-01

    Full Text Available Flavonoids, a group of compounds mainly derived from vegetables and herbal medicines, share a chemical resemblance to estrogen, and indeed some of which have been used as estrogen substitutes. In searching for possible functions of flavonoids, the neuroprotective effect in brain could lead to novel treatment, or prevention, for neurodegenerative diseases. Here, different subclasses of flavonoids were analyzed for its inductive role in neurite outgrowth of cultured PC12 cells. Amongst the tested flavonoids, a flavonol aglycone, isorhamnetin that was isolated mainly from the leaves of Ginkgo biloba L. showed robust induction in the expression of neurofilament, a protein marker for neurite outgrowth, of cultured PC12 cells. Although isorhamnetin by itself did not show significant inductive effect on neurite outgrowth of cultured PC12 cells, the application of isorhamnetin potentiated the nerve growth factor- (NGF-induced neurite outgrowth. In parallel, the expression of neurofilaments was markedly increased in the cotreatment of NGF and isorhamnetin in the cultures. The identification of these neurite-promoting flavonoids could be very useful in finding potential drugs, or food supplements, for treating various neurodegenerative diseases, including Alzheimer’s disease and depression.

  15. Human embryonic stem cell-derived neuronal cells form spontaneously active neuronal networks in vitro.

    Science.gov (United States)

    Heikkilä, Teemu J; Ylä-Outinen, Laura; Tanskanen, Jarno M A; Lappalainen, Riikka S; Skottman, Heli; Suuronen, Riitta; Mikkonen, Jarno E; Hyttinen, Jari A K; Narkilahti, Susanna

    2009-07-01

    The production of functional human embryonic stem cell (hESC)-derived neuronal cells is critical for the application of hESCs in treating neurodegenerative disorders. To study the potential functionality of hESC-derived neurons, we cultured and monitored the development of hESC-derived neuronal networks on microelectrode arrays. Immunocytochemical studies revealed that these networks were positive for the neuronal marker proteins beta-tubulin(III) and microtubule-associated protein 2 (MAP-2). The hESC-derived neuronal networks were spontaneously active and exhibited a multitude of electrical impulse firing patterns. Synchronous bursts of electrical activity similar to those reported for hippocampal neurons and rodent embryonic stem cell-derived neuronal networks were recorded from the differentiated cultures until up to 4 months. The dependence of the observed neuronal network activity on sodium ion channels was examined using tetrodotoxin (TTX). Antagonists for the glutamate receptors NMDA [D(-)-2-amino-5-phosphonopentanoic acid] and AMPA/kainate [6-cyano-7-nitroquinoxaline-2,3-dione], and for GABAA receptors [(-)-bicuculline methiodide] modulated the spontaneous electrical activity, indicating that pharmacologically susceptible neuronal networks with functional synapses had been generated. The findings indicate that hESC-derived neuronal cells can generate spontaneously active networks with synchronous communication in vitro, and are therefore suitable for use in developmental and drug screening studies, as well as for regenerative medicine.

  16. Neurine, an acetylcholine autolysis product, elevates secreted amyloid-beta protein precursor and amyloid-beta peptide levels, and lowers neuronal cell viability in culture: a role in Alzheimer's disease?

    Science.gov (United States)

    Tweedie, David; Brossi, Arnold; Chen, DeMoa; Ge, Yuan-Wen; Bailey, Jason; Yu, Qian-Sheng; Kamal, Mohammad A; Sambamurti, Kumar; Lahiri, Debomoy K; Greig, Nigel H

    2006-09-01

    Classical hallmarks of Alzheimer's disease (AD) are a synaptic loss, cholinergic neuron death, and abnormal protein deposition, particularly of toxic amyloid-beta peptide (Abeta) that is derived from amyloid-beta protein precursor (AbetaPP) by the action of beta- and gamma-secretases. The trigger(s) initiating the biochemical cascades that underpin these hallmarks have yet to be fully elucidated. The typical forebrain cholinergic cell demise associated with AD brain results in a loss of presynaptic cholinergic markers and acetylcholine (ACh). Neurine (vinyl-trimethyl-ammonium hydroxide) is a breakdown product of ACh, consequent to autolysis and is an organic poison found in cadavre brain. The time- and concentration-dependent actions of neurine were assessed in human neuroblastoma (NB, SK-N-SH) cells in culture by quantifying cell viability by lactate dehydrogenase (LDH) and MTS assay, and AbetaPP and Abeta levels by Western blot and ELISA. NB cells displayed evidence of toxicity to neurine at > or = 3 mg/ml, as demonstrated by elevated LDH levels in the culture media and a reduced cell viability shown by the MTS assay. Using subtoxic concentrations of neurine, elevations in AbetaPP and Abeta1-40 peptide levels were detected in conditioned media samples.

  17. Micropatterning Facilitates the Long-Term Growth and Analysis of iPSC-Derived Individual Human Neurons and Neuronal Networks.

    Science.gov (United States)

    Burbulla, Lena F; Beaumont, Kristin G; Mrksich, Milan; Krainc, Dimitri

    2016-08-01

    The discovery of induced pluripotent stem cells (iPSCs) and their application to patient-specific disease models offers new opportunities for studying the pathophysiology of neurological disorders. However, current methods for culturing iPSC-derived neuronal cells result in clustering of neurons, which precludes the analysis of individual neurons and defined neuronal networks. To address this challenge, cultures of human neurons on micropatterned surfaces are developed that promote neuronal survival over extended periods of time. This approach facilitates studies of neuronal development, cellular trafficking, and related mechanisms that require assessment of individual neurons and specific network connections. Importantly, micropatterns support the long-term stability of cultured neurons, which enables time-dependent analysis of cellular processes in living neurons. The approach described in this paper allows mechanistic studies of human neurons, both in terms of normal neuronal development and function, as well as time-dependent pathological processes, and provides a platform for testing of new therapeutics in neuropsychiatric disorders. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. GSK-3 as a Target for Lithium-induced Neuroprotection against Excitotoxicity in Neuronal Cultures and Animal Models of Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    De-Maw eChuang

    2011-08-01

    Full Text Available The mood stabilizer lithium inhibits glycogen synthase kinase-3 (GSK-3 directly or indirectly by enhancing serine phosphorylation of both alpha and beta isoforms. Lithium robustly protected primary brain neurons from glutamate-induced excitotoxicity; these actions were mimicked by other GSK-3 inhibitors or silencing/inhibiting GSK-3alpha and/or beta isoforms. Lithium rapidly activated Akt to enhance GSK-3 serine phosphorylation and to block glutamate-induced Akt inactivation. Lithium also upregulated Bcl-2 and suppressed glutamate-induced p53 and Bax. Induction of BDNF was required for lithium’s neuroprotection to occur. BDNF promoter IV was activated by GSK-3 inhibition using lithium or other drugs, or through gene silencing/inactivation of either isoform. Further, lithium’s neuroprotective effects were associated with inhibition of NMDA receptor-mediated calcium influx and downstream signaling. In rodent ischemic models, post-insult treatment with lithium decreased infarct volume, ameliorated neurological deficits and improved functional recovery. Upregulation of heat shock protein 70 (HSP70 and Bcl-2 as well as downregulation of p53 likely contributed to lithium’s protective effects. Delayed treatment with lithium improved functional MRI responses, which was accompanied by enhanced angiogenesis. Two GSK-3-regulated pro-angiogenic factors, matrix metalloproteinase-9 (MMP-9 and vascular endothelial growth factor were induced by lithium. Finally, lithium promoted migration of mesenchymal stem cells (MSCs by upregulation of MMP-9 through GSK-3beta inhibition. Notably, transplantation of lithium-primed MSCs into ischemic rats enhanced MSC migration to the injured brain regions and improved the neurological performance. Several other GSK-3 inhibitors have also been reported to be beneficial in rodent ischemic models. Together, GSK-3 inhibition is a rational strategy to combat ischemic stroke and other excitotoxicity-related brain disorders.

  19. Neuron-derived IgG protects neurons from complement-dependent cytotoxicity.

    Science.gov (United States)

    Zhang, Jie; Niu, Na; Li, Bingjie; McNutt, Michael A

    2013-12-01

    Passive immunity of the nervous system has traditionally been thought to be predominantly due to the blood-brain barrier. This concept must now be revisited based on the existence of neuron-derived IgG. The conventional concept is that IgG is produced solely by mature B lymphocytes, but it has now been found to be synthesized by murine and human neurons. However, the function of this endogenous IgG is poorly understood. In this study, we confirm IgG production by rat cortical neurons at the protein and mRNA levels, with 69.0 ± 5.8% of cortical neurons IgG-positive. Injury to primary-culture neurons was induced by complement leading to increases in IgG production. Blockage of neuron-derived IgG resulted in more neuronal death and early apoptosis in the presence of complement. In addition, FcγRI was found in microglia and astrocytes. Expression of FcγR I in microglia was increased by exposure to neuron-derived IgG. Release of NO from microglia triggered by complement was attenuated by neuron-derived IgG, and this attenuation could be reversed by IgG neutralization. These data demonstrate that neuron-derived IgG is protective of neurons against injury induced by complement and microglial activation. IgG appears to play an important role in maintaining the stability of the nervous system.

  20. Glutamate mediated astrocytic filtering of neuronal activity.

    Directory of Open Access Journals (Sweden)

    Gilad Wallach

    2014-12-01

    Full Text Available Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity.

  1. Glutamate Mediated Astrocytic Filtering of Neuronal Activity

    Science.gov (United States)

    Herzog, Nitzan; De Pittà, Maurizio; Jacob, Eshel Ben; Berry, Hugues; Hanein, Yael

    2014-01-01

    Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity. PMID:25521344

  2. Method of derivation and differentiation of mouse embryonic stem cells generating synchronous neuronal networks.

    Science.gov (United States)

    Gazina, Elena V; Morrisroe, Emma; Mendis, Gunarathna D C; Michalska, Anna E; Chen, Joseph; Nefzger, Christian M; Rollo, Benjamin N; Reid, Christopher A; Pera, Martin F; Petrou, Steven

    2018-01-01

    Stem cells-derived neuronal cultures hold great promise for in vitro disease modelling and drug screening. However, currently stem cells-derived neuronal cultures do not recapitulate the functional properties of primary neurons, such as network properties. Cultured primary murine neurons develop networks which are synchronised over large fractions of the culture, whereas neurons derived from mouse embryonic stem cells (ESCs) display only partly synchronised network activity and human pluripotent stem cells-derived neurons have mostly asynchronous network properties. Therefore, strategies to improve correspondence of derived neuronal cultures with primary neurons need to be developed to validate the use of stem cell-derived neuronal cultures as in vitro models. By combining serum-free derivation of ESCs from mouse blastocysts with neuronal differentiation of ESCs in morphogen-free adherent culture we generated neuronal networks with properties recapitulating those of mature primary cortical cultures. After 35days of differentiation ESC-derived neurons developed network activity very similar to that of mature primary cortical neurons. Importantly, ESC plating density was critical for network development. Compared to the previously published methods this protocol generated more synchronous neuronal networks, with high similarity to the networks formed in mature primary cortical culture. We have demonstrated that ESC-derived neuronal networks recapitulating key properties of mature primary cortical networks can be generated by optimising both stem cell derivation and differentiation. This validates the approach of using ESC-derived neuronal cultures for disease modelling and in vitro drug screening. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. High-Degree Neurons Feed Cortical Computations.

    Directory of Open Access Journals (Sweden)

    Nicholas M Timme

    2016-05-01

    Full Text Available Recent work has shown that functional connectivity among cortical neurons is highly varied, with a small percentage of neurons having many more connections than others. Also, recent theoretical developments now make it possible to quantify how neurons modify information from the connections they receive. Therefore, it is now possible to investigate how information modification, or computation, depends on the number of connections a neuron receives (in-degree or sends out (out-degree. To do this, we recorded the simultaneous spiking activity of hundreds of neurons in cortico-hippocampal slice cultures using a high-density 512-electrode array. This preparation and recording method combination produced large numbers of neurons recorded at temporal and spatial resolutions that are not currently available in any in vivo recording system. We utilized transfer entropy (a well-established method for detecting linear and nonlinear interactions in time series and the partial information decomposition (a powerful, recently developed tool for dissecting multivariate information processing into distinct parts to quantify computation between neurons where information flows converged. We found that computations did not occur equally in all neurons throughout the networks. Surprisingly, neurons that computed large amounts of information tended to receive connections from high out-degree neurons. However, the in-degree of a neuron was not related to the amount of information it computed. To gain insight into these findings, we developed a simple feedforward network model. We found that a degree-modified Hebbian wiring rule best reproduced the pattern of computation and degree correlation results seen in the real data. Interestingly, this rule also maximized signal propagation in the presence of network-wide correlations, suggesting a mechanism by which cortex could deal with common random background input. These are the first results to show that the extent to

  4. Synaptic glutamate release by postnatal rat serotonergic neurons in microculture.

    Science.gov (United States)

    Johnson, M D

    1994-02-01

    Serotonergic neurons are thought to play a role in depression and obsessive compulsive disorder. However, their functional transmitter repertoire is incompletely known. To investigate this repertoire, intracellular recordings were obtained from 132 cytochemically identified rat mesopontine serotonergic neurons that had re-established synapses in microcultures. Approximately 60% of the neurons evoked excitatory glutamatergic potentials in themselves or in target neurons. Glutamatergic transmission was frequently observed in microcultures containing a solitary serotonergic neuron. Evidence for co-release of serotonin and glutamate from single raphe neurons was also obtained. However, evidence for gamma-aminobutyric acid release by serotonergic neurons was observed in only two cases. These findings indicate that many cultured serotonergic neurons form glutamatergic synapses and may explain several observations in slices and in vivo.

  5. Frizzled-5 receptor is involved in neuronal polarity and morphogenesis of hippocampal neurons.

    Directory of Open Access Journals (Sweden)

    Paula G Slater

    Full Text Available The Wnt signaling pathway plays important roles during different stages of neuronal development, including neuronal polarization and dendritic and axonal outgrowth. However, little is known about the identity of the Frizzled receptors mediating these processes. In the present study, we investigated the role of Frizzled-5 (Fzd5 on neuronal development in cultured Sprague-Dawley rat hippocampal neurons. We found that Fzd5 is expressed early in cultured neurons on actin-rich structures localized at minor neurites and axonal growth cones. At 4 DIV, Fzd5 polarizes towards the axon, where its expression is detected mainly at the peripheral zone of axonal growth cones, with no obvious staining at dendrites; suggesting a role of Fzd5 in neuronal polarization. Overexpression of Fzd5 during the acquisition of neuronal polarity induces mislocalization of the receptor and a loss of polarized axonal markers. Fzd5 knock-down leads to loss of axonal proteins, suggesting an impaired neuronal polarity. In contrast, overexpression of Fzd5 in neurons that are already polarized did not alter polarity, but decreased the total length of axons and increased total dendrite length and arborization. Fzd5 activated JNK in HEK293 cells and the effects triggered by Fzd5 overexpression in neurons were partially prevented by inhibition of JNK, suggesting that a non-canonical Wnt signaling mechanism might be involved. Our results suggest that, Fzd5 has a role in the establishment of neuronal polarity, and in the morphogenesis of neuronal processes, in part through the activation of the non-canonical Wnt mechanism involving JNK.

