WorldWideScience

Sample records for emtinb induce neuronal

  1. Metallothionein and a peptide modeled after metallothionein, EmtinB, induce neuronal differentiation and survival through binding to receptors of the low-density lipoprotein receptor family

    DEFF Research Database (Denmark)

    Ambjørn, Malene; Asmussen, Johanne W; Lindstam, Mats

    2007-01-01

    outgrowth and survival. MT-mediated neurite outgrowth was furthermore inhibited by an anti-megalin serum. EmtinB-mediated inhibition of apoptosis occurred without a reduction of caspase-3 activity, but was associated with reduced expression of the pro-apoptotic B-cell leukemia/lymphoma-2 interacting member...

  2. A metallothionein mimetic peptide protects neurons against kainic acid-induced excitotoxicity

    DEFF Research Database (Denmark)

    Sonn, Katrin; Pankratova, Stanislava; Korshunova, Irina

    2010-01-01

    Metallothioneins I and II (MTI/II) are metal-binding proteins overexpressed in response to brain injury. Recently, we have designed a peptide, termed EmtinB, which is modeled after the beta-domain of MT-II and mimics the biological effects of MTI/II in vitro. Here, we demonstrate the neuroprotect...

  3. Daidzein induces neuritogenesis in DRG neuronal cultures

    Directory of Open Access Journals (Sweden)

    Yang Shih-Hung

    2012-08-01

    Full Text Available Absract Background Daidzein, a phytoestrogen found in isoflavone, is known to exert neurotrophic and neuroprotective effects on the nervous system. Using primary rat dorsal root ganglion (DRG neuronal cultures, we have examined the potential neurite outgrowth effect of daidzein. Methods Dissociated dorsal root ganglia (DRG cultures were used to study the signaling mechanism of daidzein-induced neuritogenesis by immunocytochemistry and Western blotting. Results In response to daidzein treatment, DRG neurons showed a significant increase in total neurite length and in tip number per neuron. The neuritogenic effect of daidzein was significantly hampered by specific blockers for Src, protein kinase C delta (PKCδ and mitogen-activated protein kinase/extracellular signal-regulated kinase kinases (MEK/ERK, but not by those for estrogen receptor (ER. Moreover, daidzein induced phosphorylation of Src, PKCδ and ERK. The activation of PKCδ by daidzein was attenuated in the presence of a Src kinase inhibitor, and that of ERK by daidzein was diminished in the presence of either a Src or PKCδ inhibitor. Conclusion Daidzein may stimulate neurite outgrowth of DRG neurons depending on Src kinase, PKCδ and ERK signaling pathway.

  4. Tetracycline inducible gene manipulation in serotonergic neurons.

    Directory of Open Access Journals (Sweden)

    Tillmann Weber

    Full Text Available The serotonergic (5-HT neuronal system has important and diverse physiological functions throughout development and adulthood. Its dysregulation during development or later in adulthood has been implicated in many neuropsychiatric disorders. Transgenic animal models designed to study the contribution of serotonergic susceptibility genes to a pathological phenotype should ideally allow to study candidate gene overexpression or gene knockout selectively in serotonergic neurons at any desired time during life. For this purpose, conditional expression systems such as the tet-system are preferable. Here, we generated a transactivator (tTA mouse line (TPH2-tTA that allows temporal and spatial control of tetracycline (Ptet controlled transgene expression as well as gene deletion in 5-HT neurons. The tTA cDNA was inserted into a 196 kb PAC containing a genomic mouse Tph2 fragment (177 kb by homologous recombination in E. coli. For functional analysis of Ptet-controlled transgene expression, TPH2-tTA mice were crossed to a Ptet-regulated lacZ reporter line (Ptet-nLacZ. In adult double-transgenic TPH2-tTA/Ptet-nLacZ mice, TPH2-tTA founder line L62-20 showed strong serotonergic β-galactosidase expression which could be completely suppressed with doxycycline (Dox. Furthermore, Ptet-regulated gene expression could be reversibly activated or inactivated when Dox was either withdrawn or added to the system. For functional analysis of Ptet-controlled, Cre-mediated gene deletion, TPH2-tTA mice (L62-20 were crossed to double transgenic Ptet-Cre/R26R reporter mice to generate TPH2-tTA/Ptet-Cre/R26R mice. Without Dox, 5-HT specific recombination started at E12.5. With permanent Dox administration, Ptet-controlled Cre-mediated recombination was absent. Dox withdrawal either postnatally or during adulthood induced efficient recombination in serotonergic neurons of all raphe nuclei, respectively. In the enteric nervous system, recombination could not be detected. We

  5. Lithium protects ethanol-induced neuronal apoptosis

    International Nuclear Information System (INIS)

    Zhong Jin; Yang Xianlin; Yao Weiguo; Lee Weihua

    2006-01-01

    Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3β, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3β (ser9). In addition, the selective GSK-3β inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits

  6. Autapse-induced synchronization in a coupled neuronal network

    International Nuclear Information System (INIS)

    Ma, Jun; Song, Xinlin; Jin, Wuyin; Wang, Chuni

    2015-01-01

    Highlights: • The functional effect of autapse on neuronal activity is detected. • Autapse driving plays active role in regulating electrical activities as pacemaker. • It confirms biological experimental results for rhythm synchronization between heterogeneous cells. - Abstract: The effect of autapse on coupled neuronal network is detected. In our studies, three identical neurons are connected with ring type and autapse connected to one neuron of the network. The autapse connected to neuron can impose time-delayed feedback in close loop on the neuron thus the dynamics of membrane potentials can be changed. Firstly, the effect of autapse driving on single neuron is confirmed that negative feedback can calm down the neuronal activity while positive feedback can excite the neuronal activity. Secondly, the collective electrical behaviors of neurons are regulated by a pacemaker, which associated with the autapse forcing. By using appropriate gain and time delay in the autapse, the neurons can reach synchronization and the membrane potentials of all neurons can oscillate with the same rhythm under mutual coupling. It indicates that autapse forcing plays an important role in changing the collective electric activities of neuronal network, and appropriate electric modes can be selected due to the switch of feedback type(positive or negative) in autapse. And the autapse-induced synchronization in network is also consistent with some biological experiments about synchronization between nonidentical neurons.

  7. CRISPR Epigenome Editing of AKAP150 in DRG Neurons Abolishes Degenerative IVD-Induced Neuronal Activation.

    Science.gov (United States)

    Stover, Joshua D; Farhang, Niloofar; Berrett, Kristofer C; Gertz, Jason; Lawrence, Brandon; Bowles, Robby D

    2017-09-06

    Back pain is a major contributor to disability and has significant socioeconomic impacts worldwide. The degenerative intervertebral disc (IVD) has been hypothesized to contribute to back pain, but a better understanding of the interactions between the degenerative IVD and nociceptive neurons innervating the disc and treatment strategies that directly target these interactions is needed to improve our understanding and treatment of back pain. We investigated degenerative IVD-induced changes to dorsal root ganglion (DRG) neuron activity and utilized CRISPR epigenome editing as a neuromodulation strategy. By exposing DRG neurons to degenerative IVD-conditioned media under both normal and pathological IVD pH levels, we demonstrate that degenerative IVDs trigger interleukin (IL)-6-induced increases in neuron activity to thermal stimuli, which is directly mediated by AKAP and enhanced by acidic pH. Utilizing this novel information on AKAP-mediated increases in nociceptive neuron activity, we developed lentiviral CRISPR epigenome editing vectors that modulate endogenous expression of AKAP150 by targeted promoter histone methylation. When delivered to DRG neurons, these epigenome-modifying vectors abolished degenerative IVD-induced DRG-elevated neuron activity while preserving non-pathologic neuron activity. This work elucidates the potential for CRISPR epigenome editing as a targeted gene-based pain neuromodulation strategy. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  8. Achalasia: virus-induced euthanasia of neurons?

    NARCIS (Netherlands)

    Boeckxstaens, Guy E.

    2008-01-01

    Achalasia, a motor disorder of the esophagus, is characterized by myenteric plexitis leading to neuronal loss. Cytotoxic T cells, isolated from the lower esophageal sphincter of achalasia patients, respond to human herpes virus-1 (HSV-1) with gamma-IFN (and to a lesser extent IL-2) production and

  9. CFTR mediates noradrenaline-induced ATP efflux from DRG neurons.

    Science.gov (United States)

    Kanno, Takeshi; Nishizaki, Tomoyuki

    2011-09-24

    In our earlier study, noradrenaline (NA) stimulated ATP release from dorsal root ganglion (DRG) neurons as mediated via β(3) adrenoceptors linked to G(s) protein involving protein kinase A (PKA) activation, to cause allodynia. The present study was conducted to understand how ATP is released from DRG neurons. In an outside-out patch-clamp configuration from acutely dissociated rat DRG neurons, single-channel currents, sensitive to the P2X receptor inhibitor PPADS, were evoked by approaching the patch-electrode tip close to a neuron, indicating that ATP is released from DRG neurons, to activate P2X receptor. NA increased the frequency of the single-channel events, but such NA effect was not found for DRG neurons transfected with the siRNA to silence the cystic fibrosis transmembrane conductance regulator (CFTR) gene. In the immunocytochemical study using acutely dissociated rat DRG cells, CFTR was expressed in neurons alone, but not satellite cells, fibroblasts, or Schwann cells. It is concluded from these results that CFTR mediates NA-induced ATP efflux from DRG neurons as an ATP channel.

  10. Zinc release contributes to hypoglycemia-induced neuronal death.

    Science.gov (United States)

    Suh, Sang Won; Garnier, Philippe; Aoyama, Koji; Chen, Yongmei; Swanson, Raymond A

    2004-08-01

    Neurons exposed to zinc exhibit activation of poly(ADP-ribose) polymerase-1 (PARP-1), an enzyme that normally participates in DNA repair but promotes cell death when extensively activated. Endogenous, vesicular zinc in brain is released to the extracellular space under conditions causing neuronal depolarization. Here, we used a rat model of insulin-induced hypoglycemia to assess the role of zinc release in PARP-1 activation and neuronal death after severe hypoglycemia. Zinc staining with N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide (TSQ) showed depletion of presynaptic vesicular zinc from hippocampal mossy fiber terminals and accumulation of weakly bound zinc in hippocampal CA1 cell bodies after severe hypoglycemia. Intracerebroventricular injection of the zinc chelator calcium ethylene-diamine tetraacetic acid (CaEDTA) blocked the zinc accumulation and significantly reduced hypoglycemia-induced neuronal death. CaEDTA also attenuated the accumulation of poly(ADP-ribose), the enzymatic product of PARP-1, in hippocampal neurons. These results suggest that zinc translocation is an intermediary step linking hypoglycemia to PARP-1 activation and neuronal death.

  11. 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.

  12. Histochemical demonstration of mercury induced changes in rat neurons

    DEFF Research Database (Denmark)

    Danscher, G; Schrøder, H D

    1979-01-01

    A histochemical method modified for ultrastructural studies of mercury induced changes is described. Rat neurons from areas known to be influenced by mercury are used as examples. The histochemical reaction, suggested to be caused by polymercury sulphide complexes, is localized to "dense bodies......" where it is visible 14 days after initiation of peroral mercury treatment (20 mg HgCl2/l drinking water)....

  13. Bistability induces episodic spike communication by inhibitory neurons in neuronal networks.

    Science.gov (United States)

    Kazantsev, V B; Asatryan, S Yu

    2011-09-01

    Bistability is one of the important features of nonlinear dynamical systems. In neurodynamics, bistability has been found in basic Hodgkin-Huxley equations describing the cell membrane dynamics. When the neuron is clamped near its threshold, the stable rest potential may coexist with the stable limit cycle describing periodic spiking. However, this effect is often neglected in network computations where the neurons are typically reduced to threshold firing units (e.g., integrate-and-fire models). We found that the bistability may induce spike communication by inhibitory coupled neurons in the spiking network. The communication is realized in the form of episodic discharges with synchronous (correlated) spikes during the episodes. A spiking phase map is constructed to describe the synchronization and to estimate basic spike phase locking modes.

  14. Prevention of hypoglycemia-induced neuronal death by minocycline

    Science.gov (United States)

    2012-01-01

    Diabetic patients who attempt strict management of blood glucose levels frequently experience hypoglycemia. Severe and prolonged hypoglycemia causes neuronal death and cognitive impairment. There is no effective tool for prevention of these unwanted clinical sequelae. Minocycline, a second-generation tetracycline derivative, has been recognized as an anti-inflammatory and neuroprotective agent in several animal models such as stroke and traumatic brain injury. In the present study, we tested whether minocycline also has protective effects on hypoglycemia-induced neuronal death and cognitive impairment. To test our hypothesis we used an animal model of insulin-induced acute hypoglycemia. Minocycline was injected intraperitoneally at 6 hours after hypoglycemia/glucose reperfusion and injected once per day for the following 1 week. Histological evaluation for neuronal death and microglial activation was performed from 1 day to 1 week after hypoglycemia. Cognitive evaluation was conducted 6 weeks after hypoglycemia. Microglial activation began to be evident in the hippocampal area at 1 day after hypoglycemia and persisted for 1 week. Minocycline injection significantly reduced hypoglycemia-induced microglial activation and myeloperoxidase (MPO) immunoreactivity. Neuronal death was significantly reduced by minocycline treatment when evaluated at 1 week after hypoglycemia. Hypoglycemia-induced cognitive impairment is also significantly prevented by the same minocycline regimen when subjects were evaluated at 6 weeks after hypoglycemia. Therefore, these results suggest that delayed treatment (6 hours post-insult) with minocycline protects against microglial activation, neuronal death and cognitive impairment caused by severe hypoglycemia. The present study suggests that minocycline has therapeutic potential to prevent hypoglycemia-induced brain injury in diabetic patients. PMID:22998689

  15. Analysis of laser-induced heating in optical neuronal guidance

    DEFF Research Database (Denmark)

    Ebbesen, Christian L.; Bruus, Henrik

    2012-01-01

    Recently, it has been shown that it is possible to control the growth direction of neuronal growth cones by stimulation with weak laser light; an effect dubbed optical neuronal guidance. The effect exists for a broad range of laser wavelengths, spot sizes, spot intensities, optical intensity...... profiles and beam modulations, but it is unknown which biophysical mechanisms govern it. Based on thermodynamic modeling and simulation using published experimental parameters as input, we argue that the guidance is linked to heating. Until now, temperature effects due to laser-induced heating...

  16. Necroptosis Mediates TNF-Induced Toxicity of Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Shan Liu

    2014-01-01

    Full Text Available Tumor necrosis factor-α (TNF-α is a critical proinflammatory cytokine regulating neuroinflammation. Elevated levels of TNF-α have been associated with various neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. However, the signaling events that lead to TNF-α-initiated neurotoxicity are still unclear. Here, we report that RIP3-mediated necroptosis, a form of regulated necrosis, is activated in the mouse hippocampus after intracerebroventricular injection of TNF-α. RIP3 deficiency attenuates TNF-α-initiated loss of hippocampal neurons. Furthermore, we characterized the molecular mechanism of TNF-α-induced neurotoxicity in HT-22 hippocampal neuronal cells. HT-22 cells are sensitive to TNF-α only upon caspase blockage and subsequently undergo necrosis. The cell death is suppressed by knockdown of CYLD or RIP1 or RIP3 or MLKL, suggesting that this necrosis is necroptosis and mediated by CYLD-RIP1-RIP3-MLKL signaling pathway. TNF-α-induced necroptosis of HT-22 cells is largely independent of both ROS accumulation and calcium influx although these events have been shown to be critical for necroptosis in certain cell lines. Taken together, these data not only provide the first in vivo evidence for a role of RIP3 in TNF-α-induced toxicity of hippocampal neurons, but also demonstrate that TNF-α promotes CYLD-RIP1-RIP3-MLKL-mediated necroptosis of hippocampal neurons largely bypassing ROS accumulation and calcium influx.

  17. Interleukin-3 prevents neuronal death induced by amyloid peptide

    Directory of Open Access Journals (Sweden)

    Otth Carola

    2007-10-01

    Full Text Available Abstract Background Interleukin-3 (IL-3 is an important glycoprotein involved in regulating biological responses such as cell proliferation, survival and differentiation. Its effects are mediated via interaction with cell surface receptors. Several studies have demonstrated the expression of IL-3 in neurons and astrocytes of the hippocampus and cortices in normal mouse brain, suggesting a physiological role of IL-3 in the central nervous system. Although there is evidence indicating that IL-3 is expressed in some neuronal populations, its physiological role in these cells is poorly known. Results In this study, we demonstrated the expression of IL-3 receptor in cortical neurons, and analyzed its influence on amyloid β (Aβ-treated cells. In these cells, IL-3 can activate at least three classical signalling pathways, Jak/STAT, Ras/MAP kinase and the PI 3-kinase. Viability assays indicated that IL-3 might play a neuroprotective role in cells treated with Aβ fibrils. It is of interest to note that our results suggest that cell survival induced by IL-3 required PI 3-kinase and Jak/STAT pathway activation, but not MAP kinase. In addition, IL-3 induced an increase of the anti-apoptotic protein Bcl-2. Conclusion Altogether these data strongly suggest that IL-3 neuroprotects neuronal cells against neurodegenerative agents like Aβ.

  18. Sensory experience regulates cortical inhibition by inducing IGF1 in VIP neurons.

    Science.gov (United States)

    Mardinly, A R; Spiegel, I; Patrizi, A; Centofante, E; Bazinet, J E; Tzeng, C P; Mandel-Brehm, C; Harmin, D A; Adesnik, H; Fagiolini, M; Greenberg, M E

    2016-03-17

    Inhibitory neurons regulate the adaptation of neural circuits to sensory experience, but the molecular mechanisms by which experience controls the connectivity between different types of inhibitory neuron to regulate cortical plasticity are largely unknown. Here we show that exposure of dark-housed mice to light induces a gene program in cortical vasoactive intestinal peptide (VIP)-expressing neurons that is markedly distinct from that induced in excitatory neurons and other subtypes of inhibitory neuron. We identify Igf1 as one of several activity-regulated genes that are specific to VIP neurons, and demonstrate that IGF1 functions cell-autonomously in VIP neurons to increase inhibitory synaptic input onto these neurons. Our findings further suggest that in cortical VIP neurons, experience-dependent gene transcription regulates visual acuity by activating the expression of IGF1, thus promoting the inhibition of disinhibitory neurons and affecting inhibition onto cortical pyramidal neurons.

  19. Ketamine-induced apoptosis in cultured rat cortical neurons

    International Nuclear Information System (INIS)

    Takadera, Tsuneo; Ishida, Akira; Ohyashiki, Takao

    2006-01-01

    Recent data suggest that anesthetic drugs cause neurodegeneration during development. Ketamine is frequently used in infants and toddlers for elective surgeries. The purpose of this study is to determine whether glycogen synthase kinase-3 (GSK-3) is involved in ketamine-induced apoptosis. Ketamine increased apoptotic cell death with morphological changes which were characterized by cell shrinkage, nuclear condensation or fragmentation. In addition, insulin growth factor-1 completely blocked the ketamine-induced apoptotic cell death. Ketamine decreased Akt phosphorylation. GSK-3 is known as a downstream target of Akt. The selective inhibitors of GSK-3 prevented the ketamine-induced apoptosis. Moreover, caspase-3 activation was accompanied by the ketamine-induced cell death and inhibited by the GSK-3 inhibitors. These results suggest that activation of GSK-3 is involved in ketamine-induced apoptosis in rat cortical neurons

  20. GPNMB ameliorates mutant TDP-43-induced motor neuron cell death.

    Science.gov (United States)

    Nagahara, Yuki; Shimazawa, Masamitsu; Ohuchi, Kazuki; Ito, Junko; Takahashi, Hitoshi; Tsuruma, Kazuhiro; Kakita, Akiyoshi; Hara, Hideaki

    2017-08-01

    Glycoprotein nonmetastatic melanoma protein B (GPNMB) aggregates are observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, but the detailed localization is still unclear. Mutations of transactive response DNA binding protein 43kDa (TDP-43) are associated with neurodegenerative diseases including ALS. In this study, we evaluated the localization of GPNMB aggregates in the spinal cord of ALS patients and the effect of GPNMB against mutant TDP-43 induced motor neuron cell death. GPNMB aggregates were not localized in the glial fibrillary acidic protein (GFAP)-positive astrocyte and ionized calcium binding adaptor molecule-1 (Iba1)-positive microglia. GPNMB aggregates were localized in the microtubule-associated protein 2 (MAP-2)-positive neuron and neurofilament H non-phosphorylated (SMI-32)-positive neuron, and these were co-localized with TDP-43 aggregates in the spinal cord of ALS patients. Mock or TDP-43 (WT, M337V, and A315T) plasmids were transfected into mouse motor neuron cells (NSC34). The expression level of GPNMB was increased by transfection of mutant TDP-43 plasmids. Recombinant GPNMB ameliorated motor neuron cell death induced by transfection of mutant TDP-43 plasmids and serum-free stress. Furthermore, the expression of phosphorylated ERK1/2 and phosphorylated Akt were decreased by this stress, and these expressions were increased by recombinant GPNMB. These results indicate that GPNMB has protective effects against mutant TDP-43 stress via activating the ERK1/2 and Akt pathways, and GPNMB may be a therapeutic target for TDP-43 proteinopathy in familial and sporadic ALS. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Corticosterone Facilitates Fluoxetine-Induced Neuronal Plasticity in the Hippocampus

    Science.gov (United States)

    Kobayashi, Katsunori; Ikeda, Yumiko; Asada, Minoru; Inagaki, Hirofumi; Kawada, Tomoyuki; Suzuki, Hidenori

    2013-01-01

    The hippocampal dentate gyrus has been implicated in a neuronal basis of antidepressant action. We have recently shown a distinct form of neuronal plasticity induced by the serotonergic antidepressant fluoxetine, that is, a reversal of maturation of the dentate granule cells in adult mice. This “dematuration” is induced in a large population of dentate neurons and maintained for at least one month after withdrawal of fluoxetine, suggesting long-lasting strong influence of dematuration on brain functioning. However, reliable induction of dematuration required doses of fluoxetine higher than suggested optimal doses for mice (10 to 18 mg/kg/day), which casts doubt on the clinical relevance of this effect. Since our previous studies were performed in naive mice, in the present study, we reexamined effects of fluoxetine using mice treated with chronic corticosterone that model neuroendocrine pathophysiology associated with depression. In corticosterone-treated mice, fluoxetine at 10 mg/kg/day downregulated expression of mature granule cell markers and attenuated strong frequency facilitation at the synapse formed by the granule cell axon mossy fiber, suggesting the induction of granule cell dematuration. In addition, fluoxetine caused marked enhancement of dopaminergic modulation at the mossy fiber synapse. In vehicle-treated mice, however, fluoxetine at this dose had no significant effects. The plasma level of fluoxetine was comparable to that in patients taking chronic fluoxetine, and corticosterone did not affect it. These results indicate that corticosterone facilitates fluoxetine-induced plastic changes in the dentate granule cells. Our finding may provide insight into neuronal mechanisms underlying enhanced responsiveness to antidepressant medication in certain pathological conditions. PMID:23675498

  2. Medial septal dysfunction by Aβ-induced KCNQ channel-block in glutamatergic neurons

    DEFF Research Database (Denmark)

    Leão, Richardson N.; Colom, Luis V.; Borgius, Lotta

    2012-01-01

    (MS) neurons in mice. In glutamatergic neurons Aβ increases firing frequency and blocks the A- and the M-current (IA and IM, respectively). While the IA block is similar in other MS neuron classes, the block of IM is specific to glutamatergic neurons. IM block and a simulated Aβ block mimic the Aβ......-induced increase in spontaneous firing in glutamatergic neurons. Calcium imaging shows that under control conditions glutamatergic neurons rarely fire while nonglutamatergic neurons fire coherently at theta frequencies. Aβ increases the firing rate of glutamatergic neurons while nonglutamatergic neurons lose theta...... firing coherence. Our results demonstrate that Aβ-induced dysfunction of glutamatergic neurons via IM decrease diminishes MS rhythmicity, which may negatively affect hippocampal rhythmogenesis and underlie the memory loss observed in Alzheimer's disease....

  3. Role of Nitric Oxide in MPTP-Induced Dopaminergic Neuron Degeneration

    National Research Council Canada - National Science Library

    Przedborski, Serge

    2002-01-01

    ...) induced dopaminergic (DA) neuron death in this mouse model of Parkinson's Disease (PD). Our previous work demonstrated that the superoxide radical is involved in the MPTP neurotoxic process in SNpc DA neurons...

  4. Neuronal human BACE1 knockin induces systemic diabetes in mice.

    Science.gov (United States)

    Plucińska, Kaja; Dekeryte, Ruta; Koss, David; Shearer, Kirsty; Mody, Nimesh; Whitfield, Phillip D; Doherty, Mary K; Mingarelli, Marco; Welch, Andy; Riedel, Gernot; Delibegovic, Mirela; Platt, Bettina

    2016-07-01

    β-Secretase 1 (BACE1) is a key enzyme in Alzheimer's disease pathogenesis that catalyses the amyloidogenic cleavage of amyloid precursor protein (APP). Recently, global Bace1 deletion was shown to protect against diet-induced obesity and diabetes, suggesting that BACE1 is a potential regulator of glucose homeostasis. Here, we investigated whether increased neuronal BACE1 is sufficient to alter systemic glucose metabolism, using a neuron-specific human BACE1 knockin mouse model (PLB4). Glucose homeostasis and adiposity were determined by glucose tolerance tests and EchoMRI, lipid species were measured by quantitative lipidomics, and biochemical and molecular alterations were assessed by western blotting, quantitative PCR and ELISAs. Glucose uptake in the brain and upper body was measured via (18)FDG-PET imaging. Physiological and molecular analyses demonstrated that centrally expressed human BACE1 induced systemic glucose intolerance in mice from 4 months of age onward, alongside a fatty liver phenotype and impaired hepatic glycogen storage. This diabetic phenotype was associated with hypothalamic pathology, i.e. deregulation of the melanocortin system, and advanced endoplasmic reticulum (ER) stress indicated by elevated central C/EBP homologous protein (CHOP) signalling and hyperphosphorylation of its regulator eukaryotic translation initiation factor 2α (eIF2α). In vivo (18)FDG-PET imaging further confirmed brain glucose hypometabolism in these mice; this corresponded with altered neuronal insulin-related signalling, enhanced protein tyrosine phosphatase 1B (PTP1B) and retinol-binding protein 4 (RBP4) levels, along with upregulation of the ribosomal protein and lipid translation machinery. Increased forebrain and plasma lipid accumulation (i.e. ceramides, triacylglycerols, phospholipids) was identified via lipidomics analysis. Our data reveal that neuronal BACE1 is a key regulator of metabolic homeostasis and provide a potential mechanism for the high

  5. Efficient and Cost-Effective Generation of Mature Neurons From Human Induced Pluripotent Stem Cells

    OpenAIRE

    Badja , Cherif; Maleeva , Galyna; El-Yazidi , Claire; Barruet , Emilie; Lasserre , Manon; Tropel , Philippe; Binetruy , Bernard; Bregestovski , Piotr; Magdinier , Frédérique

    2014-01-01

    The authors describe a feeder-free method of generating induced pluripotent stem cells by relying on the use of a chemically defined medium that overcomes the need for embryoid body formation and neuronal rosette isolation for neuronal precursors and terminally differentiated neuron production. This specific and efficient single-step strategy allows the production of mature neurons in 20–40 days with multiple applications, especially for modeling human pathologies.

  6. Anaesthesia generates neuronal insulin resistance by inducing hypothermia

    Directory of Open Access Journals (Sweden)

    Sutherland Calum

    2008-10-01

    Full Text Available Abstract Background Anaesthesia is commonly employed prior to surgical investigations and to permit icv injections in rodents. Indeed it is standard practise in many studies examining the subsequent actions of hormones and growth factors on the brain. Recent evidence that the basal activity of specific intracellular signalling proteins can be affected by anaesthesia prompted us to examine the effect of anaesthesia not only on the basal activity but also the insulin sensitivity of the major insulin signalling pathways. Results We find that urethane- and ketamine-induced anaesthesia results in rapid activation of the phosphatidylinositol (PI 3-kinase-protein kinase B (PKB signalling pathway in the brain, increases tau phosphorylation while at the same time reducing basal activity of the Ras-ERK pathway. Subsequent injection of insulin does not alter the activity of either the PI 3-kinase or ERK signalling pathways, indicating a degree of neuronal molecular insulin resistance. However, if body temperature is maintained during anaesthesia then there is no alteration in the basal activity of these signalling molecules. Subsequent response of both pathways to insulin injection is restored. Conclusion The data is consistent with a hypothermia related alteration in neuronal signalling following anaesthesia, and emphasises the importance of maintaining the body temperature of rodents when monitoring insulin (or growth factor/neurotrophic agent action in the brain of anesthetised rodents.

  7. Efficient induction of dopaminergic neuron differentiation from induced pluripotent stem cells reveals impaired mitophagy in PARK2 neurons.

    Science.gov (United States)

    Suzuki, Sadafumi; Akamatsu, Wado; Kisa, Fumihiko; Sone, Takefumi; Ishikawa, Kei-Ichi; Kuzumaki, Naoko; Katayama, Hiroyuki; Miyawaki, Atsushi; Hattori, Nobutaka; Okano, Hideyuki

    2017-01-29

    Patient-specific induced pluripotent stem cells (iPSCs) show promise for use as tools for in vitro modeling of Parkinson's disease. We sought to improve the efficiency of dopaminergic (DA) neuron induction from iPSCs by the using surface markers expressed in DA progenitors to increase the significance of the phenotypic analysis. By sorting for a CD184 high /CD44 - fraction during neural differentiation, we obtained a population of cells that were enriched in DA neuron precursor cells and achieved higher differentiation efficiencies than those obtained through the same protocol without sorting. This high efficiency method of DA neuronal induction enabled reliable detection of reactive oxygen species (ROS) accumulation and vulnerable phenotypes in PARK2 iPSCs-derived DA neurons. We additionally established a quantitative system using the mt-mKeima reporter system to monitor mitophagy in which mitochondria fuse with lysosomes and, by combining this system with the method of DA neuronal induction described above, determined that mitophagy is impaired in PARK2 neurons. These findings suggest that the efficiency of DA neuron induction is important for the precise detection of cellular phenotypes in modeling Parkinson's disease. Copyright © 2016. Published by Elsevier Inc.

  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. Cancer-induced anorexia and malaise are mediated by CGRP neurons in the parabrachial nucleus.

    Science.gov (United States)

    Campos, Carlos A; Bowen, Anna J; Han, Sung; Wisse, Brent E; Palmiter, Richard D; Schwartz, Michael W

    2017-07-01

    Anorexia is a common manifestation of chronic diseases, including cancer. Here we investigate the contribution to cancer anorexia made by calcitonin gene-related peptide (CGRP) neurons in the parabrachial nucleus (PBN) that transmit anorexic signals. We show that CGRP PBN neurons are activated in mice implanted with Lewis lung carcinoma cells. Inactivation of CGRP PBN neurons before tumor implantation prevents anorexia and loss of lean mass, and their inhibition after symptom onset reverses anorexia. CGRP PBN neurons are also activated in Apc min/+ mice, which develop intestinal cancer and lose weight despite the absence of reduced food intake. Inactivation of CGRP PBN neurons in Apc min/+ mice permits hyperphagia that counteracts weight loss, revealing a role for these neurons in a 'nonanorexic' cancer model. We also demonstrate that inactivation of CGRP PBN neurons prevents lethargy, anxiety and malaise associated with cancer. These findings establish CGRP PBN neurons as key mediators of cancer-induced appetite suppression and associated behavioral changes.

  10. Glucose rapidly induces different forms of excitatory synaptic plasticity in hypothalamic POMC neurons.

    Directory of Open Access Journals (Sweden)

    Jun Hu

    Full Text Available Hypothalamic POMC neurons are required for glucose and energy homeostasis. POMC neurons have a wide synaptic connection with neurons both within and outside the hypothalamus, and their activity is controlled by a balance between excitatory and inhibitory synaptic inputs. Brain glucose-sensing plays an essential role in the maintenance of normal body weight and metabolism; however, the effect of glucose on synaptic transmission in POMC neurons is largely unknown. Here we identified three types of POMC neurons (EPSC(+, EPSC(-, and EPSC(+/- based on their glucose-regulated spontaneous excitatory postsynaptic currents (sEPSCs, using whole-cell patch-clamp recordings. Lowering extracellular glucose decreased the frequency of sEPSCs in EPSC(+ neurons, but increased it in EPSC(- neurons. Unlike EPSC(+ and EPSC(- neurons, EPSC(+/- neurons displayed a bi-phasic sEPSC response to glucoprivation. In the first phase of glucoprivation, both the frequency and the amplitude of sEPSCs decreased, whereas in the second phase, they increased progressively to the levels above the baseline values. Accordingly, lowering glucose exerted a bi-phasic effect on spontaneous action potentials in EPSC(+/- neurons. Glucoprivation decreased firing rates in the first phase, but increased them in the second phase. These data indicate that glucose induces distinct excitatory synaptic plasticity in different subpopulations of POMC neurons. This synaptic remodeling is likely to regulate the sensitivity of the melanocortin system to neuronal and hormonal signals.

  11. Glucose Rapidly Induces Different Forms of Excitatory Synaptic Plasticity in Hypothalamic POMC Neurons

    Science.gov (United States)

    Hu, Jun; Jiang, Lin; Low, Malcolm J.; Rui, Liangyou

    2014-01-01

    Hypothalamic POMC neurons are required for glucose and energy homeostasis. POMC neurons have a wide synaptic connection with neurons both within and outside the hypothalamus, and their activity is controlled by a balance between excitatory and inhibitory synaptic inputs. Brain glucose-sensing plays an essential role in the maintenance of normal body weight and metabolism; however, the effect of glucose on synaptic transmission in POMC neurons is largely unknown. Here we identified three types of POMC neurons (EPSC(+), EPSC(−), and EPSC(+/−)) based on their glucose-regulated spontaneous excitatory postsynaptic currents (sEPSCs), using whole-cell patch-clamp recordings. Lowering extracellular glucose decreased the frequency of sEPSCs in EPSC(+) neurons, but increased it in EPSC(−) neurons. Unlike EPSC(+) and EPSC(−) neurons, EPSC(+/−) neurons displayed a bi-phasic sEPSC response to glucoprivation. In the first phase of glucoprivation, both the frequency and the amplitude of sEPSCs decreased, whereas in the second phase, they increased progressively to the levels above the baseline values. Accordingly, lowering glucose exerted a bi-phasic effect on spontaneous action potentials in EPSC(+/−) neurons. Glucoprivation decreased firing rates in the first phase, but increased them in the second phase. These data indicate that glucose induces distinct excitatory synaptic plasticity in different subpopulations of POMC neurons. This synaptic remodeling is likely to regulate the sensitivity of the melanocortin system to neuronal and hormonal signals. PMID:25127258

  12. Glucose rapidly induces different forms of excitatory synaptic plasticity in hypothalamic POMC neurons.

    Science.gov (United States)

    Hu, Jun; Jiang, Lin; Low, Malcolm J; Rui, Liangyou

    2014-01-01

    Hypothalamic POMC neurons are required for glucose and energy homeostasis. POMC neurons have a wide synaptic connection with neurons both within and outside the hypothalamus, and their activity is controlled by a balance between excitatory and inhibitory synaptic inputs. Brain glucose-sensing plays an essential role in the maintenance of normal body weight and metabolism; however, the effect of glucose on synaptic transmission in POMC neurons is largely unknown. Here we identified three types of POMC neurons (EPSC(+), EPSC(-), and EPSC(+/-)) based on their glucose-regulated spontaneous excitatory postsynaptic currents (sEPSCs), using whole-cell patch-clamp recordings. Lowering extracellular glucose decreased the frequency of sEPSCs in EPSC(+) neurons, but increased it in EPSC(-) neurons. Unlike EPSC(+) and EPSC(-) neurons, EPSC(+/-) neurons displayed a bi-phasic sEPSC response to glucoprivation. In the first phase of glucoprivation, both the frequency and the amplitude of sEPSCs decreased, whereas in the second phase, they increased progressively to the levels above the baseline values. Accordingly, lowering glucose exerted a bi-phasic effect on spontaneous action potentials in EPSC(+/-) neurons. Glucoprivation decreased firing rates in the first phase, but increased them in the second phase. These data indicate that glucose induces distinct excitatory synaptic plasticity in different subpopulations of POMC neurons. This synaptic remodeling is likely to regulate the sensitivity of the melanocortin system to neuronal and hormonal signals.

  13. Sirt3 confers protection against acrolein-induced oxidative stress in cochlear nucleus neurons.

    Science.gov (United States)

    Qu, Juan; Wu, Yong-Xiang; Zhang, Ting; Qiu, Yang; Ding, Zhong-Jia; Zha, Ding-Jun

    2018-03-01

    Acrolein is a ubiquitous dietary and environmental pollutant, which can also be generated endogenously during cellular stress. However, the molecular mechanisms underlying acrolein-induced neurotoxicity, especially in ototoxicity conditions, have not been fully determined. In this study, we investigated the mechanisms on acrolein-induced toxicity in primary cultured cochlear nucleus neurons with focus on Sirt3, a mitochondrial deacetylase. We found that acrolein treatment induced neuronal injury and programmed cell death (PCD) in a dose dependent manner in cochlear nucleus neurons, which was accompanied by increased intracellular reactive oxygen species (ROS) generation and lipid peroxidation. Acrolein exposure also significantly reduced the mitochondrial membrane potential (MMP) levels, promoted cytochrome c release and decreased mitochondrial ATP production. In addition, increased ER tracker fluorescence and activation of ER stress factors were observed after acrolein treatment, and the ER stress inhibitors were shown to attenuate acrolein-induced toxicity in cochlear nucleus neurons. The results of western blot and RT-PCR showed that acrolein markedly decreased the expression of Sirt3 at both mRNA and protein levels, and reduced the activity of downstream mitochondrial enzymes. Furthermore, overexpression of Sirt3 by lentivirus transfection partially prevented acrolein-induced neuronal injury in cochlear nucleus neurons. These results demonstrated that acrolein induces mitochondrial dysfunction and ER stress in cochlear nucleus neurons, and Sirt3 acts as an endogenous protective factor in acrolein-induced ototoxicity. Copyright © 2017. Published by Elsevier Ltd.