  6. CD133, CD15/SSEA-1, CD34 or side populations do not resume tumor-initiating properties of long-term cultured cancer stem cells from human malignant glio-neuronal tumors

    International Nuclear Information System (INIS)

    Patru, Cristina; Berhneim, Alain; Mihalescu-Maingot, Maria; Haiech, Jacques; Bièche, Ivan; Moura-Neto, Vivaldo; Daumas-Duport, Catherine; Junier, Marie-Pierre; Chneiweiss, Hervé; Romao, Luciana; Varlet, Pascale; Coulombel, Laure; Raponi, Eric; Cadusseau, Josette; Renault-Mihara, François; Thirant, Cécile; Leonard, Nadine

    2010-01-01

    Tumor initiating cells (TICs) provide a new paradigm for developing original therapeutic strategies. We screened for TICs in 47 human adult brain malignant tumors. Cells forming floating spheres in culture, and endowed with all of the features expected from tumor cells with stem-like properties were obtained from glioblastomas, medulloblastoma but not oligodendrogliomas. A long-term self-renewal capacity was particularly observed for cells of malignant glio-neuronal tumors (MGNTs). Cell sorting, karyotyping and proteomic analysis demonstrated cell stability throughout prolonged passages. Xenografts of fewer than 500 cells in Nude mouse brains induced a progressively growing tumor. CD133, CD15/LeX/Ssea-1, CD34 expressions, or exclusion of Hoechst dye occurred in subsets of cells forming spheres, but was not predictive of their capacity to form secondary spheres or tumors, or to resist high doses of temozolomide. Our results further highlight the specificity of a subset of high-grade gliomas, MGNT. TICs derived from these tumors represent a new tool to screen for innovative therapies

  7. Cell-surface expression of neuron-glial antigen 2 (NG2) and melanoma cell adhesion molecule (CD146) in heterogeneous cultures of marrow-derived mesenchymal stem cells.

    Science.gov (United States)

    Russell, Katie C; Tucker, H Alan; Bunnell, Bruce A; Andreeff, Michael; Schober, Wendy; Gaynor, Andrew S; Strickler, Karen L; Lin, Shuwen; Lacey, Michelle R; O'Connor, Kim C

    2013-10-01

    Cellular heterogeneity of mesenchymal stem cells (MSCs) impedes their use in regenerative medicine. The objective of this research is to identify potential biomarkers for the enrichment of progenitors from heterogeneous MSC cultures. To this end, the present study examines variation in expression of neuron-glial antigen 2 (NG2) and melanoma cell adhesion molecule (CD146) on the surface of MSCs derived from human bone marrow in response to culture conditions and among cell populations. Multipotent cells isolated from heterogeneous MSC cultures exhibit a greater than three-fold increase in surface expression for NG2 and greater than two-fold increase for CD146 as compared with parental and lineage-committed MSCs. For both antigens, surface expression is downregulated by greater than or equal to six-fold when MSCs become confluent. During serial passage, maximum surface expression of NG2 and CD146 is associated with minimum doubling time. Upregulation of NG2 and CD146 during loss of adipogenic potential at early passage suggests some limits to their utility as potency markers. A potential relationship between proliferation and antigen expression was explored by sorting heterogeneous MSCs into rapidly and slowly dividing groups. Fluorescence-activated cell sorting revealed that rapidly dividing MSCs display lower scatter and 50% higher NG2 surface expression than slowly dividing cells, but CD146 expression is comparable in both groups. Heterogeneous MSCs were sorted based on scatter properties and surface expression of NG2 and CD146 into high (HI) and low (LO) groups. Sc(LO)NG2(HI) and Sc(LO)NG2(HI)CD146(HI) MSCs have the highest proliferative potential of the sorted groups, with colony-forming efficiencies that are 1.5-2.2 times the value for the parental controls. The Sc(LO) gate enriches for rapidly dividing cells. Addition of the NG2(HI) gate increases cell survival to 1.5 times the parental control. Further addition of the CD146(HI) gate does not significantly

  8. Anti-inflammatory effects of dexamethasone and meloxicam on Borrelia burgdorferi-induced inflammation in neuronal cultures of dorsal root ganglia and myelinating cells of the peripheral nervous system.

    Science.gov (United States)

    Ramesh, Geeta; Meisner, Olivia C; Philipp, Mario T

    2015-12-23

    Lyme neuroborreliosis (LNB), caused by the spirochete Borrelia burgdorferi (Bb), could result in cognitive impairment, motor dysfunction, and radiculoneuritis. We hypothesized that inflammation is a key factor in LNB pathogenesis and recently evaluated the effects of dexamethasone, a steroidal anti-inflammatory drug, and meloxicam a non-steroidal anti-inflammatory drug (NSAID), in a rhesus monkey model of acute LNB. Dexamethasone treatment significantly reduced the levels of immune mediators, and prevented inflammatory and/or neurodegenerative lesions in the central and peripheral nervous systems, and apoptosis in the dorsal root ganglia (DRG). However, infected animals treated with meloxicam showed levels of inflammatory mediators, inflammatory lesions, and DRG cell apoptosis that were similar to that of the infected animals that were left untreated. To address the differential anti-inflammatory effects of dexamethasone and meloxicam on neuronal and myelinating cells of the peripheral nervous system (PNS), we evaluated the potential of these drugs to alter the levels of Bb-induced inflammatory mediators in rhesus DRG cell cultures and primary human Schwann cells (HSC), using multiplex enzyme-linked immunosorbent assays (ELISA). We also ascertained the ability of these drugs to modulate cell death as induced by live Bb in HSC using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) viability assay and the potential of dexamethasone to modulate Bb-induced apoptosis in HSC by the TUNEL assay. Earlier, we reported that dexamethasone significantly reduced Bb-induced immune mediators and apoptosis in rhesus DRG cell cultures. Here, we report that dexamethasone but not meloxicam significantly reduces the levels of several cytokines and chemokines as induced by live Bb, in HSC and DRG cell cultures. Further, meloxicam does not significantly alter Bb-induced cell death in HSC, while dexamethasone protects HSC against Bb-induced cell death. These data

  9. TGF-β2 and TGF-β3 from cultured β-amyloid-treated or 3xTg-AD-derived astrocytes may mediate astrocyte-neuron communication.

    Science.gov (United States)

    Tapella, Laura; Cerruti, Matteo; Biocotino, Isabella; Stevano, Alessio; Rocchio, Francesca; Canonico, Pier Luigi; Grilli, Mariagrazia; Genazzani, Armando A; Lim, Dmitry

    2018-02-01

    Astrocytes participate in the development and resolution of neuroinflammation in numerous ways, including the release of cytokines and growth factors. Among many, astrocytes release transforming growth factors beta (TGF-β) TGF-β1, TGF-β2 and TGF-β3. TGF-β1 is the most studied isoform, while production and release of TGF-β2 and TGF-β3 by astrocytes have been poorly characterized. Here, we report that purified cultures of hippocampal astrocytes produce mainly TGF-β3 followed by TGF-β2 and TGF-β1. Furthermore, astrocytes release principally the active form of TGF-β3 over the other two. Changes in release of TGF-β were sensitive to the calcineurin (CaN) inhibitor FK506. Starvation had no effect on TGF-β1 and TGF-β3 while TGF-β2 mRNA was significantly up-regulated in a CaN-dependent manner. We further investigated production and release of astroglial TGF-β in Alzheimer's disease-related conditions. Oligomeric β-amyloid (Aβ) down-regulated TGF-β1, while up-regulating TGF-β2 and TGF-β3, in a CaN-dependent manner. In cultured hippocampal astrocytes from 3xTg-AD mice, TGF-β2 and TGF-β3, but not TGF-β1, were up-regulated, and this was CaN-independent. In hippocampal tissues from symptomatic 3xTg-AD mice, TGF-β2 was up-regulated with respect to control mice. Finally, treatment with recombinant TGF-βs showed that TGF-β2 and TGF-β3 significantly reduced PSD95 protein in cultured hippocampal neurons, and this effect was paralleled by conditioned media from Aβ-treated astrocytes or from astrocytes from 3xTg-AD mice. Taken together, our data suggest that TGF-β2 and TGF-β3 are produced by astrocytes in a CaN-dependent manner and should be investigated further in the context of astrocyte-mediated neurodegeneration. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  10. Neuronal Survival, Morphology and Outgrowth of Spiral Ganglion Neurons Using a Defined Growth Factor Combination.

    Directory of Open Access Journals (Sweden)

    Jana Schwieger

    Full Text Available The functionality of cochlear implants (CI depends, among others, on the number and excitability of surviving spiral ganglion neurons (SGN. The spatial separation between the SGN, located in the bony axis of the inner ear, and the CI, which is inserted in the scala tympani, results in suboptimal performance of CI patients and may be decreased by attracting the SGN neurites towards the electrode contacts. Neurotrophic factors (NTFs can support neuronal survival and neurite outgrowth.Since brain-derived neurotrophic factor (BDNF is well known for its neuroprotective effect and ciliary neurotrophic factor (CNTF increases neurite outgrowth, we evaluated if the combination of BDNF and CNTF leads to an enhanced neuronal survival with extended neurite outgrowth. Both NTFs were added in effective high concentrations (BDNF 50 ng/ml, CNTF 100 ng/ml, alone and in combination, to cultured dissociated SGN of neonatal rats for 48 hours.The neuronal survival and neurite outgrowth were significantly higher in SGN treated with the combination of the two NTFs compared to treatment with each factor alone. Additionally, with respect to the morphology, the combination of BDNF and CNTF leads to a significantly higher number of bipolar neurons and a decreased number of neurons without neurites in culture.The combination of BDNF and CNTF shows a great potential to increase the neuronal survival and the number of bipolar neurons in vitro and to regenerate retracted nerve fibers.

  11. MHC-I expression renders catecholaminergic neurons susceptible to T-cell-mediated degeneration

    OpenAIRE

    Cebrián, Carolina; Zucca, Fabio A.; Mauri, Pierluigi; Steinbeck, Julius A.; Studer, Lorenz; Scherzer, Clemens R.; Kanter, Ellen; Budhu, Sadna; Mandelbaum, Jonathan; Vonsattel, Jean P.; Zecca, Luigi; Loike, John D.; Sulzer, David

    2014-01-01

    Subsets of rodent neurons are reported to express major histocompatibilty complex class I (MHC-I), but such expression has not been reported in normal adult human neurons. Here we provide evidence from immunolabel, RNA expression, and mass spectrometry analysis of postmortem samples that human catecholaminergic substantia nigra and locus coeruleus neurons express MHC-I, and that this molecule is inducible in human stem cell derived dopamine (DA) neurons. Catecholamine murine cultured neurons ...

  12. Secretory phospholipase A2-mediated neuronal cell death involves glutamate ionotropic receptors

    DEFF Research Database (Denmark)

    Kolko, Miriam; de Turco, Elena B; Diemer, Nils Henrik

    2002-01-01

    To define the significance of glutamate ionotropic receptors in sPLA -mediated neuronal cell death we used the NMDA receptor antagonist MK-801 and the AMPA receptor antagonist PNQX. In primary neuronal cell cultures both MK-801 and PNQX inhibited sPLA - and glutamate-induced neuronal death. [ H...... neuronal cell death. We conclude that glutamatergic synaptic activity modulates sPLA -induced neuronal cell death....

  13. NEURON and Python

    OpenAIRE

    Michael Hines; Andrew P Davison; Eilif Muller

    2009-01-01

    The NEURON simulation program now allows Python to be used, alone or in combination with NEURON's traditional Hoc interpreter. Adding Python to NEURON has the immediate benefit of making available a very extensive suite of analysis tools written for engineering and science. It also catalyzes NEURON software development by offering users a modern programming tool that is recognized for its flexibility and power to create and maintain complex programs. At the same time, nothing is lost because ...

  14. Soft chitosan microbeads scaffold for 3D functional neuronal networks.

    Science.gov (United States)

    Tedesco, Maria Teresa; Di Lisa, Donatella; Massobrio, Paolo; Colistra, Nicolò; Pesce, Mattia; Catelani, Tiziano; Dellacasa, Elena; Raiteri, Roberto; Martinoia, Sergio; Pastorino, Laura

    2018-02-01

    The availability of 3D biomimetic in vitro neuronal networks of mammalian neurons represents a pivotal step for the development of brain-on-a-chip experimental models to study neuronal (dys)functions and particularly neuronal connectivity. The use of hydrogel-based scaffolds for 3D cell cultures has been extensively studied in the last years. However, limited work on biomimetic 3D neuronal cultures has been carried out to date. In this respect, here we investigated the use of a widely popular polysaccharide, chitosan (CHI), for the fabrication of a microbead based 3D scaffold to be coupled to primary neuronal cells. CHI microbeads were characterized by optical and atomic force microscopies. The cell/scaffold interaction was deeply characterized by transmission electron microscopy and by immunocytochemistry using confocal microscopy. Finally, a preliminary electrophysiological characterization by micro-electrode arrays was carried out. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. In vitro study of dopaminergic central neurons radiosensitivity

    International Nuclear Information System (INIS)

    Multon, E.; Mallat, M.; Cadinu, J.; Court, L.

    1989-01-01

    An embryonic mesencephalic neuronal culture model was used to analyze the radiosensitivity of a dopaminergic neuronal population. Several criteria have allowed to evaluate the effects of a gamma irradiation. In the order of increasing sensitivity, a reduction of the dopamine uptake, a decrease of the number of differentiated dopaminergic neurons and some modifications of the size and the degree of branching or the neurites were noted. These results are preliminary and have to be confirmed [fr

  16. Neurons controlling Aplysia feeding inhibit themselves by continuous NO production.

    Directory of Open Access Journals (Sweden)

    Nimrod Miller

    2011-03-01

    Full Text Available Neural activity can be affected by nitric oxide (NO produced by spiking neurons. Can neural activity also be affected by NO produced in neurons in the absence of spiking?Applying an NO scavenger to quiescent Aplysia buccal ganglia initiated fictive feeding, indicating that NO production at rest inhibits feeding. The inhibition is in part via effects on neurons B31/B32, neurons initiating food consumption. Applying NO scavengers or nitric oxide synthase (NOS blockers to B31/B32 neurons cultured in isolation caused inactive neurons to depolarize and fire, indicating that B31/B32 produce NO tonically without action potentials, and tonic NO production contributes to the B31/B32 resting potentials. Guanylyl cyclase blockers also caused depolarization and firing, indicating that the cGMP second messenger cascade, presumably activated by the tonic presence of NO, contributes to the B31/B32 resting potential. Blocking NO while voltage-clamping revealed an inward leak current, indicating that NO prevents this current from depolarizing the neuron. Blocking nitrergic transmission had no effect on a number of other cultured, isolated neurons. However, treatment with NO blockers did excite cerebral ganglion neuron C-PR, a command-like neuron initiating food-finding behavior, both in situ, and when the neuron was cultured in isolation, indicating that this neuron also inhibits itself by producing NO at rest.Self-inhibitory, tonic NO production is a novel mechanism for the modulation of neural activity. Localization of this mechanism to critical neurons in different ganglia controlling different aspects of a behavior provides a mechanism by which a humeral signal affecting background NO production, such as the NO precursor L-arginine, could control multiple aspects of the behavior.