  14. N-Methyl-d-Aspartate (NMDA) Receptor Blockade Prevents Neuronal Death Induced by Zika Virus Infection.

    Science.gov (United States)

    Costa, Vivian V; Del Sarto, Juliana L; Rocha, Rebeca F; Silva, Flavia R; Doria, Juliana G; Olmo, Isabella G; Marques, Rafael E; Queiroz-Junior, Celso M; Foureaux, Giselle; Araújo, Julia Maria S; Cramer, Allysson; Real, Ana Luíza C V; Ribeiro, Lucas S; Sardi, Silvia I; Ferreira, Anderson J; Machado, Fabiana S; de Oliveira, Antônio C; Teixeira, Antônio L; Nakaya, Helder I; Souza, Danielle G; Ribeiro, Fabiola M; Teixeira, Mauro M

    2017-04-25

    Zika virus (ZIKV) infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N -methyl-d-aspartate receptor (NMDAR)-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801), agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP) induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration. IMPORTANCE Zika virus (ZIKV) infection is a global health emergency associated with serious neurological complications, including microcephaly and Guillain-Barré syndrome. Infection of experimental animals with ZIKV causes significant neuronal damage and microgliosis. Treatment with drugs that block NMDARs prevented neuronal damage both in vitro and in vivo These results suggest that overactivation of NMDARs contributes significantly to the neuronal damage induced by ZIKV infection, and this is amenable to inhibition by drug treatment. Copyright © 2017 Costa et al.

  15. Role of Inflammation in MPTP-Induced Dopaminergic Neuronal Death

    Science.gov (United States)

    2008-12-01

    of MPTP to MPP+ and MPP+ entry into dopaminergic neurons are key to the neurotoxic effects of MPTP and interference in any of these processes...presented at the Society for Neuroscience Meetings in 2006 Figure 1. Tempol Structure 29 Figure 2. Tempol protects dopaminergic neurons...in PD. Dopaminergic neurons in the SNpc were protected to a significant degree against the damaging effects of MPTP by M40401 whereas its isoforms

  16. Noise-Induced Transition in a Voltage-Controlled Oscillator Neuron Model

    International Nuclear Information System (INIS)

    Xie Huizhang; Liu Xuemei; Li Zhibing; Ai Baoquan; Liu Lianggang

    2008-01-01

    In the presence of Gaussian white noise, we study the properties of voltage-controlled oscillator neuron model and discuss the effects of the additive and multiplicative noise. It is found that the additive noise can accelerate and counterwork the firing of neuron, which depends on the value of central frequency of neuron itself, while multiplicative noise can induce the continuous change or mutation of membrane potential

  17. Synaptic network activity induces neuronal differentiation of adult hippocampal precursor cells through BDNF signaling

    Directory of Open Access Journals (Sweden)

    Harish Babu

    2009-09-01

    Full Text Available Adult hippocampal neurogenesis is regulated by activity. But how do neural precursor cells in the hippocampus respond to surrounding network activity and translate increased neural activity into a developmental program? Here we show that long-term potential (LTP-like synaptic activity within a cellular network of mature hippocampal neurons promotes neuronal differentiation of newly generated cells. In co-cultures of precursor cells with primary hippocampal neurons, LTP-like synaptic plasticity induced by addition of glycine in Mg2+-free media for 5 min, produced synchronous network activity and subsequently increased synaptic strength between neurons. Furthermore, this synchronous network activity led to a significant increase in neuronal differentiation from the co-cultured neural precursor cells. When applied directly to precursor cells, glycine and Mg2+-free solution did not induce neuronal differentiation. Synaptic plasticity-induced neuronal differentiation of precursor cells was observed in the presence of GABAergic neurotransmission blockers but was dependent on NMDA-mediated Ca2+ influx. Most importantly, neuronal differentiation required the release of brain-derived neurotrophic factor (BDNF from the underlying substrate hippocampal neurons as well as TrkB receptor phosphorylation in precursor cells. This suggests that activity-dependent stem cell differentiation within the hippocampal network is mediated via synaptically evoked BDNF signaling.

  18. Single neuron dynamics during experimentally induced anoxic depolarization

    NARCIS (Netherlands)

    Zandt, B.; Stigen, Tyler; ten Haken, Bernard; Netoff, Theoden; van Putten, Michel Johannes Antonius Maria

    2013-01-01

    We studied single neuron dynamics during anoxic depolarizations, which are often observed in cases of neuronal energy depletion. Anoxic and similar depolarizations play an important role in several pathologies, notably stroke, migraine, and epilepsy. One of the effects of energy depletion was

  19. Atorvastatin prevents Aβ oligomer-induced neurotoxicity in cultured rat hippocampal neurons by inhibiting Tau cleavage

    Science.gov (United States)

    Sui, Hai-juan; Zhang, Ling-ling; Liu, Zhou; Jin, Ying

    2015-01-01

    Aim: The proteolytic cleavage of Tau is involved in Aβ-induced neuronal dysfunction and cell death. In this study, we investigated whether atorvastatin could prevent Tau cleavage and hence prevent Aβ1–42 oligomer (AβO)-induced neurotoxicity in cultured cortical neurons. Methods: Cultured rat hippocampal neurons were incubated in the presence of AβOs (1.25 μmol/L) with or without atorvastatin pretreatment. ATP content and LDH in the culture medium were measured to assess the neuronal viability. Caspase-3/7 and calpain protease activities were detected. The levels of phospho-Akt, phospho-Erk1/2, phospho-GSK3β, p35 and Tau proteins were measured using Western blotting. Results: Treatment of the neurons with AβO significantly decreased the neuronal viability, induced rapid activation of calpain and caspase-3/7 proteases, accompanied by Tau degradation and relatively stable fragments generated in the neurons. AβO also suppressed Akt and Erk1/2 kinase activity, while increased GSK3β and Cdk5 activity in the neurons. Pretreatment with atorvastatin (0.5, 1, 2.5 μmol/L) dose-dependently inhibited AβO-induced activation of calpain and caspase-3/7 proteases, and effectively diminished the generation of Tau fragments, attenuated synaptic damage and increased neuronal survival. Atorvastatin pretreatment also prevented AβO-induced decreases in Akt and Erk1/2 kinase activity and the increases in GSK3β and Cdk5 kinase activity. Conclusion: Atorvastatin prevents AβO-induced neurotoxicity in cultured rat hippocampal neurons by inhibiting calpain- and caspase-mediated Tau cleavage. PMID:25891085

  20. Neuronal Cx3cr1 Deficiency Protects against Amyloid β-Induced Neurotoxicity

    Science.gov (United States)

    Dworzak, Jenny; Renvoisé, Benoît; Habchi, Johnny; Yates, Emma V.; Combadière, Christophe; Knowles, Tuomas P.; Dobson, Christopher M.; Blackstone, Craig; Paulsen, Ole; Murphy, Philip M.

    2015-01-01

    Cx3cr1, the receptor for the chemokine Cx3cl1 (fractalkine), has been implicated in the progression and severity of Alzheimer’s disease-like pathology in mice, but the underlying mechanisms remain unclear. A complicating factor is that Cx3cr1 has been demonstrated in both neurons and microglia. Here, we have dissected the differences between neuronal and microglial Cx3cr1, specifically by comparing direct amyloid-β-induced toxicity in cultured, mature, microglia-depleted hippocampal neurons from wild-type and Cx3cr1-/- mice. Wild-type neurons expressed both Cx3cl1 and Cx3cr1 and released Cx3cl1 in response to amyloid-β. Knockout of neuronal Cx3cr1 abated amyloid-β-induced lactate dehydrogenase release. Furthermore, amyloid-β differentially induced depression of pre- and postsynaptic components of miniature excitatory postsynaptic currents, in a peptide conformation-dependent manner. Knockout of neuronal Cx3cr1 abated effects of both amyloid-β conformational states, which were differentiable by aggregation kinetics and peptide morphology. We obtained similar results after both acute and chronic treatment of cultured neurons with the Cx3cr1 antagonist F1. Thus, neuronal Cx3cr1 may impact Alzheimer’s disease-like pathology by modulating conformational state-dependent amyloid-β-induced synaptotoxicity. PMID:26038823

  1. Neuronal Cx3cr1 Deficiency Protects against Amyloid β-Induced Neurotoxicity.

    Directory of Open Access Journals (Sweden)

    Jenny Dworzak

    Full Text Available Cx3cr1, the receptor for the chemokine Cx3cl1 (fractalkine, has been implicated in the progression and severity of Alzheimer's disease-like pathology in mice, but the underlying mechanisms remain unclear. A complicating factor is that Cx3cr1 has been demonstrated in both neurons and microglia. Here, we have dissected the differences between neuronal and microglial Cx3cr1, specifically by comparing direct amyloid-β-induced toxicity in cultured, mature, microglia-depleted hippocampal neurons from wild-type and Cx3cr1-/- mice. Wild-type neurons expressed both Cx3cl1 and Cx3cr1 and released Cx3cl1 in response to amyloid-β. Knockout of neuronal Cx3cr1 abated amyloid-β-induced lactate dehydrogenase release. Furthermore, amyloid-β differentially induced depression of pre- and postsynaptic components of miniature excitatory postsynaptic currents, in a peptide conformation-dependent manner. Knockout of neuronal Cx3cr1 abated effects of both amyloid-β conformational states, which were differentiable by aggregation kinetics and peptide morphology. We obtained similar results after both acute and chronic treatment of cultured neurons with the Cx3cr1 antagonist F1. Thus, neuronal Cx3cr1 may impact Alzheimer's disease-like pathology by modulating conformational state-dependent amyloid-β-induced synaptotoxicity.

  2. Cholera Toxin Induces Sustained Hyperexcitability in Myenteric, but Not Submucosal, AH Neurons in Guinea Pig Jejunum

    Directory of Open Access Journals (Sweden)

    Joel C. Bornstein

    2017-04-01

    Full Text Available Background and Aims: Cholera toxin (CT-induced hypersecretion requires activation of secretomotor pathways in the enteric nervous system (ENS. AH neurons, which have been identified as a population of intrinsic sensory neurons (ISNs, are a source of excitatory input to the secretomotor pathways. We therefore examined effects of CT in the intestinal lumen on myenteric and submucosal AH neurons.Methods: Isolated segments of guinea pig jejunum were incubated for 90 min with saline plus CT (12.5 μg/ml or CT + neurotransmitter antagonist, or CT + tetrodotoxin (TTX in their lumen. After washing CT away, submucosal or myenteric plexus preparations were dissected keeping circumferentially adjacent mucosa intact. Submucosal AH neurons were impaled adjacent to intact mucosa and myenteric AH neurons were impaled adjacent to, more than 5 mm from, and in the absence of intact mucosa. Neuronal excitability was monitored by injecting 500 ms current pulses through the recording electrode.Results: After CT pre-treatment, excitability of myenteric AH neurons adjacent to intact mucosa (n = 29 was greater than that of control neurons (n = 24, but submucosal AH neurons (n = 33, control n = 27 were unaffected. CT also induced excitability increases in myenteric AH neurons impaled distant from the mucosa (n = 6 or in its absence (n = 5. Coincubation with tetrodotoxin or SR142801 (NK3 receptor antagonist, but not SR140333 (NK1 antagonist or granisetron (5-HT3 receptor antagonist prevented the increased excitability induced by CT. Increased excitability was associated with a reduction in the characteristic AHP and an increase in the ADP of these neurons, but not a change in the hyperpolarization-activated inward current, Ih.Conclusions: CT increases excitability of myenteric, but not submucosal, AH neurons. This is neurally mediated and depends on NK3, but not 5-HT3 receptors. Therefore, CT may act to amplify the secretomotor response to CT via an increase in the

  3. Thiamine deficiency induces endoplasmic reticulum stress and oxidative stress in human neurons derived from induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Xu, Mei; Frank, Jacqueline A. [Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Ke, Zun-ji [Department of Biochemistry, Shanghai University of Traditional Chinese Medicine, Shanghai, China 201203 (China); Luo, Jia, E-mail: jialuo888@uky.edu [Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Department of Biochemistry, Shanghai University of Traditional Chinese Medicine, Shanghai, China 201203 (China)

    2017-04-01

    Thiamine (vitamin B1) deficiency (TD) plays a major role in the etiology of Wernicke's encephalopathy (WE) which is a severe neurological disorder. TD induces selective neuronal cell death, neuroinflammation, endoplasmic reticulum (ER) stress and oxidative stress in the brain which are commonly observed in many aging-related neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and progressive supranuclear palsy (PSP). However, the underlying cellular and molecular mechanisms remain unclear. The progress in this line of research is hindered due to the lack of appropriate in vitro models. The neurons derived for the human induced pluripotent stem cells (hiPSCs) provide a relevant and powerful tool for the research in pharmaceutical and environmental neurotoxicity. In this study, we for the first time used human induced pluripotent stem cells (hiPSCs)-derived neurons (iCell neurons) to investigate the mechanisms of TD-induced neurodegeneration. We showed that TD caused a concentration- and duration-dependent death of iCell neurons. TD induced ER stress which was evident by the increase in ER stress markers, such as GRP78, XBP-1, CHOP, ATF-6, phosphorylated eIF2α, and cleaved caspase-12. TD also triggered oxidative stress which was shown by the increase in the expression 2,4-dinitrophenyl (DNP) and 4-hydroxynonenal (HNE). ER stress inhibitors (STF-083010 and salubrinal) and antioxidant N-acetyl cysteine (NAC) were effective in alleviating TD-induced death of iCell neurons, supporting the involvement of ER stress and oxidative stress. It establishes that the iCell neurons are a novel tool to investigate cellular and molecular mechanisms for TD-induced neurodegeneration. - Highlights: • Thiamine deficiency (TD) causes death of human neurons in culture. • TD induces both endoplasmic reticulum (ER) stress and oxidative stress. • Alleviating ER stress and oxidative stress reduces TD-induced

  4. Thiamine deficiency induces endoplasmic reticulum stress and oxidative stress in human neurons derived from induced pluripotent stem cells

    International Nuclear Information System (INIS)

    Wang, Xin; Xu, Mei; Frank, Jacqueline A.; Ke, Zun-ji; Luo, Jia

    2017-01-01

    Thiamine (vitamin B1) deficiency (TD) plays a major role in the etiology of Wernicke's encephalopathy (WE) which is a severe neurological disorder. TD induces selective neuronal cell death, neuroinflammation, endoplasmic reticulum (ER) stress and oxidative stress in the brain which are commonly observed in many aging-related neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and progressive supranuclear palsy (PSP). However, the underlying cellular and molecular mechanisms remain unclear. The progress in this line of research is hindered due to the lack of appropriate in vitro models. The neurons derived for the human induced pluripotent stem cells (hiPSCs) provide a relevant and powerful tool for the research in pharmaceutical and environmental neurotoxicity. In this study, we for the first time used human induced pluripotent stem cells (hiPSCs)-derived neurons (iCell neurons) to investigate the mechanisms of TD-induced neurodegeneration. We showed that TD caused a concentration- and duration-dependent death of iCell neurons. TD induced ER stress which was evident by the increase in ER stress markers, such as GRP78, XBP-1, CHOP, ATF-6, phosphorylated eIF2α, and cleaved caspase-12. TD also triggered oxidative stress which was shown by the increase in the expression 2,4-dinitrophenyl (DNP) and 4-hydroxynonenal (HNE). ER stress inhibitors (STF-083010 and salubrinal) and antioxidant N-acetyl cysteine (NAC) were effective in alleviating TD-induced death of iCell neurons, supporting the involvement of ER stress and oxidative stress. It establishes that the iCell neurons are a novel tool to investigate cellular and molecular mechanisms for TD-induced neurodegeneration. - Highlights: • Thiamine deficiency (TD) causes death of human neurons in culture. • TD induces both endoplasmic reticulum (ER) stress and oxidative stress. • Alleviating ER stress and oxidative stress reduces TD-induced

  5. Palmitoylethanolamide Blunts Amyloid-β42-Induced Astrocyte Activation and Improves Neuronal Survival in Primary Mouse Cortical Astrocyte-Neuron Co-Cultures.

    Science.gov (United States)

    Beggiato, Sarah; Borelli, Andrea Celeste; Ferraro, Luca; Tanganelli, Sergio; Antonelli, Tiziana; Tomasini, Maria Cristina

    2018-01-01

    Based on the pivotal role of astrocytes in brain homeostasis and the strong metabolic cooperation existing between neurons and astrocytes, it has been suggested that astrocytic dysfunctions might cause and/or contribute to neuroinflammation and neurodegenerative processes. Therapeutic approaches aimed at both neuroprotection and neuroinflammation reduction may prove particularly effective in slowing the progression of these diseases. The endogenous lipid mediator palmitoylethanolamide (PEA) displayed neuroprotective and anti(neuro)inflammatory properties, and demonstrated interesting potential as a novel treatment for Alzheimer's disease. We firstly evaluated whether astrocytes could participate in regulating the Aβ42-induced neuronal damage, by using primary mouse astrocytes cell cultures and mixed astrocytes-neurons cultures. Furthermore, the possible protective effects of PEA against Aβ42-induced neuronal toxicity have also been investigated by evaluating neuronal viability, apoptosis, and morphometric parameters. The presence of astrocytes pre-exposed to Aβ42 (0.5μM; 24 h) induced a reduction of neuronal viability in primary mouse astrocytes-neurons co-cultures. Furthermore, under these experimental conditions, an increase in the number of neuronal apoptotic nuclei and a decrease in the number of MAP-2 positive neurons were observed. Finally, astrocytic Aβ42 pre-exposure induced an increase in the number of neurite aggregations/100μm as compared to control (i.e., untreated) astrocytes-neurons co-cultures. These effects were not observed in neurons cultured in the presence of astrocytes pre-exposed to PEA (0.1μM), applied 1 h before and maintained during Aβ42 treatment. Astrocytes contribute to Aβ42-induced neurotoxicity and PEA, by blunting Aβ42-induced astrocyte activation, improved neuronal survival in mouse astrocyte-neuron co-cultures.

  6. 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.

  7. Visualization of migration of human cortical neurons generated from induced pluripotent stem cells.

    Science.gov (United States)

    Bamba, Yohei; Kanemura, Yonehiro; Okano, Hideyuki; Yamasaki, Mami

    2017-09-01

    Neuronal migration is considered a key process in human brain development. However, direct observation of migrating human cortical neurons in the fetal brain is accompanied by ethical concerns and is a major obstacle in investigating human cortical neuronal migration. We established a novel system that enables direct visualization of migrating cortical neurons generated from human induced pluripotent stem cells (hiPSCs). We observed the migration of cortical neurons generated from hiPSCs derived from a control and from a patient with lissencephaly. Our system needs no viable brain tissue, which is usually used in slice culture. Migratory behavior of human cortical neuron can be observed more easily and more vividly by its fluorescence and glial scaffold than that by earlier methods. Our in vitro experimental system provides a new platform for investigating development of the human central nervous system and brain malformation. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Disparate roles of zinc in chemical hypoxia-induced neuronal death

    Directory of Open Access Journals (Sweden)

    Sujeong eKim

    2015-01-01

    Full Text Available Accumulating evidence has provided a causative role of zinc (Zn2+ in neuronal death following ischemic brain injury. Using a hypoxia model of primary cultured cortical neurons with hypoxia-inducing chemicals, cobalt chloride (1 mM CoCl2, deferoxamine (3 mM DFX, and sodium azide (2 mM NaN3, we evaluated whether Zn2+ is involved in hypoxic neuronal death. The hypoxic chemicals rapidly elicited intracellular Zn2+ release/accumulation in viable neurons. The immediate addition of the Zn2+ chelator, CaEDTA or N,N,N’N’-tetrakis-(2-pyridylmethyl ethylenediamine (TPEN, prevented the intracellular Zn2+ load and CoCl2-induced neuronal death, but neither 3-hour-later Zn2+ chelation nor a non-Zn2+ chelator ZnEDTA (1 mM demonstrated any effects. However, neither CaEDTA nor TPEN rescued neurons from cell death following DFX- or NaN3-induced hypoxia, whereas ZnEDTA rendered them resistant to the hypoxic injury. Instead, the immediate supplementation of Zn2+ rescued DFX- and NaN3-induced neuronal death. The iron supplementation also afforded neuroprotection against DFX-induced hypoxic injury. Thus, although intracellular Zn2+ release/accumulation is common during chemical hypoxia, Zn2+ might differently influence the subsequent fate of neurons; it appears to play a neurotoxic or neuroprotective role depending on the hypoxic chemical used. These results also suggest that different hypoxic chemicals may induce neuronal death via distinct mechanisms.

  9. Disparate roles of zinc in chemical hypoxia-induced neuronal death.

    Science.gov (United States)

    Kim, Sujeong; Seo, Jung-Woo; Oh, Shin Bi; Kim, So Hee; Kim, Inki; Suh, Nayoung; Lee, Joo-Yong

    2015-01-01

    Accumulating evidence has provided a causative role of zinc (Zn(2+)) in neuronal death following ischemic brain injury. Using a hypoxia model of primary cultured cortical neurons with hypoxia-inducing chemicals, cobalt chloride (1 mM CoCl2), deferoxamine (3 mM DFX), and sodium azide (2 mM NaN3), we evaluated whether Zn(2+) is involved in hypoxic neuronal death. The hypoxic chemicals rapidly elicited intracellular Zn(2+) release/accumulation in viable neurons. The immediate addition of the Zn(2+) chelator, CaEDTA or N,N,N'N'-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN), prevented the intracellular Zn(2+) load and CoCl2-induced neuronal death, but neither 3 hour later Zn(2+) chelation nor a non-Zn(2+) chelator ZnEDTA (1 mM) demonstrated any effects. However, neither CaEDTA nor TPEN rescued neurons from cell death following DFX- or NaN3-induced hypoxia, whereas ZnEDTA rendered them resistant to the hypoxic injury. Instead, the immediate supplementation of Zn(2+) rescued DFX- and NaN3-induced neuronal death. The iron supplementation also afforded neuroprotection against DFX-induced hypoxic injury. Thus, although intracellular Zn(2+) release/accumulation is common during chemical hypoxia, Zn(2+) might differently influence the subsequent fate of neurons; it appears to play a neurotoxic or neuroprotective role depending on the hypoxic chemical used. These results also suggest that different hypoxic chemicals may induce neuronal death via distinct mechanisms.

  10. Naphthazarin protects against glutamate-induced neuronal death via activation of the Nrf2/ARE pathway

    Energy Technology Data Exchange (ETDEWEB)

    Son, Tae Gen; Kawamoto, Elisa M.; Yu, Qian-Sheng; Greig, Nigel H. [Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, 251 Bayview Blvd., Baltimore, MD 21224 (United States); Mattson, Mark P. [Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, 251 Bayview Blvd., Baltimore, MD 21224 (United States); Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Camandola, Simonetta, E-mail: camandolasi@mail.nih.gov [Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, 251 Bayview Blvd., Baltimore, MD 21224 (United States)

    2013-04-19

    Highlights: •Naphthazarin activates the Nrf2/ARE pathway. •Naphthazarin induces Nrf2-driven genes in neurons and astrocytes. •Naphthazarin protects neurons against excitotoxicity. -- Abstract: Nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is an important cellular stress response pathway involved in neuroprotection. We previously screened several natural phytochemicals and identified plumbagin as a novel activator of the Nrf2/ARE pathway that can protect neurons against ischemic injury. Here we extended our studies to natural and synthetic derivatives of plumbagin. We found that 5,8-dimethoxy-1,4-naphthoquinone (naphthazarin) is a potent activator of the Nrf2/ARE pathway, up-regulates the expression of Nrf2-driven genes in primary neuronal and glial cultures, and protects neurons against glutamate-induced excitotoxicity.

  11. Naphthazarin protects against glutamate-induced neuronal death via activation of the Nrf2/ARE pathway

    International Nuclear Information System (INIS)

    Son, Tae Gen; Kawamoto, Elisa M.; Yu, Qian-Sheng; Greig, Nigel H.; Mattson, Mark P.; Camandola, Simonetta

    2013-01-01

    Highlights: •Naphthazarin activates the Nrf2/ARE pathway. •Naphthazarin induces Nrf2-driven genes in neurons and astrocytes. •Naphthazarin protects neurons against excitotoxicity. -- Abstract: Nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is an important cellular stress response pathway involved in neuroprotection. We previously screened several natural phytochemicals and identified plumbagin as a novel activator of the Nrf2/ARE pathway that can protect neurons against ischemic injury. Here we extended our studies to natural and synthetic derivatives of plumbagin. We found that 5,8-dimethoxy-1,4-naphthoquinone (naphthazarin) is a potent activator of the Nrf2/ARE pathway, up-regulates the expression of Nrf2-driven genes in primary neuronal and glial cultures, and protects neurons against glutamate-induced excitotoxicity

  12. Spike timing rigidity is maintained in bursting neurons under pentobarbital-induced anesthetic conditions

    Directory of Open Access Journals (Sweden)

    Risako Kato

    2016-11-01

    Full Text Available Pentobarbital potentiates γ-aminobutyric acid (GABA-mediated inhibitory synaptic transmission by prolonging the open time of GABAA receptors. However, it is unknown how pentobarbital regulates cortical neuronal activities via local circuits in vivo. To examine this question, we performed extracellular unit recording in rat insular cortex under awake and anesthetic conditions. Not a few studies apply time-rescaling theorem to detect the features of repetitive spike firing. Similar to these methods, we define an average spike interval locally in time using random matrix theory (RMT, which enables us to compare different activity states on a universal scale. Neurons with high spontaneous firing frequency (> 5 Hz and bursting were classified as HFB neurons (n = 10, and those with low spontaneous firing frequency (< 10 Hz and without bursting were classified as non-HFB neurons (n = 48. Pentobarbital injection (30 mg/kg reduced firing frequency in all HFB neurons and in 78% of non-HFB neurons. RMT analysis demonstrated that pentobarbital increased in the number of neurons with repulsion in both HFB and non-HFB neurons, suggesting that there is a correlation between spikes within a short interspike interval. Under awake conditions, in 50% of HFB and 40% of non-HFB neurons, the decay phase of normalized histograms of spontaneous firing were fitted to an exponential function, which indicated that the first spike had no correlation with subsequent spikes. In contrast, under pentobarbital-induced anesthesia conditions, the number of non-HFB neurons that were fitted to an exponential function increased to 80%, but almost no change in HFB neurons was observed. These results suggest that under both awake and pentobarbital-induced anesthetized conditions, spike firing in HFB neurons is more robustly regulated by preceding spikes than by non-HFB neurons, which may reflect the GABAA receptor-mediated regulation of cortical activities. Whole-cell patch

  13. Ca2+-induced uncoupling of Aplysia bag cell neurons.

    Science.gov (United States)

    Dargaei, Zahra; Standage, Dominic; Groten, Christopher J; Blohm, Gunnar; Magoski, Neil S

    2015-02-01

    Electrical transmission is a dynamically regulated form of communication and key to synchronizing neuronal activity. The bag cell neurons of Aplysia are a group of electrically coupled neuroendocrine cells that initiate ovulation by secreting egg-laying hormone during a prolonged period of synchronous firing called the afterdischarge. Accompanying the afterdischarge is an increase in intracellular Ca2+ and the activation of protein kinase C (PKC). We used whole cell recording from paired cultured bag cell neurons to demonstrate that electrical coupling is regulated by both Ca2+ and PKC. Elevating Ca2+ with a train of voltage steps, mimicking the onset of the afterdischarge, decreased junctional current for up to 30 min. Inhibition was most effective when Ca2+ entry occurred in both neurons. Depletion of Ca2+ from the mitochondria, but not the endoplasmic reticulum, also attenuated the electrical synapse. Buffering Ca2+ with high intracellular EGTA or inhibiting calmodulin kinase prevented uncoupling. Furthermore, activating PKC produced a small but clear decrease in junctional current, while triggering both Ca2+ influx and PKC inhibited the electrical synapse to a greater extent than Ca2+ alone. Finally, the amplitude and time course of the postsynaptic electrotonic response were attenuated after Ca2+ influx. A mathematical model of electrically connected neurons showed that excessive coupling reduced recruitment of the cells to fire, whereas less coupling led to spiking of essentially all neurons. Thus a decrease in electrical synapses could promote the afterdischarge by ensuring prompt recovery of electrotonic potentials or making the neurons more responsive to current spreading through the network. Copyright © 2015 the American Physiological Society.

  14. Spiral Waves and Multiple Spatial Coherence Resonances Induced by Colored Noise in Neuronal Network

    International Nuclear Information System (INIS)

    Tang Zhao; Li Yuye; Xi Lei; Jia Bing; Gu Huaguang

    2012-01-01

    Gaussian colored noise induced spatial patterns and spatial coherence resonances in a square lattice neuronal network composed of Morris-Lecar neurons are studied. Each neuron is at resting state near a saddle-node bifurcation on invariant circle, coupled to its nearest neighbors by electronic coupling. Spiral waves with different structures and disordered spatial structures can be alternately induced within a large range of noise intensity. By calculating spatial structure function and signal-to-noise ratio (SNR), it is found that SNR values are higher when the spiral structures are simple and are lower when the spatial patterns are complex or disordered, respectively. SNR manifest multiple local maximal peaks, indicating that the colored noise can induce multiple spatial coherence resonances. The maximal SNR values decrease as the correlation time of the noise increases. These results not only provide an example of multiple resonances, but also show that Gaussian colored noise play constructive roles in neuronal network. (general)

  15. METHAMPHETAMINE-INDUCED CELL DEATH: SELECTIVE VULNERABILITY IN NEURONAL SUBPOPULATIONS OF THE STRIATUM IN MICE

    Science.gov (United States)

    ZHU, J. P. Q.; XU, W.; ANGULO, J. A.

    2010-01-01

    Methamphetamine (METH) is an illicit and potent psychostimulant, which acts as an indirect dopamine agonist. In the striatum, METH has been shown to cause long lasting neurotoxic damage to dopaminergic nerve terminals and recently, the degeneration and death of striatal cells. The present study was undertaken to identify the type of striatal neurons that undergo apoptosis after METH. Male mice received a single high dose of METH (30 mg/kg, i.p.) and were killed 24 h later. To demonstrate that METH induces apoptosis in neurons, we combined terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining with immunohistofluorescence for the neuronal marker neuron-specific nuclear protein (NeuN). Staining for TUNEL and NeuN was colocalized throughout the striatum. METH induces apoptosis in approximately 25% of striatal neurons. Cell counts of TUNEL-positive neurons in the dorsomedial, ventromedial, dorsolateral and ventrolateral quadrants of the striatum did not reveal anatomical preference. The type of striatal neuron undergoing cell death was determined by combining TUNEL with immunohistofluorescence for selective markers of striatal neurons: dopamine- and cAMP-regulated phosphoprotein, of apparent Mr 32,000, parvalbumin, choline acetyltransferase and somatostatin (SST). METH induces apoptosis in approximately 21% of dopamine- and cAMP-regulated phosphoprotein, of apparent Mr 32,000-positive neurons (projection neurons), 45% of GABA-parvalbumin-positive neurons in the dorsal striatum, and 29% of cholinergic neurons in the dorsal–medial striatum. In contrast, the SST-positive interneurons were refractory to METH-induced apoptosis. Finally, the amount of cell loss determined with Nissl staining correlated with the amount of TUNEL staining in the striatum of METH-treated animals. In conclusion, some of the striatal projection neurons and the GABA-parvalbumin and cholinergic interneurons were removed by apoptosis in the aftermath of METH. This

  16. Influenza Virus Induces Inflammatory Response in Mouse Primary Cortical Neurons with Limited Viral Replication

    Directory of Open Access Journals (Sweden)

    Gefei Wang

    2016-01-01

    Full Text Available Unlike stereotypical neurotropic viruses, influenza A viruses have been detected in the brain tissues of human and animal models. To investigate the interaction between neurons and influenza A viruses, mouse cortical neurons were isolated, infected with human H1N1 influenza virus, and then examined for the production of various inflammatory molecules involved in immune response. We found that replication of the influenza virus in neurons was limited, although early viral transcription was not affected. Virus-induced neuron viability decreased at 6 h postinfection (p.i. but increased at 24 h p.i. depending upon the viral strain. Virus-induced apoptosis and cytopathy in primary cortical neurons were not apparent at 24 h p.i. The mRNA levels of inflammatory cytokines, chemokines, and type I interferons were upregulated at 6 h and 24 h p.i. These results indicate that the influenza virus induces inflammatory response in mouse primary cortical neurons with limited viral replication. The cytokines released in viral infection-induced neuroinflammation might play critical roles in influenza encephalopathy, rather than in viral replication-induced cytopathy.

  17. Activity deprivation induces neuronal cell death: mediation by tissue-type plasminogen activator.

    Directory of Open Access Journals (Sweden)

    Eldi Schonfeld-Dado

    Full Text Available Spontaneous activity is an essential attribute of neuronal networks and plays a critical role in their development and maintenance. Upon blockade of activity with tetrodotoxin (TTX, neurons degenerate slowly and die in a manner resembling neurodegenerative diseases-induced neuronal cell death. The molecular cascade leading to this type of slow cell death is not entirely clear. Primary post-natal cortical neurons were exposed to TTX for up to two weeks, followed by molecular, biochemical and immunefluorescence analysis. The expression of the neuronal marker, neuron specific enolase (NSE, was down-regulated, as expected, but surprisingly, there was a concomitant and striking elevation in expression of tissue-type plasminogen activator (tPA. Immunofluorescence analysis indicated that tPA was highly elevated inside affected neurons. Transfection of an endogenous tPA inhibitor, plasminogen activator inhibitor-1 (PAI-1, protected the TTX-exposed neurons from dying. These results indicate that tPA is a pivotal player in slowly progressing activity deprivation-induced neurodegeneration.

  18. α-Synuclein fibril-induced paradoxical structural and functional defects in hippocampal neurons.

    Science.gov (United States)

    Froula, Jessica M; Henderson, Benjamin W; Gonzalez, Jose Carlos; Vaden, Jada H; Mclean, John W; Wu, Yumei; Banumurthy, Gokulakrishna; Overstreet-Wadiche, Linda; Herskowitz, Jeremy H; Volpicelli-Daley, Laura A

    2018-05-01

    Neuronal inclusions composed of α-synuclein (α-syn) characterize Parkinson's Disease (PD) and Dementia with Lewy bodies (DLB). Cognitive dysfunction defines DLB, and up to 80% of PD patients develop dementia. α-Syn inclusions are abundant in the hippocampus, yet functional consequences are unclear. To determine if pathologic α-syn causes neuronal defects, we induced endogenous α-syn to form inclusions resembling those found in diseased brains by treating hippocampal neurons with α-syn fibrils. At seven days after adding fibrils, α-syn inclusions are abundant in axons, but there is no cell death at this time point, allowing us to assess for potential alterations in neuronal function that are not caused by neuron death. We found that exposure of neurons to fibrils caused a significant reduction in mushroom spine densities, adding to the growing body of literature showing that altered spine morphology is a major pathologic phenotype in synucleinopathies. The reduction in spine densities occurred only in wild type neurons and not in neurons from α-syn knockout mice, suggesting that the changes in spine morphology result from fibril-induced corruption of endogenously expressed α-syn. Paradoxically, reduced postsynaptic spine density was accompanied by increased frequency of miniature excitatory postsynaptic currents (EPSCs) and presynaptic docked vesicles, suggesting enhanced presynaptic function. Action-potential dependent activity was unchanged, suggesting compensatory mechanisms responding to synaptic defects. Although activity at the level of the synapse was unchanged, neurons exposed to α-syn fibrils, showed reduced frequency and amplitudes of spontaneous Ca 2+ transients. These findings open areas of research to determine the mechanisms that alter neuronal function in brain regions critical for cognition at time points before neuron death.

  19. Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

    International Nuclear Information System (INIS)

    Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin; Wei, Ling; Liu, Yutong; Liao, Jieying; Gao, Hui-Ming; Zhou, Hui

    2017-01-01

    Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm 2 induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm 2 ) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91 phox , p47 phox and p40 phox ); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47 phox and p67 phox translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to oxidative damage to DA neurons. Our

  20. Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China); Wei, Ling [Beijing Center for Physical & Chemical Analysis, Beijing 100089 (China); Liu, Yutong [School of Life Science, Beijing Normal University, Beijing 100875 (China); Liao, Jieying [Department of Translational Medicine, Xiamen Institute of Rare Earth Materials, Chinese Academy of Sciences, Xiamen 361024 (China); Gao, Hui-Ming [Model Animal Research Center of Nanjing University, Nanjing 211800 (China); Zhou, Hui, E-mail: hardhui@gmail.com [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China)

    2017-05-01

    Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm{sup 2} induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm{sup 2}) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91{sup phox}, p47{sup phox} and p40{sup phox}); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47{sup phox} and p67{sup phox} translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to

  1. Protective Effect of Edaravone in Primary Cerebellar Granule Neurons against Iodoacetic Acid-Induced Cell Injury

    Directory of Open Access Journals (Sweden)

    Xinhua Zhou

    2015-01-01

    Full Text Available Edaravone (EDA is clinically used for treatment of acute ischemic stroke in Japan and China due to its potent free radical-scavenging effect. However, it has yet to be determined whether EDA can attenuate iodoacetic acid- (IAA- induced neuronal death in vitro. In the present study, we investigated the effect of EDA on damage of IAA-induced primary cerebellar granule neurons (CGNs and its possible underlying mechanisms. We found that EDA attenuated IAA-induced cell injury in CGNs. Moreover, EDA significantly reduced intracellular reactive oxidative stress production, loss of mitochondrial membrane potential, and caspase 3 activity induced by IAA. Taken together, EDA protected CGNs against IAA-induced neuronal damage, which may be attributed to its antiapoptotic and antioxidative activities.

  2. Ketamine Causes Mitochondrial Dysfunction in Human Induced Pluripotent Stem Cell-Derived Neurons

    Science.gov (United States)

    Ito, Hiroyuki; Uchida, Tokujiro; Makita, Koshi

    2015-01-01

    Purpose Ketamine toxicity has been demonstrated in nonhuman mammalian neurons. To study the toxic effect of ketamine on human neurons, an experimental model of cultured neurons from human induced pluripotent stem cells (iPSCs) was examined, and the mechanism of its toxicity was investigated. Methods Human iPSC-derived dopaminergic neurons were treated with 0, 20, 100 or 500 μM ketamine for 6 and 24 h. Ketamine toxicity was evaluated by quantification of caspase 3/7 activity, reactive oxygen species (ROS) production, mitochondrial membrane potential, ATP concentration, neurotransmitter reuptake activity and NADH/NAD+ ratio. Mitochondrial morphological change was analyzed by transmission electron microscopy and confocal microscopy. Results Twenty-four-hour exposure of iPSC-derived neurons to 500 μM ketamine resulted in a 40% increase in caspase 3/7 activity (P ketamine (100 μM) decreased the ATP level (22%, P ketamine concentration, which suggests that mitochondrial dysfunction preceded ROS generation and caspase activation. Conclusions We established an in vitro model for assessing the neurotoxicity of ketamine in iPSC-derived neurons. The present data indicate that the initial mitochondrial dysfunction and autophagy may be related to its inhibitory effect on the mitochondrial electron transport system, which underlies ketamine-induced neural toxicity. Higher ketamine concentration can induce ROS generation and apoptosis in human neurons. PMID:26020236

  3. CAMKII activation is not required for maintenance of learning-induced enhancement of neuronal excitability.

    Directory of Open Access Journals (Sweden)

    Ori Liraz

    Full Text Available Pyramidal neurons in the piriform cortex from olfactory-discrimination trained rats show enhanced intrinsic neuronal excitability that lasts for several days after learning. Such enhanced intrinsic excitability is mediated by long-term reduction in the post-burst after-hyperpolarization (AHP which is generated by repetitive spike firing. AHP reduction is due to decreased conductance of a calcium-dependent potassium current, the sI(AHP. We have previously shown that learning-induced AHP reduction is maintained by persistent protein kinase C (PKC and extracellular regulated kinase (ERK activation. However, the molecular machinery underlying this long-lasting modulation of intrinsic excitability is yet to be fully described. Here we examine whether the CaMKII, which is known to be crucial in learning, memory and synaptic plasticity processes, is instrumental for the maintenance of learning-induced AHP reduction. KN93, that selectively blocks CaMKII autophosphorylation at Thr286, reduced the AHP in neurons from trained and control rat to the same extent. Consequently, the differences in AHP amplitude and neuronal adaptation between neurons from trained rats and controls remained. Accordingly, the level of activated CaMKII was similar in pirifrom cortex samples taken form trained and control rats. Our data show that although CaMKII modulates the amplitude of AHP of pyramidal neurons in the piriform cortex, its activation is not required for maintaining learning-induced enhancement of neuronal excitability.

  4. Generation of induced neurons by direct reprogramming in the mammalian cochlea.

    Science.gov (United States)

    Nishimura, K; Weichert, R M; Liu, W; Davis, R L; Dabdoub, A

    2014-09-05

    Primary auditory neurons (ANs) in the mammalian cochlea play a critical role in hearing as they transmit auditory information in the form of electrical signals from mechanosensory cochlear hair cells in the inner ear to the brainstem. Their progressive degeneration is associated with disease conditions, excessive noise exposure and aging. Replacement of ANs, which lack the ability to regenerate spontaneously, would have a significant impact on research and advancement in cochlear implants in addition to the amelioration of hearing impairment. The aim of this study was to induce a neuronal phenotype in endogenous non-neural cells in the cochlea, which is the essential organ of hearing. Overexpression of a neurogenic basic helix-loop-helix transcription factor, Ascl1, in the cochlear non-sensory epithelial cells induced neurons at high efficiency at embryonic, postnatal and juvenile stages. Moreover, induced neurons showed typical properties of neuron morphology, gene expression and electrophysiology. Our data indicate that Ascl1 alone or Ascl1 and NeuroD1 is sufficient to reprogram cochlear non-sensory epithelial cells into functional neurons. Generation of neurons from non-neural cells in the cochlea is an important step for the regeneration of ANs in the mature mammalian cochlea. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. DL-2-amino-3-phosphonopropionic acid protects primary neurons from oxygen-glucose deprivation induced injury

    Directory of Open Access Journals (Sweden)

    Di Cui

    2017-02-01

    Full Text Available Cerebral infarction is a type of ischemic stroke and is one of the main causes of irreversible brain damage. Although multiple neuroprotective agents have been investigated recently, the potential of DL-2-amino-3-phosphonopropionic acid (DL-AP3 in treating oxygen-glucose deprivation (OGD-induced neuronal injury, has not been clarified yet. This study was aimed to explore the role of DL-AP3 in primary neuronal cell cultures. Primary neurons were divided into four groups: (1 a control group that was not treated; (2 DL-AP3 group treated with 10 μM of DL-AP3; (3 OGD group, in which neurons were cultured under OGD conditions; and (4 OGD + DL-AP3 group, in which OGD model was first established and then the cells were treated with 10 μM of DL-AP3. Neuronal viability and apoptosis were measured using Cell Counting Kit-8 and flow cytometry. Expressions of phospho-Akt1 (p-Akt1 and cytochrome c were detected using Western blot. The results showed that DL-AP3 did not affect neuronal viability and apoptosis in DL-AP3 group, nor it changed p-Akt1 and cytochrome c expression (p > 0.05. In OGD + DL-AP3 group, DL-AP3 significantly attenuated the inhibitory effects of OGD on neuronal viability (p < 0.001, and reduced OGD induced apoptosis (p < 0.01. Additionally, the down-regulation of p-Akt1 and up-regulation of cytochrome c, induced by OGD, were recovered to some extent after DL-AP3 treatment (p < 0.05 or p < 0.001. Overall, DL-AP3 could protect primary neurons from OGD-induced injury by affecting the viability and apoptosis of neurons, and by regulating the expressions of p-Akt1 and cytochrome c.

  6. Thiamine deficiency induces endoplasmic reticulum stress and oxidative stress in human neurons derived from induced pluripotent stem cells.

    Science.gov (United States)

    Wang, Xin; Xu, Mei; Frank, Jacqueline A; Ke, Zun-Ji; Luo, Jia

    2017-04-01

    Thiamine (vitamin B1) deficiency (TD) plays a major role in the etiology of Wernicke's encephalopathy (WE) which is a severe neurological disorder. TD induces selective neuronal cell death, neuroinflammation, endoplasmic reticulum (ER) stress and oxidative stress in the brain which are commonly observed in many aging-related neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and progressive supranuclear palsy (PSP). However, the underlying cellular and molecular mechanisms remain unclear. The progress in this line of research is hindered due to the lack of appropriate in vitro models. The neurons derived for the human induced pluripotent stem cells (hiPSCs) provide a relevant and powerful tool for the research in pharmaceutical and environmental neurotoxicity. In this study, we for the first time used human induced pluripotent stem cells (hiPSCs)-derived neurons (iCell neurons) to investigate the mechanisms of TD-induced neurodegeneration. We showed that TD caused a concentration- and duration-dependent death of iCell neurons. TD induced ER stress which was evident by the increase in ER stress markers, such as GRP78, XBP-1, CHOP, ATF-6, phosphorylated eIF2α, and cleaved caspase-12. TD also triggered oxidative stress which was shown by the increase in the expression 2,4-dinitrophenyl (DNP) and 4-hydroxynonenal (HNE). ER stress inhibitors (STF-083010 and salubrinal) and antioxidant N-acetyl cysteine (NAC) were effective in alleviating TD-induced death of iCell neurons, supporting the involvement of ER stress and oxidative stress. It establishes that the iCell neurons are a novel tool to investigate cellular and molecular mechanisms for TD-induced neurodegeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Vagal stimulation targets select populations of intrinsic cardiac neurons to control neurally induced atrial fibrillation.

    Science.gov (United States)

    Salavatian, Siamak; Beaumont, Eric; Longpré, Jean-Philippe; Armour, J Andrew; Vinet, Alain; Jacquemet, Vincent; Shivkumar, Kalyanam; Ardell, Jeffrey L

    2016-11-01

    Mediastinal nerve stimulation (MNS) reproducibly evokes atrial fibrillation (AF) by excessive and heterogeneous activation of intrinsic cardiac (IC) neurons. This study evaluated whether preemptive vagus nerve stimulation (VNS) impacts MNS-induced evoked changes in IC neural network activity to thereby alter susceptibility to AF. IC neuronal activity in the right atrial ganglionated plexus was directly recorded in anesthetized canines (n = 8) using a linear microelectrode array concomitant with right atrial electrical activity in response to: 1) epicardial touch or great vessel occlusion vs. 2) stellate or vagal stimulation. From these stressors, post hoc analysis (based on the Skellam distribution) defined IC neurons so recorded as afferent, efferent, or convergent (afferent and efferent inputs) local circuit neurons (LCN). The capacity of right-sided MNS to modify IC activity in the induction of AF was determined before and after preemptive right (RCV)- vs. left (LCV)-sided VNS (15 Hz, 500 μs; 1.2× bradycardia threshold). Neuronal (n = 89) activity at baseline (0.11 ± 0.29 Hz) increased during MNS-induced AF (0.51 ± 1.30 Hz; P neuronal synchrony increased during neurally induced AF, a local neural network response mitigated by preemptive VNS. These antiarrhythmic effects persisted post-VNS for, on average, 26 min. In conclusion, VNS preferentially targets convergent LCNs and their interactive coherence to mitigate the potential for neurally induced AF. The antiarrhythmic properties imposed by VNS exhibit memory. Copyright © 2016 the American Physiological Society.

  8. Administration of Protocatechuic Acid Reduces Traumatic Brain Injury-Induced Neuronal Death

    Directory of Open Access Journals (Sweden)

    Sang Hwon Lee

    2017-11-01

    Full Text Available Protocatechuic acid (PCA was first purified from green tea and has shown numerous biological activities, including anti-apoptotic, anti-inflammatory, and anti-atherosclerotic effects. The effect of PCA on traumatic brain injury (TBI-induced neuronal death has not previously been evaluated. TBI is defined as damage to the brain resulting from external mechanical force, such as rapid acceleration or deceleration, impact, blast waves, or penetration by a projectile. TBI causes neuronal death in the hippocampus and cerebral cortex. The present study aimed to evaluate the therapeutic potential of PCA on TBI-induced neuronal death. Here, TBI was induced by a controlled cortical impact model using rats. PCA (30 mg/kg was injected into the intraperitoneal (ip space immediately after TBI. Neuronal death was evaluated with Fluoro Jade-B (FJB staining at 24 h after TBI. Oxidative injury was detected by 4-hydroxy-2-nonenal (4HNE, glutathione (GSH concentration was analyzed by glutathione adduct with N-ethylmaleimide (GS-NEM staining at 24 h after TBI, and microglial activation in the hippocampus was detected by CD11b immunohistochemistry at one week after TBI. We found that the proportion of degenerating neurons, oxidative injury, GSH depletion, and microglia activation in the hippocampus and cortex were all reduced by PCA treatment following TBI. Therefore, our study suggests that PCA may have therapeutic potential in preventing TBI-induced neuronal death.

  9. Generalized synchronization induced by noise and parameter mismatching in Hindmarsh-Rose neurons

    International Nuclear Information System (INIS)

    Wu Ying; Xu Jianxue; He Daihai; Earn, David J.D.

    2005-01-01

    Synchronization of two simple neuron models has been investigated in many studies. Thresholds for complete synchronization (CS) and phase synchronization (PS) have been obtained for coupling by diffusion or noise. In addition, it has been shown that it is possible for directional diffusion to induce generalized synchronization (GS) in a pair of neuron models even if the neurons are not identical (and differ in a single parameter). We study a system of two uncoupled, nonidentical Hindmarsh-Rose (HR) neurons and show that GS can be achieved by a combination of noise and changing the value of a second parameter in one of the neurons (the second parameter mismatch cancels the first). The significance of this approach will be the greatest in situations where the parameter that is originally mismatched cannot be controlled, but a suitable controllable parameter can be identified

  10. Induced pluripotent stem cell-derived neuron as a human model for testing environmentally induced developmental neurotoxicity

    Science.gov (United States)

    Induced pluripotent stem cell-derived neurons as a human model for testing environmentally induced developmental neurotoxicity Ingrid L. Druwe1, Timothy J. Shafer2, Kathleen Wallace2, Pablo Valdivia3 ,and William R. Mundy2. 1University of North Carolina, Curriculum in Toxicology...

  11. Neuroprotective effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis

    Science.gov (United States)

    Sun, Xin-zhi; Liao, Ying; Li, Wei; Guo, Li-mei

    2017-01-01

    Ganoderma lucidum polysaccharides have protective effects against apoptosis in neurons exposed to ischemia/reperfusion injury, but the mechanisms are unclear. The goal of this study was to investigate the underlying mechanisms of the effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis. Hydrogen peroxide (H2O2) was used to induce apoptosis in cultured cerebellar granule cells. In these cells, ganoderma lucidum polysaccharides remarkably suppressed H2O2-induced apoptosis, decreased expression of caspase-3, Bax and Bim and increased that of Bcl-2. These findings suggested that ganoderma lucidum polysaccharides regulate expression of apoptosis-associated proteins, inhibit oxidative stress-induced neuronal apoptosis and, therefore, have significant neuroprotective effects. PMID:28761429

  12. Induced dopaminergic neurons: A new promise for Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Zhimin Xu

    2017-04-01

    Full Text Available Motor symptoms that define Parkinson’s disease (PD are caused by the selective loss of nigral dopaminergic (DA neurons. Cell replacement therapy for PD has been focused on midbrain DA neurons derived from human fetal mesencephalic tissue, human embryonic stem cells (hESC or human induced pluripotent stem cells (iPSC. Recent development in the direct conversion of human fibroblasts to induced dopaminergic (iDA neurons offers new opportunities for transplantation study and disease modeling in PD. The iDA neurons are generated directly from human fibroblasts in a short period of time, bypassing lengthy differentiation process from human pluripotent stem cells and the concern for potentially tumorigenic mitotic cells. They exhibit functional dopaminergic neurotransmission and relieve locomotor symptoms in animal models of Parkinson’s disease. In this review, we will discuss this recent development and its implications to Parkinson’s disease research and therapy.

  13. Microtubule Abnormalities Underlying Gulf War Illness in Neurons from Human-Induced Pluripotent Cells

    Science.gov (United States)

    2016-09-01

    cells derived from human induced pluripotent stem cells (hiPSCs), originating from GW...AWARD NUMBER: W81XWH-15-1-0433 TITLE: Microtubule Abnormalities Underlying Gulf War Illness in Neurons from Human- Induced Pluripotent Cells ...A simple blood sample is taken from the soldier, and then transduced, using reliable established methods , to make the cells pluripotent .

  14. Piriform cortical glutamatergic and GABAergic neurons express coordinated plasticity for whisker-induced odor recall.

    Science.gov (United States)

    Liu, Yahui; Gao, Zilong; Chen, Changfeng; Wen, Bo; Huang, Li; Ge, Rongjing; Zhao, Shidi; Fan, Ruichen; Feng, Jing; Lu, Wei; Wang, Liping; Wang, Jin-Hui

    2017-11-10

    Neural plasticity occurs in learning and memory. Coordinated plasticity at glutamatergic and GABAergic neurons during memory formation remains elusive, which we investigate in a mouse model of associative learning by cellular imaging and electrophysiology. Paired odor and whisker stimulations lead to whisker-induced olfaction response. In mice that express this cross-modal memory, the neurons in the piriform cortex are recruited to encode newly acquired whisker signal alongside innate odor signal, and their response patterns to these associated signals are different. There are emerged synaptic innervations from barrel cortical neurons to piriform cortical neurons from these mice. These results indicate the recruitment of associative memory cells in the piriform cortex after associative memory. In terms of the structural and functional plasticity at these associative memory cells in the piriform cortex, glutamatergic neurons and synapses are upregulated, GABAergic neurons and synapses are downregulated as well as their mutual innervations are refined in the coordinated manner. Therefore, the associated activations of sensory cortices triggered by their input signals induce the formation of their mutual synapse innervations, the recruitment of associative memory cells and the coordinated plasticity between the GABAergic and glutamatergic neurons, which work for associative memory cells to encode cross-modal associated signals in their integration, associative storage and distinguishable retrieval.

  15. Naphthazarin protects against glutamate-induced neuronal death via activation of the Nrf2/ARE pathway.

    Science.gov (United States)

    Son, Tae Gen; Kawamoto, Elisa M; Yu, Qian-Sheng; Greig, Nigel H; Mattson, Mark P; Camandola, Simonetta

    2013-04-19

    Nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is an important cellular stress response pathway involved in neuroprotection. We previously screened several natural phytochemicals and identified plumbagin as a novel activator of the Nrf2/ARE pathway that can protect neurons against ischemic injury. Here we extended our studies to natural and synthetic derivatives of plumbagin. We found that 5,8-dimethoxy-1,4-naphthoquinone (naphthazarin) is a potent activator of the Nrf2/ARE pathway, up-regulates the expression of Nrf2-driven genes in primary neuronal and glial cultures, and protects neurons against glutamate-induced excitotoxicity. Published by Elsevier Inc.

  16. Vasodilatation in the rat dorsal hindpaw induced by activation of sensory neurons is reduced by Paclitaxel

    OpenAIRE

    Gracias, N.G.; Cummins, T.R.; Kelley, M.R.; Basile, D.P.; Iqbal, T.; Vasko, M.R.

    2010-01-01

    Peripheral neuropathy is a major side effect following treatment with the cancer chemotherapeutic drug paclitaxel. Whether paclitaxel-induced peripheral neuropathy is secondary to altered function of small diameter sensory neurons remains controversial. To ascertain whether the function of the small diameter sensory neurons was altered following systemic administration of paclitaxel, we injected male Sprague Dawley rats with 1 mg/kg paclitaxel every other day for a total of four doses and exa...

  17. Bee Venom Protects against Rotenone-Induced Cell Death in NSC34 Motor Neuron Cells

    Directory of Open Access Journals (Sweden)

    So Young Jung

    2015-09-01

    Full Text Available Rotenone, an inhibitor of mitochondrial complex I of the mitochondrial respiratory chain, is known to elevate mitochondrial reactive oxygen species and induce apoptosis via activation of the caspase-3 pathway. Bee venom (BV extracted from honey bees has been widely used in oriental medicine and contains melittin, apamin, adolapin, mast cell-degranulating peptide, and phospholipase A2. In this study, we tested the effects of BV on neuronal cell death by examining rotenone-induced mitochondrial dysfunction. NSC34 motor neuron cells were pretreated with 2.5 μg/mL BV and stimulated with 10 μM rotenone to induce cell toxicity. We assessed cell death by Western blotting using specific antibodies, such as phospho-ERK1/2, phospho-JNK, and cleaved capase-3 and performed an MTT assay for evaluation of cell death and mitochondria staining. Pretreatment with 2.5 μg/mL BV had a neuroprotective effect against 10 μM rotenone-induced cell death in NSC34 motor neuron cells. Pre-treatment with BV significantly enhanced cell viability and ameliorated mitochondrial impairment in rotenone-treated cellular model. Moreover, BV treatment inhibited the activation of JNK signaling and cleaved caspase-3 related to cell death and increased ERK phosphorylation involved in cell survival in rotenone-treated NSC34 motor neuron cells. Taken together, we suggest that BV treatment can be useful for protection of neurons against oxidative stress or neurotoxin-induced cell death.

  18. Generation of NSE-MerCreMer transgenic mice with tamoxifen inducible Cre activity in neurons.

    Directory of Open Access Journals (Sweden)

    Mandy Ka Man Kam

    Full Text Available To establish a genetic tool for conditional deletion or expression of gene in neurons in a temporally controlled manner, we generated a transgenic mouse (NSE-MerCreMer, which expressed a tamoxifen inducible type of Cre recombinase specifically in neurons. The tamoxifen inducible Cre recombinase (MerCreMer is a fusion protein containing Cre recombinase with two modified estrogen receptor ligand binding domains at both ends, and is driven by the neural-specific rat neural specific enolase (NSE promoter. A total of two transgenic lines were established, and expression of MerCreMer in neurons of the central and enteric nervous systems was confirmed. Transcript of MerCreMer was detected in several non-neural tissues such as heart, liver, and kidney in these lines. In the background of the Cre reporter mouse strain Rosa26R, Cre recombinase activity was inducible in neurons of adult NSE-MerCreMer mice treated with tamoxifen by intragastric gavage, but not in those fed with corn oil only. We conclude that NSE-MerCreMer lines will be useful for studying gene functions in neurons for the conditions that Cre-mediated recombination resulting in embryonic lethality, which precludes investigation of gene functions in neurons through later stages of development and in adult.

  19. Adult hippocampus derived soluble factors induce a neuronal-like phenotype in mesenchymal stem cells.

    Science.gov (United States)

    Rivera, Francisco J; Sierralta, Walter D; Minguell, Jose J; Aigner, Ludwig

    2006-10-02

    Bone marrow-derived mesenchymal stem cells (MSCs) are not restricted in their differentiation fate to cells of the mesenchymal lineage. They acquire a neural phenotype in vitro and in vivo after transplantation in the central nervous system. Here we investigated whether soluble factors derived from different brain regions are sufficient to induce a neuronal phenotype in MSCs. We incubated bone marrow-derived MSCs in conditioned medium (CM) derived from adult hippocampus (HCM), cortex (CoCM) or cerebellum (CeCM) and analyzed the cellular morphology and the expression of neuronal and glial markers. In contrast to muscle derived conditioned medium, which served as control, conditioned medium derived from the different brain regions induced a neuronal morphology and the expression of the neuronal markers GAP-43 and neurofilaments in MSCs. Hippocampus derived conditioned medium had the strongest activity. It was independent of NGF or BDNF; and it was restricted to the neuronal differentiation fate, since no induction of the astroglial marker GFAP was observed. The work indicates that soluble factors present in the brain are sufficient to induce a neuronal phenotype in MSCs.

  20. Generation of Induced Neuronal Cells by the Single Reprogramming Factor ASCL1

    Directory of Open Access Journals (Sweden)

    Soham Chanda

    2014-08-01

    Full Text Available Direct conversion of nonneural cells to functional neurons holds great promise for neurological disease modeling and regenerative medicine. We previously reported rapid reprogramming of mouse embryonic fibroblasts (MEFs into mature induced neuronal (iN cells by forced expression of three transcription factors: ASCL1, MYT1L, and BRN2. Here, we show that ASCL1 alone is sufficient to generate functional iN cells from mouse and human fibroblasts and embryonic stem cells, indicating that ASCL1 is the key driver of iN cell reprogramming in different cell contexts and that the role of MYT1L and BRN2 is primarily to enhance the neuronal maturation process. ASCL1-induced single-factor neurons (1F-iN expressed mature neuronal markers, exhibited typical passive and active intrinsic membrane properties, and formed functional pre- and postsynaptic structures. Surprisingly, ASCL1-induced iN cells were predominantly excitatory, demonstrating that ASCL1 is permissive but alone not deterministic for the inhibitory neuronal lineage.

  1. Roles of acid sphingomyelinase activation in neuronal cells apoptosis induced by microwave irradiation

    International Nuclear Information System (INIS)

    Zhang Lei; Xu Shangcheng; Zhang Guangbin; Yu Zhengping

    2009-01-01

    The present study is to examine the effect of microwave on acid sphingomyelinase (ASM) activity and expression, and to explore the role of ASM activation in neuronal cells apoptosis induced by microwave irradiation. Primary cultured hippocampal neurons were irradiated by 30 W/cm 2 microwave for 10 min, and ASM activity assay was used to investigate ASM activity alteration. RT-PCR and western blot were used to detect ASM mRNA and protein expression respectively. Apoptosis was observed by Hoechst 33342 fluorescence staining. ASM specific inhibitor imipramine was applied to inhibit ASM activation. It has been found that apoptosis rate of primary cultured hippocampal neurons increased significantly after microwave irradiation. ASM was activated while ASM mRNA and protein expression were upregulated in neurons after microwave irradiation. Pretreatment with imipramine could reverse neuronal apoptosis induced by microwave irradiation. Results show that microwave irradiation causes increment of ASM activation and expression and ASM activation is involved in microwave induced neuronal apoptosis. (authors)

  2. Fluoxetine protects against IL-1β-induced neuronal apoptosis via downregulation of p53.

    Science.gov (United States)

    Shan, Han; Bian, Yaqi; Shu, Zhaoma; Zhang, Linxia; Zhu, Jialei; Ding, Jianhua; Lu, Ming; Xiao, Ming; Hu, Gang

    2016-08-01

    Fluoxetine, a selective serotonin reuptake inhibitor, exerts neuroprotective effects in a variety of neurological diseases including stroke, but the underlying mechanism remains obscure. In the present study, we addressed the molecular events in fluoxetine against ischemia/reperfusion-induced acute neuronal injury and inflammation-induced neuronal apoptosis. We showed that treatment of fluoxetine (40 mg/kg, i.p.) with twice injections at 1 h and 12 h after transient middle cerebral artery occlusion (tMCAO) respectively alleviated neurological deficits and neuronal apoptosis in a mouse ischemic stroke model, accompanied by inhibiting interleukin-1β (IL-1β), Bax and p53 expression and upregulating anti-apoptotic protein Bcl-2 level. We next mimicked neuroinflammation in ischemic stroke with IL-1β in primary cultured cortical neurons and found that pretreatment with fluoxetine (1 μM) prevented IL-1β-induced neuronal apoptosis and upregulation of p53 expression. Furthermore, we demonstrated that p53 overexpression in N2a cell line abolished the anti-apoptotic effect of fluoxetine, indicating that p53 downregulation is required for the protective role of fluoxetine in IL-1β-induced neuronal apoptosis. Fluoxetine downregulating p53 expression could be mimicked by SB203580, a specific inhibitor of p38, but blocked by anisomycin, a p38 activator. Collectively, our findings have revealed that fluoxetine protects against IL-1β-induced neuronal apoptosis via p38-p53 dependent pathway, which give us an insight into the potential of fluoxetine in terms of opening up novel therapeutic avenues for neurological diseases including stroke. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. MDMA-induced neurotoxicity of serotonin neurons involves autophagy and rilmenidine is protective against its pathobiology.

    Science.gov (United States)

    Mercer, Linda D; Higgins, Gavin C; Lau, Chew L; Lawrence, Andrew J; Beart, Philip M

    2017-05-01

    Toxicity of 3,4-methylenedioxymethamphetamine (MDMA) towards biogenic amine neurons is well documented and in primate brain predominantly affects serotonin (5-HT) neurons. MDMA induces damage of 5-HT axons and nerve fibres and intracytoplasmic inclusions. Whilst its pathobiology involves mitochondrially-mediated oxidative stress, we hypothesised MDMA possessed the capacity to activate autophagy, a proteostatic mechanism for degradation of cellular debris. We established a culture of ventral pons from embryonic murine brain enriched in 5-HT neurons to explore mechanisms of MDMA neurotoxicity and recruitment of autophagy, and evaluated possible neuroprotective actions of the clinically approved agent rilmenidine. MDMA (100 μM-1 mM) reduced cell viability, like rapamycin (RM) and hydrogen peroxide (H 2 O 2 ), in a concentration- and time-dependent manner. Immunocytochemistry revealed dieback of 5-HT arbour: MDMA-induced injury was slower than for RM and H 2 O 2 , neuritic blebbing occurred at 48 and 72 h and Hoechst labelling revealed nuclear fragmentation with 100 μM MDMA. MDMA effected concentration-dependent inhibition of [ 3 H]5-HT uptake with 500 μM MDMA totally blocking transport. Western immunoblotting for microtubule associated protein light chain 3 (LC3) revealed autophagosome formation after treatment with MDMA. Confocal analyses and immunocytochemistry for 5-HT, Hoechst and LC3 confirmed MDMA induced autophagy with abundant LC3-positive puncta within 5-HT neurons. Rilmenidine (1 μM) protected against MDMA-induced injury and image analysis showed full preservation of 5-HT arbours. MDMA had no effect on GABA neurons, indicating specificity of action at 5-HT neurons. MDMA-induced neurotoxicity involves autophagy induction in 5-HT neurons, and rilmenidine via beneficial actions against toxic intracellular events represents a potential treatment for its pathobiology in sustained usage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. The Effects of IGF-1 on Trk Expressing DRG Neurons with HIV-gp120- Induced Neurotoxicity.

    Science.gov (United States)

    Li, Hao; Liu, Zhen; Chi, Heng; Bi, Yanwen; Song, Lijun; Liu, Huaxiang

    2016-01-01

    HIV envelope glycoprotein gp120 is the main protein that causes HIVassociated sensory neuropathy. However, the underlying mechanisms of gp120-induced neurotoxicity are still unclear. There are lack effective treatments for relieving HIV-related neuropathic symptoms caused by gp120-induced neurotoxicity. In the present study, tyrosine kinase receptor (Trk)A, TrkB, and TrkC expression in primary cultured dorsal root ganglion (DRG) neurons with gp120-induced neurotoxicity was investigated. The effects of IGF-1 on distinct Trk-positive DRG neurons with gp120-induced neurotoxicity were also determined. The results showed that gp120 not only dose-dependently induced DRG neuronal apoptosis and inhibited neuronal survival and neurite outgrowth, but also decreased distinct Trk expression levels. IGF-1 rescued DRG neurons from apoptosis and improved neuronal survival of gp120 neurotoxic DRG neurons in vitro. IGF-1 also improved TrkA and TrkB, but not TrkC, expression in gp120 neurotoxic conditions. The effects of IGF-1 could be blocked by preincubation with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. These results suggested that gp120 may have a wide range of neurotoxicity on different subpopulations of DRG neurons, while IGF-1 might only relieve some subpopulations of DRG neurons with gp120-induced neurotoxicity. These data provide novel information of mechanisms of gp120 neurotoxicity on primary sensory neurons and the potential therapeutic effects of IGF-1 on gp120-induced neurotoxicity.

  5. Aberrant neuronal activity-induced signaling and gene expression in a mouse model of RASopathy.

    Directory of Open Access Journals (Sweden)

    Franziska Altmüller

    2017-03-01

    Full Text Available Noonan syndrome (NS is characterized by reduced growth, craniofacial abnormalities, congenital heart defects, and variable cognitive deficits. NS belongs to the RASopathies, genetic conditions linked to mutations in components and regulators of the Ras signaling pathway. Approximately 50% of NS cases are caused by mutations in PTPN11. However, the molecular mechanisms underlying cognitive impairments in NS patients are still poorly understood. Here, we report the generation and characterization of a new conditional mouse strain that expresses the overactive Ptpn11D61Y allele only in the forebrain. Unlike mice with a global expression of this mutation, this strain is viable and without severe systemic phenotype, but shows lower exploratory activity and reduced memory specificity, which is in line with a causal role of disturbed neuronal Ptpn11 signaling in the development of NS-linked cognitive deficits. To explore the underlying mechanisms we investigated the neuronal activity-regulated Ras signaling in brains and neuronal cultures derived from this model. We observed an altered surface expression and trafficking of synaptic glutamate receptors, which are crucial for hippocampal neuronal plasticity. Furthermore, we show that the neuronal activity-induced ERK signaling, as well as the consecutive regulation of gene expression are strongly perturbed. Microarray-based hippocampal gene expression profiling revealed profound differences in the basal state and upon stimulation of neuronal activity. The neuronal activity-dependent gene regulation was strongly attenuated in Ptpn11D61Y neurons. In silico analysis of functional networks revealed changes in the cellular signaling beyond the dysregulation of Ras/MAPK signaling that is nearly exclusively discussed in the context of NS at present. Importantly, changes in PI3K/AKT/mTOR and JAK/STAT signaling were experimentally confirmed. In summary, this study uncovers aberrant neuronal activity-induced

  6. DL-2-amino-3-phosphonopropionic acid protects primary neurons from oxygen-glucose deprivation induced injury.

    Science.gov (United States)

    Cui, Di; Xu, Jun; Xu, Quanyi; Zuo, Guokun

    2017-02-21

    Cerebral infarction is a type of ischemic stroke and is one of the main causes of irreversible brain damage. Although multiple neuroprotective agents have been investigated recently, the potential of DL-2-amino-3-phosphonopropionic acid (DL-AP3) in treating oxygen-glucose deprivation (OGD)-induced neuronal injury, has not been clarified yet. This study was aimed to explore the role of DL-AP3 in primary neuronal cell cultures. Primary neurons were divided into four groups: (1) a control group that was not treated; (2) DL-AP3 group treated with 10 μM of DL-AP3; (3) OGD group, in which neurons were cultured under OGD conditions; and (4) OGD + DL-AP3 group, in which OGD model was first established and then the cells were treated with 10 μM of DL-AP3. Neuronal viability and apoptosis were measured using Cell Counting Kit-8 and flow cytometry. Expressions of phospho-Akt1 (p-Akt1) and cytochrome c were detected using Western blot. The results showed that DL-AP3 did not affect neuronal viability and apoptosis in DL-AP3 group, nor it changed p-Akt1 and cytochrome c expression (p > 0.05). In OGD + DL-AP3 group, DL-AP3 significantly attenuated the inhibitory effects of OGD on neuronal viability (p neurons from OGD-induced injury by affecting the viability and apoptosis of neurons, and by regulating the expressions of p-Akt1 and cytochrome c.

  7. Methamphetamine induces heme oxygenase-1 expression in cortical neurons and glia to prevent its toxicity

    International Nuclear Information System (INIS)

    Huang, Y.-N.; Wu, C.-H.; Lin, T.-C.; Wang, J.-Y.

    2009-01-01

    The impairment of cognitive and motor functions in humans and animals caused by methamphetamine (METH) administration underscores the importance of METH toxicity in cortical neurons. The heme oxygenase-1 (HO-1) exerts a cytoprotective effect against various neuronal injures; however, it remains unclear whether HO-1 is involved in METH-induced toxicity. We used primary cortical neuron/glia cocultures to explore the role of HO-1 in METH-induced toxicity. Exposure of cultured cells to various concentrations of METH (0.1, 0.5, 1, 3, 5, and 10 mM) led to cytotoxicity in a concentration-dependent manner. A METH concentration of 5 mM, which caused 50% of neuronal death and glial activation, was chosen for subsequent experiments. RT-PCR and Western blot analysis revealed that METH significantly induced HO-1 mRNA and protein expression, both preceded cell death. Double and triple immunofluorescence staining further identified HO-1-positive cells as activated astrocytes, microglia, and viable neurons, but not dying neurons. Inhibition of the p38 mitogen-activated protein kinase pathway significantly blocked HO-1 induction by METH and aggravated METH neurotoxicity. Inhibition of HO activity using tin protoporphyrine IX significantly reduced HO activity and exacerbated METH neurotoxicity. However, prior induction of HO-1 using cobalt protoporphyrine IX partially protected neurons from METH toxicity. Taken together, our results suggest that induction of HO-1 by METH via the p38 signaling pathway may be protective, albeit insufficient to completely protect cortical neurons from METH toxicity.

  8. Autophagy induction by SIRT6 is involved in oxidative stress-induced neuronal damage

    Directory of Open Access Journals (Sweden)

    Jiaxiang Shao

    2016-03-01

    Full Text Available Abstract SIRT6 is a NAD+-dependent histone deacetylase and has been implicated in the regulation of genomic stability, DNA repair, metabolic homeostasis and several diseases. The effect of SIRT6 in cerebral ischemia and oxygen/glucose deprivation (OGD has been reported, however the role of SIRT6 in oxidative stress damage remains unclear. Here we used SH-SY5Y neuronal cells and found that overexpression of SIRT6 led to decreased cell viability and increased necrotic cell death and reactive oxygen species (ROS production under oxidative stress. Mechanistic study revealed that SIRT6 induced autophagy via attenuation of AKT signaling and treatment with autophagy inhibitor 3-MA or knockdown of autophagy-related protein Atg5 rescued H2O2-induced neuronal injury. Conversely, SIRT6 inhibition suppressed autophagy and reduced oxidative stress-induced neuronal damage. These results suggest that SIRT6 might be a potential therapeutic target for neuroprotection.