  17. Integrated microfluidic platforms for investigating neuronal networks

    Science.gov (United States)

    Kim, Hyung Joon

    This dissertation describes the development and application of integrated microfluidics-based assay platforms to study neuronal activities in the nervous system in-vitro. The assay platforms were fabricated using soft lithography and micro/nano fabrication including microfluidics, surface patterning, and nanomaterial synthesis. The use of integrated microfluidics-based assay platform allows culturing and manipulating many types of neuronal tissues in precisely controlled microenvironment. Furthermore, they provide organized multi-cellular in-vitro model, long-term monitoring with live cell imaging, and compatibility with molecular biology techniques and electrophysiology experiment. In this dissertation, the integrated microfluidics-based assay platforms are developed for investigation of neuronal activities such as local protein synthesis, impairment of axonal transport by chemical/physical variants, growth cone path finding under chemical/physical cues, and synaptic transmission in neuronal circuit. Chapter 1 describes the motivation, objectives, and scope for developing in-vitro platform to study various neuronal activities. Chapter 2 introduces microfluidic culture platform for biochemical assay with large-scale neuronal tissues that are utilized as model system in neuroscience research. Chapter 3 focuses on the investigation of impaired axonal transport by beta-Amyloid and oxidative stress. The platform allows to control neuronal processes and to quantify mitochondrial movement in various regions of axons away from applied drugs. Chapter 4 demonstrates the development of microfluidics-based growth cone turning assay to elucidate the mechanism underlying axon guidance under soluble factors and shear flow. Using this platform, the behaviors of growth cone of mammalian neurons are verified under the gradient of inhibitory molecules and also shear flow in well-controlled manner. In Chapter 5, I combine in-vitro multicellular model with microfabricated MEA

  18. Sensory neurons do not induce motor neuron loss in a human stem cell model of spinal muscular atrophy.

    Science.gov (United States)

    Schwab, Andrew J; Ebert, Allison D

    2014-01-01

    Spinal muscular atrophy (SMA) is an autosomal recessive disorder leading to paralysis and early death due to reduced SMN protein. It is unclear why there is such a profound motor neuron loss, but recent evidence from fly and mouse studies indicate that cells comprising the whole sensory-motor circuit may contribute to motor neuron dysfunction and loss. Here, we used induced pluripotent stem cells derived from SMA patients to test whether sensory neurons directly contribute to motor neuron loss. We generated sensory neurons from SMA induced pluripotent stem cells and found no difference in neuron generation or survival, although there was a reduced calcium response to depolarizing stimuli. Using co-culture of SMA induced pluripotent stem cell derived sensory neurons with control induced pluripotent stem cell derived motor neurons, we found no significant reduction in motor neuron number or glutamate transporter boutons on motor neuron cell bodies or neurites. We conclude that SMA sensory neurons do not overtly contribute to motor neuron loss in this human stem cell system.

  19. Peripheral Neuron Survival and Outgrowth on Graphene

    Directory of Open Access Journals (Sweden)

    Domenica Convertino

    2018-01-01

    Full Text Available Graphene displays properties that make it appealing for neuroregenerative medicine, yet its interaction with peripheral neurons has been scarcely investigated. Here, we culture on graphene two established models for peripheral neurons: PC12 cells and DRG primary neurons. We perform a nano-resolved analysis of polymeric coatings on graphene and combine optical microscopy and viability assays to assess the material cytocompatibility and influence on differentiation. We find that differentiated PC12 cells display a remarkably increased neurite length on graphene (up to 27% with respect to controls. Notably, DRG primary neurons survive both on bare and coated graphene. They present dense axonal networks on coated graphene, while they form cell islets characterized by dense axonal bundles on uncoated graphene. These findings indicate that graphene holds potential for nerve tissue regeneration and might pave the road to novel concepts of active nerve conduits.

  20. Schwann cells promote neuronal differentiation of bone marrow ...

    African Journals Online (AJOL)

    It has been suggested that the BMSCs have the capacity to differentiate into neurons under specific experimental conditions, using chemical factors. In this study, we showed that BMSCs can be induced to differentiate into neuron-like cells when they are co-cultured with Schwann cells by Brdu pulse label technology.

  1. Axonal regeneration and neuronal function are preserved in motor neurons lacking ß-actin in vivo.

    Directory of Open Access Journals (Sweden)

    Thomas R Cheever

    2011-03-01

    Full Text Available The proper localization of ß-actin mRNA and protein is essential for growth cone guidance and axon elongation in cultured neurons. In addition, decreased levels of ß-actin mRNA and protein have been identified in the growth cones of motor neurons cultured from a mouse model of Spinal Muscular Atrophy (SMA, suggesting that ß-actin loss-of-function at growth cones or pre-synaptic nerve terminals could contribute to the pathogenesis of this disease. However, the role of ß-actin in motor neurons in vivo and its potential relevance to disease has yet to be examined. We therefore generated motor neuron specific ß-actin knock-out mice (Actb-MNsKO to investigate the function of ß-actin in motor neurons in vivo. Surprisingly, ß-actin was not required for motor neuron viability or neuromuscular junction maintenance. Skeletal muscle from Actb-MNsKO mice showed no histological indication of denervation and did not significantly differ from controls in several measurements of physiologic function. Finally, motor axon regeneration was unimpaired in Actb-MNsKO mice, suggesting that ß-actin is not required for motor neuron function or regeneration in vivo.

  2. Neurite outgrowth in human iPSC-derived neurons

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data on morphology of rat and human neurons in cell culture. This dataset is associated with the following publication: Druwe, I., T. Freudenrich , K. Wallace , T....

  3. Recurrently connected and localized neuronal communities initiate coordinated spontaneous activity in neuronal networks.

    Science.gov (United States)

    Lonardoni, Davide; Amin, Hayder; Di Marco, Stefano; Maccione, Alessandro; Berdondini, Luca; Nieus, Thierry

    2017-07-01

    Developing neuronal systems intrinsically generate coordinated spontaneous activity that propagates by involving a large number of synchronously firing neurons. In vivo, waves of spikes transiently characterize the activity of developing brain circuits and are fundamental for activity-dependent circuit formation. In vitro, coordinated spontaneous spiking activity, or network bursts (NBs), interleaved within periods of asynchronous spikes emerge during the development of 2D and 3D neuronal cultures. Several studies have investigated this type of activity and its dynamics, but how a neuronal system generates these coordinated events remains unclear. Here, we investigate at a cellular level the generation of network bursts in spontaneously active neuronal cultures by exploiting high-resolution multielectrode array recordings and computational network modelling. Our analysis reveals that NBs are generated in specialized regions of the network (functional neuronal communities) that feature neuronal links with high cross-correlation peak values, sub-millisecond lags and that share very similar structural connectivity motifs providing recurrent interactions. We show that the particular properties of these local structures enable locally amplifying spontaneous asynchronous spikes and that this mechanism can lead to the initiation of NBs. Through the analysis of simulated and experimental data, we also show that AMPA currents drive the coordinated activity, while NMDA and GABA currents are only involved in shaping the dynamics of NBs. Overall, our results suggest that the presence of functional neuronal communities with recurrent local connections allows a neuronal system to generate spontaneous coordinated spiking activity events. As suggested by the rules used for implementing our computational model, such functional communities might naturally emerge during network development by following simple constraints on distance-based connectivity.

  4. Recurrently connected and localized neuronal communities initiate coordinated spontaneous activity in neuronal networks.

    Directory of Open Access Journals (Sweden)

    Davide Lonardoni

    2017-07-01

    Full Text Available Developing neuronal systems intrinsically generate coordinated spontaneous activity that propagates by involving a large number of synchronously firing neurons. In vivo, waves of spikes transiently characterize the activity of developing brain circuits and are fundamental for activity-dependent circuit formation. In vitro, coordinated spontaneous spiking activity, or network bursts (NBs, interleaved within periods of asynchronous spikes emerge during the development of 2D and 3D neuronal cultures. Several studies have investigated this type of activity and its dynamics, but how a neuronal system generates these coordinated events remains unclear. Here, we investigate at a cellular level the generation of network bursts in spontaneously active neuronal cultures by exploiting high-resolution multielectrode array recordings and computational network modelling. Our analysis reveals that NBs are generated in specialized regions of the network (functional neuronal communities that feature neuronal links with high cross-correlation peak values, sub-millisecond lags and that share very similar structural connectivity motifs providing recurrent interactions. We show that the particular properties of these local structures enable locally amplifying spontaneous asynchronous spikes and that this mechanism can lead to the initiation of NBs. Through the analysis of simulated and experimental data, we also show that AMPA currents drive the coordinated activity, while NMDA and GABA currents are only involved in shaping the dynamics of NBs. Overall, our results suggest that the presence of functional neuronal communities with recurrent local connections allows a neuronal system to generate spontaneous coordinated spiking activity events. As suggested by the rules used for implementing our computational model, such functional communities might naturally emerge during network development by following simple constraints on distance-based connectivity.

  5. Corticospinal mirror neurons

    OpenAIRE

    Kraskov, A.; Philipp, R.; Waldert, S.; Vigneswaran, G.; Quallo, M. M.; Lemon, R. N.

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like p...

  6. MS-377, a selective sigma receptor ligand, indirectly blocks the action of PCP in the N-methyl-D-aspartate receptor ion-channel complex in primary cultured rat neuronal cells.

    Science.gov (United States)

    Karasawa, Jun-ichi; Yamamoto, Hideko; Yamamoto, Toshifumi; Sagi, Naoki; Horikomi, Kazutoshi; Sora, Ichiro

    2002-02-22

    MS-377 ((R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate) is a antipsychotic agent that binds to sigma-1 receptor. MS-377 showed anti-dopaminergic and anti-serotonergic activities and antagonistic action against phencyclidine (PCP)-induced behaviors in an animal model. These anti-psychotic activities of MS-377 are attributable to association with sigma-1 receptor. However, the mechanism by which the sigma-1 receptor ligands exact those numerous effects remains to be elucidated. In the present study, we evaluated the effect of MS-377 on N-methyl-D-aspartate (NMDA) receptor ion-channel complex in primary cultured rat neuronal cells. First, we examined the effect of MS-377 on NMDA-induced Ca2+ influx with fura-2/ AM loaded cells. MS-377 showed no effects on the basal Ca2+ concentration and NMDA-induced Ca2+ influx by itself PCP and SKF-10047 reduced the NMDA-induced increase in intracellular Ca2+ concentration. Pre-incubation of 1 microM MS-377 was found to significantly block the reduction by PCP or SKF-10047 of the NMDA-induced Ca2+ influx. Second, the effect of MS-377 on [3H]MK-801 intact cell binding was examined. PCP, haloperidol and (+)-pentazocine inhibited [3H]MK-801 binding, although MS-377 showed no effect by itself Pre-treatment of MS-377 markedly reversed the inhibition of [3H]MK-801 binding by PCP in a dose-dependent manner. These effects of MS-377 may depend on its affinity for the sigma-1 receptor, because MS-377 is a selective sigma-1 receptor ligand without any affinity for NMDA receptor ion-channel complex. These observations suggest that the MS-377 indirectly modulated the NMDA receptor ion-channel complex, and the anti-psychotic activities of MS-377, in part, are attributable to such on action via sigma-1 receptor.

  7. The neuroprotective efficacy of cell-penetrating peptides TAT, penetratin, Arg-9, and Pep-1 in glutamic acid, kainic acid, and in vitro ischemia injury models using primary cortical neuronal cultures.

    Science.gov (United States)

    Meloni, Bruno P; Craig, Amanda J; Milech, Nadia; Hopkins, Richard M; Watt, Paul M; Knuckey, Neville W

    2014-03-01

    Cell-penetrating peptides (CPPs) are small peptides (typically 5-25 amino acids), which are used to facilitate the delivery of normally non-permeable cargos such as other peptides, proteins, nucleic acids, or drugs into cells. However, several recent studies have demonstrated that the TAT CPP has neuroprotective properties. Therefore, in this study, we assessed the TAT and three other CPPs (penetratin, Arg-9, Pep-1) for their neuroprotective properties in cortical neuronal cultures following exposure to glutamic acid, kainic acid, or in vitro ischemia (oxygen-glucose deprivation). Arg-9, penetratin, and TAT-D displayed consistent and high level neuroprotective activity in both the glutamic acid (IC50: 0.78, 3.4, 13.9 μM) and kainic acid (IC50: 0.81, 2.0, 6.2 μM) injury models, while Pep-1 was ineffective. The TAT-D isoform displayed similar efficacy to the TAT-L isoform in the glutamic acid model. Interestingly, Arg-9 was the only CPP that displayed efficacy when washed-out prior to glutamic acid exposure. Neuroprotection following in vitro ischemia was more variable with all peptides providing some level of neuroprotection (IC50; Arg-9: 6.0 μM, TAT-D: 7.1 μM, penetratin/Pep-1: >10 μM). The positive control peptides JNKI-1D-TAT (JNK inhibitory peptide) and/or PYC36L-TAT (AP-1 inhibitory peptide) were neuroprotective in all models. Finally, in a post-glutamic acid treatment experiment, Arg-9 was highly effective when added immediately after, and mildly effective when added 15 min post-insult, while the JNKI-1D-TAT control peptide was ineffective when added post-insult. These findings demonstrate that different CPPs have the ability to inhibit neurodamaging events/pathways associated with excitotoxic and ischemic injuries. More importantly, they highlight the need to interpret neuroprotection studies when using CPPs as delivery agents with caution. On a positive note, the cytoprotective properties of CPPs suggests they are ideal carrier molecules to

  8. Novel cell separation method for molecular analysis of neuron-astrocyte cocultures

    Directory of Open Access Journals (Sweden)

    Andrea eGoudriaan

    2014-01-01

    Full Text Available Over the last decade, the importance of astrocyte-neuron communication in neuronal development and synaptic plasticity has become increasingly clear. Since neuron-astrocyte interactions represent highly dynamic and reciprocal processes, we hypothesized that many astrocyte genes may be regulated as a consequence of their interactions with maturing neurons. In order to identify such neuron-responsive astrocyte genes in vitro, we sought to establish an expedite technique for separation of neurons from co-cultured astrocytes. Our newly established method makes use of cold jet, which exploits different adhesion characteristics of subpopulations of cells (Jirsova et al., 1997, and is rapid, performed under ice-cold conditions and avoids protease-mediated isolation of astrocytes or time-consuming centrifugation, yielding intact astrocyte mRNA with approximately 90% of neuronal RNA removed. Using this purification method, we executed genome-wide profiling in which RNA derived from astrocyte-only cultures was compared with astrocyte RNA derived from differentiating neuron-astrocyte co-cultures. Data analysis determined that many astrocytic mRNAs and biological processes are regulated by neuronal interaction. Our results validate the cold jet as an efficient method to separate astrocytes from neurons in co-culture, and reveals that neurons induce robust gene-expression changes in co-cultured astrocytes.

  9. Neuropeptides as endogenous neuronal growth regulatory factors on serotonergic maturation

    Energy Technology Data Exchange (ETDEWEB)

    Davila-Garcia, M.I.

    1989-01-01

    Products of the proopiomelanocortin molecule as well as leu- and met-enkephalin were tested for their effects on serotonergic neuronal maturation. High affinity uptake of ({sup 3}H)5-HT and morphometrics using immunocytochemistry specific for serotonergic neurons were used to monitor neuronal maturation. Cultured brainstem raphe neurons from 14 day fetuses, in the presence or absence of target tissue, were administered neuropeptides at various concentrations for 1,3 or 5 days in culture. ACTH peptides stimulate neurite length and, with the endorphins, the expression of ({sup 3}H)5-HT uptake by serotonergic fetal neurons cultured alone but had no effect when these neurons were cocultured with hippocampal target cells. A daily dose of leu-enkephalin to these cells inhibited neuronal uptake after 5 days of exposure and decreased neurite cell length in 24 hr cultures. In contrast, a single dose of leu-enkephalin at plating stimulated uptake after 5 days while co-administration of bacitracin inhibited uptake expression. Naloxone reversed the opioid effect and stimulated uptake when administered alone. Desulfated-CCK, which resembles leu-enkephalin, was equally potent as leu-enkephalin in inhibiting uptake.