  9. Glucose and insulin induce Ca2+ signaling in nesfatin-1 neurons in the hypothalamic paraventricular nucleus.

    Science.gov (United States)

    Gantulga, Darambazar; Maejima, Yuko; Nakata, Masanori; Yada, Toshihiko

    2012-04-20

    Nucleobindin-2 derived nesfatin-1 in the hypothalamic paraventricular nucleus (PVN) plays a role in inhibition of feeding. The neural pathways downstream of PVN nesfatin-1 have been extensively investigated. However, regulation of the PVN nesfatin-1 neurons remains unclear. Since starvation decreases and refeeding stimulates nesfatin-1 expression specifically in the PVN, this study aimed to clarify direct effects of meal-evoked metabolic factors, glucose and insulin, on PVN nesfatin-1 neurons. High glucose (10mM) and insulin (10(-13)M) increased cytosolic calcium concentration ([Ca(2+)](i)) in 55 of 331 (16.6%) and 32 of 249 (12.9%) PVN neurons, respectively. Post [Ca(2+)](i) measurement immunocytochemistry identified that 58.2% of glucose-responsive and 62.5% of insulin-responsive neurons were immunoreactive to nesfatin-1. Furthermore, a fraction of the glucose-responsive nesfatin-1 neurons also responded to insulin, and vice versa. Some of the neurons that responded to neither glucose nor insulin were recruited to [Ca(2+)](i) increases by glucose and insulin in combination. Our data demonstrate that glucose and insulin directly interact with and increase [Ca(2+)](i) in nesfatin-1 neurons in the PVN, and that the nesfatin-1 neuron is the primary target for them in the PVN. The results suggest that high glucose- and insulin-induced activation of PVN nesfatin-1 neurons serves as a mechanism through which meal ingestion stimulates nesfatin-1 neurons in the PVN and thereby produces satiety. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. N-Methyl-d-Aspartate (NMDA Receptor Blockade Prevents Neuronal Death Induced by Zika Virus Infection

    Directory of Open Access Journals (Sweden)

    Vivian V. Costa

    2017-04-01

    Full Text Available Zika virus (ZIKV infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N-methyl-d-aspartate receptor (NMDAR-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801, agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration.

  11. Antioxidant enzyme gene delivery to protect from HIV-1 gp120-induced neuronal apoptosis.

    Science.gov (United States)

    Agrawal, L; Louboutin, J-P; Reyes, B A S; Van Bockstaele, E J; Strayer, D S

    2006-12-01

    Human immunodeficiency virus-1 (HIV-1) infection in the central nervous system (CNS) may lead to neuronal loss and progressively deteriorating CNS function: HIV-1 gene products, especially gp120, induce free radical-mediated apoptosis. Reactive oxygen species (ROS), are among the potential mediators of these effects. Neurons readily form ROS after gp120 exposure, and so might be protected from ROS-mediated injury by antioxidant enzymes such as Cu/Zn-superoxide dismutase (SOD1) and/or glutathione peroxidase (GPx1). Both enzymes detoxify oxygen free radicals. As they are highly efficient gene delivery vehicles for neurons, recombinant SV40-derived vectors were used for these studies. Cultured mature neurons derived from NT2 cells and primary fetal neurons were transduced with rSV40 vectors carrying human SOD1 and/or GPx1 cDNAs, then exposed to gp120. Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. Transduction efficiency of both neuron populations was >95%, as assayed by immunostaining. Transgene expression was also ascertained by Western blotting and direct assays of enzyme activity. Gp120 induced apoptosis in a high percentage of unprotected NT2-N. Transduction with SV(SOD1) and SV(GPx1) before gp120 challenge reduced neuronal apoptosis by >90%. Even greater protection was seen in cells treated with both vectors in sequence. Given singly or in combination, they protect neuronal cells from HIV-1-gp120 induced apoptosis. We tested whether rSV40 s can deliver antioxidant enzymes to the CNS in vivo: intracerebral injection of SV(SOD1) or SV(GPx1) into the caudate putamen of rat brain yielded excellent transgene expression in neurons. In vivo transduction using SV(SOD1) also protected neurons from subsequent gp120-induced apoptosis after injection of both into the caudate putamen of rat brain. Thus, SOD1 and GPx1 can be delivered by SV40 vectors in vitro or in vivo. This approach may merit consideration for

  12. Vagal stimulation targets select populations of intrinsic cardiac neurons to control neurally induced atrial fibrillation

    Science.gov (United States)

    Salavatian, Siamak; Beaumont, Eric; Longpré, Jean-Philippe; Armour, J. Andrew; Vinet, Alain; Jacquemet, Vincent; Shivkumar, Kalyanam

    2016-01-01

    Mediastinal nerve stimulation (MNS) reproducibly evokes atrial fibrillation (AF) by excessive and heterogeneous activation of intrinsic cardiac (IC) neurons. This study evaluated whether preemptive vagus nerve stimulation (VNS) impacts MNS-induced evoked changes in IC neural network activity to thereby alter susceptibility to AF. IC neuronal activity in the right atrial ganglionated plexus was directly recorded in anesthetized canines (n = 8) using a linear microelectrode array concomitant with right atrial electrical activity in response to: 1) epicardial touch or great vessel occlusion vs. 2) stellate or vagal stimulation. From these stressors, post hoc analysis (based on the Skellam distribution) defined IC neurons so recorded as afferent, efferent, or convergent (afferent and efferent inputs) local circuit neurons (LCN). The capacity of right-sided MNS to modify IC activity in the induction of AF was determined before and after preemptive right (RCV)- vs. left (LCV)-sided VNS (15 Hz, 500 μs; 1.2× bradycardia threshold). Neuronal (n = 89) activity at baseline (0.11 ± 0.29 Hz) increased during MNS-induced AF (0.51 ± 1.30 Hz; P < 0.001). Convergent LCNs were preferentially activated by MNS. Preemptive RCV reduced MNS-induced changes in LCN activity (by 70%) while mitigating MNS-induced AF (by 75%). Preemptive LCV reduced LCN activity by 60% while mitigating AF potential by 40%. IC neuronal synchrony increased during neurally induced AF, a local neural network response mitigated by preemptive VNS. These antiarrhythmic effects persisted post-VNS for, on average, 26 min. In conclusion, VNS preferentially targets convergent LCNs and their interactive coherence to mitigate the potential for neurally induced AF. The antiarrhythmic properties imposed by VNS exhibit memory. PMID:27591222

  13. Mitochondrial mislocalization underlies Abeta42-induced neuronal dysfunction in a Drosophila model of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Kanae Iijima-Ando

    2009-12-01

    Full Text Available The amyloid-beta 42 (Abeta42 is thought to play a central role in the pathogenesis of Alzheimer's disease (AD. However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial damage or neurodegeneration. In contrast, organization of microtubule or global axonal transport was not significantly altered at this stage. Abeta42-induced behavioral defects were exacerbated by genetic reductions in mitochondrial transport, and were modulated by cAMP levels and PKA activity. Levels of putative PKA substrate phosphoproteins were reduced in the Abeta42 fly brains. Importantly, perturbations in mitochondrial transport in neurons were sufficient to disrupt PKA signaling and induce late-onset behavioral deficits, suggesting a mechanism whereby mitochondrial mislocalization contributes to Abeta42-induced neuronal dysfunction. These results demonstrate that mislocalization of mitochondria underlies the pathogenic effects of Abeta42 in vivo.

  14. Inhibitory Effect of Lycopene on Amyloid-β-Induced Apoptosis in Neuronal Cells.

    Science.gov (United States)

    Hwang, Sinwoo; Lim, Joo Weon; Kim, Hyeyoung

    2017-08-16

    Alzheimer's disease (AD) is a fatal neurodegenerative disease. Brain amyloid-β deposition is a crucial feature of AD, causing neuronal cell death by inducing oxidative damage. Reactive oxygen species (ROS) activate NF-κB, which induces expression of Nucling. Nucling is a pro-apoptotic factor recruiting the apoptosome complex. Lycopene is an antioxidant protecting from oxidative stress-induced cell damage. We investigated whether lycopene inhibits amyloid-β-stimulated apoptosis through reducing ROS and inhibiting mitochondrial dysfunction and NF-κB-mediated Nucling expression in neuronal SH-SY5Y cells. We prepared cells transfected with siRNA for Nucling or nontargeting control siRNA to determine the role of Nucling in amyloid-β-induced apoptosis. The amyloid-β increased intracellular and mitochondrial ROS levels, apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), NF-kB activation and Nucling expression, while cell viability, mitochondrial membrane potential, and oxygen consumption rate decreased in SH-SY5Y cells. Lycopene inhibited these amyloid-β-induced alterations. However, amyloid-β did not induce apoptosis, determined by cell viability and apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), in the cells transfected with siRNA for Nucling. Lycopene inhibited apoptosis by reducing ROS, and by inhibiting mitochondrial dysfunction and NF-κB-target gene Nucling expression in neuronal cells. Lycopene may be beneficial for preventing oxidative stress-mediated neuronal death in patients with neurodegeneration.

  15. Oleuropein isolated from Fraxinus rhynchophylla inhibits glutamate-induced neuronal cell death by attenuating mitochondrial dysfunction.

    Science.gov (United States)

    Kim, Mi Hye; Min, Ju-Sik; Lee, Joon Yeop; Chae, Unbin; Yang, Eun-Ju; Song, Kyung-Sik; Lee, Hyun-Shik; Lee, Hong Jun; Lee, Sang-Rae; Lee, Dong-Seok

    2017-04-27

    Glutamate-induced neurotoxicity is related to excessive oxidative stress accumulation and results in the increase of neuronal cell death. In addition, glutamate has been reported to lead to neurodegenerative diseases, including Parkinson's and Alzheimer's diseases.It is well known that Fraxinus rhynchophylla contains a significant level of oleuropein (Ole), which exerts various pharmacological effects. However, the mechanism of neuroprotective effects of Ole is still poorly defined. In this study, we aimed to investigate whether Ole prevents glutamate-induced toxicity in HT-22 hippocampal neuronal cells. The exposure of the glutamate treatment caused neuronal cell death through an alteration of Bax/Bcl-2 expression and translocation of mitochondrial apoptosis-inducing factor (AIF) to the cytoplasm of HT-22 cells. In addition, glutamate induced an increase in dephosphorylation of dynamin-related protein 1 (Drp1), mitochondrial fragmentation, and mitochondrial dysfunction. The pretreatment of Ole decreased Bax expression, increased Bcl-2 expression, and inhibited the translocation of mitochondrial AIF to the cytoplasm. Furthermore, Ole amended a glutamate-induced mitochondrial dynamic imbalance and reduced the number of cells with fragmented mitochondria, regulating the phosphorylation of Drp1 at amino acid residue serine 637. In conclusion, our results show that Ole has a preventive effect against glutamate-induced toxicity in HT-22 hippocampal neuronal cells. Therefore, these data imply that Ole may be an efficient approach for the treatment of neurodegenerative diseases.

  16. Hippocampal adaptive response following extensive neuronal loss in an inducible transgenic mouse model.

    Directory of Open Access Journals (Sweden)

    Kristoffer Myczek

    Full Text Available Neuronal loss is a common component of a variety of neurodegenerative disorders (including Alzheimer's, Parkinson's, and Huntington's disease and brain traumas (stroke, epilepsy, and traumatic brain injury. One brain region that commonly exhibits neuronal loss in several neurodegenerative disorders is the hippocampus, an area of the brain critical for the formation and retrieval of memories. Long-lasting and sometimes unrecoverable deficits caused by neuronal loss present a unique challenge for clinicians and for researchers who attempt to model these traumas in animals. Can these deficits be recovered, and if so, is the brain capable of regeneration following neuronal loss? To address this significant question, we utilized the innovative CaM/Tet-DT(A mouse model that selectively induces neuronal ablation. We found that we are able to inflict a consistent and significant lesion to the hippocampus, resulting in hippocampally-dependent behavioral deficits and a long-lasting upregulation in neurogenesis, suggesting that this process might be a critical part of hippocampal recovery. In addition, we provide novel evidence of angiogenic and vasculature changes following hippocampal neuronal loss in CaM/Tet-DTA mice. We posit that angiogenesis may be an important factor that promotes neurogenic upregulation following hippocampal neuronal loss, and both factors, angiogenesis and neurogenesis, can contribute to the adaptive response of the brain for behavioral recovery.

  17. Brain-derived neurotrophic factor mediates estradiol-induced dendritic spine formation in hippocampal neurons

    Science.gov (United States)

    Murphy, Diane D.; Cole, Nelson B.; Segal, Menahem

    1998-01-01

    Dendritic spines are of major importance in information processing and memory formation in central neurons. Estradiol has been shown to induce an increase of dendritic spine density on hippocampal neurons in vivo and in vitro. The neurotrophin brain-derived neurotrophic factor (BDNF) recently has been implicated in neuronal maturation, plasticity, and regulation of GABAergic interneurons. We now demonstrate that estradiol down-regulates BDNF in cultured hippocampal neurons to 40% of control values within 24 hr of exposure. This, in turn, decreases inhibition and increases excitatory tone in pyramidal neurons, leading to a 2-fold increase in dendritic spine density. Exogenous BDNF blocks the effects of estradiol on spine formation, and BDNF depletion with a selective antisense oligonucleotide mimics the effects of estradiol. Addition of BDNF antibodies also increases spine density, and diazepam, which facilitates GABAergic neurotransmission, blocks estradiol-induced spine formation. These observations demonstrate a functional link between estradiol, BDNF as a potent regulator of GABAergic interneurons, and activity-dependent formation of dendritic spines in hippocampal neurons. PMID:9736750

  18. Role for PKC-ε in neuronal death induced by oxidative stress

    International Nuclear Information System (INIS)

    Jung, Yi-Sook; Ryu, Bo Rum; Lee, Bo Kyung; Mook-Jung, Inhee; Kim, Seung Up; Lee, Soo Hwan; Baik, Eun Joo; Moon, Chang-Hyun

    2004-01-01

    We investigated which isoforms of PKCs can be modulated and what their roles are during L-buthionine-S,R-sulfoximine (BSO)-induced neuronal death. We observed the isoform specific translocation of PKC-ε from the soluble fraction to the particulate in cortical neurons treated with 10 mM BSO. The translocation of PKC-ε by BSO was blocked by antioxidant trolox, suggesting the PKC-ε as a downstream of reactive oxygen species (ROS) elevated by BSO. Trolox inhibited the ROS elevation and the neuronal death in BSO-treated cortical cells. The BSO-induced neuronal death was remarkably inhibited by both the pharmacological inhibition of PKC-ε with εV1-2 and the functional blockade for PKC-ε through overexpression of PKC-ε V1 region, suggesting the detrimental role of PKC-ε. These results suggest that PKC-ε is the major PKC isoform involved in the pathways triggered by ROS, leading to neuronal death in BSO-treated cortical neurons

  19. TFEB ameliorates the impairment of the autophagy-lysosome pathway in neurons induced by doxorubicin

    Science.gov (United States)

    Moruno Manchon, Jose Felix; Uzor, Ndidi-Ese; Kesler, Shelli R.; Wefel, Jeffrey S.; Townley, Debra M.; Nagaraja, Archana Sidalaghatta; Pradeep, Sunila; Mangala, Lingegowda S.; Sood, Anil K.; Tsvetkov, Andrey S.

    2016-01-01

    Doxorubicin, a commonly used chemotherapy agent, induces severe cardio- and neurotoxicity. Molecular mechanisms of cardiotoxicity have been extensively studied, but mechanisms by which doxorubicin exhibits its neurotoxic properties remain unclear. Here, we show that doxorubicin impairs neuronal autophagy, leading to the accumulation of an autophagy substrate p62. Neurons treated with doxorubicin contained autophagosomes, damaged mitochondria, and lipid droplets. The brains from mice treated with pegylated liposomal doxorubicin exhibited autophagosomes, often with mitochondria, lipofuscin, and lipid droplets. Interestingly, lysosomes were less acidic in doxorubicin-treated neurons. Overexpression of the transcription factor EB (TFEB), which controls the autophagy-lysosome axis, increased survival of doxorubicin-treated neurons. 2-Hydroxypropyl-β-cyclodextrin (HPβCD), an activator of TFEB, also promoted neuronal survival, decreased the levels of p62, and lowered the pH in lysosomes. Taken together, substantial changes induced by doxorubicin contribute to neurotoxicity, cognitive disturbances in cancer patients and survivors, and accelerated brain aging. The TFEB pathway might be a new approach for mitigating damage of neuronal autophagy caused by doxorubicin. PMID:27992857

  20. 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

    2010-01-01

    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, β-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 µM 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. PMID:16546145

  1. Induced Pluripotent Stem Cell Models of Progranulin-Deficient Frontotemporal Dementia Uncover Specific Reversible Neuronal Defects

    Directory of Open Access Journals (Sweden)

    Sandra Almeida

    2012-10-01

    Full Text Available The pathogenic mechanisms of frontotemporal dementia (FTD remain poorly understood. Here we generated multiple induced pluripotent stem cell lines from a control subject, a patient with sporadic FTD, and an FTD patient with a novel heterozygous GRN mutation (progranulin [PGRN] S116X. In neurons and microglia differentiated from PGRN S116X induced pluripotent stem cells, the levels of intracellular and secreted PGRN were reduced, establishing patient-specific cellular models of PGRN haploinsufficiency. Through a systematic screen of inducers of cellular stress, we found that PGRN S116X neurons, but not sporadic FTD neurons, exhibited increased sensitivity to staurosporine and other kinase inhibitors. Moreover, the serine/threonine kinase S6K2, a component of the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways, was specifically downregulated in PGRN S116X neurons. Both increased sensitivity to kinase inhibitors and reduced S6K2 were rescued by PGRN expression. Our findings identify cell-autonomous, reversible defects in patient neurons with PGRN deficiency, and provide a compelling model for studying PGRN-dependent pathogenic mechanisms and testing potential therapies.

  2. Endogenous α-crystallin inhibits expression of caspase-3 induced by hypoxia in retinal neurons.

    Science.gov (United States)

    Ying, Xi; Peng, Yanli; Zhang, Jiaping; Wang, Xingli; Wu, Nan; Zeng, Yuxiao; Wang, Yi

    2014-08-28

    To investigate the expression of endogenous, hypoxic stress-induced α-crystallin and caspase-3 in rat retinal neurons in vitro. Retinal neurons were cultured from Long-Evans rats. The expression of endogenous α-crystallin was analyzed by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). Furthermore, hypoxic exposure was performed in cultured cells, and the expression of endogenous α-crystallin and caspase-3 was assayed by Western blotting. Positive α-crystallin staining was observed in cultured retinal neurons, and expression of endogenous α-crystallin mRNA peaked 3-5d after inoculation (Pendogenous, hypoxic stress-induced α-crystallin expression increased gradually, peaking 6h after hypoxia. The expression was more abundant compared to the control (Pendogenous α-crystallin in retinal neurons, especially over-expression induced by hypoxic stress, results in the down regulation of caspase-3. The data suggest that endogenous α-crystallin may act as an endogenous neuroprotective factor in retinal neurons. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Activation of AMP-activated protein kinase by tributyltin induces neuronal cell death

    International Nuclear Information System (INIS)

    Nakatsu, Yusuke; Kotake, Yaichiro; Hino, Atsuko; Ohta, Shigeru

    2008-01-01

    AMP-activated protein kinase (AMPK), a member of the metabolite-sensing protein kinase family, is activated by energy deficiency and is abundantly expressed in neurons. The environmental pollutant, tributyltin chloride (TBT), is a neurotoxin, and has been reported to decrease cellular ATP in some types of cells. Therefore, we investigated whether TBT activates AMPK, and whether its activation contributes to neuronal cell death, using primary cultures of cortical neurons. Cellular ATP levels were decreased 0.5 h after exposure to 500 nM TBT, and the reduction was time-dependent. It was confirmed that most neurons in our culture system express AMPK, and that TBT induced phosphorylation of AMPK. Compound C, an AMPK inhibitor, reduced the neurotoxicity of TBT, suggesting that AMPK is involved in TBT-induced cell death. Next, the downstream target of AMPK activation was investigated. Nitric oxide synthase, p38 phosphorylation and Akt dephosphorylation were not downstream of TBT-induced AMPK activation because these factors were not affected by compound C, but glutamate release was suggested to be controlled by AMPK. Our results suggest that activation of AMPK by TBT causes neuronal death through mediating glutamate release

  4. Dynamics of Time Delay-Induced Multiple Synchronous Behaviors in Inhibitory Coupled Neurons

    Science.gov (United States)

    Gu, Huaguang; Zhao, Zhiguo

    2015-01-01

    The inhibitory synapse can induce synchronous behaviors different from the anti-phase synchronous behaviors, which have been reported in recent studies. In the present paper, synchronous behaviors are investigated in the motif model composed of reciprocal inhibitory coupled neurons with endogenous bursting and time delay. When coupling strength is weak, synchronous behavior appears at a single interval of time delay within a bursting period. When coupling strength is strong, multiple synchronous behaviors appear at different intervals of time delay within a bursting period. The different bursting patterns of synchronous behaviors, and time delays and coupling strengths that can induce the synchronous bursting patterns can be well interpreted by the dynamics of the endogenous bursting pattern of isolated neuron, which is acquired by the fast-slow dissection method, combined with the inhibitory coupling current. For an isolated neuron, when a negative impulsive current with suitable strength is applied at different phases of the bursting, multiple different bursting patterns can be induced. For a neuron in the motif, the inhibitory coupling current, of which the application time and strength is modulated by time delay and coupling strength, can cause single or multiple synchronous firing patterns like the negative impulsive current when time delay and coupling strength is suitable. The difference compared to the previously reported multiple synchronous behaviors that appear at time delays wider than a period of the endogenous firing is discussed. The results present novel examples of synchronous behaviors in the neuronal network with inhibitory synapses and provide a reasonable explanation. PMID:26394224

  5. Fractal characterization of acupuncture-induced spike trains of rat WDR neurons

    International Nuclear Information System (INIS)

    Chen, Yingyuan; Guo, Yi; Wang, Jiang; Hong, Shouhai; Wei, Xile; Yu, Haitao; Deng, Bin

    2015-01-01

    Highlights: •Fractal analysis is a valuable tool for measuring MA-induced neural activities. •In course of the experiments, the spike trains display different fractal properties. •The fractal properties reflect the long-term modulation of MA on WDR neurons. •The results may explain the long-lasting effects induced by acupuncture. -- Abstract: The experimental and the clinical studies have showed manual acupuncture (MA) could evoke multiple responses in various neural regions. Characterising the neuronal activities in these regions may provide more deep insights into acupuncture mechanisms. This paper used fractal analysis to investigate MA-induced spike trains of Wide Dynamic Range (WDR) neurons in rat spinal dorsal horn, an important relay station and integral component in processing acupuncture information. Allan factor and Fano factor were utilized to test whether the spike trains were fractal, and Allan factor were used to evaluate the scaling exponents and Hurst exponents. It was found that these two fractal exponents before and during MA were different significantly. During MA, the scaling exponents of WDR neurons were regulated in a small range, indicating a special fractal pattern. The neuronal activities were long-range correlated over multiple time scales. The scaling exponents during and after MA were similar, suggesting that the long-range correlations not only displayed during MA, but also extended to after withdrawing the needle. Our results showed that fractal analysis is a useful tool for measuring acupuncture effects. MA could modulate neuronal activities of which the fractal properties change as time proceeding. This evolution of fractal dynamics in course of MA experiments may explain at the level of neuron why the effect of MA observed in experiment and in clinic are complex, time-evolutionary, long-range even lasting for some time after stimulation

  6. A novel perspective on neuron study: damaging and promoting effects in different neurons induced by mechanical stress.

    Science.gov (United States)

    Wang, Yazhou; Wang, Wei; Li, Zong; Hao, Shilei; Wang, Bochu

    2016-10-01

    A growing volume of experimental evidence demonstrates that mechanical stress plays a significant role in growth, proliferation, apoptosis, gene expression, electrophysiological properties and many other aspects of neurons. In this review, first, the mechanical microenvironment and properties of neurons under in vivo conditions are introduced and analyzed. Second, research works in recent decades on the effects of different mechanical forces, especially compression and tension, on various neurons, including dorsal root ganglion neurons, retinal ganglion cells, cerebral cortex neurons, hippocampus neurons, neural stem cells, and other neurons, are summarized. Previous research results demonstrate that mechanical stress can not only injure neurons by damaging their morphology, impacting their electrophysiological characteristics and gene expression, but also promote neuron self-repair. Finally, some future perspectives in neuron research are discussed.

  7. Cultured hypothalamic neurons are resistant to inflammation and insulin resistance induced by saturated fatty acids.

    Science.gov (United States)

    Choi, Sun Ju; Kim, Francis; Schwartz, Michael W; Wisse, Brent E

    2010-06-01

    Hypothalamic inflammation induced by high-fat feeding causes insulin and leptin resistance and contributes to the pathogenesis of obesity. Since in vitro exposure to saturated fatty acids causes inflammation and insulin resistance in many cultured cell types, we determined how cultured hypothalamic neurons respond to this stimulus. Two murine hypothalamic neuronal cell cultures, N43/5 and GT1-7, were exposed to escalating concentrations of saturated fatty acids for up to 24 h. Harvested cells were evaluated for activation of inflammation by gene expression and protein content. Insulin-treated cells were evaluated for induction of markers of insulin receptor signaling (p-IRS, p-Akt). In both hypothalamic cell lines, inflammation was induced by prototypical inflammatory mediators LPS and TNFalpha, as judged by induction of IkappaBalpha (3- to 5-fold) and IL-6 (3- to 7-fold) mRNA and p-IkappaBalpha protein, and TNFalpha pretreatment reduced insulin-mediated p-Akt activation by 30% (P fatty acid (100, 250, or 500 microM for neurons, whereas they did in control muscle and endothelial cell lines. Despite the lack of evidence of inflammatory signaling, saturated fatty acid exposure in cultured hypothalamic neurons causes endoplasmic reticulum stress, induces mitogen-activated protein kinase, and causes apoptotic cell death with prolonged exposure. We conclude that saturated fatty acid exposure does not induce inflammatory signaling or insulin resistance in cultured hypothalamic neurons. Therefore, hypothalamic neuronal inflammation in the setting of DIO may involve an indirect mechanism mediated by saturated fatty acids on nonneuronal cells.

  8. Chronic ciguatoxin treatment induces synaptic scaling through voltage gated sodium channels in cortical neurons.

    Science.gov (United States)

    Martín, Víctor; Vale, Carmen; Rubiolo, Juan A; Roel, Maria; Hirama, Masahiro; Yamashita, Shuji; Vieytes, Mercedes R; Botana, Luís M

    2015-06-15

    Ciguatoxins are sodium channels activators that cause ciguatera, one of the most widespread nonbacterial forms of food poisoning, which presents with long-term neurological alterations. In central neurons, chronic perturbations in activity induce homeostatic synaptic mechanisms that adjust the strength of excitatory synapses and modulate glutamate receptor expression in order to stabilize the overall activity. Immediate early genes, such as Arc and Egr1, are induced in response to activity changes and underlie the trafficking of glutamate receptors during neuronal homeostasis. To better understand the long lasting neurological consequences of ciguatera, it is important to establish the role that chronic changes in activity produced by ciguatoxins represent to central neurons. Here, the effect of a 30 min exposure of 10-13 days in vitro (DIV) cortical neurons to the synthetic ciguatoxin CTX 3C on Arc and Egr1 expression was evaluated using real-time polymerase chain reaction approaches. Since the toxin increased the mRNA levels of both Arc and Egr1, the effect of CTX 3C in NaV channels, membrane potential, firing activity, miniature excitatory postsynaptic currents (mEPSCs), and glutamate receptors expression in cortical neurons after a 24 h exposure was evaluated using electrophysiological and western blot approaches. The data presented here show that CTX 3C induced an upregulation of Arc and Egr1 that was prevented by previous coincubation of the neurons with the NaV channel blocker tetrodotoxin. In addition, chronic CTX 3C caused a concentration-dependent shift in the activation voltage of NaV channels to more negative potentials and produced membrane potential depolarization. Moreover, 24 h treatment of cortical neurons with 5 nM CTX 3C decreased neuronal firing and induced synaptic scaling mechanisms, as evidenced by a decrease in the amplitude of mEPSCs and downregulation in the protein level of glutamate receptors that was also prevented by tetrodotoxin

  9. Hypoxic pretreatment protects against neuronal damage of the rat hippocampus induced by severe hypoxia.

    Science.gov (United States)

    Gorgias, N; Maidatsi, P; Tsolaki, M; Alvanou, A; Kiriazis, G; Kaidoglou, K; Giala, M

    1996-04-01

    The present study investigates whether under conditions of successive hypoxic exposures pretreatment with mild (15% O(2)) or moderate (10% O(2)) hypoxia, protects hippocampal neurones against damage induced by severe (3% O(2)) hypoxia. The ultrastructural findings were also correlated with regional superoxide dismutase (SOD) activity changes. In unpretreated rats severe hypoxia induced ultrastructural changes consistent with the aspects of delayed neuronal death (DND). However, in preexposed animals hippocampal damage was attenuated in an inversely proportional way with the severity of the hypoxic pretreatment. The ultrastructural hypoxic tolerance findings were also closely related to increased regional SOD activity levels. Thus the activation of the endogenous antioxidant defense by hypoxic preconditioning, protects against hippocampal damage induced by severe hypoxia. The eventual contribution of increased endogenous adenosine and/or reduced excitotoxicity to induce hypoxic tolerance is discussed.

  10. Intracellular Methamphetamine Prevents the Dopamine-induced Enhancement of Neuronal Firing*

    Science.gov (United States)

    Saha, Kaustuv; Sambo, Danielle; Richardson, Ben D.; Lin, Landon M.; Butler, Brittany; Villarroel, Laura; Khoshbouei, Habibeh

    2014-01-01

    The dysregulation of the dopaminergic system is implicated in multiple neurological and neuropsychiatric disorders such as Parkinson disease and drug addiction. The primary target of psychostimulants such as amphetamine and methamphetamine is the dopamine transporter (DAT), the major regulator of extracellular dopamine levels in the brain. However, the behavioral and neurophysiological correlates of methamphetamine and amphetamine administration are unique from one another, thereby suggesting these two compounds impact dopaminergic neurotransmission differentially. We further examined the unique mechanisms by which amphetamine and methamphetamine regulate DAT function and dopamine neurotransmission; in the present study we examined the impact of extracellular and intracellular amphetamine and methamphetamine on the spontaneous firing of cultured midbrain dopaminergic neurons and isolated DAT-mediated current. In dopaminergic neurons the spontaneous firing rate was enhanced by extracellular application of amphetamine > dopamine > methamphetamine and was DAT-dependent. Amphetamine > methamphetamine similarly enhanced DAT-mediated inward current, which was sensitive to isosmotic substitution of Na+ or Cl− ion. Although isosmotic substitution of extracellular Na+ ions blocked amphetamine and methamphetamine-induced DAT-mediated inward current similarly, the removal of extracellular Cl− ions preferentially blocked amphetamine-induced inward current. The intracellular application of methamphetamine, but not amphetamine, prevented the dopamine-induced increase in the spontaneous firing of dopaminergic neurons and the corresponding DAT-mediated inward current. The results reveal a new mechanism for methamphetamine-induced dysregulation of dopaminergic neurons. PMID:24962577

  11. Rat model of cancer-induced bone pain: changes in nonnociceptive sensory neurons in vivo

    Directory of Open Access Journals (Sweden)

    Yong Fang Zhu

    2017-08-01

    Conclusion:. After induction of the CIBP model, Aβ-fiber LTMs at >2 weeks but not <1 week had undergone changes in electrophysiological properties. Importantly, changes observed are consistent with observations in models of peripheral neuropathy. Thus, Aβ-fiber nonnociceptive primary sensory neurons might be involved in the peripheral sensitization and tumor-induced tactile hypersensitivity in CIBP.

  12. Mitochondrial permeability transition pore inhibitors prevent ethanol-induced neuronal death in mice.

    Science.gov (United States)

    Lamarche, Frederic; Carcenac, Carole; Gonthier, Brigitte; Cottet-Rousselle, Cecile; Chauvin, Christiane; Barret, Luc; Leverve, Xavier; Savasta, Marc; Fontaine, Eric

    2013-01-18

    Ethanol induces brain injury by a mechanism that remains partly unknown. Mitochondria play a key role in cell death processes, notably through the opening of the permeability transition pore (PTP). Here, we tested the effect of ethanol and PTP inhibitors on mitochondrial physiology and cell viability both in vitro and in vivo. Direct addition of ethanol up to 100 mM on isolated mouse brain mitochondria slightly decreased oxygen consumption but did not affect PTP regulation. In comparison, when isolated from ethanol-treated (two doses of 2 g/kg, 2 h apart) 7-day-old mouse pups, brain mitochondria displayed a transient decrease in oxygen consumption but no change in PTP regulation or H2O2 production. Conversely, exposure of primary cultured astrocytes and neurons to 20 mM ethanol for 3 days led to a transient PTP opening in astrocytes without affecting cell viability and to a permanent PTP opening in 10 to 20% neurons with the same percentage of cell death. Ethanol-treated mouse pups displayed a widespread caspase-3 activation in neurons but not in astrocytes and dramatic behavioral alterations. Interestingly, two different PTP inhibitors (namely, cyclosporin A and nortriptyline) prevented both ethanol-induced neuronal death in vivo and ethanol-induced behavioral modifications. We conclude that PTP opening is involved in ethanol-induced neurotoxicity in the mouse.

  13. Volume regulated anion channel currents of rat hippocampal neurons and their contribution to oxygen-and-glucose deprivation induced neuronal death.

    Directory of Open Access Journals (Sweden)

    Huaqiu Zhang

    2011-02-01

    Full Text Available Volume-regulated anion channels (VRAC are widely expressed chloride channels that are critical for the cell volume regulation. In the mammalian central nervous system, the physiological expression of neuronal VRAC and its role in cerebral ischemia are issues largely unknown. We show that hypoosmotic medium induce an outwardly rectifying chloride conductance in CA1 pyramidal neurons in rat hippocampal slices. The induced chloride conductance was sensitive to some of the VRAC inhibitors, namely, IAA-94 (300 µM and NPPB (100 µM, but not to tamoxifen (10 µM. Using oxygen-and-glucose deprivation (OGD to simulate ischemic conditions in slices, VRAC activation appeared after OGD induced anoxic depolarization (AD that showed a progressive increase in current amplitude over the period of post-OGD reperfusion. The OGD induced VRAC currents were significantly inhibited by inhibitors for glutamate AMPA (30 µM NBQX and NMDA (40 µM AP-5 receptors in the OGD solution, supporting the view that induction of AD requires an excessive Na(+-loading via these receptors that in turn to activate neuronal VRAC. In the presence of NPPB and DCPIB in the post-OGD reperfusion solution, the OGD induced CA1 pyramidal neuron death, as measured by TO-PRO-3-I staining, was significantly reduced, although DCPIB did not appear to be an effective neuronal VRAC blocker. Altogether, we show that rat hippocampal pyramidal neurons express functional VRAC, and ischemic conditions can initial neuronal VRAC activation that may contribute to ischemic neuronal damage.

  14. Characterization of Induced Pluripotent Stem Cell-derived Human Serotonergic Neurons

    Directory of Open Access Journals (Sweden)

    Lining Cao

    2017-05-01

    Full Text Available In the brain, the serotonergic neurons located in the raphe nucleus are the unique resource of the neurotransmitter serotonin, which plays a pivotal role in the regulation of brain development and functions. Dysfunction of the serotonin system is present in many psychiatric disorders. Lack of in vitro functional human model limits the understanding of human central serotonergic system and its related diseases and clinical applications. Previously, we have developed a method generating human serotonergic neurons from induced pluripotent stem cells (iPSCs. In this study, we analyzed the features of these human iPSCs-derived serotonergic neurons both in vitro and in vivo. We found that these human serotonergic neurons are sensitive to the selective neurotoxin 5, 7-Dihydroxytryptamine (5,7-DHT in vitro. After being transplanted into newborn mice, the cells not only expressed their typical molecular markers, but also showed the migration and projection to the host’s cerebellum, hindbrain and spinal cord. The data demonstrate that these human iPSCs-derived neurons exhibit the typical features as the serotonergic neurons in the brain, which provides a solid foundation for studying on human serotonin system and its related disorders.

  15. [Peripheral facial nerve lesion induced long-term dendritic retraction in pyramidal cortico-facial neurons].

    Science.gov (United States)

    Urrego, Diana; Múnera, Alejandro; Troncoso, Julieta

    2011-01-01

    Little evidence is available concerning the morphological modifications of motor cortex neurons associated with peripheral nerve injuries, and the consequences of those injuries on post lesion functional recovery. Dendritic branching of cortico-facial neurons was characterized with respect to the effects of irreversible facial nerve injury. Twenty-four adult male rats were distributed into four groups: sham (no lesion surgery), and dendritic assessment at 1, 3 and 5 weeks post surgery. Eighteen lesion animals underwent surgical transection of the mandibular and buccal branches of the facial nerve. Dendritic branching was examined by contralateral primary motor cortex slices stained with the Golgi-Cox technique. Layer V pyramidal (cortico-facial) neurons from sham and injured animals were reconstructed and their dendritic branching was compared using Sholl analysis. Animals with facial nerve lesions displayed persistent vibrissal paralysis throughout the five week observation period. Compared with control animal neurons, cortico-facial pyramidal neurons of surgically injured animals displayed shrinkage of their dendritic branches at statistically significant levels. This shrinkage persisted for at least five weeks after facial nerve injury. Irreversible facial motoneuron axonal damage induced persistent dendritic arborization shrinkage in contralateral cortico-facial neurons. This morphological reorganization may be the physiological basis of functional sequelae observed in peripheral facial palsy patients.

  16. Effects of lipopolysaccharide-induced inflammation on expression of growth-associated genes by corticospinal neurons

    Directory of Open Access Journals (Sweden)

    Lieberman AR

    2006-01-01

    Full Text Available Abstract Background Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker. Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation. Results Application of LPS induced a gradient of inflammation through the full depth of the motor cortex and promoted c-Jun and SCG10 expression for up to 2 weeks, and GAP-43 upregulation for 3 days by many corticospinal neurons, but had very limited effects on neuronal ATF3 expression. However, many glial cells in the subcortical white matter upregulated ATF3. LPS did not promote sprouting of anterogradely labelled corticospinal axons, which did not grow into or beyond a cervical lesion site. Conclusion Inflammation produced by topical application of LPS promoted increased expression of some growth-associated genes in the cell bodies of corticospinal neurons, but was insufficient to promote regeneration of the corticospinal tract.