  10. [Two-nuclear neurons: sincitial fusion or amitotic division].

    Science.gov (United States)

    Sotnikov, O S; Frumkina, L E; Lactionova, A A; Paramonova, N M; Novakovskaia, S A

    2011-01-01

    In the review the history of research two-nuclear neurons is stated and two hypotheses about mechanisms of their formation are analysed: by sincitial fusion or amytotic divisions. The facts of discrepancy of the former orthodox cellular theory categorically denying possibility sincitial of communications in nervous system and of sincitial fusion neurons are mentioned. As an example results of ultrastructural researches of occurrence sincitium in a cortex of the big brain of rats, in autonomic ganglions, in hypocampus and a cerebellum of adult animals are presented. The video data of the sincitial fusion of live neurons and the mechanism of formation multinuclear neurons in tissue culture are analyzed. Existing data about amytotic a way of formation two-nuclear neurons are critically considered. The conclusion becomes, that the mechanism of formation two-nuclear neurons is cellular fusion. Simultaneously the review confirms our representations about existence in nervous system sincitial interneural communications.

  11. Genomic and biochemical approaches in the discovery of mechanisms for selective neuronal vulnerability to oxidative stress.

    Science.gov (United States)

    Wang, Xinkun; Zaidi, Asma; Pal, Ranu; Garrett, Alexander S; Braceras, Rogelio; Chen, Xue-wen; Michaelis, Mary L; Michaelis, Elias K

    2009-02-19

    Oxidative stress (OS) is an important factor in brain aging and neurodegenerative diseases. Certain neurons in different brain regions exhibit selective vulnerability to OS. Currently little is known about the underlying mechanisms of this selective neuronal vulnerability. The purpose of this study was to identify endogenous factors that predispose vulnerable neurons to OS by employing genomic and biochemical approaches. In this report, using in vitro neuronal cultures, ex vivo organotypic brain slice cultures and acute brain slice preparations, we established that cerebellar granule (CbG) and hippocampal CA1 neurons were significantly more sensitive to OS (induced by paraquat) than cerebral cortical and hippocampal CA3 neurons. To probe for intrinsic differences between in vivo vulnerable (CA1 and CbG) and resistant (CA3 and cerebral cortex) neurons under basal conditions, these neurons were collected by laser capture microdissection from freshly excised brain sections (no OS treatment), and then subjected to oligonucleotide microarray analysis. GeneChip-based transcriptomic analyses revealed that vulnerable neurons had higher expression of genes related to stress and immune response, and lower expression of energy generation and signal transduction genes in comparison with resistant neurons. Subsequent targeted biochemical analyses confirmed the lower energy levels (in the form of ATP) in primary CbG neurons compared with cortical neurons. Low energy reserves and high intrinsic stress levels are two underlying factors for neuronal selective vulnerability to OS. These mechanisms can be targeted in the future for the protection of vulnerable neurons.

  12. Innervation by a GABAergic neuron depresses spontaneous release in glutamatergic neurons and unveils the clamping phenotype of synaptotagmin-1

    DEFF Research Database (Denmark)

    Wierda, Keimpe D B; Sørensen, Jakob Balslev

    2014-01-01

    from mice cultured on astrocyte islands with "homotypic" glutamatergic or GABAergic pairs and autaptic neurons. We measured mEPSC and mIPSC frequencies simultaneously from both neurons. Neuronal pairs formed both interneuronal synaptic and autaptic connections indiscriminately. We find that whereas m......EPSC and mIPSC frequencies did not deviate between autaptic and synaptic connections, the frequency of mEPSCs in mixed pairs was strongly depressed compared with either autaptic neurons or glutamatergic pairs. Simultaneous imaging of synapses, or comparison to evoked release amplitudes, showed......EPSC frequencies were increased by a factor of four in the synaptotagmin-1-null neurons, which is in line with data obtained from mixed cultures. The effect persisted after incubation with BAPTA-AM. We conclude that spontaneous GABA release exerts control over mEPSC release, and GABAergic innervation...

  13. Kappe neurons, a novel population of olfactory sensory neurons

    OpenAIRE

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-01-01

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons ar...

  14. Corticospinal mirror neurons.

    Science.gov (United States)

    Kraskov, A; Philipp, R; Waldert, S; Vigneswaran, G; Quallo, M M; Lemon, R N

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited 'classical' mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation ('suppression mirror-neurons'). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others.

  15. NEURON and Python.

    Science.gov (United States)

    Hines, Michael L; Davison, Andrew P; Muller, Eilif

    2009-01-01

    The NEURON simulation program now allows Python to be used, alone or in combination with NEURON's traditional Hoc interpreter. Adding Python to NEURON has the immediate benefit of making available a very extensive suite of analysis tools written for engineering and science. It also catalyzes NEURON software development by offering users a modern programming tool that is recognized for its flexibility and power to create and maintain complex programs. At the same time, nothing is lost because all existing models written in Hoc, including graphical user interface tools, continue to work without change and are also available within the Python context. An example of the benefits of Python availability is the use of the xml module in implementing NEURON's Import3D and CellBuild tools to read MorphML and NeuroML model specifications.

  16. Neurovascular coupling protects neurons against hypoxic injury via inhibition of potassium currents by generation of nitric oxide in direct neuron and endothelium cocultures.

    Science.gov (United States)

    Wu, Kun-Wei; Kou, Zeng-Wei; Mo, Jia-Lin; Deng, Xu-Xu; Sun, Feng-Yan

    2016-10-15

    This study examined the effect of neuron-endothelial coupling on the survival of neurons after ischemia and the possible mechanism underlying that effect. Whole-cell patch-clamp experiments were performed on cortical neurons cultured alone or directly cocultured with brain microvascular endothelial cells (BMEC). Propidium iodide (PI) and NeuN staining were performed to examine neuronal death following oxygen and glucose deprivation (OGD). We found that the neuronal transient outward potassium currents (I A ) decreased in the coculture system, whereas the outward delayed-rectifier potassium currents (I K ) did not. Sodium nitroprusside, a NO donor, enhanced BMEC-induced I A inhibition and nitro-l-arginine methylester, a NOS inhibitor, partially prevented this inhibition. Moreover, the neurons directly cocultured with BMEC showed more resistance to OGD-induced injury compared with the neurons cultured alone, and that neuroprotective effect was abolished by treatment with NS5806, an activator of the I A . These results indicate that vascular endothelial cells assist neurons to prevent hypoxic injury via inhibiting neuronal I A by production of NO in the direct neuron-BMEC coculture system. These results further provide direct evidence of functional coupling between neurons and vascular endothelial cells. This study clearly demonstrates that vascular endothelial cells play beneficial roles in the pathophysiological processes of neurons after hypoxic injury, suggesting that the improvement of neurovascular coupling or functional remodeling may become an important therapeutic target for preventing brain injury. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Neuronal-glial trafficking

    International Nuclear Information System (INIS)

    Bachelard, H.S.

    2001-01-01

    Full text: The name 'glia' originates from the Greek word for glue, because astro glia (or astrocytes) were thought only to provide an anatomical framework for the electrically-excitable neurones. However, awareness that astrocytes perform vital roles in protecting the neurones, which they surround, emerged from evidence that they act as neuroprotective K + -sinks, and that they remove potentially toxic extracellular glutamate from the vicinity of the neurones. The astrocytes convert the glutamate to non-toxic glutamine which is returned to the neurones and used to replenish transmitter glutamate. This 'glutamate-glutamine cycle' (established in the 1960s by Berl and his colleagues) also contributes to protecting the neurones against a build-up of toxic ammonia. Glial cells also supply the neurones with components for free-radical scavenging glutathione. Recent studies have revealed that glial cells play a more positive interactive role in furnishing the neurones with fuels. Studies using radioactive 14 C, 13 C-MRS and 15 N-GCMS have revealed that glia produce alanine, lactate and proline for consumption by neurones, with increased formation of neurotransmitter glutamate. On neuronal activation the release of NH 4 + and glutamate from the neurones stimulates glucose uptake and glycolysis in the glia to produce more alanine, which can be regarded as an 'alanine-glutamate cycle' Use of 14 C-labelled precursors provided early evidence that neurotransmitter GABA may be partly derived from glial glutamine, and this has been confirmed recently in vivo by MRS isotopomer analysis of the GABA and glutamine labelled from 13 C-acetate. Relative rates of intermediary metabolism in glia and neurones can be calculated using a combination of [1- 13 C] glucose and [1,2- 13 C] acetate. When glutamate is released by neurones there is a net neuronal loss of TCA intermediates which have to be replenished. Part of this is derived from carboxylation of pyruvate, (pyruvate carboxylase

  18. Single neuron computation

    CERN Document Server

    McKenna, Thomas M; Zornetzer, Steven F

    1992-01-01

    This book contains twenty-two original contributions that provide a comprehensive overview of computational approaches to understanding a single neuron structure. The focus on cellular-level processes is twofold. From a computational neuroscience perspective, a thorough understanding of the information processing performed by single neurons leads to an understanding of circuit- and systems-level activity. From the standpoint of artificial neural networks (ANNs), a single real neuron is as complex an operational unit as an entire ANN, and formalizing the complex computations performed by real n

  19. Mesmerising mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2010-06-01

    Mirror neurons have been hailed as the key to understanding social cognition. I argue that three currents of thought-relating to evolution, atomism and telepathy-have magnified the perceived importance of mirror neurons. When they are understood to be a product of associative learning, rather than an adaptation for social cognition, mirror neurons are no longer mesmerising, but they continue to raise important questions about both the psychology of science and the neural bases of social cognition. Copyright 2010 Elsevier Inc. All rights reserved.

  20. Species and Sex Differences in the Morphogenic Response of Primary Rodent Neurons to 3,3'-Dichlorobiphenyl (PCB 11).

    Science.gov (United States)

    Sethi, Sunjay; Keil, Kimberly P; Lein, Pamela J

    2017-12-23

    PCB 11 is an emerging global pollutant that we recently showed promotes axonal and dendritic growth in primary rat neuronal cell cultures. Here, we address the influence of sex and species on neuronal responses to PCB 11. Neuronal morphology was quantified in sex-specific primary hippocampal and cortical neuron-glia co-cultures derived from neonatal C57BL/6J mice and Sprague Dawley rats exposed for 48 h to vehicle (0.1% DMSO) or PCB 11 at concentrations ranging from 1 fM to 1 nM. Total axonal length was quantified in tau-1 immunoreactive neurons at day in vitro (DIV) 2; dendritic arborization was assessed by Sholl analysis at DIV 9 in neurons transfected with MAP2B-FusRed. In mouse cultures, PCB 11 enhanced dendritic arborization in female, but not male, hippocampal neurons and male, but not female, cortical neurons. In rat cultures, PCB 11 promoted dendritic arborization in male and female hippocampal and cortical neurons. PCB 11 also increased axonal growth in mouse and rat neurons of both sexes and neuronal cell types. These data demonstrate that PCB 11 exerts sex-specific effects on neuronal morphogenesis that vary depending on species, neurite type, and neuronal cell type. These findings have significant implications for risk assessment of this emerging developmental neurotoxicant.

  1. Distinctive glial and neuronal interfacing on nanocrystalline diamond.

    Directory of Open Access Journals (Sweden)

    Amel Bendali

    Full Text Available Direct electrode/neuron interfacing is a key challenge to achieve high resolution of neuronal stimulation required for visual prostheses. Neuronal interfacing on biomaterials commonly requires the presence of glial cells and/or protein coating. Nanocrystalline diamond is a highly mechanically stable biomaterial with a remarkably large potential window for the electrical stimulation of tissues. Using adult retinal cell cultures from rats, we found that glial cells and retinal neurons grew equally well on glass and nanocrystalline diamond. The use of a protein coating increased cell survival, particularly for glial cells. However, bipolar neurons appeared to grow even in direct contact with bare diamond. We investigated whether the presence of glial cells contributed to this direct neuron/diamond interface, by using purified adult retinal ganglion cells to seed diamond and glass surfaces with and without protein coatings. Surprisingly, these fully differentiated spiking neurons survived better on nanocrystalline diamond without any protein coating. This greater survival was indicated by larger cell numbers and the presence of longer neurites. When a protein pattern was drawn on diamond, neurons did not grow preferentially on the coated area, by contrast to their behavior on a patterned glass. This study highlights the interesting biocompatibility properties of nanocrystalline diamond, allowing direct neuronal interfacing, whereas a protein coating was required for glial cell growth.

  2. Distinctive glial and neuronal interfacing on nanocrystalline diamond.

    Science.gov (United States)

    Bendali, Amel; Agnès, Charles; Meffert, Simone; Forster, Valérie; Bongrain, Alexandre; Arnault, Jean-Charles; Sahel, José-Alain; Offenhäusser, Andreas; Bergonzo, Philippe; Picaud, Serge

    2014-01-01

    Direct electrode/neuron interfacing is a key challenge to achieve high resolution of neuronal stimulation required for visual prostheses. Neuronal interfacing on biomaterials commonly requires the presence of glial cells and/or protein coating. Nanocrystalline diamond is a highly mechanically stable biomaterial with a remarkably large potential window for the electrical stimulation of tissues. Using adult retinal cell cultures from rats, we found that glial cells and retinal neurons grew equally well on glass and nanocrystalline diamond. The use of a protein coating increased cell survival, particularly for glial cells. However, bipolar neurons appeared to grow even in direct contact with bare diamond. We investigated whether the presence of glial cells contributed to this direct neuron/diamond interface, by using purified adult retinal ganglion cells to seed diamond and glass surfaces with and without protein coatings. Surprisingly, these fully differentiated spiking neurons survived better on nanocrystalline diamond without any protein coating. This greater survival was indicated by larger cell numbers and the presence of longer neurites. When a protein pattern was drawn on diamond, neurons did not grow preferentially on the coated area, by contrast to their behavior on a patterned glass. This study highlights the interesting biocompatibility properties of nanocrystalline diamond, allowing direct neuronal interfacing, whereas a protein coating was required for glial cell growth.

  3. Neuronal Networks on Nanocellulose Scaffolds.

    Science.gov (United States)

    Jonsson, Malin; Brackmann, Christian; Puchades, Maja; Brattås, Karoline; Ewing, Andrew; Gatenholm, Paul; Enejder, Annika

    2015-11-01

    Proliferation, integration, and neurite extension of PC12 cells, a widely used culture model for cholinergic neurons, were studied in nanocellulose scaffolds biosynthesized by Gluconacetobacter xylinus to allow a three-dimensional (3D) extension of neurites better mimicking neuronal networks in tissue. The interaction with control scaffolds was compared with cationized nanocellulose (trimethyl ammonium betahydroxy propyl [TMAHP] cellulose) to investigate the impact of surface charges on the cell interaction mechanisms. Furthermore, coatings with extracellular matrix proteins (collagen, fibronectin, and laminin) were investigated to determine the importance of integrin-mediated cell attachment. Cell proliferation was evaluated by a cellular proliferation assay, while cell integration and neurite propagation were studied by simultaneous label-free Coherent anti-Stokes Raman Scattering and second harmonic generation microscopy, providing 3D images of PC12 cells and arrangement of nanocellulose fibrils, respectively. Cell attachment and proliferation were enhanced by TMAHP modification, but not by protein coating. Protein coating instead promoted active interaction between the cells and the scaffold, hence lateral cell migration and integration. Irrespective of surface modification, deepest cell integration measured was one to two cell layers, whereas neurites have a capacity to integrate deeper than the cell bodies in the scaffold due to their fine dimensions and amoeba-like migration pattern. Neurites with lengths of >50 μm were observed, successfully connecting individual cells and cell clusters. In conclusion, TMAHP-modified nanocellulose scaffolds promote initial cellular scaffold adhesion, which combined with additional cell-scaffold treatments enables further formation of 3D neuronal networks.