  17. Prevention of acute/severe hypoglycemia-induced neuron death by lactate administration

    OpenAIRE

    Won, Seok Joon; Jang, Bong Geom; Yoo, Byung Hoon; Sohn, Min; Lee, Min Woo; Choi, Bo Young; Kim, Jin Hee; Song, Hong Ki; Suh, Sang Won

    2012-01-01

    Hypoglycemia-induced cerebral neuropathy can occur in patients with diabetes who attempt tight control of blood glucose and may lead to cognitive dysfunction. Accumulating evidence from animal models suggests that hypoglycemia-induced neuronal death is not a simple result of glucose deprivation, but is instead the end result of a multifactorial process. In particular, the excessive activation of poly (ADP-ribose) polymerase-1 (PARP-1) consumes cytosolic nicotinamide adenine dinucleotide (NAD+...

  18. Maintenance and Neuronal Differentiation of Chicken Induced Pluripotent Stem-Like Cells

    OpenAIRE

    Dai, Rui; Rossello, Ricardo; Chen, Chun-chun; Kessler, Joeran; Davison, Ian; Hochgeschwender, Ute; Jarvis, Erich D.

    2014-01-01

    Pluripotent stem cells have the potential to become any cell in the adult body, including neurons and glia. Avian stem cells could be used to study questions, like vocal learning, that would be difficult to examine with traditional mouse models. Induced pluripotent stem cells (iPSCs) are differentiated cells that have been reprogrammed to a pluripotent stem cell state, usually using inducing genes or other molecules. We recently succeeded in generating avian iPSC-like cells using mammalian ge...

  19. Induced Pluripotent Stem Cell Models of Progranulin-Deficient Frontotemporal Dementia Uncover Specific Reversible Neuronal Defects

    Science.gov (United States)

    Almeida, Sandra; Zhang, Zhijun; Coppola, Giovanni; Mao, Wenjie; Futai, Kensuke; Karydas, Anna; Geschwind, Michael D.; Tartaglia, M. Carmela; Gao, Fuying; Gianni, Davide; Sena-Esteves, Miguel; Geschwind, Daniel H.; Miller, Bruce L.; Farese, Robert V.; Gao, Fen-Biao

    2012-01-01

    SUMMARY The pathogenic mechanisms of frontotemporal dementia (FTD) remain poorly understood. Here we generated multiple induced pluripotent stem cell (iPSC) lines from a control subject, a patient with sporadic FTD, and an FTD patient with a novel GRN mutation (PGRN S116X). In neurons and microglia differentiated from PGRN S116X iPSCs, the levels of intracellular and secreted progranulin were reduced, establishing patient-specific cellular models of progranulin haploinsufficiency. Through a systematic screen of inducers of cellular stress, we found that PGRN S116X neurons, but not sporadic FTD neurons, exhibited increased sensitivity to staurosporine and other kinase inhibitors. Moreover, the serine/threonine kinase S6K2, a component of the PI3K and MAPK pathways, was specifically downregulated in PGRN S116X neurons. Both increased sensitivity to kinase inhibitors and reduced S6K2 were rescued by progranulin expression. Our findings identify cell-autonomous, reversible defects in patient neurons with progranulin deficiency and provide a new model for studying progranulin-dependent pathogenic mechanisms and testing potential therapies. PMID:23063362

  20. Mechanism of mesenchymal stem cell-induced neuron recovery and anti-inflammation.

    Science.gov (United States)

    Huang, Peng; Gebhart, Nichole; Richelson, Elliott; Brott, Thomas G; Meschia, James F; Zubair, Abba C

    2014-10-01

    After ischemic or hemorrhagic stroke, neurons in the penumbra surrounding regions of irreversible injury are vulnerable to delayed but progressive damage as a result of ischemia and hemin-induced neurotoxicity. There is no effective treatment to rescue such dying neurons. Mesenchymal stem cells (MSCs) hold promise for rescue of these damaged neurons. In this study, we evaluated the efficacy and mechanism of MSC-induced neuro-regeneration and immune modulation. Oxygen-glucose deprivation (OGD) was used in our study. M17 neuronal cells were subjected to OGD stress then followed by co-culture with MSCs. Rescue effects were evaluated using proliferation and apoptosis assays. Cytokine assay and quantitative polymerase chain reaction were used to explore the underlying mechanism. Antibody and small molecule blocking experiments were also performed to further understand the mechanism. We showed that M17 proliferation was significantly decreased and the rate of apoptosis increased after exposure to OGD. These effects could be alleviated via co-culture with MSCs. Tumor necrosis factor-α was found elevated after OGD stress and was back to normal levels after co-culture with MSCs. We believe these effects involve interleukin-6 and vascular endothelial growth factor signaling pathways. Our studies have shown that MSCs have anti-inflammatory properties and the capacity to rescue injured neurons. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  1. Modeling chemotherapeutic neurotoxicity with human induced pluripotent stem cell-derived neuronal cells.

    Directory of Open Access Journals (Sweden)

    Heather E Wheeler

    Full Text Available There are no effective agents to prevent or treat chemotherapy-induced peripheral neuropathy (CIPN, the most common non-hematologic toxicity of chemotherapy. Therefore, we sought to evaluate the utility of human neuron-like cells derived from induced pluripotent stem cells (iPSCs as a means to study CIPN. We used high content imaging measurements of neurite outgrowth phenotypes to compare the changes that occur to iPSC-derived neuronal cells among drugs and among individuals in response to several classes of chemotherapeutics. Upon treatment of these neuronal cells with the neurotoxic drug paclitaxel, vincristine or cisplatin, we identified significant differences in five morphological phenotypes among drugs, including total outgrowth, mean/median/maximum process length, and mean outgrowth intensity (P < 0.05. The differences in damage among drugs reflect differences in their mechanisms of action and clinical CIPN manifestations. We show the potential of the model for gene perturbation studies by demonstrating decreased expression of TUBB2A results in significantly increased sensitivity of neurons to paclitaxel (0.23 ± 0.06 decrease in total neurite outgrowth, P = 0.011. The variance in several neurite outgrowth and apoptotic phenotypes upon treatment with one of the neurotoxic drugs is significantly greater between than within neurons derived from four different individuals (P < 0.05, demonstrating the potential of iPSC-derived neurons as a genetically diverse model for CIPN. The human neuron model will allow both for mechanistic studies of specific genes and genetic variants discovered in clinical studies and for screening of new drugs to prevent or treat CIPN.

  2. Characterization of energy and neurotransmitter metabolism in cortical glutamatergic neurons derived from human induced pluripotent stem cells: A novel approach to study metabolism in human neurons.

    Science.gov (United States)

    Aldana, Blanca I; Zhang, Yu; Lihme, Maria Fog; Bak, Lasse K; Nielsen, Jørgen E; Holst, Bjørn; Hyttel, Poul; Freude, Kristine K; Waagepetersen, Helle S

    2017-06-01

    Alterations in the cellular metabolic machinery of the brain are associated with neurodegenerative disorders such as Alzheimer's disease. Novel human cellular disease models are essential in order to study underlying disease mechanisms. In the present study, we characterized major metabolic pathways in neurons derived from human induced pluripotent stem cells (hiPSC). With this aim, cultures of hiPSC-derived neurons were incubated with [U- 13 C]glucose, [U- 13 C]glutamate or [U- 13 C]glutamine. Isotopic labeling in metabolites was determined using gas chromatography coupled to mass spectrometry, and cellular amino acid content was quantified by high-performance liquid chromatography. Additionally, we evaluated mitochondrial function using real-time assessment of oxygen consumption via the Seahorse XF e 96 Analyzer. Moreover, in order to validate the hiPSC-derived neurons as a model system, a metabolic profiling was performed in parallel in primary neuronal cultures of mouse cerebral cortex and cerebellum. These serve as well-established models of GABAergic and glutamatergic neurons, respectively. The hiPSC-derived neurons were previously characterized as being forebrain-specific cortical glutamatergic neurons. However, a comparable preparation of predominantly mouse cortical glutamatergic neurons is not available. We found a higher glycolytic capacity in hiPSC-derived neurons compared to mouse neurons and a substantial oxidative metabolism through the mitochondrial tricarboxylic acid (TCA) cycle. This finding is supported by the extracellular acidification and oxygen consumption rates measured in the cultured human neurons. [U- 13 C]Glutamate and [U- 13 C]glutamine were found to be efficient energy substrates for the neuronal cultures originating from both mice and humans. Interestingly, isotopic labeling in metabolites from [U- 13 C]glutamate was higher than that from [U- 13 C]glutamine. Although the metabolic profile of hiPSC-derived neurons in vitro was

  3. Dehydration-induced modulation of κ-opioid inhibition of vasopressin neurone activity

    Science.gov (United States)

    Scott, Victoria; Bishop, Valerie R; Leng, Gareth; Brown, Colin H

    2009-01-01

    Dehydration increases vasopressin (antidiuretic hormone) secretion from the posterior pituitary gland to reduce water loss in the urine. Vasopressin secretion is determined by action potential firing in vasopressin neurones, which can exhibit continuous, phasic (alternating periods of activity and silence), or irregular activity. Autocrine κ-opioid inhibition contributes to the generation of activity patterning of vasopressin neurones under basal conditions and so we used in vivo extracellular single unit recording to test the hypothesis that changes in autocrine κ-opioid inhibition drive changes in activity patterning of vasopressin neurones during dehydration. Dehydration increased the firing rate of rat vasopressin neurones displaying continuous activity (from 7.1 ± 0.5 to 9.0 ± 0.6 spikes s−1) and phasic activity (from 4.2 ± 0.7 to 7.8 ± 0.9 spikes s−1), but not those displaying irregular activity. The dehydration-induced increase in phasic activity was via an increase in intraburst firing rate. The selective κ-opioid receptor antagonist nor-binaltorphimine increased the firing rate of phasic neurones in non-dehydrated rats (from 3.4 ± 0.8 to 5.3 ± 0.6 spikes s−1) and dehydrated rats (from 6.4 ± 0.5 to 9.1 ± 1.2 spikes s−1), indicating that κ-opioid feedback inhibition of phasic bursts is maintained during dehydration. In a separate series of experiments, prodynorphin mRNA expression was increased in vasopressin neurones of hyperosmotic rats, compared to hypo-osmotic rats. Hence, it appears that dynorphin expression in vasopressin neurones undergoes dynamic changes in proportion to the required secretion of vasopressin so that, even under stimulated conditions, autocrine feedback inhibition of vasopressin neurones prevents over-excitation. PMID:19822541

  4. Fractalkine is a "find-me" signal released by neurons undergoing ethanol-induced apoptosis.

    Science.gov (United States)

    Sokolowski, Jennifer D; Chabanon-Hicks, Chloe N; Han, Claudia Z; Heffron, Daniel S; Mandell, James W

    2014-01-01

    Apoptotic neurons generated during normal brain development or secondary to pathologic insults are efficiently cleared from the central nervous system. Several soluble factors, including nucleotides, cytokines, and chemokines are released from injured neurons, signaling microglia to find and clear debris. One such chemokine that serves as a neuronal-microglial communication factor is fractalkine, with roles demonstrated in several models of adult neurological disorders. Lacking, however, are studies investigating roles for fractalkine in perinatal brain injury, an important clinical problem with no effective therapies. We used a well-characterized mouse model of ethanol-induced apoptosis to assess the role of fractalkine in neuronal-microglial signaling. Quantification of apoptotic debris in fractalkine-knockout (KO) and CX3CR1-KO mice following ethanol treatment revealed increased apoptotic bodies compared to wild type mice. Ethanol-induced injury led to release of soluble, extracellular fractalkine. The extracellular media harvested from apoptotic brains induces microglial migration in a fractalkine-dependent manner that is prevented by neutralization of fractalkine with a blocking antibody or by deficiency in the receptor, CX3CR1. This suggests fractalkine acts as a "find-me" signal, recruiting microglial processes toward apoptotic cells to promote their clearance. Next, we aimed to determine whether there are downstream alterations in cytokine gene expression due to fractalkine signaling. We examined mRNA expression in fractalkine-KO and CX3CR1-KO mice after alcohol-induced apoptosis and found differences in cytokine production in the brains of these KOs by 6 h after ethanol treatment. Collectively, this suggests that fractalkine acts as a "find me" signal released by apoptotic neurons, and subsequently plays a critical role in modulating both clearance and inflammatory cytokine gene expression after ethanol-induced apoptosis.

  5. Fractalkine is a "find-me" signal released by neurons undergoing ethanol-induced apoptosis

    Directory of Open Access Journals (Sweden)

    Jennifer D Sokolowski

    2014-11-01

    Full Text Available Apoptotic neurons generated during normal brain development or secondary to pathologic insults are efficiently cleared from the central nervous system. Several soluble factors, including nucleotides, cytokines, and chemokines are released from injured neurons, signaling microglia to find and clear debris. One such chemokine that serves as a neuronal-microglial communication factor is fractalkine, with roles demonstrated in several models of adult neurological disorders. Lacking, however, are studies investigating roles for fractalkine in perinatal brain injury, an important clinical problem with no effective therapies. We used a well-characterized mouse model of ethanol-induced apoptosis to assess the role of fractalkine in neuronal-microglial signaling. Quantification of apoptotic debris in fractalkine-knockout and CX3CR1-knockout mice following ethanol treatment revealed increased apoptotic bodies compared to wild type mice. Ethanol-induced injury led to release of soluble, extracellular fractalkine. The extracellular media harvested from apoptotic brains induces microglial migration in a fractalkine-dependent manner that is prevented by neutralization of fractalkine with a blocking antibody or by deficiency in the receptor, CX3CR1. This suggests fractalkine acts as a ‘find-me’ signal, recruiting microglial processes toward apoptotic cells to promote their clearance. Next, we aimed to determine whether there are downstream alterations in cytokine gene expression due to fractalkine signaling. We examined mRNA expression in fractalkine-knockout and CX3CR1-knockout mice after alcohol-induced apoptosis and found differences in cytokine production in the brains of these knockouts by 6 hours after ethanol treatment. Collectively, this suggests that fractalkine acts as a ‘find me’ signal released by apoptotic neurons, and subsequently plays a critical role in modulating both phagocytic clearance and inflammatory cytokine gene expression after

  6. Psilocybin-induced spiritual experiences and insightfulness are associated with synchronization of neuronal oscillations.

    Science.gov (United States)

    Kometer, Michael; Pokorny, Thomas; Seifritz, Erich; Volleinweider, Franz X

    2015-10-01

    During the last years, considerable progress has been made toward understanding the neuronal basis of consciousness by using sophisticated behavioral tasks, brain-imaging techniques, and various psychoactive drugs. Nevertheless, the neuronal mechanisms underlying some of the most intriguing states of consciousness, including spiritual experiences, remain unknown. To elucidate state of consciousness-related neuronal mechanisms, human subjects were given psilocybin, a naturally occurring serotonergic agonist and hallucinogen that has been used for centuries to induce spiritual experiences in religious and medical rituals. In this double-blind, placebo-controlled study, 50 healthy human volunteers received a moderate dose of psilocybin, while high-density electroencephalogram (EEG) recordings were taken during eyes-open and eyes-closed resting states. The current source density and the lagged phase synchronization of neuronal oscillations across distributed brain regions were computed and correlated with psilocybin-induced altered states of consciousness. Psilocybin decreased the current source density of neuronal oscillations at 1.5-20 Hz within a neural network comprising the anterior and posterior cingulate cortices and the parahippocampal regions. Most intriguingly, the intensity levels of psilocybin-induced spiritual experience and insightfulness correlated with the lagged phase synchronization of delta oscillations (1.5-4 Hz) between the retrosplenial cortex, the parahippocampus, and the lateral orbitofrontal area. These results provide systematic evidence for the direct association of a specific spatiotemporal neuronal mechanism with spiritual experiences and enhanced insight into life and existence. The identified mechanism may constitute a pathway for modulating mental health, as spiritual experiences can promote sustained well-being and psychological resilience.

  7. γ-Tocotrienol does not substantially protect DS neurons from hydrogen peroxide-induced oxidative injury

    Directory of Open Access Journals (Sweden)

    Then Sue-Mian

    2012-01-01

    Full Text Available Abstract Background Down syndrome (DS neurons are more susceptible to oxidative stress and previous studies have shown that vitamin E was able to reduce oxidative stress and improve DS neurons' viability. Therefore, this study was done to investigate the protective role of γ-tocotrienol (γT3 in DS neurons from hydrogen peroxide (H2O2 -induced oxidative stress. The pro-apoptosis tendency of γT3 was compared to α-tocopherol (αT in non-stress condition as well. Methods Primary culture of DS and euploid neurons were divided into six groups of treatment: control, H2O2, γT3 pre-treatment with H2O2, γT3 only, αT pre-treatment with H2O2 and αT only. The treatments were assessed by MTS assay and apoptosis assay by single-stranded DNA (ssDNA apoptosis ELISA assay, Hoechst and Neu-N immunofluorescence staining. The cellular uptake of γT3 and αT was determined by HPLC while protein expressions were determined by Western blot. Comparison between groups was made by the Student's t test, one-way ANOVA and Bonferroni adjustment as well as two-way ANOVA for multiple comparisons. Results One day incubation of γT3 was able to reduced apoptosis of DS neurons by 10%, however γT3 was cytotoxic at longer incubation period (14 days and at concentrations ≥ 100 μM. Pre-treatment of αT and γT3 only attenuate apoptosis and increase cell viability in H2O2-treated DS and euploid neurons by 10% in which the effects were minimal to maintain most of the DS cells' morphology. γT3 act as a free radical scavenger by reducing ROS generated by H2O2. In untreated controls, DS neurons showed lower Bcl-2/Bax ratio and p53 expression compared to normal neurons, while cPKC and PKC-δ expressions were higher in DS neurons. On the other hand, pre-treatment of γT3 in H2O2-treated DS neurons have reduced Bcl-2/Bax ratio, which was not shown in euploid neurons. This suggests that pre-treatment of γT3 did not promote DS cell survival. Meanwhile γT3 and αT treatments

  8. CREB Selectively Controls Learning-Induced Structural Remodeling of Neurons

    Science.gov (United States)

    Middei, Silvia; Spalloni, Alida; Longone, Patrizia; Pittenger, Christopher; O'Mara, Shane M.; Marie, Helene; Ammassari-Teule, Martine

    2012-01-01

    The modulation of synaptic strength associated with learning is post-synaptically regulated by changes in density and shape of dendritic spines. The transcription factor CREB (cAMP response element binding protein) is required for memory formation and in vitro dendritic spine rearrangements, but its role in learning-induced remodeling of neurons…

  9. Mechanism for Prenatal LPS-Induced DA Neuron Loss

    Science.gov (United States)

    2005-03-01

    Pike B, Root H, Rubenstein J, Boyer R, Stenroos ES, Chan- 26. drasekharappa S, Athanassiadou A, Papapetropoulos T, Johnson Yurek DM, Fletcher- Tumer A...diethylstilbestrol-induced cancers . Ann. N. Y. Acad. Sci. Capobianco, L., Battaglia, G., De Blasi, A., Nicoletti, F., Paparelli, 983, 161-169. A., 2004

  10. Neuronal activity rapidly induces transcription of the CREB-regulated microRNA-132, in vivo

    DEFF Research Database (Denmark)

    Nudelman, Aaron Samuel; DiRocco, Derek P; Lambert, Talley J

    2010-01-01

    Activity-dependent changes in gene-expression are believed to underlie the molecular representation of memory. In this study, we report that in vivo activation of neurons rapidly induces the CREB-regulated microRNA miR-132. To determine if production of miR-132 is regulated by neuronal activity its......, olfactory bulb, and striatum by contextual fear conditioning, odor-exposure, and cocaine-injection, respectively, also increased pri-miR-132. Induction kinetics of pri-miR-132 were monitored and found to parallel those of immediate early genes, peaking at 45 min and returning to basal levels within 2 h...

  11. Toxicity to sensory neurons and Schwann cells in experimental linezolid-induced peripheral neuropathy.

    Science.gov (United States)

    Bobylev, Ilja; Maru, Helina; Joshi, Abhijeet R; Lehmann, Helmar C

    2016-03-01

    Peripheral neuropathy is a common side effect of prolonged treatment with linezolid. This study aimed to explore injurious effects of linezolid on cells of the peripheral nervous system and to establish in vivo and in vitro models of linezolid-induced peripheral neuropathy. C57BL/6 mice were treated with linezolid or vehicle over a total period of 4 weeks. Animals were monitored by weight, nerve conduction studies and behavioural tests. Neuropathic changes were assessed by morphometry on sciatic nerves and epidermal nerve fibre density in skin sections. Rodent sensory neuron and Schwann cell cultures were exposed to linezolid in vitro and assessed for mitochondrial dysfunction. Prolonged treatment with linezolid induced a mild, predominantly small sensory fibre neuropathy in vivo. Exposure of Schwann cells and sensory neurons to linezolid in vitro caused mitochondrial dysfunction primarily in neurons (and less prominently in Schwann cells). Sensory axonopathy could be partially prevented by co-administration of the Na(+)/Ca(2+) exchanger blocker KB-R7943. Clinical and pathological features of linezolid-induced peripheral neuropathy can be replicated in in vivo and in vitro models. Mitochondrial dysfunction may contribute to the axonal damage to sensory neurons that occurs after linezolid exposure. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Laforin prevents stress-induced polyglucosan body formation and Lafora disease progression in neurons.

    Science.gov (United States)

    Wang, Yin; Ma, Keli; Wang, Peixiang; Baba, Otto; Zhang, Helen; Parent, Jack M; Zheng, Pan; Liu, Yang; Minassian, Berge A; Liu, Yan

    2013-08-01

    Glycogen, the largest cytosolic macromolecule, is soluble because of intricate construction generating perfect hydrophilic-surfaced spheres. Little is known about neuronal glycogen function and metabolism, though progress is accruing through the neurodegenerative epilepsy Lafora disease (LD) proteins laforin and malin. Neurons in LD exhibit Lafora bodies (LBs), large accumulations of malconstructed insoluble glycogen (polyglucosans). We demonstrated that the laforin-malin complex reduces LBs and protects neuronal cells against endoplasmic reticulum stress-induced apoptosis. We now show that stress induces polyglucosan formation in normal neurons in culture and in the brain. This is mediated by increased glucose-6-phosphate allosterically hyperactivating muscle glycogen synthase (GS1) and is followed by activation of the glycogen digesting enzyme glycogen phosphorylase. In the absence of laforin, stress-induced polyglucosans are undigested and accumulate into massive LBs, and in laforin-deficient mice, stress drastically accelerates LB accumulation and LD. The mechanism through which laforin-malin mediates polyglucosan degradation remains unclear but involves GS1 dephosphorylation by laforin. Our work uncovers the presence of rapid polyglucosan metabolism as part of the normal physiology of neuroprotection. We propose that deficiency in the degradative phase of this metabolism, leading to LB accumulation and resultant seizure predisposition and neurodegeneration, underlies LD.

  13. Creatine protects against mitochondrial dysfunction associated with HIV-1 Tat-induced neuronal injury

    Science.gov (United States)

    Stevens, Patrick R.; Gawryluk, Jeremy W.; Hui, Liang; Chen, Xuesong; Geiger, Jonathan D.

    2015-01-01

    HIV-1 infected individuals are living longer but experiencing a prevalence rate of over 50% for HIV-1 associated neurocognitive disorders (HAND) for which no effective treatment is available. Viral and cellular factors secreted by HIV-1 infected cells leads to neuronal injury and HIV-1 Tat continues to be implicated in the pathogenesis of HAND. Here we tested the hypothesis that creatine protected against HIV-1 Tat-induced neuronal injury by preventing mitochondrial bioenergetic crisis and/or redox catastrophe. Creatine blocked HIV-1 Tat1-72-induced increases in neuron cell death and synaptic area loss. Creatine protected against HIV-1 Tat-induced decreases in ATP. Creatine and creatine plus HIV-1 Tat increased cellular levels of creatine, and creatine plus HIV-1 Tat further decreased ratios of phosphocreatine to creatine observed with creatine or HIV-1 Tat treatments alone. Additionally, creatine protected against HIV-1 Tat-induced mitochondrial hypopolarization and HIV-1 Tat-induced mitochondrial permeability transition pore opening. Thus, creatine may be a useful adjunctive therapy against HAND. PMID:25613139

  14. Lycopene Prevents Amyloid [Beta]-Induced Mitochondrial Oxidative Stress and Dysfunctions in Cultured Rat Cortical Neurons.

    Science.gov (United States)

    Qu, Mingyue; Jiang, Zheng; Liao, Yuanxiang; Song, Zhenyao; Nan, Xinzhong

    2016-06-01

    Brains affected by Alzheimer's disease (AD) show a large spectrum of mitochondrial alterations at both morphological and genetic level. The causal link between β-amyloid (Aβ) and mitochondrial dysfunction has been established in cellular models of AD. We observed previously that lycopene, a member of the carotenoid family of phytochemicals, could counteract neuronal apoptosis and cell damage induced by Aβ and other neurotoxic substances, and that this neuroprotective action somehow involved the mitochondria. The present study aims to investigate the effects of lycopene on mitochondria in cultured rat cortical neurons exposed to Aβ. It was found that lycopene attenuated Aβ-induced oxidative stress, as evidenced by the decreased intracellular reactive oxygen species generation and mitochondria-derived superoxide production. Additionally, lycopene ameliorated Aβ-induced mitochondrial morphological alteration, opening of the mitochondrial permeability transition pores and the consequent cytochrome c release. Lycopene also improved mitochondrial complex activities and restored ATP levels in Aβ-treated neuron. Furthermore, lycopene prevented mitochondrial DNA damages and improved the protein level of mitochondrial transcription factor A in mitochondria. Those results indicate that lycopene protects mitochondria against Aβ-induced damages, at least in part by inhibiting mitochondrial oxidative stress and improving mitochondrial function. These beneficial effects of lycopene may account for its protection against Aβ-induced neurotoxicity.

  15. Mechanism for Prenatal LPS-Induced DA Neuron Loss

    Science.gov (United States)

    2006-09-01

    Neurol 355:479–489. rooks AI, Chadwick CA, Gelbard HA, Cory-Slechta DA, Federoff HJ (1999) Paraquat elicited neurobehavioral syndrome caused by do...Stadler, J., Chandran, J., Klinefelter , G. R., Blackstone, C., and Cookson, M. R. (2003) J. Biol. Chem. 278, 36588–36595 4. Macedo, M. G., Anar, B...fluctuations Reserpine induced a parkinsonism-like syndrome in some PROGRESSION IN PD 241 Table 2. Comparison of Human PD Characteristics With Animal Models

  16. R-citalopram prevents the neuronal adaptive changes induced by escitalopram.

    Science.gov (United States)

    Mnie-Filali, Ouissame; Faure, Céline; Mansari, Mostafa El; Lambás-Señas, Laura; Bérod, Anne; Zimmer, Luc; Sánchez, Connie; Haddjeri, Nasser

    2007-10-08

    This study examined the long-term effects of the antidepressant escitalopram on rat serotonin (5-HT) neuronal activity and hippocampal neuroplasticity. In the dorsal raphe nucleus, a 2-week treatment with escitalopram (10 mg/kg/day, subcutaneous) did not modify the firing activity of 5-HT neurons, whereas a cotreatment with R-citalopram (20 mg/kg/day, subcutaneous) decreased it. In the dentate gyrus of dorsal hippocampus, escitalopram increased significantly (57%) the number of de novo cells and this was prevented by a cotreatment with R-citalopram. The present results support the role of the allosteric modulation of the 5-HT transporter in the regulation of the recovery of 5-HT neuronal activity and long-lasting hippocampal cellular plasticity induced by escitalopram, two adaptive changes presumably associated with the antidepressant response.

  17. ALS-associated mutant FUS induces selective motor neuron degeneration through toxic gain of function.

    Science.gov (United States)

    Sharma, Aarti; Lyashchenko, Alexander K; Lu, Lei; Nasrabady, Sara Ebrahimi; Elmaleh, Margot; Mendelsohn, Monica; Nemes, Adriana; Tapia, Juan Carlos; Mentis, George Z; Shneider, Neil A

    2016-02-04

    Mutations in FUS cause amyotrophic lateral sclerosis (ALS), including some of the most aggressive, juvenile-onset forms of the disease. FUS loss-of-function and toxic gain-of-function mechanisms have been proposed to explain how mutant FUS leads to motor neuron degeneration, but neither has been firmly established in the pathogenesis of ALS. Here we characterize a series of transgenic FUS mouse lines that manifest progressive, mutant-dependent motor neuron degeneration preceded by early, structural and functional abnormalities at the neuromuscular junction. A novel, conditional FUS knockout mutant reveals that postnatal elimination of FUS has no effect on motor neuron survival or function. Moreover, endogenous FUS does not contribute to the onset of the ALS phenotype induced by mutant FUS. These findings demonstrate that FUS-dependent motor degeneration is not due to loss of FUS function, but to the gain of toxic properties conferred by ALS mutations.

  18. Heterogeneous delay-induced asynchrony and resonance in a small-world neuronal network system

    Science.gov (United States)

    Yu, Wen-Ting; Tang, Jun; Ma, Jun; Yang, Xianqing

    2016-06-01

    A neuronal network often involves time delay caused by the finite signal propagation time in a given biological network. This time delay is not a homogenous fluctuation in a biological system. The heterogeneous delay-induced asynchrony and resonance in a noisy small-world neuronal network system are numerically studied in this work by calculating synchronization measure and spike interval distribution. We focus on three different delay conditions: double-values delay, triple-values delay, and Gaussian-distributed delay. Our results show the following: 1) the heterogeneity in delay results in asynchronous firing in the neuronal network, and 2) maximum synchronization could be achieved through resonance given that the delay values are integer or half-integer times of each other.

  19. Chronic Hypergravity Induces Changes in the Dopaminergic Neuronal System in Drosophila Melanogaster

    Science.gov (United States)

    Pelos, Andrew; Hosamani, Ravikumar; Bhattacharya, Sharmila

    2017-01-01

    Upon atmospheric exitre-entry and during training, astronauts are subjected to temporary periods of hypergravity, which has been implicated in the activation of oxidative stress pathways contributing to mitochondrial dysfunction and neuronal degeneration. The pathogenesis of Parkinsons disease and other neurodegenerative disorders is associated with oxidative damage to neurons involved in dopamine systems of the brain. Our study aims to examine the effects of a hypergravitational developmental environment on the degeneration of dopaminergic systems in Drosophila melanogaster. Male and female flies (Gal4-UAS transgenic line) were hatched and raised to adulthood in centrifugal hypergravity (97rpm, 3g). The nuclear expression of the reporter, Green Fluorescent Protein (GFP) is driven by the dopaminergic enzyme tyrosine hydroxylase (TH) promoter, allowing for the targeted visualization of dopamine producing neurons. After being raised to adulthood and kept in hypergravity until 18 days of age, flies were dissected and the expression of TH was measured by fluorescence confocal microscopy. TH expression in the fly brains was used to obtain counts of healthy dopaminergic neurons for flies raised in chronic hypergravity and control groups. Dopaminergic neuron expression data were compared with those of previous studies that limited hypergravity exposure to late life in order to determine the flies adaptability to the gravitational environment when raised from hatching through adulthood. Overall, we observed a significant effect of chronic hypergravity exposure contributing to deficits in dopaminergic neuron expression (p 0.003). Flies raised in 3g had on average lower dopaminergic neuron counts (mean 97.7) when compared with flies raised in 1g (mean 122.8). We suspect these lower levels of TH expression are a result of oxidative dopaminergic cell loss in flies raised in hypergravity. In future studies, we hope to further elucidate the mechanism by which hypergravity-induced

  20. A simplified protocol for differentiation of electrophysiologically mature neuronal networks from human induced pluripotent stem cells.

    Science.gov (United States)

    Gunhanlar, N; Shpak, G; van der Kroeg, M; Gouty-Colomer, L A; Munshi, S T; Lendemeijer, B; Ghazvini, M; Dupont, C; Hoogendijk, W J G; Gribnau, J; de Vrij, F M S; Kushner, S A

    2017-04-18

    Progress in elucidating the molecular and cellular pathophysiology of neuropsychiatric disorders has been hindered by the limited availability of living human brain tissue. The emergence of induced pluripotent stem cells (iPSCs) has offered a unique alternative strategy using patient-derived functional neuronal networks. However, methods for reliably generating iPSC-derived neurons with mature electrophysiological characteristics have been difficult to develop. Here, we report a simplified differentiation protocol that yields electrophysiologically mature iPSC-derived cortical lineage neuronal networks without the need for astrocyte co-culture or specialized media. This protocol generates a consistent 60:40 ratio of neurons and astrocytes that arise from a common forebrain neural progenitor. Whole-cell patch-clamp recordings of 114 neurons derived from three independent iPSC lines confirmed their electrophysiological maturity, including resting membrane potential (-58.2±1.0 mV), capacitance (49.1±2.9 pF), action potential (AP) threshold (-50.9±0.5 mV) and AP amplitude (66.5±1.3 mV). Nearly 100% of neurons were capable of firing APs, of which 79% had sustained trains of mature APs with minimal accommodation (peak AP frequency: 11.9±0.5 Hz) and 74% exhibited spontaneous synaptic activity (amplitude, 16.03±0.82 pA; frequency, 1.09±0.17 Hz). We expect this protocol to be of broad applicability for implementing iPSC-based neuronal network models of neuropsychiatric disorders.Molecular Psychiatry advance online publication, 18 April 2017; doi:10.1038/mp.2017.56.

  1. Thermo-responsive polymeric nanoparticles for enhancing neuronal differentiation of human induced pluripotent stem cells.

    Science.gov (United States)

    Seo, Hye In; Cho, Ann-Na; Jang, Jiho; Kim, Dong-Wook; Cho, Seung-Woo; Chung, Bong Geun

    2015-10-01

    We report thermo-responsive retinoic acid (RA)-loaded poly(N-isopropylacrylamide)-co-acrylamide (PNIPAM-co-Am) nanoparticles for directing human induced pluripotent stem cell (hiPSC) fate. Fourier transform infrared spectroscopy and (1)H nuclear magnetic resonance analysis confirmed that RA was efficiently incorporated into PNIAPM-co-Am nanoparticles (PCANs). The size of PCANs dropped with increasing temperatures (300-400 nm at room temperature, 80-90 nm at 37°C) due to its phase transition from hydrophilic to hydrophobic. Due to particle shrinkage caused by this thermo-responsive property of PCANs, RA could be released from nanoparticles in the cells upon cellular uptake. Immunocytochemistry and quantitative real-time polymerase chain reaction analysis demonstrated that neuronal differentiation of hiPSC-derived neuronal precursors was enhanced after treatment with 1-2 μg/ml RA-loaded PCANs. Therefore, we propose that this PCAN could be a potentially powerful carrier for effective RA delivery to direct hiPSC fate to neuronal lineage. The use of induced pluripotent stem cells (iPSCs) has been at the forefront of research in the field of regenerative medicine, as these cells have the potential to differentiate into various terminal cell types. In this article, the authors utilized a thermo-responsive polymer, Poly(N-isopropylacrylamide) (PNIPAM), as a delivery platform for retinoic acid. It was shown that neuronal differentiation could be enhanced in hiPSC-derived neuronal precursor cells. This method may pave a way for future treatment of neuronal diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Neuregulin-1 is neuroprotective in a rat model of organophosphate-induced delayed neuronal injury

    International Nuclear Information System (INIS)

    Li, Yonggang; Lein, Pamela J.; Liu, Cuimei; Bruun, Donald A.; Giulivi, Cecilia; Ford, Gregory D.; Tewolde, Teclemichael; Ross-Inta, Catherine; Ford, Byron D.

    2012-01-01

    Current medical countermeasures against organophosphate (OP) nerve agents are effective in reducing mortality, but do not sufficiently protect the CNS from delayed brain damage and persistent neurological symptoms. In this study, we examined the efficacy of neuregulin-1 (NRG-1) in protecting against delayed neuronal cell death following acute intoxication with the OP diisopropylflurophosphate (DFP). Adult male Sprague–Dawley rats were pretreated with pyridostigmine (0.1 mg/kg BW, i.m.) and atropine methylnitrate (20 mg/kg BW, i.m.) prior to DFP (9 mg/kg BW, i.p.) intoxication to increase survival and reduce peripheral signs of cholinergic toxicity but not prevent DFP-induced seizures or delayed neuronal injury. Pretreatment with NRG-1 did not protect against seizures in rats exposed to DFP. However, neuronal injury was significantly reduced in most brain regions by pretreatment with NRG-1 isoforms NRG-EGF (3.2 μg/kg BW, i.a) or NRG-GGF2 (48 μg/kg BW, i.a.) as determined by FluroJade-B labeling in multiple brain regions at 24 h post-DFP injection. NRG-1 also blocked apoptosis and oxidative stress-mediated protein damage in the brains of DFP-intoxicated rats. Administration of NRG-1 at 1 h after DFP injection similarly provided significant neuroprotection against delayed neuronal injury. These findings identify NRG-1 as a promising adjuvant therapy to current medical countermeasures for enhancing neuroprotection against acute OP intoxication. -- Highlights: ► NRG-1 blocked DFP induced neuronal injury. ► NRG-1 did not protect against seizures in rats exposed to DFP. ► NRG-1 blocked apoptosis and oxidative stress in the brains of DFP-intoxicated rats. ► Administration of NRG-1 at 1 h after DFP injection prevented delayed neuronal injury.

  3. Effects of aromatic amino acids on glutamate-induced neuronal cell death

    International Nuclear Information System (INIS)

    Zafar, Z.; Sumners, C.