  4. Corticospinal mirror neurons

    Science.gov (United States)

    Kraskov, A.; Philipp, R.; Waldert, S.; Vigneswaran, G.; Quallo, M. M.; Lemon, R. N.

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons’ discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited ‘classical’ mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation (‘suppression mirror-neurons’). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others. PMID:24778371

  5. Neurons have an active glycogen metabolism that contributes to tolerance to hypoxia

    Science.gov (United States)

    Saez, Isabel; Duran, Jordi; Sinadinos, Christopher; Beltran, Antoni; Yanes, Oscar; Tevy, María F; Martínez-Pons, Carlos; Milán, Marco; Guinovart, Joan J

    2014-01-01

    Glycogen is present in the brain, where it has been found mainly in glial cells but not in neurons. Therefore, all physiologic roles of brain glycogen have been attributed exclusively to astrocytic glycogen. Working with primary cultured neurons, as well as with genetically modified mice and flies, here we report that—against general belief—neurons contain a low but measurable amount of glycogen. Moreover, we also show that these cells express the brain isoform of glycogen phosphorylase, allowing glycogen to be fully metabolized. Most importantly, we show an active neuronal glycogen metabolism that protects cultured neurons from hypoxia-induced death and flies from hypoxia-induced stupor. Our findings change the current view of the role of glycogen in the brain and reveal that endogenous neuronal glycogen metabolism participates in the neuronal tolerance to hypoxic stress. PMID:24569689

  6. Maturation of Spinal Motor Neurons Derived from Human Embryonic Stem Cells

    Science.gov (United States)

    Takazawa, Tomonori; Croft, Gist F.; Amoroso, Mackenzie W.; Studer, Lorenz; Wichterle, Hynek; MacDermott, Amy B.

    2012-01-01

    Our understanding of motor neuron biology in humans is derived mainly from investigation of human postmortem tissue and more indirectly from live animal models such as rodents. Thus generation of motor neurons from human embryonic stem cells and human induced pluripotent stem cells is an important new approach to model motor neuron function. To be useful models of human motor neuron function, cells generated in vitro should develop mature properties that are the hallmarks of motor neurons in vivo such as elaborated neuronal processes and mature electrophysiological characteristics. Here we have investigated changes in morphological and electrophysiological properties associated with maturation of neurons differentiated from human embryonic stem cells expressing GFP driven by a motor neuron specific reporter (Hb9::GFP) in culture. We observed maturation in cellular morphology seen as more complex neurite outgrowth and increased soma area over time. Electrophysiological changes included decreasing input resistance and increasing action potential firing frequency over 13 days in vitro. Furthermore, these human embryonic stem cell derived motor neurons acquired two physiological characteristics that are thought to underpin motor neuron integrated function in motor circuits; spike frequency adaptation and rebound action potential firing. These findings show that human embryonic stem cell derived motor neurons develop functional characteristics typical of spinal motor neurons in vivo and suggest that they are a relevant and useful platform for studying motor neuron development and function and for modeling motor neuron diseases. PMID:22802953

  7. Direct Reprogramming of Spiral Ganglion Non-neuronal Cells into Neurons: Toward Ameliorating Sensorineural Hearing Loss by Gene Therapy

    Directory of Open Access Journals (Sweden)

    Teppei Noda

    2018-02-01

    Full Text Available Primary auditory neurons (PANs play a critical role in hearing by transmitting sound information from the inner ear to the brain. Their progressive degeneration is associated with excessive noise, disease and aging. The loss of PANs leads to permanent hearing impairment since they are incapable of regenerating. Spiral ganglion non-neuronal cells (SGNNCs, comprised mainly of glia, are resident within the modiolus and continue to survive after PAN loss. These attributes make SGNNCs an excellent target for replacing damaged PANs through cellular reprogramming. We used the neurogenic pioneer transcription factor Ascl1 and the auditory neuron differentiation factor NeuroD1 to reprogram SGNNCs into induced neurons (iNs. The overexpression of both Ascl1 and NeuroD1 in vitro generated iNs at high efficiency. Transcriptome analyses revealed that iNs displayed a transcriptome profile resembling that of endogenous PANs, including expression of several key markers of neuronal identity: Tubb3, Map2, Prph, Snap25, and Prox1. Pathway analyses indicated that essential pathways in neuronal growth and maturation were activated in cells upon neuronal induction. Furthermore, iNs extended projections toward cochlear hair cells and cochlear nucleus neurons when cultured with each respective tissue. Taken together, our study demonstrates that PAN-like neurons can be generated from endogenous SGNNCs. This work suggests that gene therapy can be a viable strategy to treat sensorineural hearing loss caused by degeneration of PANs.

  8. Direct Reprogramming of Spiral Ganglion Non-neuronal Cells into Neurons: Toward Ameliorating Sensorineural Hearing Loss by Gene Therapy.

    Science.gov (United States)

    Noda, Teppei; Meas, Steven J; Nogami, Jumpei; Amemiya, Yutaka; Uchi, Ryutaro; Ohkawa, Yasuyuki; Nishimura, Koji; Dabdoub, Alain

    2018-01-01

    Primary auditory neurons (PANs) play a critical role in hearing by transmitting sound information from the inner ear to the brain. Their progressive degeneration is associated with excessive noise, disease and aging. The loss of PANs leads to permanent hearing impairment since they are incapable of regenerating. Spiral ganglion non-neuronal cells (SGNNCs), comprised mainly of glia, are resident within the modiolus and continue to survive after PAN loss. These attributes make SGNNCs an excellent target for replacing damaged PANs through cellular reprogramming. We used the neurogenic pioneer transcription factor Ascl1 and the auditory neuron differentiation factor NeuroD1 to reprogram SGNNCs into induced neurons (iNs). The overexpression of both Ascl1 and NeuroD1 in vitro generated iNs at high efficiency. Transcriptome analyses revealed that iNs displayed a transcriptome profile resembling that of endogenous PANs, including expression of several key markers of neuronal identity: Tubb3, Map2, Prph, Snap25, and Prox1. Pathway analyses indicated that essential pathways in neuronal growth and maturation were activated in cells upon neuronal induction. Furthermore, iNs extended projections toward cochlear hair cells and cochlear nucleus neurons when cultured with each respective tissue. Taken together, our study demonstrates that PAN-like neurons can be generated from endogenous SGNNCs. This work suggests that gene therapy can be a viable strategy to treat sensorineural hearing loss caused by degeneration of PANs.

  9. Physiological characterisation of human iPS-derived dopaminergic neurons.

    Directory of Open Access Journals (Sweden)

    Elizabeth M Hartfield

    Full Text Available Human induced pluripotent stem cells (hiPSCs offer the potential to study otherwise inaccessible cell types. Critical to this is the directed differentiation of hiPSCs into functional cell lineages. This is of particular relevance to research into neurological disease, such as Parkinson's disease (PD, in which midbrain dopaminergic neurons degenerate during disease progression but are unobtainable until post-mortem. Here we report a detailed study into the physiological maturation over time of human dopaminergic neurons in vitro. We first generated and differentiated hiPSC lines into midbrain dopaminergic neurons and performed a comprehensive characterisation to confirm dopaminergic functionality by demonstrating dopamine synthesis, release, and re-uptake. The neuronal cultures include cells positive for both tyrosine hydroxylase (TH and G protein-activated inward rectifier potassium channel 2 (Kir3.2, henceforth referred to as GIRK2, representative of the A9 population of substantia nigra pars compacta (SNc neurons vulnerable in PD. We observed for the first time the maturation of the slow autonomous pace-making (<10 Hz and spontaneous synaptic activity typical of mature SNc dopaminergic neurons using a combination of calcium imaging and electrophysiology. hiPSC-derived neurons exhibited inositol tri-phosphate (IP3 receptor-dependent release of intracellular calcium from the endoplasmic reticulum in neuronal processes as calcium waves propagating from apical and distal dendrites, and in the soma. Finally, neurons were susceptible to the dopamine neuron-specific toxin 1-methyl-4-phenylpyridinium (MPP+ which reduced mitochondrial membrane potential and altered mitochondrial morphology. Mature hiPSC-derived dopaminergic neurons provide a neurophysiologically-defined model of previously inaccessible vulnerable SNc dopaminergic neurons to bridge the gap between clinical PD and animal models.

  10. Therapeutic potential of mesenchymal stromal cells and MSC conditioned medium in Amyotrophic Lateral Sclerosis (ALS--in vitro evidence from primary motor neuron cultures, NSC-34 cells, astrocytes and microglia.

    Directory of Open Access Journals (Sweden)

    Hui Sun

    Full Text Available Administration of mesenchymal stromal cells (MSC improves functional outcome in the SOD1G93A mouse model of the degenerative motor neuron disorder amyotrophic lateral sclerosis (ALS as well as in models of other neurological disorders. We have now investigated the effect of the interaction between MSC and motor neurons (derived from both non-transgenic and mutant SOD1G93A transgenic mice, NSC-34 cells and glial cells (astrocytes, microglia (derived again from both non-transgenic and mutant SOD1G93A ALS transgenic mice in vitro. In primary motor neurons, NSC-34 cells and astrocytes, MSC conditioned medium (MSC CM attenuated staurosporine (STS - induced apoptosis in a concentration-dependent manner. Studying MSC CM-induced expression of neurotrophic factors in astrocytes and NSC-34 cells, we found that glial cell line-derived neurotrophic factor (GDNF and ciliary neurotrophic factor (CNTF gene expression in astrocytes were significantly enhanced by MSC CM, with differential responses of non-transgenic and mutant astrocytes. Expression of Vascular Endothelial Growth Factor (VEGF in NSC-34 cells was significantly upregulated upon MSC CM-treatment. MSC CM significantly reduced the expression of the cytokines TNFα and IL-6 and iNOS both in transgenic and non-transgenic astrocytes. Gene expression of the neuroprotective chemokine Fractalkine (CX3CL1 was also upregulated in mutant SOD1G93A transgenic astrocytes by MSC CM treatment. Correspondingly, MSC CM increased the respective receptor, CX3CR1, in mutant SOD1G93A transgenic microglia. Our data demonstrate that MSC modulate motor neuronal and glial response to apoptosis and inflammation. MSC therefore represent an interesting candidate for further preclinical and clinical evaluation in ALS.

  11. Neuron-glia interactions in glutamatergic neurotransmission

    DEFF Research Database (Denmark)

    Schousboe, A; Sickmann, H M; Bak, Lasse Kristoffer

    2011-01-01

    Glutamatergic neurotransmission accounts for a considerable part of energy consumption related to signaling in the brain. Chemical energy is provided by adenosine triphosphate (ATP) formed in glycolysis and tricarboxylic acid (TCA) cycle combined with oxidative phosphorylation. It is not clear...... theses processes also has not been fully elucidated. Cultured astrocytes and neurons were utilized to monitor these processes related to glutamatergic neurotransmission. Inhibitors of glycolysis and TCA cycle in combination with pathway-selective substrates were used to study glutamate uptake and release...

  12. The Edible Red Alga Porphyra yezoensis Promotes Neuronal Survival and Cytoarchitecture in Primary Hippocampal Neurons.

    Science.gov (United States)

    Mohibbullah, Md; Bhuiyan, Mohammad Maqueshudul Haque; Hannan, Md Abdul; Getachew, Paulos; Hong, Yong-Ki; Choi, Jae-Suk; Choi, In Soon; Moon, Il Soo

    2016-07-01

    The edible red alga Porphyra yezoensis is among the most popular marine algae and is of economic and medicinal importance. In the present study, the neurotrophic and neuroprotective activities of the ethanol extract of P. yezoensis (PYE) were investigated in primary cultures of hippocampal neurons. Results revealed that PYE significantly increased neurite outgrowth at an optimal concentration of 15 µg/mL. PYE dose-dependently increased viable cells, significantly accelerated the rate of neuronal differentiation in cultures, promoted axodendritic arborization, and eventually induced synaptogenesis. In addition to morphological development, PYE also promoted functional maturation as indicated by the staining of live cultures with FM 1-43. Moreover, PYE increased neuronal survivability, which was attributed to reduced apoptosis and its ROS scavenging activity. Taurine, a major organic acid in PYE (2.584/100 mg of dry PYE) promoted neurite outgrowth in a dose-dependent manner, and this promotion was suppressed by the taurine antagonist isethionic acid. The study indicates that PYE and its active component, taurine, facilitate neuronal development and maturation and have a neuroprotective effect.

  13. Progranulin is expressed within motor neurons and promotes neuronal cell survival

    Directory of Open Access Journals (Sweden)

    Kay Denis G

    2009-10-01

    Full Text Available Abstract Background Progranulin is a secreted high molecular weight growth factor bearing seven and one half copies of the cysteine-rich granulin-epithelin motif. While inappropriate over-expression of the progranulin gene has been associated with many cancers, haploinsufficiency leads to atrophy of the frontotemporal lobes and development of a form of dementia (frontotemporal lobar degeneration with ubiquitin positive inclusions, FTLD-U associated with the formation of ubiquitinated inclusions. Recent reports indicate that progranulin has neurotrophic effects, which, if confirmed would make progranulin the only neuroprotective growth factor that has been associated genetically with a neurological disease in humans. Preliminary studies indicated high progranulin gene expression in spinal cord motor neurons. However, it is uncertain what the role of Progranulin is in normal or diseased motor neuron function. We have investigated progranulin gene expression and subcellular localization in cultured mouse embryonic motor neurons and examined the effect of progranulin over-expression and knockdown in the NSC-34 immortalized motor neuron cell line upon proliferation and survival. Results In situ hybridisation and immunohistochemical techniques revealed that the progranulin gene is highly expressed by motor neurons within the mouse spinal cord and in primary cultures of dissociated mouse embryonic spinal cord-dorsal root ganglia. Confocal microscopy coupled to immunocytochemistry together with the use of a progranulin-green fluorescent protein fusion construct revealed progranulin to be located within compartments of the secretory pathway including the Golgi apparatus. Stable transfection of the human progranulin gene into the NSC-34 motor neuron cell line stimulates the appearance of dendritic structures and provides sufficient trophic stimulus to survive serum deprivation for long periods (up to two months. This is mediated at least in part through

  14. Neuronal avalanches and learning

    Energy Technology Data Exchange (ETDEWEB)

    Arcangelis, Lucilla de, E-mail: dearcangelis@na.infn.it [Department of Information Engineering and CNISM, Second University of Naples, 81031 Aversa (Italy)

    2011-05-01

    Networks of living neurons represent one of the most fascinating systems of biology. If the physical and chemical mechanisms at the basis of the functioning of a single neuron are quite well understood, the collective behaviour of a system of many neurons is an extremely intriguing subject. Crucial ingredient of this complex behaviour is the plasticity property of the network, namely the capacity to adapt and evolve depending on the level of activity. This plastic ability is believed, nowadays, to be at the basis of learning and memory in real brains. Spontaneous neuronal activity has recently shown features in common to other complex systems. Experimental data have, in fact, shown that electrical information propagates in a cortex slice via an avalanche mode. These avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of complex systems and successful models have been developed to describe their behaviour. In this contribution we discuss a statistical mechanical model for the complex activity in a neuronal network. The model implements the main physiological properties of living neurons and is able to reproduce recent experimental results. Then, we discuss the learning abilities of this neuronal network. Learning occurs via plastic adaptation of synaptic strengths by a non-uniform negative feedback mechanism. The system is able to learn all the tested rules, in particular the exclusive OR (XOR) and a random rule with three inputs. The learning dynamics exhibits universal features as function of the strength of plastic adaptation. Any rule could be learned provided that the plastic adaptation is sufficiently slow.