    2005-01-01

    Glutamate accumulation is believed to lead to overstimulation of glutamate receptors which results in neuronal death. The protective effects of aromatic amino acids on glutamate induced neuronal cell death were examined using rat cerebral cortical neurons. Neuronal death is quantified by measuring lactate dehydrogenase (LDH) using a spectrophotometric microtiter plate reader (ELISA reader). Neuronal cells were incubated with varying doses of glutamate plus or minus the aromatic amino acid D-Phenylalanine (D-Phe) for different time periods to observe protection against cytotoxicity. Percent cytotoxicity was seen to follow a dose dependent rise with increasing concentrations of glutamate, reaching a plateau at around 100 -500 uM glutamate. Lower levels of cytotoxicity were achieved with cell exposed to D-Phe and Dibromo tyrosine (DBrT). 48-hour experimental runs were also carried out to further investigate the mode of action of D-Phe. It was found that the difference between cytotoxicity levels of control cells and protected cells was higher over longer time. (author)

  4. Quinacrine pretreatment reduces microwave-induced neuronal damage by stabilizing the cell membrane

    Science.gov (United States)

    Ding, Xue-feng; Wu, Yan; Qu, Wen-rui; Fan, Ming; Zhao, Yong-qi

    2018-01-01

    Quinacrine, widely used to treat parasitic diseases, binds to cell membranes. We previously found that quinacrine pretreatment reduced microwave radiation damage in rat hippocampal neurons, but the molecular mechanism remains poorly understood. Considering the thermal effects of microwave radiation and the protective effects of quinacrine on heat damage in cells, we hypothesized that quinacrine would prevent microwave radiation damage to cells in a mechanism associated with cell membrane stability. To test this, we used retinoic acid to induce PC12 cells to differentiate into neuron-like cells. We then pretreated the neurons with quinacrine (20 and 40 mM) and irradiated them with 50 mW/cm2 microwaves for 3 or 6 hours. Flow cytometry, atomic force microscopy and western blot assays revealed that irradiated cells pretreated with quinacrine showed markedly less apoptosis, necrosis, and membrane damage, and greater expression of heat shock protein 70, than cells exposed to microwave irradiation alone. These results suggest that quinacrine stabilizes the neuronal membrane structure by upregulating the expression of heat shock protein 70, thus reducing neuronal injury caused by microwave radiation. PMID:29623929

  5. Delayed rectifier potassium channels are involved in SO2 derivative-induced hippocampal neuronal injury.

    Science.gov (United States)

    Li, Guangke; Sang, Nan

    2009-01-01

    Recent studies implicate the possible neurotoxicity of SO(2), however, its mechanisms remain unclear. In the present study, we investigated SO(2) derivative-induced effect on delayed rectifier potassium channels (I(K)) and cellular death/apoptosis in primary cultured hippocampal neurons. The results demonstrate that SO(2) derivatives (NaHSO(3) and Na(2)SO(3), 3:1M/M) effectively augmented I(K) and promoted the activation of delayed rectifier potassium channels. Also, SO(2) derivatives increased neuronal death percentage and contributed to the formation of DNA ladder in concentration-dependent manners. Interestingly, the neuronal death and DNA ladder formation, caused by SO(2) derivatives, could be attenuated by the delayed rectifier potassium channel blocker (tetraethylammonium, TEA), but not by the transient outward potassium channel blocker (4-aminopyridine, 4-AP). It implies that stimulating delayed rectifier potassium channels were involved in SO(2) derivative-caused hippocampal neuronal insults, and blocking these channels might be one of the possibly clinical treatment for SO(2)-caused neuronal dysfunction.

  6. Delay-induced diversity of firing behavior and ordered chaotic firing in adaptive neuronal networks

    International Nuclear Information System (INIS)

    Gong Yubing; Wang Li; Xu Bo

    2012-01-01

    In this paper, we study the effect of time delay on the firing behavior and temporal coherence and synchronization in Newman–Watts thermosensitive neuron networks with adaptive coupling. At beginning, the firing exhibit disordered spiking in absence of time delay. As time delay is increased, the neurons exhibit diversity of firing behaviors including bursting with multiple spikes in a burst, spiking, bursting with four, three and two spikes, firing death, and bursting with increasing amplitude. The spiking is the most ordered, exhibiting coherence resonance (CR)-like behavior, and the firing synchronization becomes enhanced with the increase of time delay. As growth rate of coupling strength or network randomness increases, CR-like behavior shifts to smaller time delay and the synchronization of firing increases. These results show that time delay can induce diversity of firing behaviors in adaptive neuronal networks, and can order the chaotic firing by enhancing and optimizing the temporal coherence and enhancing the synchronization of firing. However, the phenomenon of firing death shows that time delay may inhibit the firing of adaptive neuronal networks. These findings provide new insight into the role of time delay in the firing activity of adaptive neuronal networks, and can help to better understand the complex firing phenomena in neural networks.

  7. 3-Hydroxybutyrate regulates energy metabolism and induces BDNF expression in cerebral cortical neurons.

    Science.gov (United States)

    Marosi, Krisztina; Kim, Sang Woo; Moehl, Keelin; Scheibye-Knudsen, Morten; Cheng, Aiwu; Cutler, Roy; Camandola, Simonetta; Mattson, Mark P

    2016-12-01

    During fasting and vigorous exercise, a shift of brain cell energy substrate utilization from glucose to the ketone 3-hydroxybutyrate (3OHB) occurs. Studies have shown that 3OHB can protect neurons against excitotoxicity and oxidative stress, but the underlying mechanisms remain unclear. Neurons maintained in the presence of 3OHB exhibited increased oxygen consumption and ATP production, and an elevated NAD + /NADH ratio. We found that 3OHB metabolism increases mitochondrial respiration which drives changes in expression of brain-derived neurotrophic factor (BDNF) in cultured cerebral cortical neurons. The mechanism by which 3OHB induces Bdnf gene expression involves generation of reactive oxygen species, activation of the transcription factor NF-κB, and activity of the histone acetyltransferase p300/EP300. Because BDNF plays important roles in synaptic plasticity and neuronal stress resistance, our findings suggest cellular signaling mechanisms by which 3OHB may mediate adaptive responses of neurons to fasting, exercise, and ketogenic diets. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  8. CX3CL1-mediated macrophage activation contributed to paclitaxel-induced DRG neuronal apoptosis and painful peripheral neuropathy.

    Science.gov (United States)

    Huang, Zhen-Zhen; Li, Dai; Liu, Cui-Cui; Cui, Yu; Zhu, He-Quan; Zhang, Wen-Wen; Li, Yong-Yong; Xin, Wen-Jun

    2014-08-01

    Painful peripheral neuropathy is a dose-limiting side effect of paclitaxel therapy, which hampers the optimal clinical management of chemotherapy in cancer patients. Currently the underlying mechanisms remain largely unknown. Here we showed that the clinically relevant dose of paclitaxel (3×8mg/kg, cumulative dose 24mg/kg) induced significant upregulation of the chemokine CX3CL1 in the A-fiber primary sensory neurons in vivo and in vitro and infiltration of macrophages into the dorsal root ganglion (DRG) in rats. Paclitaxel treatment also increased cleaved caspase-3 expression, induced the loss of primary afferent terminal fibers and decreased sciatic-evoked A-fiber responses in the spinal dorsal horn, indicating DRG neuronal apoptosis induced by paclitaxel. In addition, the paclitaxel-induced DRG neuronal apoptosis occurred exclusively in the presence of macrophage in vitro study. Intrathecal or systemic injection of CX3CL1 neutralizing antibody blocked paclitaxel-induced macrophage recruitment and neuronal apoptosis in the DRG, and also attenuated paclitaxel-induced allodynia. Furthermore, depletion of macrophage by systemic administration of clodronate inhibited paclitaxel-induced allodynia. Blocking CX3CL1 decreased activation of p38 MAPK in the macrophage, and inhibition of p38 MAPK activity blocked the neuronal apoptosis and development of mechanical allodynia induced by paclitaxel. These findings provide novel evidence that CX3CL1-recruited macrophage contributed to paclitaxel-induced DRG neuronal apoptosis and painful peripheral neuropathy. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Prevention of acute/severe hypoglycemia-induced neuron death by lactate administration.

    Science.gov (United States)

    Won, Seok Joon; Jang, Bong Geom; Yoo, Byung Hoon; Sohn, Min; Lee, Min Woo; Choi, Bo Young; Kim, Jin Hee; Song, Hong Ki; Suh, Sang Won

    2012-06-01

    Hypoglycemia-induced cerebral neuropathy can occur in patients with diabetes who attempt tight control of blood glucose and may lead to cognitive dysfunction. Accumulating evidence from animal models suggests that hypoglycemia-induced neuronal death is not a simple result of glucose deprivation, but is instead the end result of a multifactorial process. In particular, the excessive activation of poly (ADP-ribose) polymerase-1 (PARP-1) consumes cytosolic nicotinamide adenine dinucleotide (NAD(+)), resulting in energy failure. In this study, we investigate whether lactate administration in the absence of cytosolic NAD(+) affords neuroprotection against hypoglycemia-induced neuronal death. Intraperitoneal injection of sodium L-lactate corrected arterial blood pH and blood lactate concentration after hypoglycemia. Lactate administered without glucose was not sufficient to promote electroencephalogram recovery from an isoelectric state during hypoglycemia. However, supplementation of glucose with lactate reduced neuronal death by ∼80% in the hippocampus. Hypoglycemia-induced superoxide production and microglia activation was also substantially reduced by administration of lactate. Taken together, these results suggest an intriguing possibility: that increasing brain lactate following hypoglycemia offsets the decrease in NAD(+) due to overactivation of PARP-1 by acting as an alternative energy substrate that can effectively bypass glycolysis and be fed directly to the citric acid cycle to maintain cellular ATP levels.

  10. Neural Control of Startle-Induced Locomotion by the Mushroom Bodies and Associated Neurons in Drosophila

    Directory of Open Access Journals (Sweden)

    Jun Sun

    2018-03-01

    Full Text Available Startle-induced locomotion is commonly used in Drosophila research to monitor locomotor reactivity and its progressive decline with age or under various neuropathological conditions. A widely used paradigm is startle-induced negative geotaxis (SING, in which flies entrapped in a narrow column react to a gentle mechanical shock by climbing rapidly upwards. Here we combined in vivo manipulation of neuronal activity and splitGFP reconstitution across cells to search for brain neurons and putative circuits that regulate this behavior. We show that the activity of specific clusters of dopaminergic neurons (DANs afferent to the mushroom bodies (MBs modulates SING, and that DAN-mediated SING regulation requires expression of the DA receptor Dop1R1/Dumb, but not Dop1R2/Damb, in intrinsic MB Kenyon cells (KCs. We confirmed our previous observation that activating the MB α'β', but not αβ, KCs decreased the SING response, and we identified further MB neurons implicated in SING control, including KCs of the γ lobe and two subtypes of MB output neurons (MBONs. We also observed that co-activating the αβ KCs antagonizes α'β' and γ KC-mediated SING modulation, suggesting the existence of subtle regulation mechanisms between the different MB lobes in locomotion control. Overall, this study contributes to an emerging picture of the brain circuits modulating locomotor reactivity in Drosophila that appear both to overlap and differ from those underlying associative learning and memory, sleep/wake state and stress-induced hyperactivity.

  11. MicroRNA-132 protects hippocampal neurons against oxygen-glucose deprivation-induced apoptosis.

    Science.gov (United States)

    Sun, Zu-Zhen; Lv, Zhan-Yun; Tian, Wen-Jing; Yang, Yan

    2017-09-01

    Hypoxic-ischemic brain injury (HIBI) results in death or long-term neurologic impairment in both adults and children. In this study, we investigated the effects of microRNA-132 (miR-132) dysregulation on oxygen-glucose deprivation (OGD)-induced apoptosis in fetal rat hippocampal neurons, in order to reveal the therapeutic potential of miR-132 on HIBI. MiR-132 dysregulation was induced prior to OGD exposure by transfection of primary fetal rat hippocampal neurons with miR-132 mimic or miR-132 inhibitor. The effects of miR-132 overexpression and suppression on OGD-stimulated hippocampal neurons were evaluated by detection of cell viability, apoptotic cells rate, and the expression of apoptosis-related proteins. Besides, TargetScan database and dual luciferase activity assay were used to seek a target gene of miR-132. As a result, miR-132 was highly expressed in hippocampal neurons following 2 h of OGD exposure. MiR-132 overexpression significantly increased OGD-diminished cell viability and reduced OGD-induced apoptosis at 12, 24, and 48 h post-OGD. MiR-132 overexpression significantly down-regulated the expressions of Bax, cytochrome c, and caspase-9, but up-regulated BCl-2. Caspase-3 activity was also significantly decreased by miR-132 overexpression. Furthermore, FOXO3 was a direct target of miR-132, and it was negatively regulated by miR-132. To conclude, our results provide evidence that miR-132 protects hippocampal neurons against OGD injury by inhibiting apoptosis.

  12. Oncostatin M induces heat hypersensitivity by gp130-dependent sensitization of TRPV1 in sensory neurons

    Directory of Open Access Journals (Sweden)

    Langeslag Michiel

    2011-12-01

    Full Text Available Abstract Oncostatin M (OSM is a member of the interleukin-6 cytokine family and regulates eg. gene activation, cell survival, proliferation and differentiation. OSM binds to a receptor complex consisting of the ubiquitously expressed signal transducer gp130 and the ligand binding OSM receptor subunit, which is expressed on a specific subset of primary afferent neurons. In the present study, the effect of OSM on heat nociception was investigated in nociceptor-specific gp130 knock-out (SNS-gp130-/- and gp130 floxed (gp130fl/fl mice. Subcutaneous injection of pathophysiologically relevant concentrations of OSM into the hind-paw of C57BL6J wild type mice significantly reduced paw withdrawal latencies to heat stimulation. In contrast to gp130fl/fl mice, OSM did not induce heat hypersensitivity in vivo in SNS-gp130-/- mice. OSM applied at the receptive fields of sensory neurons in in vitro skin-nerve preparations showed that OSM significantly increased the discharge rate during a standard ramp-shaped heat stimulus. The capsaicin- and heat-sensitive ion channel TRPV1, expressed on a subpopulation of nociceptive neurons, has been shown to play an important role in inflammation-induced heat hypersensitivity. Stimulation of cultured dorsal root ganglion neurons with OSM resulted in potentiation of capsaicin induced ionic currents. In line with these recordings, mice with a null mutation of the TRPV1 gene did not show any signs of OSM-induced heat hypersensitivity in vivo. The present data suggest that OSM induces thermal hypersensitivity by directly sensitizing nociceptors via OSMR-gp130 receptor mediated potentiation of TRPV1.

  13. Enhancement of synaptic transmission induced by BDNF in cultured cortical neurons

    Science.gov (United States)

    He, Jun; Gong, Hui; Zeng, Shaoqun; Li, Yanling; Luo, Qingming

    2005-03-01

    Brain-derived neurotrophic factor (BDNF), like other neurotrophins, has long-term effects on neuronal survival and differentiation; furthermore, BDNF has been reported to exert an acute potentiation of synaptic activity and are critically involved in long-term potentiation (LTP). We found that BDNF rapidly induced potentiation of synaptic activity and an increase in the intracellular Ca2+ concentration in cultured cortical neurons. Within minutes of BDNF application to cultured cortical neurons, spontaneous firing rate was dramatically increased as were the frequency and amplitude of excitatory spontaneous postsynaptic currents (EPSCs). Fura-2 recordings showed that BDNF acutely elicited an increase in intracellular calcium concentration ([Ca2+]c). This effect was partially dependent on [Ca2+]o; The BDNF-induced increase in [Ca2+]c can not be completely blocked by Ca2+-free solution. It was completely blocked by K252a and partially blocked by Cd2+ and TTX. The results demonstrate that BDNF can enhances synaptic transmission and that this effect is accompanied by a rise in [Ca2+]c that requires two route: the release of Ca2+ from intracellular calcium stores and influx of extracellular Ca2+ through voltage-dependent Ca2+ channels in cultured cortical neurons.

  14. NMDA Receptors on Dopaminoceptive Neurons Are Essential for Drug-Induced Conditioned Place Preference.

    Science.gov (United States)

    Sikora, Magdalena; Tokarski, Krzysztof; Bobula, Bartosz; Zajdel, Joanna; Jastrzębska, Kamila; Cieślak, Przemysław Eligiusz; Zygmunt, Magdalena; Sowa, Joanna; Smutek, Magdalena; Kamińska, Katarzyna; Gołembiowska, Krystyna; Engblom, David; Hess, Grzegorz; Przewlocki, Ryszard; Rodriguez Parkitna, Jan

    2016-01-01

    Plasticity of the brain's dopamine system plays a crucial role in adaptive behavior by regulating appetitive motivation and the control of reinforcement learning. In this study, we investigated drug- and natural-reward conditioned behaviors in a mouse model in which the NMDA receptor-dependent plasticity of dopaminoceptive neurons was disrupted. We generated a transgenic mouse line with inducible selective inactivation of the NR1 subunit in neurons expressing dopamine D1 receptors (the NR1(D1CreERT2) mice). Whole-cell recordings of spontaneous EPSCs on neurons in the nucleus accumbens confirmed that a population of neurons lacked the NMDA receptor-dependent component of the current. This effect was accompanied by impaired long-term potentiation in the nucleus accumbens and in the CA1 area of the ventral, but not the dorsal, hippocampus. Mutant mice did not differ from control animals when tested for pavlovian or instrumental conditioning. However, NR1(D1CreERT2) mice acquired no preference for a context associated with administration of drugs of abuse. In the conditioned place preference paradigm, mutant mice did not spend more time in the context paired with cocaine, morphine, or ethanol, although these mice acquired a preference for sucrose jelly and an aversion to naloxone injections, as normal. Thus, we observed that the selective inducible ablation of the NMDA receptors specifically blocks drug-associated context memory with no effect on positive reinforcement in general.

  15. NMDA Receptors on Dopaminoceptive Neurons Are Essential for Drug-Induced Conditioned Place Preference123

    Science.gov (United States)

    Tokarski, Krzysztof; Bobula, Bartosz; Zygmunt, Magdalena; Smutek, Magdalena; Kamińska, Katarzyna; Gołembiowska, Krystyna; Hess, Grzegorz; Przewlocki, Ryszard

    2016-01-01

    Abstract Plasticity of the brain’s dopamine system plays a crucial role in adaptive behavior by regulating appetitive motivation and the control of reinforcement learning. In this study, we investigated drug- and natural-reward conditioned behaviors in a mouse model in which the NMDA receptor-dependent plasticity of dopaminoceptive neurons was disrupted. We generated a transgenic mouse line with inducible selective inactivation of the NR1 subunit in neurons expressing dopamine D1 receptors (the NR1D1CreERT2 mice). Whole-cell recordings of spontaneous EPSCs on neurons in the nucleus accumbens confirmed that a population of neurons lacked the NMDA receptor-dependent component of the current. This effect was accompanied by impaired long-term potentiation in the nucleus accumbens and in the CA1 area of the ventral, but not the dorsal, hippocampus. Mutant mice did not differ from control animals when tested for pavlovian or instrumental conditioning. However, NR1D1CreERT2 mice acquired no preference for a context associated with administration of drugs of abuse. In the conditioned place preference paradigm, mutant mice did not spend more time in the context paired with cocaine, morphine, or ethanol, although these mice acquired a preference for sucrose jelly and an aversion to naloxone injections, as normal. Thus, we observed that the selective inducible ablation of the NMDA receptors specifically blocks drug-associated context memory with no effect on positive reinforcement in general. PMID:27294197

  16. Differentiation and Characterization of Dopaminergic Neurons From Baboon Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Grow, Douglas A; Simmons, DeNard V; Gomez, Jorge A; Wanat, Matthew J; McCarrey, John R; Paladini, Carlos A; Navara, Christopher S

    2016-09-01

    : The progressive death of dopamine producing neurons in the substantia nigra pars compacta is the principal cause of symptoms of Parkinson's disease (PD). Stem cells have potential therapeutic use in replacing these cells and restoring function. To facilitate development of this approach, we sought to establish a preclinical model based on a large nonhuman primate for testing the efficacy and safety of stem cell-based transplantation. To this end, we differentiated baboon fibroblast-derived induced pluripotent stem cells (biPSCs) into dopaminergic neurons with the application of specific morphogens and growth factors. We confirmed that biPSC-derived dopaminergic neurons resemble those found in the human midbrain based on cell type-specific expression of dopamine markers TH and GIRK2. Using the reverse transcriptase quantitative polymerase chain reaction, we also showed that biPSC-derived dopaminergic neurons express PAX6, FOXA2, LMX1A, NURR1, and TH genes characteristic of this cell type in vivo. We used perforated patch-clamp electrophysiology to demonstrate that biPSC-derived dopaminergic neurons fired spontaneous rhythmic action potentials and high-frequency action potentials with spike frequency adaption upon injection of depolarizing current. Finally, we showed that biPSC-derived neurons released catecholamines in response to electrical stimulation. These results demonstrate the utility of the baboon model for testing and optimizing the efficacy and safety of stem cell-based therapeutic approaches for the treatment of PD. Functional dopamine neurons were produced from baboon induced pluripotent stem cells, and their properties were compared to baboon midbrain cells in vivo. The baboon has advantages as a clinically relevant model in which to optimize the efficacy and safety of stem cell-based therapies for neurodegenerative diseases, such as Parkinson's disease. Baboons possess crucial neuroanatomical and immunological similarities to humans, and baboon

  17. [ERK activation effects on GABA secretion inhibition induced by SDF-1 in hippocampal neurons of rats].

    Science.gov (United States)

    Zhang, Zi-juan; Guo, Mei-xia; Xing, Ying

    2015-09-01

    To investigate the effect of extracellular regulating kinase (ERK) signaling pathway on the secretion of gamma-aminobutyric acid (GABA) in cultured rat hippocampal neurons induced by stromal cell derived factor-1 (SDF-1). The hippocampal neurons of newborn SD rats were cultured and identified in vitro; the phosphorylation level of ERK1/2 was examined by Western blot; ELISA was used to detect the effect of PD98059, a ERK1/2 specific blocker on GABA secretion of cultured hippocampal neurons and Western blot were adopted to measure the protein expression levels of glutamate decarboxylase (GAD65/67) and gamma aminobutyric acid transporter (GAT); after blocking ERK1/2 signaling pathway with PD98059; RT-PCR was used to detect the mRNA expression levels of GAT-1 and GAD65 after treated with PD98059. The levels of ERKl/2 phosphorylation were increased significantly by SDF1 acting on hippocampal neurons, and CX-CR4 receptor blocker AMD3100, could inhibit SDF-1 induced ERK1/2 activation; SDF-1 could inhibit the secretion of GABA in cultured hippocampal neurons, and ERK1/2 specific inhibitor PD98059, could partly reverse the inhibition of GABA secretion by SDF-1. The effects of SDF-1 on cultured hippocampal neurons was to decrease the mRNA genesis of glutamic acid decarboxylase GAD65 and GABA transporter GAT-1, besides, ERK inhibitor PD98059 could effectively flip the effect of SDF-1. The results of Western blot showed that SDF-1 could inhibit the protein expression of GAT-1 and GAD65/67 in hippocampal neurons and the inhibition of GAT-1 and GAD65/67 protein expression could be partially restored by ERK1/2 blocker. SDF-1 acts on the CXCR4 of hippocampal neurons in vitro, and inhibits the expression of GAD by activating the ERK1/2 signaling pathway, and this may represent one possible pathway of GABA secretion inhibition.

  18. Characterization of energy and neurotransmitter metabolism in cortical glutamatergic neurons derived from human induced pluripotent stem cells

    DEFF Research Database (Denmark)

    Aldana, Blanca I; Zhang, Yu; Lihme, Maria Fog

    2017-01-01

    pathways in neurons derived from human induced pluripotent stem cells (hiPSC). With this aim, cultures of hiPSC-derived neurons were incubated with [U-(13)C]glucose, [U-(13)C]glutamate or [U-(13)C]glutamine. Isotopic labeling in metabolites was determined using gas chromatography coupled to mass...

  19. Decay Accelerating Factor (CD55) Protects Neuronal Cells from Chemical Hypoxia-Induced Injury

    Science.gov (United States)

    2010-04-09

    Pavlakovic G, Isom GE: Dopaminergic neurotoxicity of cyanide: neurochemical, histological and behavioral characterization. Toxicol Appl Pharmacol...provided the original work is properly cited. ResearchDecay accelerating factor (CD55) protects neuronal cells from chemical hypoxia-induced injury...deposition of C3a/C5a and membrane attack complex (MAC or C5b-9) production. The present study investigates the ability of DAF to protect primary cultured

  20. Ejaculation Induced by the Activation of Crz Neurons Is Rewarding to Drosophila Males.

    Science.gov (United States)

    Zer-Krispil, Shir; Zak, Hila; Shao, Lisha; Ben-Shaanan, Shir; Tordjman, Lea; Bentzur, Assa; Shmueli, Anat; Shohat-Ophir, Galit

    2018-05-07

    The reward system is a collection of circuits that reinforce behaviors necessary for survival [1, 2]. Given the importance of reproduction for survival, actions that promote successful mating induce pleasurable feeling and are positively reinforced [3, 4]. This principle is conserved in Drosophila, where successful copulation is naturally rewarding to male flies, induces long-term appetitive memories [5], increases brain levels of neuropeptide F (NPF, the fly homolog of neuropeptide Y), and prevents ethanol, known otherwise as rewarding to flies [6, 7], from being rewarding [5]. It is not clear which of the multiple sensory and motor responses performed during mating induces perception of reward. Sexual interactions with female flies that do not reach copulation are not sufficient to reduce ethanol consumption [5], suggesting that only successful mating encounters are rewarding. Here, we uncoupled the initial steps of mating from its final steps and tested the ability of ejaculation to mimic the rewarding value of full copulation. We induced ejaculation by activating neurons that express the neuropeptide corazonin (CRZ) [8] and subsequently measured different aspects of reward. We show that activating Crz-expressing neurons is rewarding to male flies, as they choose to reside in a zone that triggers optogenetic stimulation of Crz neurons and display conditioned preference for an odor paired with the activation. Reminiscent of successful mating, repeated activation of Crz neurons increases npf levels and reduces ethanol consumption. Our results demonstrate that ejaculation stimulated by Crz/Crz-receptor signaling serves as an essential part of the mating reward mechanism in Drosophila. VIDEO ABSTRACT. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Higher sensitivity to cadmium induced cell death of basal forebrain cholinergic neurons: A cholinesterase dependent mechanism

    International Nuclear Information System (INIS)

    Del Pino, Javier; Zeballos, Garbriela; Anadon, María José; Capo, Miguel Andrés; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2014-01-01

    Cadmium is an environmental pollutant, which is a cause of concern because it can be greatly concentrated in the organism causing severe damage to a variety of organs including the nervous system which is one of the most affected. Cadmium has been reported to produce learning and memory dysfunctions and Alzheimer like symptoms, though the mechanism is unknown. On the other hand, cholinergic system in central nervous system (CNS) is implicated on learning and memory regulation, and it has been reported that cadmium can affect cholinergic transmission and it can also induce selective toxicity on cholinergic system at peripheral level, producing cholinergic neurons loss, which may explain cadmium effects on learning and memory processes if produced on central level. The present study is aimed at researching the selective neurotoxicity induced by cadmium on cholinergic system in CNS. For this purpose we evaluated, in basal forebrain region, the cadmium toxic effects on neuronal viability and the cholinergic mechanisms related to it on NS56 cholinergic mourine septal cell line. This study proves that cadmium induces a more pronounced, but not selective, cell death on acetylcholinesterase (AChE) on cholinergic neurons. Moreover, MTT and LDH assays showed a dose dependent decrease of cell viability in NS56 cells. The ACh treatment of SN56 cells did not revert cell viability reduction induced by cadmium, but siRNA transfection against AChE partially reduced it. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on the function and viability of neurons, and the possible relevance of cadmium in the pathogenesis of neurodegenerative diseases

  2. Neuronal erythropoietin overexpression is protective against kanamycin-induced hearing loss in mice.

    Science.gov (United States)

    Bächinger, David; Horvath, Lukas; Eckhard, Andreas; Goosmann, Madeline M; Honegger, Tim; Gassmann, Max; Vogel, Johannes; Naldi, Arianne Monge

    2018-07-01

    Aminoglycosides have detrimental effects on the hair cells of the inner ear, yet these agents indisputably are one of the cornerstones in antibiotic therapy. Hence, there is a demand for strategies to prevent aminoglycoside-induced ototoxicity, which are not available today. In vitro data suggests that the pleiotropic growth factor erythropoietin (EPO) is neuroprotective against aminoglycoside-induced hair cell loss. Here, we use a mouse model with EPO-overexpression in neuronal tissue to evaluate whether EPO could also in vivo protect from aminoglycoside-induced hearing loss. Auditory brainstem response (ABR) thresholds were measured in 12-weeks-old mice before and after treatment with kanamycin for 15 days, which resulted in both C57BL/6 and EPO-transgenic animals in a high-frequency hearing loss. However, ABR threshold shifts in EPO-transgenic mice were significantly lower than in C57BL/6 mice (mean difference in ABR threshold shift 13.6 dB at 32 kHz, 95% CI 3.8-23.4 dB, p = 0.003). Correspondingly, quantification of hair cells and spiral ganglion neurons by immunofluorescence revealed that EPO-transgenic mice had a significantly lower hair cell and spiral ganglion neuron loss than C57BL/6 mice. In conclusion, neuronal overexpression of EPO is protective against aminoglycoside-induce hearing loss, which is in accordance with its known neuroprotective effects in other organs, such as the eye or the brain. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Protection against methamphetamine-induced neurotoxicity to neostriatal dopaminergic neurons by adenosine receptor activation.

    Science.gov (United States)

    Delle Donne, K T; Sonsalla, P K

    1994-12-01

    Methamphetamine (METH)-induced neurotoxicity to nigrostriatal dopaminergic neurons in experimental animals appears to have a glutamatergic component because blockade of N-methyl-D-aspartate receptors prevents the neuropathologic consequences. Because adenosine affords neuroprotection against various forms of glutamate-mediated neuronal damage, the present studies were performed to investigate whether adenosine plays a protective role in METH-induced toxicity. METH-induced decrements in neostriatal dopamine content and tyrosine hydroxylase activity in mice were potentiated by concurrent treatment with caffeine, a nonselective adenosine antagonist that blocks both A1 and A2 adenosine receptors. In contrast, chronic treatment of mice with caffeine through their drinking water for 4 weeks, which increased the number of adenosine A1 receptors in the neostriatum and frontal cortex, followed by drug washout, prevented the neurochemical changes produced by the treatment of mice with METH treatment. In contrast, this treatment did not prevent 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine-induced dopaminergic neurotoxicity. Furthermore, concurrent administration of cyclopentyladenosine, an adenosine A1 receptor agonist, attenuated the METH-induced neurochemical changes. This protection by cyclopentyladenosine was blocked by cyclopentyltheophylline, an A1 receptor antagonist. These results indicate that activation of A1 receptors can protect against METH-induced neurotoxicity in mice.

  4. ESTIMATION OF THE NUMBER OF NEURONS IN THE HIPPOCAMPUS OF RATS WITH PENICILLIN INDUCED EPILEPSY

    Directory of Open Access Journals (Sweden)

    Ilgaz Akdogan

    2011-05-01

    Full Text Available Epilepsy is a neurological disease arising from strong and uncontrollable electrical firings of a group of neurons in the central nervous system. Experimental epileptic models have been developed to assess the physiopathology of epileptic seizures. This study was undertaken to estimate the number of neurons in the rat hippocampus with penicillin induced epilepsy, using a stereological method, "the optical fractionator". In the experimental group, 500 IU penicillin-G was injected intra-cortically, and in the control group, the same volume of saline was administered. A week later, the animals were decapitated and their brains were removed by craniatomy. Frozen brains were cut with a thickness of 150 ěm in a cryostat. Sections were collected by systematic random sampling and stained with hematoxylen-eosin. Microscopic images of pyramidal cell layers from hippocampus CA1, CA2 and CA3 subfields were then transferred to a monitor, using a 100x objective (N.A. = 1.25. Using the optical disector method, the neurons were counted in the frames and determined with a fractionator sampling scheme. The total pyramidal neuron number was then estimated using the optical fractionator method. The total pyramidal neuron number was found to be statistically lower in the experimental group (mean = 142,888 ± 11,745 than in the control group (mean = 177,953 ± 10,907 (p < 0.05. The results suggest that a decrease in the hippocampal neuronal number in a penicillin model of epilepsy can be determined objectively and efficiently using the optical fractionator method.

  5. Transcriptome Analysis of Chemically-Induced Sensory Neuron Ablation in Zebrafish.

    Directory of Open Access Journals (Sweden)

    Jane A Cox

    Full Text Available Peripheral glia are known to have a critical role in the initial response to axon damage and degeneration. However, little is known about the cellular responses of non-myelinating glia to nerve injury. In this study, we analyzed the transcriptomes of wild-type and mutant (lacking peripheral glia zebrafish larvae that were treated with metronidazole. This treatment allowed us to conditionally and selectively ablate cranial sensory neurons whose axons are ensheathed only by non-myelinating glia. While transcripts representing over 27,000 genes were detected by RNAseq, only a small fraction (~1% of genes were found to be differentially expressed in response to neuronal degeneration in either line at either 2 hrs or 5 hrs of metronidazole treatment. Analysis revealed that most expression changes (332 out of the total of 458 differentially expressed genes occurred over a continuous period (from 2 to 5 hrs of metronidazole exposure, with a small number of genes showing changes limited to only the 2 hr (55 genes or 5 hr (71 genes time points. For genes with continuous alterations in expression, some of the most meaningful sets of enriched categories in the wild-type line were those involving the inflammatory TNF-alpha and IL6 signaling pathways, oxidoreductase activities and response to stress. Intriguingly, these changes were not observed in the mutant line. Indeed, cluster analysis indicated that the effects of metronidazole treatment on gene expression was heavily influenced by the presence or absence of glia, indicating that the peripheral non-myelinating glia play a significant role in the transcriptional response to sensory neuron degeneration. This is the first transcriptome study of metronidazole-induced neuronal death in zebrafish and the response of non-myelinating glia to sensory neuron degeneration. We believe this study provides important insight into the mechanisms by which non-myelinating glia react to neuronal death and degeneration in

  6. Specific reactions of different striatal neuron types in morphology induced by quinolinic acid in rats.

    Directory of Open Access Journals (Sweden)

    Qiqi Feng

    Full Text Available Huntington's disease (HD is a neurological degenerative disease and quinolinic acid (QA has been used to establish HD model in animals through the mechanism of excitotoxicity. Yet the specific pathological changes and the underlying mechanisms are not fully elucidated. We aimed to reveal the specific morphological changes of different striatal neurons in the HD model. Sprague-Dawley (SD rats were subjected to unilaterally intrastriatal injections of QA to mimic the HD model. Behavioral tests, histochemical and immunhistochemical stainings as well as Western blots were applied in the present study. The results showed that QA-treated rats had obvious motor and cognitive impairments when compared with the control group. Immunohistochemical detection showed a great loss of NeuN+ neurons and Darpp32+ projection neurons in the transition zone in the QA group when compared with the control group. The numbers of parvalbumin (Parv+ and neuropeptide Y (NPY+ interneurons were both significantly reduced while those of calretinin (Cr+ and choline acetyltransferase (ChAT+ were not changed notably in the transition zone in the QA group when compared to the controls. Parv+, NPY+ and ChAT+ interneurons were not significantly increased in fiber density while Cr+ neurons displayed an obvious increase in fiber density in the transition zone in QA-treated rats. The varicosity densities of Parv+, Cr+ and NPY+ interneurons were all raised in the transition zone after QA treatment. In conclusion, the present study revealed that QA induced obvious behavioral changes as well as a general loss of striatal projection neurons and specific morphological changes in different striatal interneurons, which may help further explain the underlying mechanisms and the specific functions of various striatal neurons in the pathological process of HD.

  7. Protective role of AgRP neuron's PDK1 against salt-induced hypertension.

    Science.gov (United States)

    Zhang, Boyang; Nakata, Masanori; Lu, Ming; Nakae, Jun; Okada, Takashi; Ogawa, Wataru; Yada, Toshihiko

    2018-06-12

    In the hypothalamic arcuate nucleus (ARC), orexigenic agouti-related peptide (AgRP) neurons regulate feeding behavior and energy homeostasis. The 3-phosphoinositide-dependent protein kinase-1 (PDK1) in AgRP neurons serves as a major signaling molecule for leptin and insulin, the hormones regulating feeding behavior, energy homeostasis and circulation. However, it is unclear whether PDK1 in AGRP neurons is also involved in regulation of blood pressure. This study explored it by generating and analyzing AgRP neuron-specific PDK1 knockout (Agrp-Pdk1 flox/flox ) mice and effect of high salt diet on blood pressure in KO and WT mice was analyzed. Under high salt diet feeding, systolic blood pressure (SBP) of Agrp-Pdk1 flox/flox mice was significantly elevated compared to Agrp-Cre mice. When the high salt diet was switched to control low salt diet, SBP of Agrp-Pdk1 flox/flox mice returned to the basal level observed in Agrp-Cre mice within 1 week. In Agrp-Pdk1 flox/flox mice, urinary noradrenalin excretion and NUCB2 mRNA expression in hypothalamic paraventricular nucleus (PVN) were markedly upregulated. Moreover, silencing of NUCB2 in the PVN counteracted the rises in urinary noradrenalin excretions and SBP. These results demonstrate a novel role of PDK1 in AgRP neurons to counteract the high salt diet-induced hypertension by preventing hyperactivation of PVN nesfatin-1 neurons. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Histamine induces microglia activation and dopaminergic neuronal toxicity via H1 receptor activation.

    Science.gov (United States)

    Rocha, Sandra M; Saraiva, Tatiana; Cristóvão, Ana C; Ferreira, Raquel; Santos, Tiago; Esteves, Marta; Saraiva, Cláudia; Je, Goun; Cortes, Luísa; Valero, Jorge; Alves, Gilberto; Klibanov, Alexander; Kim, Yoon-Seong; Bernardino, Liliana

    2016-06-04

    Histamine is an amine widely known as a peripheral inflammatory mediator and as a neurotransmitter in the central nervous system. Recently, it has been suggested that histamine acts as an innate modulator of microglial activity. Herein, we aimed to disclose the role of histamine in microglial phagocytic activity and reactive oxygen species (ROS) production and to explore the consequences of histamine-induced neuroinflammation in dopaminergic (DA) neuronal survival. The effect of histamine on phagocytosis was assessed both in vitro by using a murine N9 microglial cell line and primary microglial cell cultures and in vivo. Cells were exposed to IgG-opsonized latex beads or phosphatidylserine (PS) liposomes to evaluate Fcγ or PS receptor-mediated microglial phagocytosis, respectively. ROS production and protein levels of NADPH oxidases and Rac1 were assessed as a measure of oxidative stress. DA neuronal survival was evaluated in vivo by counting the number of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) of mice. We found that histamine triggers microglial phagocytosis via histamine receptor 1 (H1R) activation and ROS production via H1R and H4R activation. By using apocynin, a broad NADPH oxidase (Nox) inhibitor, and Nox1 knockout mice, we found that the Nox1 signaling pathway is involved in both phagocytosis and ROS production induced by histamine in vitro. Interestingly, both apocynin and annexin V (used as inhibitor of PS-induced phagocytosis) fully abolished the DA neurotoxicity induced by the injection of histamine in the SN of adult mice in vivo. Blockade of H1R protected against histamine-induced Nox1 expression and death of DA neurons in vivo. Overall, our results highlight the relevance of histamine in the modulation of microglial activity that ultimately may interfere with neuronal survival in the context of Parkinson's disease (PD) and, eventually, other neurodegenerative diseases which are accompanied by microglia-induced

  9. Carbon monoxide-induced delayed amnesia, delayed neuronal death and change in acetylcholine concentration in mice

    International Nuclear Information System (INIS)

    Nabeshima, T.; Katoh, A.; Ishimaru, H.; Yoneda, Y.; Ogita, K.; Murase, K.; Ohtsuka, H.; Inari, K.; Fukuta, T.; Kameyama, T.

    1991-01-01

    We investigated the interrelationship of delayed amnesia, delayed neuronal death and changes in acetylcholine concentration induced by carbon monoxide (CO)-exposure in mice. In the test for retention of the passive avoidance task, amnesia was observed 5 and 7 days after CO-exposure when the mice were exposed to CO 1 day after training; in the case when the mice were exposed to CO 5 and 7 days before training, amnesia was also observed in a retention test given 1 day after training. The number of pyramidal cells in the hippocampal CA1 subfield was lower than that of the control 3, 5 and 7 days after CO-exposure. But the neurodegeneration in the parietal cortex, area 1, was not observed until 7 days after CO-exposure. The findings indicated that the amnesia and the neuronal death were produced after a delay when the mice were exposed to CO. In addition, the delayed amnesia was closely related to the delayed neuronal death in the hippocampal CA1 subfield. Moreover, [3H]glutamate and [3H]glycine binding sites did not change after CO-exposure but, 7 days after CO-exposure, the concentration of acetylcholine and the binding of [3H]quinuclidinyl benzilate in the frontal cortex and the striatum were found to have significantly changed, but those in the hippocampus did not show significant change. Therefore, we suggest that delayed amnesia induced by CO-exposure may result from delayed neuronal death in the hippocampal CA1 subfield and dysfunction in the acetylcholinergic neurons, in the frontal cortex, the striatum and/or the hippocampus

  10. Carbon monoxide-induced delayed amnesia, delayed neuronal death and change in acetylcholine concentration in mice

    Energy Technology Data Exchange (ETDEWEB)

    Nabeshima, T.; Katoh, A.; Ishimaru, H.; Yoneda, Y.; Ogita, K.; Murase, K.; Ohtsuka, H.; Inari, K.; Fukuta, T.; Kameyama, T. (Meijo Univ., Nagoya (Japan))

    1991-01-01

    We investigated the interrelationship of delayed amnesia, delayed neuronal death and changes in acetylcholine concentration induced by carbon monoxide (CO)-exposure in mice. In the test for retention of the passive avoidance task, amnesia was observed 5 and 7 days after CO-exposure when the mice were exposed to CO 1 day after training; in the case when the mice were exposed to CO 5 and 7 days before training, amnesia was also observed in a retention test given 1 day after training. The number of pyramidal cells in the hippocampal CA1 subfield was lower than that of the control 3, 5 and 7 days after CO-exposure. But the neurodegeneration in the parietal cortex, area 1, was not observed until 7 days after CO-exposure. The findings indicated that the amnesia and the neuronal death were produced after a delay when the mice were exposed to CO. In addition, the delayed amnesia was closely related to the delayed neuronal death in the hippocampal CA1 subfield. Moreover, (3H)glutamate and (3H)glycine binding sites did not change after CO-exposure but, 7 days after CO-exposure, the concentration of acetylcholine and the binding of (3H)quinuclidinyl benzilate in the frontal cortex and the striatum were found to have significantly changed, but those in the hippocampus did not show significant change. Therefore, we suggest that delayed amnesia induced by CO-exposure may result from delayed neuronal death in the hippocampal CA1 subfield and dysfunction in the acetylcholinergic neurons, in the frontal cortex, the striatum and/or the hippocampus.

  11. High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons

    Science.gov (United States)

    Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D

    2016-01-01

    Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1ARH) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1ARH neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1ARH neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1ARH neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1ARH neurons. We propose that Kiss1ARH neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. DOI: http://dx.doi.org/10.7554/eLife.16246.001 PMID:27549338

  12. Medullary Reticular Neurons Mediate Neuropeptide Y-Induced Metabolic Inhibition and Mastication.

    Science.gov (United States)

    Nakamura, Yoshiko; Yanagawa, Yuchio; Morrison, Shaun F; Nakamura, Kazuhiro

    2017-02-07

    Hypothalamic neuropeptide Y (NPY) elicits hunger responses to increase the chances of surviving starvation: an inhibition of metabolism and an increase in feeding. Here we elucidate a key central circuit mechanism through which hypothalamic NPY signals drive these hunger responses. GABAergic neurons in the intermediate and parvicellular reticular nuclei (IRt/PCRt) of the medulla oblongata, which are activated by NPY-triggered neural signaling from the hypothalamus, potentially through the nucleus tractus solitarius, mediate the NPY-induced inhibition of metabolic thermogenesis in brown adipose tissue (BAT) via their innervation of BAT sympathetic premotor neurons. Intriguingly, the GABAergic IRt/PCRt neurons innervating the BAT sympathetic premotor region also innervate the masticatory motor region, and stimulation of the IRt/PCRt elicits mastication and increases feeding as well as inhibits BAT thermogenesis. These results indicate that GABAergic IRt/PCRt neurons mediate hypothalamus-derived hunger signaling by coordinating both autonomic and feeding motor systems to reduce energy expenditure and to promote feeding. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Synthetic ciguatoxin CTX 3C induces a rapid imbalance in neuronal excitability.

    Science.gov (United States)

    Martín, Victor; Vale, Carmen; Hirama, Masahiro; Yamashita, Shuji; Rubiolo, Juan Andrés; Vieytes, Mercedes R; Botana, Luis M

    2015-06-15

    Ciguatera is a human global disease caused by the consumption of contaminated fish that have accumulated ciguatoxins (CTXs), sodium channel activator toxins. Symptoms of ciguatera include neurological alterations such as paraesthesiae, dysaesthesiae, depression, and heightened nociperception, among others. An important issue to understand these long-term neurological alterations is to establish the role that changes in activity produced by CTX 3C represent to neurons. Here, the effects of synthetic ciguatoxin CTX 3C on membrane potential, spontaneous spiking, and properties of synaptic transmission in cultured cortical neurons of 11-18 days in vitro (DIV) were evaluated using electrophysiological approaches. CTX 3C induced a large depolarization that decreased neuronal firing and caused a rapid inward tonic current that was primarily GABAergic. Moreover, the toxin enhanced the amplitude of miniature postsynaptic inhibitory currents (mIPSCs), whereas it decreased the amplitude of miniature postsynaptic excitatory currents (mEPSCs). The frequency of mIPSCs increased, whereas the frequency of mEPSCs remained unaltered. We describe, for the first time, that a rapid membrane depolarization caused by CTX 3C in cortical neurons activates mechanisms that tend to suppress electrical activity by shifting the balance between excitatory and inhibitory synaptic transmission toward inhibition. Indeed, these results suggest that the acute effects of CTX on synaptic transmission could underlie some of the neurological symptoms caused by ciguatera in humans.

  14. mGluR5 ablation in cortical glutamatergic neurons increases novelty-induced locomotion.

    Directory of Open Access Journals (Sweden)

    Chris P Jew

    Full Text Available The group I metabotropic glutamate receptor 5 (mGluR5 has been implicated in the pathology of various neurological disorders including schizophrenia, ADHD, and autism. mGluR5-dependent synaptic plasticity has been described at a variety of neural connections and its signaling has been implicated in several behaviors. These behaviors include locomotor reactivity to novel environment, sensorimotor gating, anxiety, and cognition. mGluR5 is expressed in glutamatergic neurons, inhibitory neurons, and glia in various brain regions. In this study, we show that deleting mGluR5 expression only in principal cortical neurons leads to defective cannabinoid receptor 1 (CB1R dependent synaptic plasticity in the prefrontal cortex. These cortical glutamatergic mGluR5 knockout mice exhibit increased novelty-induced locomotion, and their locomotion can be further enhanced by treatment with the psychostimulant methylphenidate. Despite a modest reduction in repetitive behaviors, cortical glutamatergic mGluR5 knockout mice are normal in sensorimotor gating, anxiety, motor balance/learning and fear conditioning behaviors. These results show that mGluR5 signaling in cortical glutamatergic neurons is required for precisely modulating locomotor reactivity to a novel environment but not for sensorimotor gating, anxiety, motor coordination, several forms of learning or social interactions.

  15. Endogenous fatty acid ethanolamides suppress nicotine-induced activation of mesolimbic dopamine neurons through nuclear receptors.

    Science.gov (United States)

    Melis, Miriam; Pillolla, Giuliano; Luchicchi, Antonio; Muntoni, Anna Lisa; Yasar, Sevil; Goldberg, Steven R; Pistis, Marco

    2008-12-17

    Nicotine stimulates the activity of mesolimbic dopamine neurons, which is believed to mediate the rewarding and addictive properties of tobacco use. Accumulating evidence suggests that the endocannabinoid system might play a major role in neuronal mechanisms underlying the rewarding properties of drugs of abuse, including nicotine. Here, we investigated the modulation of nicotine effects by the endocannabinoid system on dopamine neurons in the ventral tegmental area with electrophysiological techniques in vivo and in vitro. We discovered that pharmacological inhibition of fatty acid amide hydrolase (FAAH), the enzyme that catabolizes fatty acid ethanolamides, among which the endocannabinoid anandamide (AEA) is the best known, suppressed nicotine-induced excitation of dopamine cells. Importantly, this effect was mimicked by the administration of the FAAH substrates oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), but not methanandamide, the hydrolysis resistant analog of AEA. OEA and PEA are naturally occurring lipid signaling molecules structurally related to AEA, but devoid of affinity for cannabinoid receptors. They blocked the effects of nicotine by activation of the peroxisome proliferator-activated receptor-alpha (PPAR-alpha), a nuclear receptor transcription factor involved in several aspects of lipid metabolism and energy balance. Activation of PPAR-alpha triggered a nongenomic stimulation of tyrosine kinases, which might lead to phosphorylation and negative regulation of neuronal nicotinic acetylcholine receptors. These data indicate for the first time that the anorexic lipids OEA and PEA possess neuromodulatory properties as endogenous ligands of PPAR-alpha in the brain and provide a potential new target for the treatment of nicotine addiction.

  16. The Neuron-Specific Protein TMEM59L Mediates Oxidative Stress-Induced Cell Death.

    Science.gov (United States)

    Zheng, Qiuyang; Zheng, Xiaoyuan; Zhang, Lishan; Luo, Hong; Qian, Lingzhi; Fu, Xing; Liu, Yiqian; Gao, Yuehong; Niu, Mengxi; Meng, Jian; Zhang, Muxian; Bu, Guojun; Xu, Huaxi; Zhang, Yun-Wu

    2017-08-01

    TMEM59L is a newly identified brain-specific membrane-anchored protein with unknown functions. Herein we found that both TMEM59L and its homolog, TMEM59, are localized in Golgi and endosomes. However, in contrast to a ubiquitous and relatively stable temporal expression of TMEM59, TMEM59L expression was limited in neurons and increased during development. We also found that both TMEM59L and TMEM59 interacted with ATG5 and ATG16L1, and that overexpression of them triggered cell autophagy. However, overexpression of TMEM59L induced intrinsic caspase-dependent apoptosis more dramatically than TMEM59. In addition, downregulation of TMEM59L prevented neuronal cell death and caspase-3 activation caused by hydrogen peroxide insults and reduced the lipidation of LC3B. Finally, we found that AAV-mediated knockdown of TMEM59L in mice significantly ameliorated caspase-3 activation, increased mouse duration in the open arm during elevated plus maze test, reduced mouse immobility time during forced swim test, and enhanced mouse memory during Y-maze and Morris water maze tests. Together, our study indicates that TMEM59L is a pro-apoptotic neuronal protein involved in animal behaviors such as anxiety, depression, and memory, and that TMEM59L downregulation protects neurons against oxidative stress.

  17. Routes to Chaos Induced by a Discontinuous Resetting Process in a Hybrid Spiking Neuron Model.

    Science.gov (United States)

    Nobukawa, Sou; Nishimura, Haruhiko; Yamanishi, Teruya

    2018-01-10

    Several hybrid spiking neuron models combining continuous spike generation mechanisms and discontinuous resetting processes following spiking have been proposed. The Izhikevich neuron model, for example, can reproduce many spiking patterns. This model clearly possesses various types of bifurcations and routes to chaos under the effect of a state-dependent jump in the resetting process. In this study, we focus further on the relation between chaotic behaviour and the state-dependent jump, approaching the subject by comparing spiking neuron model versions with and without the resetting process. We first adopt a continuous two-dimensional spiking neuron model in which the orbit in the spiking state does not exhibit divergent behaviour. We then insert the resetting process into the model. An evaluation using the Lyapunov exponent with a saltation matrix and a characteristic multiplier of the Poincar'e map reveals that two types of chaotic behaviour (i.e. bursting chaotic spikes and near-period-two chaotic spikes) are induced by the resetting process. In addition, we confirm that this chaotic bursting state is generated from the periodic spiking state because of the slow- and fast-scale dynamics that arise when jumping to the hyperpolarization and depolarization regions, respectively.

  18. Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

    Science.gov (United States)

    Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

    2015-02-01

    Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

  19. Direct Conversion of Equine Adipose-Derived Stem Cells into Induced Neuronal Cells Is Enhanced in Three-Dimensional Culture.

    Science.gov (United States)

    Petersen, Gayle F; Hilbert, Bryan J; Trope, Gareth D; Kalle, Wouter H J; Strappe, Padraig M

    2015-12-01

    The ability to culture neurons from horses may allow further investigation into equine neurological disorders. In this study, we demonstrate the generation of induced neuronal cells from equine adipose-derived stem cells (EADSCs) using a combination of lentiviral vector expression of the neuronal transcription factors Brn2, Ascl1, Myt1l (BAM) and NeuroD1 and a defined chemical induction medium, with βIII-tubulin-positive induced neuronal cells displaying a distinct neuronal morphology of rounded and compact cell bodies, extensive neurite outgrowth, and branching of processes. Furthermore, we investigated the effects of dimensionality on neuronal transdifferentiation, comparing conventional two-dimensional (2D) monolayer culture against three-dimensional (3D) culture on a porous polystyrene scaffold. Neuronal transdifferentiation was enhanced in 3D culture, with evenly distributed cells located on the surface and throughout the scaffold. Transdifferentiation efficiency was increased in 3D culture, with an increase in mean percent conversion of more than 100% compared to 2D culture. Additionally, induced neuronal cells were shown to transit through a Nestin-positive precursor state, with MAP2 and Synapsin 2 expression significantly increased in 3D culture. These findings will help to increase our understanding of equine neuropathogenesis, with prospective roles in disease modeling, drug screening, and cellular replacement for treatment of equine neurological disorders.

  20. Loss of aPKCλ in differentiated neurons disrupts the polarity complex but does not induce obvious neuronal loss or disorientation in mouse brains.

    Directory of Open Access Journals (Sweden)

    Tomoyuki Yamanaka

    Full Text Available Cell polarity plays a critical role in neuronal differentiation during development of the central nervous system (CNS. Recent studies have established the significance of atypical protein kinase C (aPKC and its interacting partners, which include PAR-3, PAR-6 and Lgl, in regulating cell polarization during neuronal differentiation. However, their roles in neuronal maintenance after CNS development remain unclear. Here we performed conditional deletion of aPKCλ, a major aPKC isoform in the brain, in differentiated neurons of mice by camk2a-cre or synapsinI-cre mediated gene targeting. We found significant reduction of aPKCλ and total aPKCs in the adult mouse brains. The aPKCλ deletion also reduced PAR-6β, possibly by its destabilization, whereas expression of other related proteins such as PAR-3 and Lgl-1 was unaffected. Biochemical analyses suggested that a significant fraction of aPKCλ formed a protein complex with PAR-6β and Lgl-1 in the brain lysates, which was disrupted by the aPKCλ deletion. Notably, the aPKCλ deletion mice did not show apparent cell loss/degeneration in the brain. In addition, neuronal orientation/distribution seemed to be unaffected. Thus, despite the polarity complex disruption, neuronal deletion of aPKCλ does not induce obvious cell loss or disorientation in mouse brains after cell differentiation.

  1. The Ketone Body, β-Hydroxybutyrate Stimulates the Autophagic Flux and Prevents Neuronal Death Induced by Glucose Deprivation in Cortical Cultured Neurons.

    Science.gov (United States)

    Camberos-Luna, Lucy; Gerónimo-Olvera, Cristian; Montiel, Teresa; Rincon-Heredia, Ruth; Massieu, Lourdes

    2016-03-01

    Glucose is the major energy substrate in brain, however, during ketogenesis induced by starvation or prolonged hypoglycemia, the ketone bodies (KB), acetoacetate and β-hydroxybutyrate (BHB) can substitute for glucose. KB improve neuronal survival in diverse injury models, but the mechanisms by which KB prevent neuronal damage are still not well understood. In the present study we have investigated whether protection by the D isomer of BHB (D-BHB) against neuronal death induced by glucose deprivation (GD), is related to autophagy. Autophagy is a lysosomal-dependent degradation process activated during nutritional stress, which leads to the digestion of damaged proteins and organelles providing energy for cell survival. Results show that autophagy is activated in cortical cultured neurons during GD, as indicated by the increase in the levels of the lipidated form of the microtubule associated protein light chain 3 (LC3-II), and the number of autophagic vesicles. At early phases of glucose reintroduction (GR), the levels of p62 declined suggesting that the degradation of the autophagolysosomal content takes place at this time. In cultures exposed to GD and GR in the presence of D-BHB, the levels of LC3-II and p62 rapidly declined and remained low during GR, suggesting that the KB stimulates the autophagic flux preventing autophagosome accumulation and improving neuronal survival.

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

    Science.gov (United States)

    Jayakumar, A R; Bak, L K; Rama Rao, K V; Waagepetersen, H S; Schousboe, A; Norenberg, M D

    2016-02-01

    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 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 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 contribute to the development of neuronal injury. Cell viability was assayed using the release of the cytoplasmic enzyme lactate dehydrogenase (LDH), together with fluorescence-based cell staining (calcein and ethidium homodimer-1 for live and dead cells, respectively). Trauma had no effect on the LDH release in neurons from 1 to 18 h. However, a significant increase in LDH release was detected at 24 h after trauma. Similar findings were identified when traumatized neurons were stained with fluorescent markers. Additionally (13)C-labeling of glutamate showed a small, but statistically significant decrease at 14 h after trauma. However, trauma had no effect on the cycling ratio of the TCA cycle at any time-period examined. These findings indicate that trauma does not cause a disturbance in oxidative metabolism of any of the substrates used for neurons. Accordingly, such metabolic disturbance does not appear to contribute to the neuronal death in the early stages following trauma.

  3. Stochastic resonance induced by novel random transitions of motion of FitzHugh-Nagumo neuron model

    International Nuclear Information System (INIS)

    Zhang Guangjun; Xu Jianxue

    2005-01-01

    In contrast to the previous studies which have dealt with stochastic resonance induced by random transitions of system motion between two coexisting limit cycle attractors in the FitzHugh-Nagumo (FHN) neuron model after Hopf bifurcation and which have dealt with the phenomenon of stochastic resonance induced by external noise when the model with periodic input has only one attractor before Hopf bifurcation, in this paper we have focused our attention on stochastic resonance (SR) induced by a novel transition behavior, the transitions of motion of the model among one attractor on the left side of bifurcation point and two attractors on the right side of bifurcation point under the perturbation of noise. The results of research show: since one bifurcation of transition from one to two limit cycle attractors and the other bifurcation of transition from two to one limit cycle attractors occur in turn besides Hopf bifurcation, the novel transitions of motion of the model occur when bifurcation parameter is perturbed by weak internal noise; the bifurcation point of the model may stochastically slightly shift to the left or right when FHN neuron model is perturbed by external Gaussian distributed white noise, and then the novel transitions of system motion also occur under the perturbation of external noise; the novel transitions could induce SR alone, and when the novel transitions of motion of the model and the traditional transitions between two coexisting limit cycle attractors after bifurcation occur in the same process the SR also may occur with complicated behaviors types; the mechanism of SR induced by external noise when FHN neuron model with periodic input has only one attractor before Hopf bifurcation is related to this kind of novel transition mentioned above

  4. 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.

  5. Calcineurin Dysregulation Underlies Spinal Cord Injury-Induced K+ Channel Dysfunction in DRG Neurons.

    Science.gov (United States)

    Zemel, Benjamin M; Muqeem, Tanziyah; Brown, Eric V; Goulão, Miguel; Urban, Mark W; Tymanskyj, Stephen R; Lepore, Angelo C; Covarrubias, Manuel

    2017-08-23

    Dysfunction of the fast-inactivating Kv3.4 potassium current in dorsal root ganglion (DRG) neurons contributes to the hyperexcitability associated with persistent pain induced by spinal cord injury (SCI). However, the underlying mechanism is not known. In light of our previous work demonstrating modulation of the Kv3.4 channel by phosphorylation, we investigated the role of the phosphatase calcineurin (CaN) using electrophysiological, molecular, and imaging approaches in adult female Sprague Dawley rats. Pharmacological inhibition of CaN in small-diameter DRG neurons slowed repolarization of the somatic action potential (AP) and attenuated the Kv3.4 current. Attenuated Kv3.4 currents also exhibited slowed inactivation. We observed similar effects on the recombinant Kv3.4 channel heterologously expressed in Chinese hamster ovary cells, supporting our findings in DRG neurons. Elucidating the molecular basis of these effects, mutation of four previously characterized serines within the Kv3.4 N-terminal inactivation domain eliminated the effects of CaN inhibition on the Kv3.4 current. SCI similarly induced concurrent Kv3.4 current attenuation and slowing of inactivation. Although there was little change in CaN expression and localization after injury, SCI induced upregulation of the native regulator of CaN 1 (RCAN1) in the DRG at the transcript and protein levels. Consistent with CaN inhibition resulting from RCAN1 upregulation, overexpression of RCAN1 in naive DRG neurons recapitulated the effects of pharmacological CaN inhibition on the Kv3.4 current and the AP. Overall, these results demonstrate a novel regulatory pathway that links CaN, RCAN1, and Kv3.4 in DRG neurons. Dysregulation of this pathway might underlie a peripheral mechanism of pain sensitization induced by SCI. SIGNIFICANCE STATEMENT Pain sensitization associated with spinal cord injury (SCI) involves poorly understood maladaptive modulation of neuronal excitability. Although central mechanisms have

  6. Dopamine Attenuates Ketamine-Induced Neuronal Apoptosis in the Developing Rat Retina Independent of Early Synchronized Spontaneous Network Activity.

    Science.gov (United States)

    Dong, Jing; Gao, Lingqi; Han, Junde; Zhang, Junjie; Zheng, Jijian

    2017-07-01

    Deprivation of spontaneous rhythmic electrical activity in early development by anesthesia administration, among other interventions, induces neuronal apoptosis. However, it is unclear whether enhancement of neuronal electrical activity attenuates neuronal apoptosis in either normal development or after anesthesia exposure. The present study investigated the effects of dopamine, an enhancer of spontaneous rhythmic electrical activity, on ketamine-induced neuronal apoptosis in the developing rat retina. TUNEL and immunohistochemical assays indicated that ketamine time- and dose-dependently aggravated physiological and ketamine-induced apoptosis and inhibited early-synchronized spontaneous network activity. Dopamine administration reversed ketamine-induced neuronal apoptosis, but did not reverse the inhibitory effects of ketamine on early synchronized spontaneous network activity despite enhancing it in controls. Blockade of D1, D2, and A2A receptors and inhibition of cAMP/PKA signaling partially antagonized the protective effect of dopamine against ketamine-induced apoptosis. Together, these data indicate that dopamine attenuates ketamine-induced neuronal apoptosis in the developing rat retina by activating the D1, D2, and A2A receptors, and upregulating cAMP/PKA signaling, rather than through modulation of early synchronized spontaneous network activity.

  7. Parameter Diversity Induced Multiple Spatial Coherence Resonances and Spiral Waves in Neuronal Network with and Without Noise

    International Nuclear Information System (INIS)

    Li Yuye; Jia Bing; Gu Huaguang; An Shucheng

    2012-01-01

    Diversity in the neurons and noise are inevitable in the real neuronal network. In this paper, parameter diversity induced spiral waves and multiple spatial coherence resonances in a two-dimensional neuronal network without or with noise are simulated. The relationship between the multiple resonances and the multiple transitions between patterns of spiral waves are identified. The coherence degrees induced by the diversity are suppressed when noise is introduced and noise density is increased. The results suggest that natural nervous system might profit from both parameter diversity and noise, provided a possible approach to control formation and transition of spiral wave by the cooperation between the diversity and noise. (general)

  8. Ferulic acid promotes survival and differentiation of neural stem cells to prevent gentamicin-induced neuronal hearing loss.

    Science.gov (United States)

    Gu, Lintao; Cui, Xinhua; Wei, Wei; Yang, Jia; Li, Xuezhong

    2017-11-15

    Neural stem cells (NSCs) have exhibited promising potential in therapies against neuronal hearing loss. Ferulic acid (FA) has been widely reported to enhance neurogenic differentiation of different stem cells. We investigated the role of FA in promoting NSC transplant therapy to prevent gentamicin-induced neuronal hearing loss. NSCs were isolated from mouse cochlear tissues to establish in vitro culture, which were then treated with FA. The survival and differentiation of NSCs were evaluated. Subsequently, neurite outgrowth and excitability of the in vitro neuronal network were assessed. Gentamicin was used to induce neuronal hearing loss in mice, in the presence and absence of FA, followed by assessments of auditory brainstem response (ABR) and distortion product optoacoustic emissions (DPOAE) amplitude. FA promoted survival, neurosphere formation and differentiation of NSCs, as well as neurite outgrowth and excitability of in vitro neuronal network. Furthermore, FA restored ABR threshold shifts and DPOAE in gentamicin-induced neuronal hearing loss mouse model in vivo. Our data, for the first time, support potential therapeutic efficacy of FA in promoting survival and differentiation of NSCs to prevent gentamicin-induced neuronal hearing loss. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Ethanol enhances GABA-induced 36Cl-influx in primary spinal cord cultured neurons

    International Nuclear Information System (INIS)

    Ticku, M.K.; Lowrimore, P.; Lehoullier, P.

    1986-01-01

    Ethanol has a pharmacological profile similar to other centrally acting drugs, which facilitate GABAergic transmission. GABA is known to produce its effects by increasing the conductance to Cl- ions. In this study, we have examined the effect of ethanol on GABA-induced 36Cl-influx in primary spinal cord cultured neurons. GABA produces a concentration-dependent, and saturable effect on 36Cl-influx in these neurons. Ethanol potentiates the effect of GABA on 36Cl-influx in these neurons. GABA (20 microM) increased the 36Cl-influx by 75% over the basal value, and in the presence of 50 mM ethanol, the observed increase was 142%. Eadie-Hoffstee analysis of the saturation curves indicated that ethanol decreases the Km value of GABA (10.6 microM to 4.2 microM), and also increases the Vmax. Besides potentiating the effect of GABA, ethanol also appears to have a direct effect in the absence of added GABA. These results suggest that ethanol enhances GABA-induced 36Cl-influx and indicate a role of GABAergic system in the actions of ethanol. These results also support the behavioral and electrophysiological studies, which have implicated GABA systems in the actions of ethanol. The potential mechanism(s) and the role of direct effect of ethanol is not clear at this time, but is currently being investigated

  10. Protective Effect of Edaravone on Glutamate-Induced Neurotoxicity in Spiral Ganglion Neurons

    Directory of Open Access Journals (Sweden)

    Xiaohui Bai

    2016-01-01

    Full Text Available Glutamate is an important excitatory neurotransmitter in mammalian brains, but excessive amount of glutamate can cause “excitotoxicity” and lead to neuronal death. As bipolar neurons, spiral ganglion neurons (SGNs function as a “bridge” in transmitting auditory information from the ear to the brain and can be damaged by excessive glutamate which results in sensorineural hearing loss. In this study, edaravone, a free radical scavenger, elicited both preventative and therapeutic effects on SGNs against glutamate-induced cell damage that was tested by MTT assay and trypan blue staining. Ho.33342 and PI double staining revealed that apoptosis as well as necrosis took place during glutamate treatment, and apoptosis was the main type of cell death. Oxidative stress played an important role in glutamate-induced cell damage but pretreatment with edaravone alleviated cell death. Results of western blot demonstrated that mechanisms underlying the toxicity of glutamate and the protection of edaravone were related to the PI3K pathway and Bcl-2 protein family.

  11. Protective Effect of Edaravone on Glutamate-Induced Neurotoxicity in Spiral Ganglion Neurons

    Science.gov (United States)

    Bai, Xiaohui; Zhang, Chi; Chen, Aiping; Liu, Wenwen; Li, Jianfeng; Sun, Qian

    2016-01-01

    Glutamate is an important excitatory neurotransmitter in mammalian brains, but excessive amount of glutamate can cause “excitotoxicity” and lead to neuronal death. As bipolar neurons, spiral ganglion neurons (SGNs) function as a “bridge” in transmitting auditory information from the ear to the brain and can be damaged by excessive glutamate which results in sensorineural hearing loss. In this study, edaravone, a free radical scavenger, elicited both preventative and therapeutic effects on SGNs against glutamate-induced cell damage that was tested by MTT assay and trypan blue staining. Ho.33342 and PI double staining revealed that apoptosis as well as necrosis took place during glutamate treatment, and apoptosis was the main type of cell death. Oxidative stress played an important role in glutamate-induced cell damage but pretreatment with edaravone alleviated cell death. Results of western blot demonstrated that mechanisms underlying the toxicity of glutamate and the protection of edaravone were related to the PI3K pathway and Bcl-2 protein family. PMID:27957345

  12. Melatonin Modulates Neuronal Cell Death Induced by Endoplasmic Reticulum Stress under Insulin Resistance Condition.

    Science.gov (United States)

    Song, Juhyun; Kim, Oh Yoen

    2017-06-10

    Insulin resistance (IR) is an important stress factor in the central nervous system, thereby aggravating neuropathogenesis and triggering cognitive decline. Melatonin, which is an antioxidant phytochemical and synthesized by the pineal gland, has multiple functions in cellular responses such as apoptosis and survival against stress. This study investigated whether melatonin modulates the signaling of neuronal cell death induced by endoplasmic reticulum (ER) stress under IR condition using SH-SY5Y neuroblastoma cells. Apoptosis cell death signaling markers (cleaved Poly [ADP-ribose] polymerase 1 (PARP), p53, and Bax) and ER stress markers (phosphorylated eIF2α (p-eIF2α), ATF4, CHOP, p-IRE1 , and spliced XBP1 (sXBP1)) were measured using reverse transcription-PCR, quantitative PCR, and western blottings. Immunofluorescence staining was also performed for p-ASK1 and p-IRE1 . The mRNA or protein expressions of cell death signaling markers and ER stress markers were increased under IR condition, but significantly attenuated by melatonin treatment. Insulin-induced activation of ASK1 ( p-ASK1 ) was also dose dependently attenuated by melatonin treatment. The regulatory effect of melatonin on neuronal cells under IR condition was associated with ASK1 signaling. In conclusion, the result suggested that melatonin may alleviate ER stress under IR condition, thereby regulating neuronal cell death signaling.

  13. Val66Met polymorphism of BDNF alters prodomain structure to induce neuronal growth cone retraction.

    Science.gov (United States)

    Anastasia, Agustin; Deinhardt, Katrin; Chao, Moses V; Will, Nathan E; Irmady, Krithi; Lee, Francis S; Hempstead, Barbara L; Bracken, Clay

    2013-01-01

    A common single-nucleotide polymorphism (SNP) in the human brain-derived neurotrophic factor (BDNF) gene results in a Val66Met substitution in the BDNF prodomain region. This SNP is associated with alterations in memory and with enhanced risk to develop depression and anxiety disorders in humans. Here we show that the isolated BDNF prodomain is detected in the hippocampus and that it can be secreted from neurons in an activity-dependent manner. Using nuclear magnetic resonance spectroscopy and circular dichroism, we find that the prodomain is intrinsically disordered, and the Val66Met substitution induces structural changes. Surprisingly, application of Met66 (but not Val66) BDNF prodomain induces acute growth cone retraction and a decrease in Rac activity in hippocampal neurons. Expression of p75(NTR) and differential engagement of the Met66 prodomain to the SorCS2 receptor are required for this effect. These results identify the Met66 prodomain as a new active ligand, which modulates neuronal morphology.

  14. 3-hydroxymorphinan is neurotrophic to dopaminergic neurons and is also neuroprotective against LPS-induced neurotoxicity.

    Science.gov (United States)

    Zhang, Wei; Qin, Liya; Wang, Tongguang; Wei, Sung-Jen; Gao, Hui-ming; Liu, Jie; Wilson, Belinda; Liu, Bin; Zhang, Wanqin; Kim, Hyoung-Chun; Hong, Jau-Shyong

    2005-03-01

    The purpose of this study was to develop a novel therapy for Parkinson's disease (PD). We recently reported that dextromethorphan (DM), an active ingredient in a variety of widely used anticough remedies, protected dopaminergic neurons in rat primary mesencephalic neuron-glia cultures against lipopolysaccharide (LPS)-mediated degeneration and provided potent protection for dopaminergic neurons in a MPTP mouse model. The underlying mechanism for the protective effect of DM was attributed to its anti-inflammatory activity through inhibition of microglia activation. In an effort to develop more potent compounds for the treatment of PD, we have screened a series of analogs of DM, and 3-hydroxymorphinan (3-HM) emerged as a promising candidate for this purpose. Our study using primary mesencephalic neuron-glia cultures showed that 3-HM provided more potent neuroprotection against LPS-induced dopaminergic neurotoxicity than its parent compound. The higher potency of 3-HM was attributed to its neurotrophic effect in addition to the anti-inflammatory effect shared by both DM and 3-HM. First, we showed that 3-HM exerted potent neuroprotective and neurotrophic effects on dopaminergic neurons in rat primary mesencephalic neuron-glia cultures treated with LPS. The neurotrophic effect of 3-HM was glia-dependent since 3-HM failed to show any protective effect in the neuron-enriched cultures. We subsequently demonstrated that it was the astroglia, not the microglia, that contributed to the neurotrophic effect of 3-HM. This conclusion was based on the reconstitution studies, in which we added different percentages of microglia (10-20%) or astroglia (40-50%) back to the neuron-enriched cultures and found that 3-HM was neurotrophic after the addition of astroglia, but not microglia. Furthermore, 3-HM-treated astroglia-derived conditioned media exerted a significant neurotrophic effect on dopaminergic neurons. It appeared likely that 3-HM caused the release of neurotrophic factor

  15. Oxaliplatin-induced loss of phosphorylated heavy neurofilament subunit neuronal immunoreactivity in rat DRG tissue

    Directory of Open Access Journals (Sweden)

    Connor Bronwen

    2009-11-01

    Full Text Available Abstract Background Oxaliplatin and related chemotherapeutic drugs cause painful chronic peripheral neuropathies in cancer patients. We investigated changes in neuronal size profiles and neurofilament immunoreactivity in L5 dorsal root ganglion (DRG tissue of adult female Wistar rats after multiple-dose treatment with oxaliplatin, cisplatin, carboplatin or paclitaxel. Results After treatment with oxaliplatin, phosphorylated neurofilament heavy subunit (pNF-H immunoreactivity was reduced in neuronal cell bodies, but unchanged in nerve fibres, of the L5 DRG. Morphometric analysis confirmed significant changes in the number (-75%; P P P = 0.82, NF-M (-1%, P = 0.96 or NF-H (0%; P = 0.93 after oxaliplatin treatment, although the sizes of parvalbumin (-29%, P = 0.047, NF-M (-11%, P = 0.038 and NF-H (-28%; P = 0.0033 immunoreactive neurons were reduced. In an independent comparison of different chemotherapeutic agents, the number of pNF-H-immunoreactive neurons was significantly altered by oxaliplatin (-77.2%; P P = 0.03 but not by carboplatin or paclitaxel, and their mean cell body area was significantly changed by oxaliplatin (-31.1%; P = 0.008 but not by cisplatin, carboplatin or paclitaxel. Conclusion This study has demonstrated a specific pattern of loss of pNF-H immunoreactivity in rat DRG tissue that corresponds with the relative neurotoxicity of oxaliplatin, cisplatin and carboplatin. Loss of pNF-H may be mechanistically linked to oxaliplatin-induced neuronal atrophy, and serves as a readily measureable endpoint of its neurotoxicity in the rat model.