  15. Reelin secreted by GABAergic neurons regulates glutamate receptor homeostasis.

    Directory of Open Access Journals (Sweden)

    Cecilia Gonzalez Campo

    Full Text Available BACKGROUND: Reelin is a large secreted protein of the extracellular matrix that has been proposed to participate to the etiology of schizophrenia. During development, reelin is crucial for the correct cytoarchitecture of laminated brain structures and is produced by a subset of neurons named Cajal-Retzius. After birth, most of these cells degenerate and reelin expression persists in postnatal and adult brain. The phenotype of neurons that bind secreted reelin and whether the continuous secretion of reelin is required for physiological functions at postnatal stages remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Combining immunocytochemical and pharmacological approaches, we first report that two distinct patterns of reelin expression are present in cultured hippocampal neurons. We show that in hippocampal cultures, reelin is secreted by GABAergic neurons displaying an intense reelin immunoreactivity (IR. We demonstrate that secreted reelin binds to receptors of the lipoprotein family on neurons with a punctate reelin IR. Secondly, using calcium imaging techniques, we examined the physiological consequences of reelin secretion blockade. Blocking protein secretion rapidly and reversibly changes the subunit composition of N-methyl-D-aspartate glutamate receptors (NMDARs to a predominance of NR2B-containing NMDARs. Addition of recombinant or endogenously secreted reelin rescues the effects of protein secretion blockade and reverts the fraction of NR2B-containing NMDARs to control levels. Therefore, the continuous secretion of reelin is necessary to control the subunit composition of NMDARs in hippocampal neurons. CONCLUSIONS/SIGNIFICANCE: Our data show that the heterogeneity of reelin immunoreactivity correlates with distinct functional populations: neurons synthesizing and secreting reelin and/or neurons binding reelin. Furthermore, we show that continuous reelin secretion is a strict requirement to maintain the composition of NMDARs. We propose

  16. Reactive astrocytes secrete lcn2 to promote neuron death

    Science.gov (United States)

    Bi, Fangfang; Huang, Cao; Tong, Jianbin; Qiu, Guang; Huang, Bo; Wu, Qinxue; Li, Fang; Xu, Zuoshang; Bowser, Robert; Xia, Xu-Gang; Zhou, Hongxia

    2013-01-01

    Glial reaction is a common feature of neurodegenerative diseases. Recent studies have suggested that reactive astrocytes gain neurotoxic properties, but exactly how reactive astrocytes contribute to neurotoxicity remains to be determined. Here, we identify lipocalin 2 (lcn2) as an inducible factor that is secreted by reactive astrocytes and that is selectively toxic to neurons. We show that lcn2 is induced in reactive astrocytes in transgenic rats with neuronal expression of mutant human TAR DNA-binding protein 43 (TDP-43) or RNA-binding protein fused in sarcoma (FUS). Therefore, lcn2 is induced in activated astrocytes in response to neurodegeneration, but its induction is independent of TDP-43 or FUS expression in astrocytes. We found that synthetic lcn2 is cytotoxic to primary neurons in a dose-dependent manner, but is innocuous to astrocytes, microglia, and oligodendrocytes. Lcn2 toxicity is increased in neurons that express a disease gene, such as mutant FUS or TDP-43. Conditioned medium from rat brain slice cultures with neuronal expression of mutant TDP-43 contains abundant lcn2 and is toxic to primary neurons as well as neurons in cultured brain slice from WT rats. Partial depletion of lcn2 by immunoprecipitation reduced conditioned medium-mediated neurotoxicity. Our data indicate that reactive astrocytes secrete lcn2, which is a potent neurotoxic mediator. PMID:23431168

  17. Activation of nuclear factor-kappa B via endogenous tumor necrosis factor alpha regulates survival of axotomized adult sensory neurons

    NARCIS (Netherlands)

    Fernyhough, P; Smith, DR; Schapansky, J; Van Der Ploeg, R; Gardiner, NJ; Tweed, CW; Kontos, A; Freeman, L; Purves-Tyson, TD; Glazner, GW

    2005-01-01

    Embryonic dorsal root ganglion (DRG) neurons die after axonal damage in vivo, and cultured embryonic DRG neurons require exogenous neurotrophic factors that activate the neuroprotective transcription factor nuclear factor-kappaB(NF-kappaB) for survival. In contrast, adult DRG neurons survive

  18. Vasoactive intestinal peptide and electrical activity influence neuronal survival

    International Nuclear Information System (INIS)

    Brenneman, D.E.; Eiden, L.E.

    1986-01-01

    Blockage of electrical activity in dissociated spinal cord cultures results in a significant loss of neurons during a critical period in development. Decreases in neuronal cell numbers and 125 I-labeled tetanus toxin fixation produced by electrical blockage with tetrodotoxin (TTX) were prevented by addition of vasoactive intestinal peptide (VIP) to the nutrient medium. The most effective concentration of VIP was 0.1 nM. At higher concentrations, the survival-enhancing effect of VIP on TTX-treated cultures was attenuated. Addition of the peptide alone had no significant effect on neuronal cell counts or tetanus toxin fixation. With the same experimental conditions, two closely related peptides, PHI-27 (peptide, histidyl-isoleucine amide) and secretin, were found not to increase the number of neurons in TTX-treated cultures. Interference with VIP action by VIP antiserum resulted in neuronal losses that were not significantly different from those observed after TTX treatment. These data indicate that under conditions of electrical blockade a neurotrophic action of VIP on neuronal survival can be demonstrated

  19. Dipeptide Piracetam Analogue Noopept Improves Viability of Hippocampal HT-22 Neurons in the Glutamate Toxicity Model.

    Science.gov (United States)

    Antipova, T A; Nikolaev, S V; Ostrovskaya, P U; Gudasheva, T A; Seredenin, S B

    2016-05-01

    Effect of noopept (N-phenylacetyl-prolylglycine ethyl ester) on viability of neurons exposed to neurotoxic action of glutamic acid (5 mM) was studied in vitro in immortalized mouse hippocampal HT-22 neurons. Noopept added to the medium before or after glutamic acid improved neuronal survival in a concentration range of 10-11-10-5 M. Comparison of the effective noopept concentrations determined in previous studies on cultured cortical and cerebellar neurons showed that hippocampal neurons are more sensitive to the protective effect of noopept.

  20. Kappe neurons, a novel population of olfactory sensory neurons.

    Science.gov (United States)

    Ahuja, Gaurav; Bozorg Nia, Shahrzad; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I

    2014-02-10

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons are identified by their Go-like immunoreactivity, and show a distinct spatial distribution within the olfactory epithelium, similar to, but significantly different from that of crypt neurons. Furthermore, kappe neurons project to a single identified target glomerulus within the olfactory bulb, mdg5 of the mediodorsal cluster, whereas crypt neurons are known to project exclusively to the mdg2 glomerulus. Kappe neurons are negative for established markers of ciliated, microvillous and crypt neurons, but appear to have microvilli. Kappe neurons constitute the fourth type of olfactory sensory neurons reported in teleost fishes and their existence suggests that encoding of olfactory stimuli may require a higher complexity than hitherto assumed already in the peripheral olfactory system.

  1. Stochastic neuron models

    CERN Document Server

    Greenwood, Priscilla E

    2016-01-01

    This book describes a large number of open problems in the theory of stochastic neural systems, with the aim of enticing probabilists to work on them. This includes problems arising from stochastic models of individual neurons as well as those arising from stochastic models of the activities of small and large networks of interconnected neurons. The necessary neuroscience background to these problems is outlined within the text, so readers can grasp the context in which they arise. This book will be useful for graduate students and instructors providing material and references for applying probability to stochastic neuron modeling. Methods and results are presented, but the emphasis is on questions where additional stochastic analysis may contribute neuroscience insight. An extensive bibliography is included. Dr. Priscilla E. Greenwood is a Professor Emerita in the Department of Mathematics at the University of British Columbia. Dr. Lawrence M. Ward is a Professor in the Department of Psychology and the Brain...

  2. Management of synchronized network activity by highly active neurons

    International Nuclear Information System (INIS)

    Shein, Mark; Raichman, Nadav; Ben-Jacob, Eshel; Volman, Vladislav; Hanein, Yael

    2008-01-01

    Increasing evidence supports the idea that spontaneous brain activity may have an important functional role. Cultured neuronal networks provide a suitable model system to search for the mechanisms by which neuronal spontaneous activity is maintained and regulated. This activity is marked by synchronized bursting events (SBEs)—short time windows (hundreds of milliseconds) of rapid neuronal firing separated by long quiescent periods (seconds). However, there exists a special subset of rapidly firing neurons whose activity also persists between SBEs. It has been proposed that these highly active (HA) neurons play an important role in the management (i.e. establishment, maintenance and regulation) of the synchronized network activity. Here, we studied the dynamical properties and the functional role of HA neurons in homogeneous and engineered networks, during early network development, upon recovery from chemical inhibition and in response to electrical stimulations. We found that their sequences of inter-spike intervals (ISI) exhibit long time correlations and a unimodal distribution. During the network's development and under intense inhibition, the observed activity follows a transition period during which mostly HA neurons are active. Studying networks with engineered geometry, we found that HA neurons are precursors (the first to fire) of the spontaneous SBEs and are more responsive to electrical stimulations

  3. Review Essay: Mirror Neurons in the Discourse of Social Sciences

    Directory of Open Access Journals (Sweden)

    Henning Pätzold

    2010-08-01

    Full Text Available Since their discovery in the mid-1990s, mirror neurons have been the subject of continuous discussions in neurosciences as well as in the social sciences. The interest of scientists outside the life sciences in mirror neurons is primarily based on the fact that mirror neurons not only have epistemological meaning, but also seem to play an important role in processes of social insights and emotions, like empathy. With her book, Nadia ZABOURA provides a new contribution from a social and cultural sciences point of view, which critically reflects the discussion on mirror neurons and its consequences on the social sciences and humanities. Starting off from philosophical approaches to the mind-matter-dualism and the question of intersubjectivity, she explores the meaning of mirror neurons for the debate on empathy and communication. By discussing concepts of philosophy and communication sciences as well as current knowledge on mirror neurons, she concludes that they do not provide a stable basis for any material reductionism, which would explain phenomena like intersubjectivity only by recordable neuronal processes. The book refers to a variety of related theories (ranging from DESCARTES through to MEAD and TOMASELLO; these references are inspiring, yet they stay cursory for the most part. All in all the book offers avenues for further inquiry on the issues in focus, and can rather be taken as "tour of suggestions" through the topical field of mirror neurons and the related research. URN: urn:nbn:de:0114-fqs1003245

  4. Textural guidance cues for controlling process outgrowth of mammalian neurons.

    Science.gov (United States)

    Hanson, Jennifer N; Motala, Michael J; Heien, Michael L; Gillette, Martha; Sweedler, Jonathan; Nuzzo, Ralph G

    2009-01-07

    We explore textural cues as a mechanism for controlling neuronal process outgrowth in primary cultures of mammalian neurons. The work uses a form of decal transfer lithography to generate arrays of PDMS posts of various dimensions and spacings on glass substrates that are rendered growth-compliant by subsequent treatment with a protein activator. Hippocampal neurons plated on these substrates are used to determine how the posts direct process growth by acting as attachment points or guidance cues. Textural features varying over a large range, even as large as 100 microm in diameter, dramatically affect process growth. Indeed, two growth regimes are observed; at the smaller feature sizes considered, process branching strongly aligns (at right angles) along the post mesh, while neuronal outgrowth on the larger feature sizes elicits process wrapping. The latter behavior most strongly manifests in neurons plated initially at approximately 100 cells/mm(2), where the cells were able to form networks, while for isolated neurons, the cells exhibit poorer viability and development. Bag cell neurons from Aplysia californica also display regular growth patterns, but in this case are guided by contact avoidance of the posts, a behavior qualitatively different than that of the hippocampal neurons.

  5. NEUROD1 Instructs Neuronal Conversion in Non-Reactive Astrocytes.

    Science.gov (United States)

    Brulet, Rebecca; Matsuda, Taito; Zhang, Ling; Miranda, Carlos; Giacca, Mauro; Kaspar, Brian K; Nakashima, Kinichi; Hsieh, Jenny

    2017-06-06

    Currently, all methods for converting non-neuronal cells into neurons involve injury to the brain; however, whether neuronal transdifferentiation can occur long after the period of insult remains largely unknown. Here, we use the transcription factor NEUROD1, previously shown to convert reactive glial cells to neurons in the cortex, to determine whether astrocyte-to-neuron transdifferentiation can occur under physiological conditions. We utilized adeno-associated virus 9 (AAV9), which crosses the blood-brain barrier without injury, to deliver NEUROD1 to astrocytes through an intravascular route. Interestingly, we found that a small, but significant number of non-reactive astrocytes converted to neurons in the striatum, but not the cortex. Moreover, astrocytes cultured to minimize their proliferative potential also exhibited limited neuronal transdifferentiation with NEUROD1 expression. Our results show that a single transcription factor can induce astrocyte-to-neuron conversion under physiological conditions, potentially facilitating future clinical approaches long after the acute injury phase. Published by Elsevier Inc.

  6. Comparative Neuronal Differentiation of Self-Renewing Neural Progenitor Cell Lines Obtained from Human Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Chiara eVerpelli

    2013-10-01

    Full Text Available Most human neuronal disorders are associated with genetic alterations that cause defects in neuronal development and induce precocious neurodegeneration. In order to fully characterize the molecular mechanisms underlying the onset of these devastating diseases, it is important to establish in vitro models able to recapitulate the human pathology as closely as possible. Here we compared three different differentiation protocols for obtaining functional neurons from human induced pluripotent stem cells (hiPSCs: human neural progenitors (hNPs obtained from hiPSCs were differentiated by co-culturing them with rat primary neurons, glial cells or simply by culturing them on matrigel in neuronal differentiation medium, and the differentiation level was compared using immunofluorescence, biochemical and electrophysiological methods.We show that the differentiated neurons displayed distinct maturation properties depending on the protocol used and the faster morphological and functional maturation was obtained when hNPs were co-cultured with rat primary neurons.

  7. Robot-Embodied Neuronal Networks as an Interactive Model of Learning.

    Science.gov (United States)

    Shultz, Abraham M; Lee, Sangmook; Guaraldi, Mary; Shea, Thomas B; Yanco, Holly C

    2017-01-01

    The reductionist approach of neuronal cell culture has been useful for analyses of synaptic signaling. Murine cortical neurons in culture spontaneously form an ex vivo network capable of transmitting complex signals, and have been useful for analyses of several fundamental aspects of neuronal development hitherto difficult to clarify in situ . However, these networks lack the ability to receive and respond to sensory input from the environment as do neurons in vivo . Establishment of these networks in culture chambers containing multi-electrode arrays allows recording of synaptic activity as well as stimulation. This article describes the embodiment of ex vivo neuronal networks neurons in a closed-loop cybernetic system, consisting of digitized video signals as sensory input and a robot arm as motor output. In this system, the neuronal network essentially functions as a simple central nervous system. This embodied network displays the ability to track a target in a naturalistic environment. These findings underscore that ex vivo neuronal networks can respond to sensory input and direct motor output. These analyses may contribute to optimization of neuronal-computer interfaces for perceptive and locomotive prosthetic applications. Ex vivo networks display critical alterations in signal patterns following treatment with subcytotoxic concentrations of amyloid-beta. Future studies including comparison of tracking accuracy of embodied networks prepared from mice harboring key mutations with those from normal mice, accompanied with exposure to Abeta and/or other neurotoxins, may provide a useful model system for monitoring subtle impairment of neuronal function as well as normal and abnormal development.

  8. Brucella abortus-activated microglia induce neuronal death through primary phagocytosis.

    Science.gov (United States)

    Rodríguez, Ana M; Delpino, M Victoria; Miraglia, M Cruz; Costa Franco, Miriam M; Barrionuevo, Paula; Dennis, Vida A; Oliveira, Sergio C; Giambartolomei, Guillermo H

    2017-07-01

    Inflammation has long been implicated as a contributor to pathogenesis in neurobrucellosis. Many of the associated neurocognitive symptoms of neurobrucellosis may be the result of neuronal dysfunction resulting from the inflammatory response induced by Brucella abortus infection in the central nervous system. In this manuscript, we describe an immune mechanism for inflammatory activation of microglia that leads to neuronal death upon B. abortus infection. B. abortus was unable to infect or harm primary cultures of mouse neurons. However, when neurons were co-cultured with microglia and infected with B. abortus significant neuronal loss occurred. This phenomenon was dependent on TLR2 activation by Brucella lipoproteins. Neuronal death was not due to apoptosis, but it was dependent on the microglial release of nitric oxide (NO). B. abortus infection stimulated microglial proliferation, phagocytic activity and engulfment of neurons. NO secreted by B. abortus-activated microglia induced neuronal exposure of the "eat-me" signal phosphatidylserine (PS). Blocking of PS-binding to protein milk fat globule epidermal growth factor-8 (MFG-E8) or microglial vitronectin receptor-MFG-E8 interaction was sufficient to prevent neuronal loss by inhibiting microglial phagocytosis without affecting their activation. Taken together, our results indicate that B. abortus is not directly toxic to neurons; rather, these cells become distressed and are killed by phagocytosis in the inflammatory surroundings generated by infected microglia. Neuronal loss induced by B. abortus-activated microglia may explain, in part, the neurological deficits observed during neurobrucellosis. © 2017 Wiley Periodicals, Inc.

  9. Characterization of astrocytic and neuronal benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Bender, A.S.

    1988-01-01

    Primary cultures of astrocytes and neurons express benzodiazepine receptors. Neuronal benzodiazepine receptors were of high-affinity, K{sub D} values were 7.5-43 nM and the densities of receptors (B{sub max}) were 924-4131 fmol/mg protein. Astrocytes posses a high-affinity benzodiazepine receptor, K{sub D} values were 6.6-13 nM. The B{sub max} values were 6,033-12,000 fmol/mg protein. The pharmacological profile of the neuronal benzodiazepine receptor was that of the central-type benzodiazepine receptor, where clonazepam has a high-affinity and Ro 5-4864 (4{prime}-chlorodiazepam) has a low-affinity. Whereas astrocytic benzoidazepine receptor was characteristic of the so called peripheral-type benzodiazepine receptors, which shows a high-affinity towards Ro 5-4863, and a low-affinity towards clonazepam. The astrocytic benzodiazepine receptors was functionally correlated with voltage dependent calcium channels, since dihydropyridines and benzodiazepines interacted with ({sup 3}H) diazepam and ({sup 3}H) nitrendipine receptors with the same rank order of potency, showing a statistically significant correlation. No such correlation was observed in neurons.

  10. Morphine decreases enteric neuron excitability via inhibition of sodium channels.

    Directory of Open Access Journals (Sweden)

    Tricia H Smith

    Full Text Available Gastrointestinal peristalsis is significantly dependent on the enteric nervous system. Constipation due to reduced peristalsis is a major side-effect of morphine, which limits the chronic usefulness of this excellent pain reliever in man. The ionic basis for the inhibition of enteric neuron excitability by morphine is not well characterized as previous studies have mainly utilized microelectrode recordings from whole mount myenteric plexus preparations in guinea pigs. Here we have developed a Swiss-Webster mouse myenteric neuron culture and examined their electrophysiological properties by patch-clamp techniques and determined the mechanism for morphine-induced decrease in neuronal excitability. Isolated neurons in culture were confirmed by immunostaining with pan-neuronal marker, β-III tubulin and two populations were identified by calbindin and calretinin staining. Distinct neuronal populations were further identified based on the presence and absence of an afterhyperpolarization (AHP. Cells with AHP expressed greater density of sodium currents. Morphine (3 µM significantly reduced the amplitude of the action potential, increased the threshold for spike generation but did not alter the resting membrane potential. The decrease in excitability resulted from inhibition of sodium currents. In the presence of morphine, the steady-state voltage dependence of Na channels was shifted to the left with almost 50% of channels unavailable for activation from hyperpolarized potentials. During prolonged exposure to morphine (two hours, action potentials recovered, indicative of the development of tolerance in single enteric neurons. These results demonstrate the feasibility of isolating mouse myenteric neurons and establish sodium channel inhibition as a mechanism for morphine-induced decrease in neuronal excitability.

  11. Quinolinic acid induces disrupts cytoskeletal homeostasis in striatal neurons. Protective role of astrocyte-neuron interaction.

    Science.gov (United States)

    Pierozan, Paula; Ferreira, Fernanda; de Lima, Bárbara Ortiz; Pessoa-Pureur, Regina

    2015-02-01

    Quinolinic acid (QUIN) is an endogenous metabolite of the kynurenine pathway involved in several neurological disorders. Among the several mechanisms involved in QUIN-mediated toxicity, disruption of the cytoskeleton has been demonstrated in striatally injected rats and in striatal slices. The present work searched for the actions of QUIN in primary striatal neurons. Neurons exposed to 10 µM QUIN presented hyperphosphorylated neurofilament (NF) subunits (NFL, NFM, and NFH). Hyperphosphorylation was abrogated in the presence of protein kinase A and protein kinase C inhibitors H89 (20 μM) and staurosporine (10 nM), respectively, as well as by specific antagonists to N-methyl-D-aspartate (50 µM DL-AP5) and metabotropic glutamate receptor 1 (100 µM MPEP). Also, intra- and extracellular Ca(2+) chelators (10 µM BAPTA-AM and 1 mM EGTA, respectively) and Ca(2+) influx through L-type voltage-dependent Ca(2+) channel (10 µM verapamil) are implicated in QUIN-mediated effects. Cells immunostained for the neuronal markers βIII-tubulin and microtubule-associated protein 2 showed altered neurite/neuron ratios and neurite outgrowth. NF hyperphosphorylation and morphological alterations were totally prevented by conditioned medium from QUIN-treated astrocytes. Cocultured astrocytes and neurons interacted with one another reciprocally, protecting them against QUIN injury. Cocultured cells preserved their cytoskeletal organization and cell morphology together with unaltered activity of the phosphorylating system associated with the cytoskeleton. This article describes cytoskeletal disruption as one of the most relevant actions of QUIN toxicity in striatal neurons in culture with soluble factors secreted by astrocytes, with neuron-astrocyte interaction playing a role in neuroprotection. © 2014 Wiley Periodicals, Inc.

  12. Somatodendritic and excitatory postsynaptic distribution of neuron-type dystrophin isoform, Dp40, in hippocampal neurons.

    Science.gov (United States)

    Fujimoto, Takahiro; Itoh, Kyoko; Yaoi, Takeshi; Fushiki, Shinji

    2014-09-12

    The Duchenne muscular dystrophy (DMD) gene produces multiple dystrophin (Dp) products due to the presence of several promoters. We previously reported the existence of a novel short isoform of Dp, Dp40, in adult mouse brain. However, the exact biochemical expression profile and cytological distribution of the Dp40 protein remain unknown. In this study, we generated a polyclonal antibody against the NH2-terminal region of the Dp40 and identified the expression profile of Dp40 in the mouse brain. Through an analysis using embryonic and postnatal mouse cerebrums, we found that Dp40 emerged from the early neonatal stages until adulthood, whereas Dp71, an another Dp short isoform, was highly detected in both prenatal and postnatal cerebrums. Intriguingly, relative expressions of Dp40 and Dp71 were prominent in cultured dissociated neurons and non-neuronal cells derived from mouse hippocampus, respectively. Furthermore, the immunocytological distribution of Dp40 was analyzed in dissociated cultured neurons, revealing that Dp40 is detected in the soma and its dendrites, but not in the axon. It is worthy to note that Dp40 is localized along the subplasmalemmal region of the dendritic shafts, as well as at excitatory postsynaptic sites. Thus, Dp40 was identified as a neuron-type Dp possibly involving dendritic and synaptic functions. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. ULTRASTRUCTURAL CHANGES OF THE NEURONAL ...

    African Journals Online (AJOL)

    ULTRASTRUCTURAL CHANGES OF THE NEURONAL COMPONENT IN THE DETRUSOR MUSCLE FOLLOWING SACRAL ROOT STIMULATION OF DECENTRALIZED ... Early sacral root electric stimulation decreased the incidence of neuronal degeneration in decentralized detrusor muscle, together with improving the ...

  14. An In-vitro Preparation of Isolated Enteric Neurons and Glia from the Myenteric Plexus of the Adult Mouse

    OpenAIRE

    Smith, Tricia H.; Ngwainmbi, Joy; Grider, John R.; Dewey, William L.; Akbarali, Hamid I.

    2013-01-01

    The enteric nervous system is a vast network of neurons and glia running the length of the gastrointestinal tract that functionally controls gastrointestinal motility. A procedure for the isolation and culture of a mixed population of neurons and glia from the myenteric plexus is described. The primary cultures can be maintained for over 7 days, with connections developing among the neurons and glia. The longitudinal muscle strip with the attached myenteric plexus is stripped from the underly...

  15. Neuronal survival in the brain: neuron type-specific mechanisms

    DEFF Research Database (Denmark)

    Pfisterer, Ulrich Gottfried; Khodosevich, Konstantin

    2017-01-01

    Neurogenic regions of mammalian brain produce many more neurons that will eventually survive and reach a mature stage. Developmental cell death affects both embryonically produced immature neurons and those immature neurons that are generated in regions of adult neurogenesis. Removal of substantial...... for survival in a certain brain region. This review focuses on how immature neurons survive during normal and impaired brain development, both in the embryonic/neonatal brain and in brain regions associated with adult neurogenesis, and emphasizes neuron type-specific mechanisms that help to survive for various...

  16. Neuronal substrate of eating disorders

    OpenAIRE

    Timofeeva, Elena; Calvez, Juliane

    2014-01-01

    Eating disorders are devastating and life-threatening psychiatric diseases. Although clinical and experimental investigations have significantly progressed in discovering the neuronal causes of eating disorders, the exact neuronal and molecular mechanisms of the development and maintenance of these pathologies are not fully understood. The complexity of the neuronal substrate of eating disorders hampers progress in revealing the precise mechanisms. The present re...

  17. Motor neuron disease in blacks

    African Journals Online (AJOL)

    1989-08-19

    Aug 19, 1989 ... We reported earlier that motor neuron disease occurs more commonly among blacks than Parkinson's disease, which is relatively rare in this race group.! The hypothesis that these conditions, and other neuronal abiotrophies, are the result of previous subclinical neuronal insult and subsequent age-related.

  18. Neuroprotective and Neurorescue Effects of a Novel Polymeric Nanoparticle Formulation of Curcumin (NanoCurc™) in the Neuronal Cell Culture and Animal Model: Implications for Alzheimer’s Disease

    Science.gov (United States)

    Ray, Balmiki; Bisht, Savita; Maitra, Amarnath; Maitra, Anirban; Lahiri, Debomoy K.

    2012-01-01

    Alzheimer’s disease (AD) is characterized by deposition of amyloid-β (Aβ) plaques within the brain parenchyma followed by synaptic loss and neuronal death. Deposited Aβ reacts with activated microglia to produce reactive oxygen species (ROS) and cytochemokines, which lead to severe neuroinflammation. Curcumin is a yellow polyphenol compound found in turmeric, a widely used culinary ingredient that possesses anti-inflammatory and anti-cancer properties and may show efficacy as a potential therapeutic agent in several neuro-inflammatory diseases including AD. However, poor aqueous solubility and sub-optimal systemic absorption from the gastrointestinal tract may represent factors contributing to its failure in clinical trials. To increase curcumin’s bioavailability, a polymeric nanoparticle encapsulated curcumin (NanoCurc™) was formulated which is completely water soluble. NanoCurc™ treatment protects neuronally differentiated human SK-N-SH cells from ROS (H2O2) mediated insults. NanoCurc™ also rescues differentiated human SK-N-SH cells, which were previously insulted with H2O2. In vivo, intraperitoneal (IP) NanoCurc™ injection at a dose of 25 mg/kg twice daily in athymic mice resulted in significant curcumin levels in the brain (0.32 μg/g). Biochemical study of NanoCurc™-treated athymic mice revealed decreased levels of H2O2 as well as caspase 3 and caspase 7 activities in the brain, accompanied by increased glutathione (GSH) concentrations. Increased free to oxidized glutathione (GSH : GSSH) ratio in athymic mice brain versus controls also indicated a favorable redox intracellular environment. Taken together, these results suggest that NanoCurc™ represents an optimized formulation worthy of assessing the therapeutic value of curcumin in AD. PMID:20930270

  19. CNF1 Improves Astrocytic Ability to Support Neuronal Growth and Differentiation In vitro

    OpenAIRE

    Malchiodi-Albedi, Fiorella; Paradisi, Silvia; Di Nottia, Michela; Simone, Daiana; Travaglione, Sara; Falzano, Loredana; Guidotti, Marco; Frank, Claudio; Cutarelli, Alessandro; Fabbri, Alessia; Fiorentini, Carla

    2012-01-01

    Modulation of cerebral Rho GTPases activity in mice brain by intracerebral administration of Cytotoxic Necrotizing Factor 1 (CNF1) leads to enhanced neurotransmission and synaptic plasticity and improves learning and memory. To gain more insight into the interactions between CNF1 and neuronal cells, we used primary neuronal and astrocytic cultures from rat embryonic brain to study CNF1 effects on neuronal differentiation, focusing on dendritic tree growth and synapse formation, which are stri...

  20. Co-culture with bone marrow stromal cells protects PC12 neuronal cells from tumor necrosis factor-α-induced apoptosis by inhibiting the tumor necrosis factor receptor/caspase signaling pathway.

    Science.gov (United States)

    Li, Li; Wang, Jing; Tang, Ling; Yu, Xin; Sui, Yi; Zhang, Chaodong

    2015-07-01

    Bone marrow stromal cells (BMSCs), derived from the mesoderm, have been applied in the repair and reconstruction of injured tissues. The present study was conducted to explore the effects of BMSCs on cell viability of tumor necrosis factor-α (TNF-α)-stimulated PC12 cells. PC12 cells were co-cultured with BMSCs under TNF-α treatment, with normal PC12 cells as controls. Results from an MTT assay indicated that BMSCs significantly increased cell growth and proliferation of TNF-α-treated PC12 cells (survival rates were 56.71 and 76.86% for the positive control (PC) and co-culture group, respectively). Furthermore, Annexin V/propidium iodide staining and flow cytometric analysis demonstrated that TNF-α increased PC12-cell apoptosis from 3.49 to 40.74% in the negative control and PC group, and the apoptotic rate was significantly reduced upon co-culture with BMSCs to 16.97%. In addition, data from reverse transcription-quantitative polymerase chain reaction and western blot analyses illustrated that TNF-α-induced upregulation in TNF receptor (TNFR)-1 (TNFR1) and caspase-8 expression in PC12 cells were partially reversed by co-culture with BMSCs. In conclusion, the present study suggested that BMSCs protect PC12 cells against stimulation with TNF-α, which is partially mediated through the TNFR/caspase signaling pathway. The results of the present study also suggested a therapeutic use of BMSCs in clinical neurodegenerative diseases.

  1. A5-Positive Primary Sensory Neurons Are Nonpermissive for Productive Infection with Herpes Simplex Virus 1 In Vitro▿

    Science.gov (United States)

    Bertke, Andrea S.; Swanson, Sophia M.; Chen, Jenny; Imai, Yumi; Kinchington, Paul R.; Margolis, Todd P.

    2011-01-01

    Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) establish latency and express the latency-associated transcript (LAT) preferentially in different murine sensory neuron populations, with most HSV-1 LAT expression in A5+ neurons and most HSV-2 LAT expression in KH10+ neurons. To study the mechanisms regulating the establishment of HSV latency in specific subtypes of neurons, cultured dissociated adult murine trigeminal ganglion (TG) neurons were assessed for relative permissiveness for productive infection. In contrast to that for neonatal TG, the relative distribution of A5+ and KH10+ neurons in cultured adult TG was similar to that seen in vivo. Productive infection with HSV was restricted, and only 45% of cultured neurons could be productively infected with either HSV-1 or HSV-2. A5+ neurons supported productive infection with HSV-2 but were selectively nonpermissive for productive infection with HSV-1, a phenomenon that was not due to restricted viral entry or DNA uncoating, since HSV-1 expressing β-galactosidase under the control of the neurofilament promoter was detected in ∼90% of cultured neurons, with no preference for any neuronal subtype. Infection with HSV-1 reporter viruses expressing enhanced green fluorescent protein (EGFP) from immediate early (IE), early, and late gene promoters indicated that the block to productive infection occurred before IE gene expression. Trichostatin A treatment of quiescently infected neurons induced productive infection preferentially from non-A5+ neurons, demonstrating that the nonpermissive neuronal subtype is also nonpermissive for reactivation. Thus, HSV-1 is capable of entering the majority of sensory neurons in vitro; productive infection occurs within a subset of these neurons; and this differential distribution of productive infection is determined at or before the expression of the viral IE genes. PMID:21507969

  2. Selected statins produce rapid spinal motor neuron loss in vitro

    Directory of Open Access Journals (Sweden)

    Murinson Beth B

    2012-06-01

    Full Text Available Abstract Background Hmg-CoA reductase inhibitors (statins are widely used to prevent disease associated with vascular disease and hyperlipidemia. Although side effects are uncommon, clinical observations suggest statin exposure may exacerbate neuromuscular diseases, including peripheral neuropathy and amyotrophic lateral sclerosis. Although some have postulated class-effects, prior studies of hepatocytes and myocytes indicate that the statins may exhibit differential effects. Studies of neuronal cells have been limited. Methods We examined the effects of statins on cultured neurons and Schwann cells. Cultured spinal motor neurons were grown on transwell inserts and assessed for viability using immunochemical staining for SMI-32. Cultured cortical neurons and Schwann cells were assessed using dynamic viability markers. Results 7 days of exposure to fluvastatin depleted spinal motor neurons in a dose-dependent manner with a KD of  Conclusions It is known from pharmacokinetic studies that daily treatment of young adults with fluvastatin can produce serum levels in the single micromolar range. We conclude that specific mechanisms may explain neuromuscular disease worsening with statins and further study is needed.

  3. Nitric oxide regulates neuronal activity via calcium-activated potassium channels.

    Directory of Open Access Journals (Sweden)

    Lei Ray Zhong

    Full Text Available Nitric oxide (NO is an unconventional membrane-permeable messenger molecule that has been shown to play various roles in the nervous system. How NO modulates ion channels to affect neuronal functions is not well understood. In gastropods, NO has been implicated in regulating the feeding motor program. The buccal motoneuron, B19, of the freshwater pond snail Helisoma trivolvis is active during the hyper-retraction phase of the feeding motor program and is located in the vicinity of NO-producing neurons in the buccal ganglion. Here, we asked whether B19 neurons might serve as direct targets of NO signaling. Previous work established NO as a key regulator of growth cone motility and neuronal excitability in another buccal neuron involved in feeding, the B5 neuron. This raised the question whether NO might modulate the electrical activity and neuronal excitability of B19 neurons as well, and if so whether NO acted on the same or a different set of ion channels in both neurons. To study specific responses of NO on B19 neurons and to eliminate indirect effects contributed by other cells, the majority of experiments were performed on single cultured B19 neurons. Addition of NO donors caused a prolonged depolarization of the membrane potential and an increase in neuronal excitability. The effects of NO could mainly be attributed to the inhibition of two types of calcium-activated potassium channels, apamin-sensitive and iberiotoxin-sensitive potassium channels. NO was found to also cause a depolarization in B19 neurons in situ, but only after NO synthase activity in buccal ganglia had been blocked. The results suggest that NO acts as a critical modulator of neuronal excitability in B19 neurons, and that calcium-activated potassium channels may serve as a common target of NO in neurons.

  4. Tinbergen on mirror neurons

    OpenAIRE

    Heyes, Cecilia

    2014-01-01

    Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology—the discovery of mirror neurons (MNs). Here, I use Tinbergen's original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that ...

  5. Evolution after mirror neurons: tapping the shared manifold through secondary adaptation.

    Science.gov (United States)

    Gervais, Matthew M

    2014-04-01

    Cook et al. laudably call for careful comparative research into the development of mirror neurons. However, they do so within an impoverished evolutionary framework that does not clearly distinguish ultimate and proximate causes and their reciprocal relations. As a result, they overlook evidence for the reliable develop of mirror neurons in biological and cultural traits evolved to work through them.

  6. Blueberries and neuronal aging.

    Science.gov (United States)

    Shukitt-Hale, Barbara

    2012-01-01

    As the population of people in the United States over the age of 65 years continues to increase, so too will the incidence of age-related pathologies, including decreases in cognitive and motor function. In cases of severe deficits in memory or motor function, hospitalization and/or custodial care would be a likely outcome. This means that unless some way is found to reduce these age-related decrements in neuronal function, health care costs will continue to rise exponentially. Evidence is accumulating that consumption of blueberries may be one strategy to forestall or even reverse age-related neuronal deficits, as well as their subsequent behavioral manifestations, in order to increase healthy aging. Research suggests that the polyphenolic compounds found in blueberries exert their beneficial effects either through their ability to lower oxidative stress and inflammation or directly by altering the signaling involved in neuronal communication. These interventions, in turn, may protect against age-related deficits in cognitive and motor function. Appropriately, the US Department of Agriculture has figured prominently in these discoveries, through the efforts of two USDA researchers who worked for the department 100 years apart. Copyright © 2012 S. Karger AG, Basel.

  7. Neural Transplantation Model Using Integration Co-culture Chamber

    Science.gov (United States)

    Shimba, Kenta; Saito, Atsushi; Takeuchi, Akimasa; Takayama, Yuzo; Kotani, Kiyoshi; Jimbo, Yasuhiko

    Regenerative medicine is a promising therapy for injuries and diseases of the central nervous system (CNS). Implantation of stem cell-derived neurons into the recipient tissue is one of the key processes of the therapy. How the implanted cells establish functional connections with the intact neurons, and whether the established connections are maintained stably for a long time, remain unknown. Here, we report a novel co-culture device for visualizing interconnections between primary and differentiated neuronal cultures, and long-term monitoring of neuronal activity. A circular micro-chamber surrounded by another chamber is aligned on a microelectrode array (MEA). These chambers are interconnected through 36 micro-tunnels. Stem cell-derived neurons were cultured in the inner circular chamber, and primary neurons taken from mouse cortices were cultured in the surrounding chamber. Neurites outgrew into the micro-tunnels from both primary and differentiated neurons. The immunofluorescence images indicate that synaptic connections are formed between them. Propagation of electrical activity was observed 6 days after starting co-culture. More than half of the spontaneous activity was initiated from primary neurons, and probability of activity propagation to the stem cell-derived neurons gradually increased with culture days. These results suggest that our device is feasible for long-term monitoring of interaction between stem cell-derived cells and the recipient tissue.

  8. NT2 derived neuronal and astrocytic network signalling.

    Directory of Open Access Journals (Sweden)

    Eric J Hill

    Full Text Available A major focus of stem cell research is the generation of neurons that may then be implanted to treat neurodegenerative diseases. However, a picture is emerging where astrocytes are partners to neurons in sustaining and modulating brain function. We therefore investigated the functional properties of NT2 derived astrocytes and neurons using electrophysiological and calcium imaging approaches. NT2 neurons (NT2Ns expressed sodium dependent action potentials, as well as responses to depolarisation and the neurotransmitter glutamate. NT2Ns exhibited spontaneous and coordinated calcium elevations in clusters and in extended processes, indicating local and long distance signalling. Tetrodotoxin sensitive network activity could also be evoked by electrical stimulation. Similarly, NT2 astrocytes (NT2As exhibited morphology and functional properties consistent with this glial cell type. NT2As responded to neuronal activity and to exogenously applied neurotransmitters with calcium elevations, and in contrast to neurons, also exhibited spontaneous rhythmic calcium oscillations. NT2As also generated propagating calcium waves that were gap junction and purinergic signalling dependent. Our results show that NT2 derived astrocytes exhibit appropriate functionality and that NT2N networks interact with NT2A networks in co-culture. These findings underline the utility of such cultures to investigate human brain cell type signalling under controlled conditions. Furthermore, since stem cell derived neuron function and survival is of great importance therapeutically, our findings suggest that the presence of complementary astrocytes may be valuable in supporting stem cell derived neuronal networks. Indeed, this also supports the intriguing possibility of selective therapeutic replacement of astrocytes in diseases where these cells are either lost or lose functionality.

  9. Somatodendritic and excitatory postsynaptic distribution of neuron-type dystrophin isoform, Dp40, in hippocampal neurons

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Takahiro; Itoh, Kyoko, E-mail: kxi14@koto.kpu-m.ac.jp; Yaoi, Takeshi; Fushiki, Shinji

    2014-09-12

    Highlights: • Identification of dystrophin (Dp) shortest isoform, Dp40, is a neuron-type Dp. • Dp40 expression is temporally and differentially regulated in comparison to Dp71. • Somatodendritic and nuclear localization of Dp40. • Dp40 is localized to excitatory postsynapses. • Dp40 might play roles in dendritic and synaptic functions. - Abstract: The Duchenne muscular dystrophy (DMD) gene produces multiple dystrophin (Dp) products due to the presence of several promoters. We previously reported the existence of a novel short isoform of Dp, Dp40, in adult mouse brain. However, the exact biochemical expression profile and cytological distribution of the Dp40 protein remain unknown. In this study, we generated a polyclonal antibody against the NH{sub 2}-terminal region of the Dp40 and identified the expression profile of Dp40 in the mouse brain. Through an analysis using embryonic and postnatal mouse cerebrums, we found that Dp40 emerged from the early neonatal stages until adulthood, whereas Dp71, an another Dp short isoform, was highly detected in both prenatal and postnatal cerebrums. Intriguingly, relative expressions of Dp40 and Dp71 were prominent in cultured dissociated neurons and non-neuronal cells derived from mouse hippocampus, respectively. Furthermore, the immunocytological distribution of Dp40 was analyzed in dissociated cultured neurons, revealing that Dp40 is detected in the soma and its dendrites, but not in the axon. It is worthy to note that Dp40 is localized along the subplasmalemmal region of the dendritic shafts, as well as at excitatory postsynaptic sites. Thus, Dp40 was identified as a neuron-type Dp possibly involving dendritic and synaptic functions.

  10. Somatodendritic and excitatory postsynaptic distribution of neuron-type dystrophin isoform, Dp40, in hippocampal neurons

    International Nuclear Information System (INIS)

    Fujimoto, Takahiro; Itoh, Kyoko; Yaoi, Takeshi; Fushiki, Shinji

    2014-01-01

    Highlights: • Identification of dystrophin (Dp) shortest isoform, Dp40, is a neuron-type Dp. • Dp40 expression is temporally and differentially regulated in comparison to Dp71. • Somatodendritic and nuclear localization of Dp40. • Dp40 is localized to excitatory postsynapses. • Dp40 might play roles in dendritic and synaptic functions. - Abstract: The Duchenne muscular dystrophy (DMD) gene produces multiple dystrophin (Dp) products due to the presence of several promoters. We previously reported the existence of a novel short isoform of Dp, Dp40, in adult mouse brain. However, the exact biochemical expression profile and cytological distribution of the Dp40 protein remain unknown. In this study, we generated a polyclonal antibody against the NH 2 -terminal region of the Dp40 and identified the expression profile of Dp40 in the mouse brain. Through an analysis using embryonic and postnatal mouse cerebrums, we found that Dp40 emerged from the early neonatal stages until adulthood, whereas Dp71, an another Dp short isoform, was highly detected in both prenatal and postnatal cerebrums. Intriguingly, relative expressions of Dp40 and Dp71 were prominent in cultured dissociated neurons and non-neuronal cells derived from mouse hippocampus, respectively. Furthermore, the immunocytological distribution of Dp40 was analyzed in dissociated cultured neurons, revealing that Dp40 is detected in the soma and its dendrites, but not in the axon. It is worthy to note that Dp40 is localized along the subplasmalemmal region of the dendritic shafts, as well as at excitatory postsynaptic sites. Thus, Dp40 was identified as a neuron-type Dp possibly involving dendritic and synaptic functions

  11. DELTAMETHRIN AND PERMETHRIN DECREASE SPONTANEOUS ACTIVITY IN NEURONAL NETWORKS IN VITRO.

    Science.gov (United States)

    Effects of pyrethroid insecticides on spontaneous electrical activity were investigated in primary cultures of cortical or spinal cord neurons grown on microelectrode arrays. Bicuculline (40 ¿M) was utilized to block fast GABAergic transmission, and concentration-dependent effect...

  12. Phosphoinositide-3-kinase activation controls synaptogenesis and spinogenesis in hippocampal neurons.

    Science.gov (United States)

    Cuesto, Germán; Enriquez-Barreto, Lilian; Caramés, Cristina; Cantarero, Marta; Gasull, Xavier; Sandi, Carmen; Ferrús, Alberto; Acebes, Ángel; Morales, Miguel

    2011-02-23

    The possibility of changing the number of synapses may be an important asset in the treatment of neurological diseases. In this context, the synaptogenic role of the phosphoinositide-3-kinase (PI3K) signaling cascade has been previously demonstrated in Drosop