  16. Regulation of angiotensin II-induced neuromodulation by MARCKS in brain neurons.

    Science.gov (United States)

    Lu, D; Yang, H; Lenox, R H; Raizada, M K

    1998-07-13

    Angiotensin II (Ang II) exerts chronic stimulatory actions on tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), and the norepinephrine transporter (NET), in part, by influencing the transcription of their genes. These neuromodulatory actions of Ang II involve Ras-Raf-MAP kinase signal transduction pathways (Lu, D., H. Yang, and M.K. Raizada. 1997. J. Cell Biol. 135:1609-1617). In this study, we present evidence to demonstrate participation of another signaling pathway in these neuronal actions of Ang II. It involves activation of protein kinase C (PKC)beta subtype and phosphorylation and redistribution of myristoylated alanine-rich C kinase substrate (MARCKS) in neurites. Ang II caused a dramatic redistribution of MARCKS from neuronal varicosities to neurites. This was accompanied by a time-dependent stimulation of its phosphorylation, that was mediated by the angiotensin type 1 receptor subtype (AT1). Incubation of neurons with PKCbeta subtype specific antisense oligonucleotide (AON) significantly attenuated both redistribution and phosphorylation of MARCKS. Furthermore, depletion of MARCKS by MARCKS-AON treatment of neurons resulted in a significant decrease in Ang II-stimulated accumulation of TH and DbetaH immunoreactivities and [3H]NE uptake activity in synaptosomes. In contrast, mRNA levels of TH, DbetaH, and NET were not influenced by MARKS-AON treatment. MARCKS pep148-165, which contains PKC phosphorylation sites, inhibited Ang II stimulation of MARCKS phosphorylation and reduced the amount of TH, DbetaH, and [3H]NE uptake in neuronal synaptosomes. These observations demonstrate that phosphorylation of MARCKS by PKCbeta and its redistribution from varicosities to neurites is important in Ang II-induced synaptic accumulation of TH, DbetaH, and NE. They suggest that a coordinated stimulation of transcription of TH, DbetaH, and NET, mediated by Ras-Raf-MAP kinase followed by their transport mediated by PKCbeta-MARCKS pathway are key in persistent

  17. Quantitative glycomics monitoring of induced pluripotent- and embryonic stem cells during neuronal differentiation

    Directory of Open Access Journals (Sweden)

    Michiyo Terashima

    2014-11-01

    Full Text Available Alterations in the structure of cell surface glycoforms occurring during the stages of stem cell differentiation remain unclear. We describe a rapid glycoblotting-based cellular glycomics method for quantitatively evaluating changes in glycoform expression and structure during neuronal differentiation of murine induced pluripotent stem cells (iPSCs and embryonic stem cells (ESCs. Our results show that changes in the expression of cellular N-glycans are comparable during the differentiation of iPSCs and ESCs. The expression of bisect-type N-glycans was significantly up-regulated in neurons that differentiated from both iPSCs and ESCs. From a glycobiological standpoint, iPSCs are an alternative neural cell source in addition to ESCs.

  18. 25-Hydroxyvitamin D depletion does not exacerbate MPTP-induced dopamine neuron damage in mice.

    Directory of Open Access Journals (Sweden)

    E Danielle Dean

    Full Text Available Recent clinical evidence supports a link between 25-hydroxyvitamin D insufficiency (serum 25-hydroxyvitamin D [25(OHD] levels <30 ng/mL and Parkinson's disease. To investigate the effect of 25(OHD depletion on neuronal susceptibility to toxic insult, we induced a state of 25(OHD deficiency in mice and then challenged them with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP. We found there was no significant difference between control and 25(OHD-deficient animals in striatal dopamine levels or dopamine transporter and tyrosine hydroxylase expression after lesioning with MPTP. Additionally, we found no difference in tyrosine hydroxylase expression in the substantia nigra pars compacta. Our data suggest that reducing 25(OHD serum levels in mice has no effect on the vulnerability of nigral dopaminergic neurons in vivo in this model system of parkinsonism.

  19. Autapse-induced multiple stochastic resonances in a modular neuronal network

    Science.gov (United States)

    Yang, XiaoLi; Yu, YanHu; Sun, ZhongKui

    2017-08-01

    This study investigates the nontrivial effects of autapse on stochastic resonance in a modular neuronal network subjected to bounded noise. The resonance effect of autapse is detected by imposing a self-feedback loop with autaptic strength and autaptic time delay to each constituent neuron. Numerical simulations have demonstrated that bounded noise with the proper level of amplitude can induce stochastic resonance; moreover, the noise induced resonance dynamics can be significantly shaped by the autapse. In detail, for a specific range of autaptic strength, multiple stochastic resonances can be induced when the autaptic time delays are appropriately adjusted. These appropriately adjusted delays are detected to nearly approach integer multiples of the period of the external weak signal when the autaptic strength is very near zero; otherwise, they do not match the period of the external weak signal when the autaptic strength is slightly greater than zero. Surprisingly, in both cases, the differences between arbitrary two adjacent adjusted autaptic delays are always approximately equal to the period of the weak signal. The phenomenon of autaptic delay induced multiple stochastic resonances is further confirmed to be robust against the period of the external weak signal and the intramodule probability of subnetwork. These findings could have important implications for weak signal detection and information propagation in realistic neural systems.

  20. Evaluation of the neuronal apoptotic pathways involved in cytoskeletal disruption-induced apoptosis.

    Science.gov (United States)

    Jordà, Elvira G; Verdaguer, Ester; Jimenez, Andrés; Arriba, S Garcia de; Allgaier, Clemens; Pallàs, Mercè; Camins, Antoni

    2005-08-01

    The cytoskeleton is critical to neuronal functioning and survival. Cytoskeletal alterations are involved in several neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. We studied the possible pathways involved in colchicine-induced apoptosis in cerebellar granule neurons (CGNs). Although colchicine evoked an increase in caspase-3, caspase-6 and caspase-9 activation, selective caspase inhibitors did not attenuate apoptosis. Inhibitors of other cysteine proteases such as PD150606 (a calpain-specific inhibitor), Z-Phe-Ala fluoromethyl ketone (a cathepsins-inhibitors) and N(alpha)-p-tosyl-l-lysine chloromethyl ketone (serine-proteases inhibitor) also had no effect on cell death/apoptosis induced by colchicine. However, BAPTA-AM 10 microM (intracellular calcium chelator) prevented apoptosis mediated by cytoskeletal alteration. These data indicate that calcium modulates colchicine-induced apoptosis in CGNs. PARP-1 inhibitors did not prevent apoptosis mediated by colchicine. Finally, colchicine-induced apoptosis in CGNs was attenuated by kenpaullone, a cdk5 inhibitor. Kenpaullone and indirubin also prevented cdk5/p25 activation mediated by colchicine. These findings indicate that cytoskeletal alteration can compromise cdk5 activation, regulating p25 formation and suggest that cdk5 inhibitors attenuate apoptosis mediated by cytoskeletal alteration. The present data indicate the potential therapeutic value of drugs that prevent the formation of p25 for the treatment of neurodegenerative disorders.

  1. Characterization of calcium signals in human induced pluripotent stem cell-derived dentate gyrus neuronal progenitors and mature neurons, stably expressing an advanced calcium indicator protein.

    Science.gov (United States)

    Vőfély, Gergő; Berecz, Tünde; Szabó, Eszter; Szebényi, Kornélia; Hathy, Edit; Orbán, Tamás I; Sarkadi, Balázs; Homolya, László; Marchetto, Maria C; Réthelyi, János M; Apáti, Ágota

    2018-04-01

    Pluripotent stem cell derived human neuronal progenitor cells (hPSC-NPCs) and their mature neuronal cell culture derivatives may efficiently be used for central nervous system (CNS) drug screening, including the investigation of ligand-induced calcium signalization. We have established hippocampal NPC cultures derived from human induced PSCs, which were previously generated by non-integrating Sendai virus reprogramming. Using established protocols these NPCs were differentiated into hippocampal dentate gyrus neurons. In order to study calcium signaling without the need of dye loading, we have stably expressed an advanced calcium indicator protein (GCaMP6fast) in the NPCs using the Sleeping Beauty transposon system. We observed no significant effects of the long-term GCaMP6 expression on NPC morphology, gene expression pattern or neural differentiation capacity. In order to compare the functional properties of GCaMP6-expressing neural cells and the corresponding parental cells loaded with calcium indicator dye Fluo-4, a detailed characterization of calcium signals was performed. We found that the calcium signals induced by ATP, glutamate, LPA, or proteases - were similar in these two systems. Moreover, the presence of the calcium indicator protein allowed for a sensitive, repeatable detection of changes in calcium signaling during the process of neurogenesis and neuronal maturation. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. The effects of piracetam on heroin-induced CPP and neuronal apoptosis in rats.

    Science.gov (United States)

    Xu, Peng; Li, Min; Bai, Yanping; Lu, Wei; Ling, Xiaomei; Li, Weidong

    2015-05-01

    Piracetam is a positive allosteric modulator of the AMPA receptor that has been used in the treatment of cognitive disorders for decades. Recent surveys and drug analyses have demonstrated that a heroin mixture adulterated with piracetam has spread rapidly in heroin addicts in China, but its addictive properties and the damage it causes to the central neural system are currently unknown. The effect of piracetam on the reward properties of heroin was assessed by conditioned place preference (CPP). Electron microscopy and radioimmunoassay were used to compare the effects of heroin mixed with equivalent piracetam (HP) and heroin alone on neuronal apoptosis and the levels of beta-endorphin (β-EP) in different brain subregions within the corticolimbic system, respectively. Piracetam significantly enhanced heroin-induced CPP expression while piracetam itself didn't induce CPP. Morphological observations showed that HP-treated rats had less neuronal apoptosis than heroin-treated group. Interestingly, HP normalized the levels of β-EP in the medial prefrontal cortex (mPFC) and core of the nucleus accumbens (AcbC) subregions, in where heroin-treated rats showed decreased levels of β-EP. These results indicate that piracetam potentiate the heroin-induced CPP and protect neurons from heroin-induced apoptosis. The protective role of HP might be related to the restoration of β-EP levels by piracetam. Our findings may provide a potential interpretation for the growing trend of HP abuse in addicts in China. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. 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.

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

    Science.gov (United States)

    Okada, Yoshinori; Okada, Mizue

    2013-04-01

    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). 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. 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. From these results, we suggest that some plant seed extracts offer protection against Aβ-mediated cell death.

  5. Visualization of odor-induced neuronal activity by immediate early gene expression

    Directory of Open Access Journals (Sweden)

    Bepari Asim K

    2012-11-01

    Full Text Available Abstract Background Sensitive detection of sensory-evoked neuronal activation is a key to mechanistic understanding of brain functions. Since immediate early genes (IEGs are readily induced in the brain by environmental changes, tracing IEG expression provides a convenient tool to identify brain activity. In this study we used in situ hybridization to detect odor-evoked induction of ten IEGs in the mouse olfactory system. We then analyzed IEG induction in the cyclic nucleotide-gated channel subunit A2 (Cnga2-null mice to visualize residual neuronal activity following odorant exposure since CNGA2 is a key component of the olfactory signal transduction pathway in the main olfactory system. Results We observed rapid induction of as many as ten IEGs in the mouse olfactory bulb (OB after olfactory stimulation by a non-biological odorant amyl acetate. A robust increase in expression of several IEGs like c-fos and Egr1 was evident in the glomerular layer, the mitral/tufted cell layer and the granule cell layer. Additionally, the neuronal IEG Npas4 showed steep induction from a very low basal expression level predominantly in the granule cell layer. In Cnga2-null mice, which are usually anosmic and sexually unresponsive, glomerular activation was insignificant in response to either ambient odorants or female stimuli. However, a subtle induction of c-fos took place in the OB of a few Cnga2-mutants which exhibited sexual arousal. Interestingly, very strong glomerular activation was observed in the OB of Cnga2-null male mice after stimulation with either the neutral odor amyl acetate or the predator odor 2, 3, 5-trimethyl-3-thiazoline (TMT. Conclusions This study shows for the first time that in vivo olfactory stimulation can robustly induce the neuronal IEG Npas4 in the mouse OB and confirms the odor-evoked induction of a number of IEGs. As shown in previous studies, our results indicate that a CNGA2-independent signaling pathway(s may activate the

  6. Blast induces oxidative stress, inflammation, neuronal loss and subsequent short-term memory impairment in rats.

    Science.gov (United States)

    Cho, H J; Sajja, V S S S; Vandevord, P J; Lee, Y W

    2013-12-03

    Molecular and cellular mechanisms of brain injury after exposure to blast overpressure (BOP) are not clearly known. The present study hypothesizes that pro-oxidative and pro-inflammatory pathways in the brain may be responsible for neuronal loss and behavioral deficits following BOP exposure. Male Sprague-Dawley rats were anesthetized and exposed to calibrated BOP of 129.23±3.01kPa while controls received only anesthesia. In situ dihydroethidium fluorescence staining revealed that BOP significantly increased the production of reactive oxygen species in the brain. In addition, real-time reverse transcriptase-polymerase chain reaction, immunofluorescence staining and enzyme-linked immunosorbent assay demonstrated a significant up-regulation of mRNA and protein expressions of pro-inflammatory mediators, such as interferon-γ and monocyte chemoattractant protein-1, in brains collected from BOP-exposed animals compared with the controls. Furthermore, immunoreactivity of neuronal nuclei in brains indicated that fewer neurons were present following BOP exposure. Moreover, novel object recognition paradigm showed a significant impairment in the short-term memory at 2weeks following BOP exposure. These results suggest that pro-oxidative and pro-inflammatory environments in the brain could play a potential role in BOP-induced neuronal loss and behavioral deficits. It may provide a foundation for defining a molecular and cellular basis of the pathophysiology of blast-induced neurotrauma (BINT). It will also contribute to the development of new therapeutic approaches selectively targeting these pathways, which have great potential in the diagnosis and therapy of BINT. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. E2f1 mediates high glucose-induced neuronal death in cultured mouse retinal explants.

    Science.gov (United States)

    Wang, Yujiao; Zhou, Yi; Xiao, Lirong; Zheng, Shijie; Yan, Naihong; Chen, Danian

    2017-10-02

    Diabetic retinopathy (DR) is the most common complication of diabetes and remains one of the major causes of blindness in the world; infants born to diabetic mothers have higher risk of developing retinopathy of prematurity (ROP). While hyperglycemia is a major risk factor, the molecular and cellular mechanisms underlying DR and diabetic ROP are poorly understood. To explore the consequences of retinal cells under high glucose, we cultured wild type or E2f1 -/- mouse retinal explants from postnatal day 8 with normal glucose, high osmotic or high glucose media. Explants were also incubated with cobalt chloride (CoCl 2 ) to mimic the hypoxic condition. We showed that, at 7 days post exposure to high glucose, retinal explants displayed elevated cell death, ectopic cell division and intact retinal vascular plexus. Cell death mainly occurred in excitatory neurons, such as ganglion and bipolar cells, which were also ectopically dividing. Many Müller glial cells reentered the cell cycle; some had irregular morphology or migrated to other layers. High glucose inhibited the hyperoxia-induced blood vessel regression of retinal explants. Moreover, inactivation of E2f1 rescued high glucose-induced ectopic division and cell death of retinal neurons, but not ectopic cell division of Müller glial cells and vascular phenotypes. This suggests that high glucose has direct but distinct effects on retinal neurons, glial cells and blood vessels, and that E2f1 mediates its effects on retinal neurons. These findings shed new light onto mechanisms of DR and the fetal retinal abnormalities associated with maternal diabetes, and suggest possible new therapeutic strategies.

  8. Protection of dichlorvos induced oxidative stress and nigrostriatal neuronal death by chronic Coenzyme Q10 pretreatment

    International Nuclear Information System (INIS)

    Binukumar, BK; Gupta, Nidhi; Bal, Amanjit; Gill, Kiran Dip

    2011-01-01

    Numerous epidemiological studies have shown an association between pesticide exposure and increased risk of developing Parkinson's diseases. Oxidative stress generated as a result of mitochondrial dysfunction has been implicated as an important factor in the etiology of Parkinson's disease. Previously, we reported that chronic dichlorvos exposure causes mitochondrial impairments and nigrostriatal neuronal death in rats. The present study was designed to test whether Coenzyme Q 10 (CoQ 10 ) administration has any neuroprotective effect against dichlorvos mediated nigrostriatal neuronal death, α-synuclein aggregation, and motor dysfunction. Male albino rats were administered dichlorvos by subcutaneous injection at a dose of 2.5 mg/kg body weight over a period of 12 weeks. Results obtained there after showed that dichlorvos exposure leads to enhanced mitochondrial ROS production, α-synuclein aggregation, decreased dopamine and its metabolite levels resulting in nigrostriatal neurodegeneration. Pretreatment by Coenzyme Q 10 (4.5 mg/kg ip for 12 weeks) to dichlorvos treated animals significantly attenuated the extent of nigrostriatal neuronal damage, in terms of decreased ROS production, increased dopamine and its metabolite levels, and restoration of motor dysfunction when compared to dichlorvos treated animals. Thus, the present study shows that Coenzyme Q 10 administration may attenuate dichlorvos induced nigrostriatal neurodegeneration, α-synuclein aggregation and motor dysfunction by virtue of its antioxidant action. - Highlights: → CoQ 10 administration attenuates dichlorvos induced nigrostriatal neurodegenaration. → CoQ 10 pre treatment leads to preservation of TH-IR neurons. → CoQ 10 may decrease oxidative damage and α-synuclin aggregation. → CoQ 10 treatment enhances motor function and protects rats from catalepsy.

  9. Unexpected neuronal protection of SU5416 against 1-Methyl-4-phenylpyridinium ion-induced toxicity via inhibiting neuronal nitric oxide synthase.

    Directory of Open Access Journals (Sweden)

    Wei Cui

    Full Text Available SU5416 was originally designed as a potent and selective inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2 for cancer therapy. In this study, we have found for the first time that SU5416 unexpectedly prevented 1-methyl-4-phenylpyridinium ion (MPP(+-induced neuronal apoptosis in cerebellar granule neurons, and decreased 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP-induced loss of dopaminergic neurons and impairment of swimming behavior in zebrafish in a concentration-dependent manner. However, VEGFR-2 kinase inhibitor II, another specific VEGFR-2 inhibitor, failed to reverse neurotoxicity at the concentration exhibiting anti-angiogenic activity, strongly suggesting that the neuroprotective effect of SU5416 is independent from its anti-angiogenic action. SU5416 potently reversed MPP(+-increased intracellular nitric oxide level with an efficacy similar to 7-nitroindazole, a specific neuronal nitric oxide synthase (nNOS inhibitor. Western blotting analysis showed that SU5416 reduced the elevation of nNOS protein expression induced by MPP(+. Furthermore, SU5416 directly inhibited the enzyme activity of rat cerebellum nNOS with an IC(50 value of 22.7 µM. In addition, knock-down of nNOS expression using short hairpin RNA (shRNA abolished the neuroprotective effects of SU5416 against MPP(+-induced neuronal loss. Our results strongly demonstrate that SU5416 might exert its unexpected neuroprotective effects by concurrently reducing nNOS protein expression and directly inhibiting nNOS enzyme activity. In view of the capability of SU5416 to cross the blood-brain barrier and the safety for human use, our findings further indicate that SU5416 might be a novel drug candidate for neurodegenerative disorders, particularly those associated with NO-mediated neurotoxicity.

  10. Mitochondrial dysfunction precedes depression of AMPK/AKT signaling in insulin resistance induced by high glucose in primary cortical neurons.

    Science.gov (United States)

    Peng, Yunhua; Liu, Jing; Shi, Le; Tang, Ying; Gao, Dan; Long, Jiangang; Liu, Jiankang

    2016-06-01

    Recent studies have demonstrated brain insulin signaling impairment and mitochondrial dysfunction in diabetes. Hyperinsulinemia and hyperlipidemia arising from diabetes have been linked to neuronal insulin resistance, and hyperglycemia induces peripheral sensory neuronal impairment and mitochondrial dysfunction. However, how brain glucose at diabetic conditions elicits cortical neuronal insulin signaling impairment and mitochondrial dysfunction remains unknown. In the present study, we cultured primary cortical neurons with high glucose levels and investigated the neuronal mitochondrial function and insulin response. We found that mitochondrial function was declined in presence of 10 mmol/L glucose, prior to the depression of AKT signaling in primary cortical neurons. We further demonstrated that the cerebral cortex of db/db mice exhibited both insulin resistance and loss of mitochondrial complex components. Moreover, we found that adenosine monophosphate-activated protein kinase (AMPK) inactivation is involved in high glucose-induced mitochondrial dysfunction and insulin resistance in primary cortical neurons and neuroblastoma cells, as well as in cerebral cortex of db/db mice, and all these impairments can be rescued by mitochondrial activator, resveratrol. Taken together, our results extend the finding that high glucose (≥10 mmol/L) comparable to diabetic brain extracellular glucose level leads to neuronal mitochondrial dysfunction and resultant insulin resistance, and targeting mitochondria-AMPK signaling might be a promising strategy to protect against diabetes-related neuronal impairment in central nerves system. We found that high glucose (≥10 mmol/L), comparable to diabetic brain extracellular glucose level, leads to neuronal mitochondrial dysfunction and resultant insulin resistance in an AMPK-dependent manner, and targeting mitochondria-AMPK signaling might be a promising strategy to protect against diabetes-related neuronal impairment in central

  11. Excitation of lateral habenula neurons as a neural mechanism underlying ethanol‐induced conditioned taste aversion

    Science.gov (United States)

    Keefe, Kristen A.; Taha, Sharif A.

    2016-01-01

    Key points The lateral habenula (LHb) has been implicated in regulation of drug‐seeking behaviours through aversion‐mediated learning.In this study, we recorded neuronal activity in the LHb of rats during an operant task before and after ethanol‐induced conditioned taste aversion (CTA) to saccharin.Ethanol‐induced CTA caused significantly higher baseline firing rates in LHb neurons, as well as elevated firing rates in response to cue presentation, lever press and saccharin taste.In a separate cohort of rats, we found that bilateral LHb lesions blocked ethanol‐induced CTA.Our results strongly suggest that excitation of LHb neurons is required for ethanol‐induced CTA, and point towards a mechanism through which LHb firing may regulate voluntary ethanol consumption. Abstract Ethanol, like other drugs of abuse, has both rewarding and aversive properties. Previous work suggests that sensitivity to ethanol's aversive effects negatively modulates voluntary alcohol intake and thus may be important in vulnerability to developing alcohol use disorders. We previously found that rats with lesions of the lateral habenula (LHb), which is implicated in aversion‐mediated learning, show accelerated escalation of voluntary ethanol consumption. To understand neural encoding in the LHb contributing to ethanol‐induced aversion, we recorded neural firing in the LHb of freely behaving, water‐deprived rats before and after an ethanol‐induced (1.5 g kg−1 20% ethanol, i.p.) conditioned taste aversion (CTA) to saccharin taste. Ethanol‐induced CTA strongly decreased motivation for saccharin in an operant task to obtain the tastant. Comparison of LHb neural firing before and after CTA induction revealed four main differences in firing properties. First, baseline firing after CTA induction was significantly higher. Second, firing evoked by cues signalling saccharin availability shifted from a pattern of primarily inhibition before CTA to primarily excitation after CTA

  12. Excitation of lateral habenula neurons as a neural mechanism underlying ethanol-induced conditioned taste aversion.

    Science.gov (United States)

    Tandon, Shashank; Keefe, Kristen A; Taha, Sharif A

    2017-02-15

    The lateral habenula (LHb) has been implicated in regulation of drug-seeking behaviours through aversion-mediated learning. In this study, we recorded neuronal activity in the LHb of rats during an operant task before and after ethanol-induced conditioned taste aversion (CTA) to saccharin. Ethanol-induced CTA caused significantly higher baseline firing rates in LHb neurons, as well as elevated firing rates in response to cue presentation, lever press and saccharin taste. In a separate cohort of rats, we found that bilateral LHb lesions blocked ethanol-induced CTA. Our results strongly suggest that excitation of LHb neurons is required for ethanol-induced CTA, and point towards a mechanism through which LHb firing may regulate voluntary ethanol consumption. Ethanol, like other drugs of abuse, has both rewarding and aversive properties. Previous work suggests that sensitivity to ethanol's aversive effects negatively modulates voluntary alcohol intake and thus may be important in vulnerability to developing alcohol use disorders. We previously found that rats with lesions of the lateral habenula (LHb), which is implicated in aversion-mediated learning, show accelerated escalation of voluntary ethanol consumption. To understand neural encoding in the LHb contributing to ethanol-induced aversion, we recorded neural firing in the LHb of freely behaving, water-deprived rats before and after an ethanol-induced (1.5 g kg -1 20% ethanol, i.p.) conditioned taste aversion (CTA) to saccharin taste. Ethanol-induced CTA strongly decreased motivation for saccharin in an operant task to obtain the tastant. Comparison of LHb neural firing before and after CTA induction revealed four main differences in firing properties. First, baseline firing after CTA induction was significantly higher. Second, firing evoked by cues signalling saccharin availability shifted from a pattern of primarily inhibition before CTA to primarily excitation after CTA induction. Third, CTA induction reduced

  13. 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.

  14. Neuronal Orphan G-Protein Coupled Receptor Proteins Mediate Plasmalogens-Induced Activation of ERK and Akt Signaling.

    Directory of Open Access Journals (Sweden)

    Md Shamim Hossain

    Full Text Available The special glycerophospholipids plasmalogens (Pls are enriched in the brain and reported to prevent neuronal cell death by enhancing phosphorylation of Akt and ERK signaling in neuronal cells. Though the activation of Akt and ERK was found to be necessary for the neuronal cells survival, it was not known how Pls enhanced cellular signaling. To answer this question, we searched for neuronal specific orphan GPCR (G-protein coupled receptor proteins, since these proteins were believed to play a role in cellular signal transduction through the lipid rafts, where both Pls and some GPCRs were found to be enriched. In the present study, pan GPCR inhibitor significantly reduced Pls-induced ERK signaling in neuronal cells, suggesting that Pls could activate GPCRs to induce signaling. We then checked mRNA expression of 19 orphan GPCRs and 10 of them were found to be highly expressed in neuronal cells. The knockdown of these 10 neuronal specific GPCRs by short hairpin (sh-RNA lentiviral particles revealed that the Pls-mediated phosphorylation of ERK was inhibited in GPR1, GPR19, GPR21, GPR27 and GPR61 knockdown cells. We further found that the overexpression of these GPCRs enhanced Pls-mediated phosphorylation of ERK and Akt in cells. Most interestingly, the GPCRs-mediated cellular signaling was reduced significantly when the endogenous Pls were reduced. Our cumulative data, for the first time, suggest a possible mechanism for Pls-induced cellular signaling in the nervous system.

  15. Succinate-induced neuronal mitochondrial fission and hexokinase II malfunction in ischemic stroke: Therapeutical effects of kaempferol.

    Science.gov (United States)

    Wu, Bin; Luo, Hong; Zhou, Xu; Cheng, Cai-Yi; Lin, Lin; Liu, Bao-Lin; Liu, Kang; Li, Ping; Yang, Hua

    2017-09-01

    Mitochondrial dysfunction is known as one of causative factors in ischemic stroke, leading to neuronal cell death. The present work was undertaken to investigate whether succinate induces neuron apoptosis by regulating mitochondrial morphology and function. In neurons, oxygen-glucose deprivation induced succinate accumulation due to the reversal of succinate dehydrogenase (SDH) activation, leading to mitochondrial fission. Kaempferol inhibited mitochondrial fission and maintained mitochondrial HK-II through activation of Akt, and thereby protected neurons from succinate-mediated ischemi injury. Knockdown of Akt2 with siRNA diminished the effect of kaempferol, indicating that kaempferol suppressed dynamin-related protein 1 (Drp1) activation and promoted HK-II mitochondrial binding dependently on Akt. Moreover, we demonstrated that kaempferol potentiated autophagy during oxygen and glucose deprivation, contributing to protecting neuron survival against succinate insult. In vivo, oral administration of kaempferol in mice attenuated the infract volume after ischemic and reperfusion (I/R) injury and reproduced the similar mitochondrial protective effect in the brain infract area. This study indicates that succinate accumulation plays a pivotal role in I/R injury-induced neuronal mitochondrial dysfunction, and suggests that modulation of Drp1 phosphorylation might be potential therapeutic strategy to protect neuron mitochondrial integrity and treat ischemic stroke. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Moderately delayed post-insult treatment with normobaric hyperoxia reduces excitotoxin-induced neuronal degeneration but increases ischemia-induced brain damage

    Directory of Open Access Journals (Sweden)

    Haelewyn Benoit

    2011-04-01

    Full Text Available Abstract Background The use and benefits of normobaric oxygen (NBO in patients suffering acute ischemic stroke is still controversial. Results Here we show for the first time to the best of our knowledge that NBO reduces both NMDA-induced calcium influxes in vitro and NMDA-induced neuronal degeneration in vivo, but increases oxygen and glucose deprivation-induced cell injury in vitro and ischemia-induced brain damage produced by middle cerebral artery occlusion in vivo. Conclusions Taken together, these results indicate that NBO reduces excitotoxin-induced calcium influx and subsequent neuronal degeneration but favors ischemia-induced brain damage and neuronal death. These findings highlight the complexity of the mechanisms involved by the use of NBO in patients suffering acute ischemic stroke.

  17. A time course analysis of the electrophysiological properties of neurons differentiated from human induced pluripotent stem cells (iPSCs.

    Directory of Open Access Journals (Sweden)

    Deborah Prè

    Full Text Available Many protocols have been designed to differentiate human embryonic stem cells (ESCs and human induced pluripotent stem cells (iPSCs into neurons. Despite the relevance of electrophysiological properties for proper neuronal function, little is known about the evolution over time of important neuronal electrophysiological parameters in iPSC-derived neurons. Yet, understanding the development of basic electrophysiological characteristics of iPSC-derived neurons is critical for evaluating their usefulness in basic and translational research. Therefore, we analyzed the basic electrophysiological parameters of forebrain neurons differentiated from human iPSCs, from day 31 to day 55 after the initiation of neuronal differentiation. We assayed the developmental progression of various properties, including resting membrane potential, action potential, sodium and potassium channel currents, somatic calcium transients and synaptic activity. During the maturation of iPSC-derived neurons, the resting membrane potential became more negative, the expression of voltage-gated sodium channels increased, the membrane became capable of generating action potentials following adequate depolarization and, at day 48-55, 50% of the cells were capable of firing action potentials in response to a prolonged depolarizing current step, of which 30% produced multiple action potentials. The percentage of cells exhibiting miniature excitatory post-synaptic currents increased over time with a significant increase in their frequency and amplitude. These changes were associated with an increase of Ca2+ transient frequency. Co-culturing iPSC-derived neurons with mouse glial cells enhanced the development of electrophysiological parameters as compared to pure iPSC-derived neuronal cultures. This study demonstrates the importance of properly evaluating the electrophysiological status of the newly generated neurons when using stem cell technology, as electrophysiological properties of

  18. 9-Cis retinoic acid protects against methamphetamine-induced neurotoxicity in nigrostriatal dopamine neurons.

    Science.gov (United States)

    Reiner, David J; Yu, Seong-Jin; Shen, Hui; He, Yi; Bae, Eunkyung; Wang, Yun

    2014-04-01

    Methamphetamine (MA) is a drug of abuse as well as a dopaminergic neurotoxin. 9-Cis retinoic acid (9cRA), a biologically active derivative of vitamin A, has protective effects against damage caused by H(2)O(2) and oxygen-glucose deprivation in vitro as well as infarction and terminal deoxynucleotidyl transferase-mediated dNTP nick-end labeling (TUNEL) labeling in ischemic brain. The purpose of this study was to examine if there was a protective role for 9cRA against MA toxicity in nigrostriatal dopaminergic neurons. Primary dopaminergic neurons, prepared from rat embryonic ventral mesencephalic tissue, were treated with MA. High doses of MA decreased tyrosine hydroxylase (TH) immunoreactivity while increasing TUNEL labeling. These toxicities were significantly reduced by 9cRA. 9cRA also inhibited the export of Nur77 from nucleus to cytosol, a response that activates apoptosis. The interaction of 9cRA and MA in vivo was next examined in adult rats. 9cRA was delivered intracerebroventricularly; MA was given (5 mg/kg, 4×) one day later. Locomotor behavior was measured 2 days after surgery for a period of 48 h. High doses of MA significantly reduced locomotor activity and TH immunoreactivity in striatum. Administration of 9cRA antagonized these changes. Previous studies have shown that 9cRA can induce bone morphogenetic protein-7 (BMP7) expression and that administration of BMP7 attenuates MA toxicity. We demonstrated that MA treatment significantly reduced BMP7 mRNA expression in nigra. Noggin (a BMP antagonist) antagonized 9cRA-induced behavioral recovery and 9cRA-induced normalization of striatal TH levels. Our data suggest that 9cRA has a protective effect against MA-mediated neurodegeneration in dopaminergic neurons via upregulation of BMP.

  19. Resveratrol Protects Dopamine Neurons Against Lipopolysaccharide-Induced Neurotoxicity through Its Anti-Inflammatory Actions

    Science.gov (United States)

    Zhang, Feng; Shi, Jing-Shan; Zhou, Hui; Wilson, Belinda; Hong, Jau-Shyong

    2010-01-01

    Parkinson's disease (PD) is the second most common neurodegenerative disease characterized by a progressive loss of dopamine (DA) neurons in the substantia nigra. Accumulating evidence indicates that inhibition of microglia-mediated neuroinflammation may become a reliable protective strategy for PD. Resveratrol, a nonflavonoid polyphenol naturally found in red wine and grapes, has been known to possess antioxidant, anticancer, and anti-inflammatory properties. Although recent studies have shown that resveratrol provided neuroprotective effects against ischemia, seizure, and neurodegenerative disorders, the mechanisms underlying its beneficial effects on dopaminergic neurodegeneration are poorly defined. In this study, rat primary midbrain neuron-glia cultures were used to elucidate the molecular mechanisms underlying resveratrol-mediated neuroprotection. The results clearly demonstrated that resveratrol protected DA neurons against lipopolysaccharide (LPS)-induced neurotoxicity in concentration- and time-dependent manners through the inhibition of microglial activation and the subsequent reduction of proinflammatory factor release. Mechanistically, resveratrol-mediated neuroprotection was attributed to the inhibition of NADPH oxidase. This conclusion is supported by the following observations. First, resveratrol reduced NADPH oxidase-mediated generation of reactive oxygen species. Second, LPS-induced translocation of NADPH oxidase cytosolic subunit p47 to the cell membrane was significantly attenuated by resveratrol. Third and most importantly, resveratrol failed to exhibit neuroprotection in cultures from NADPH oxidase-deficient mice. Furthermore, this neuroprotection was also related to an attenuation of the activation of mitogen-activated protein kinases and nuclear factor-κB signaling pathways in microglia. These findings suggest that resveratrol exerts neuroprotection against LPS-induced dopaminergic neurodegeneration, and NADPH oxidase may be a major player

  20. Serotonin neurones have anti-convulsant effects and reduce seizure-induced mortality

    Science.gov (United States)

    Buchanan, Gordon F; Murray, Nicholas M; Hajek, Michael A; Richerson, George B

    2014-01-01

    Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy. Defects in central control of breathing are important contributors to the pathophysiology of SUDEP, and serotonin (5-HT) system dysfunction may be involved. Here we examined the effect of 5-HT neurone elimination or 5-HT reduction on seizure risk and seizure-induced mortality. Adult Lmx1bf/f/p mice, which lack >99% of 5-HT neurones in the CNS, and littermate controls (Lmx1bf/f) were subjected to acute seizure induction by maximal electroshock (MES) or pilocarpine, variably including electroencephalography, electrocardiography, plethysmography, mechanical ventilation or pharmacological therapy. Lmx1bf/f/p mice had a lower seizure threshold and increased seizure-induced mortality. Breathing ceased during most seizures without recovery, whereas cardiac activity persisted for up to 9 min before terminal arrest. The mortality rate of mice of both genotypes was reduced by mechanical ventilation during the seizure or 5-HT2A receptor agonist pretreatment. The selective serotonin reuptake inhibitor citalopram reduced mortality of Lmx1bf/f but not of Lmx1bf/f/p mice. In C57BL/6N mice, reduction of 5-HT synthesis with para-chlorophenylalanine increased MES-induced seizure severity but not mortality. We conclude that 5-HT neurones raise seizure threshold and decrease seizure-related mortality. Death ensued from respiratory failure, followed by terminal asystole. Given that SUDEP often occurs in association with generalised seizures, some mechanisms causing death in our model might be shared with those leading to SUDEP. This model may help determine the relationship between seizures, 5-HT system dysfunction, breathing and death, which may lead to novel ways to prevent SUDEP. PMID:25107926

  1. Neuroglobin overexpression inhibits oxygen-glucose deprivation-induced mitochondrial permeability transition pore opening in primary cultured mouse cortical neurons.

    Science.gov (United States)

    Yu, Zhanyang; Liu, Ning; Li, Yadan; Xu, Jianfeng; Wang, Xiaoying

    2013-08-01

    Neuroglobin (Ngb) is an endogenous neuroprotective molecule against hypoxic/ischemic brain injury, but the underlying mechanisms remain largely undefined. Our recent study revealed that Ngb can bind to voltage-dependent anion channel (VDAC), a regulator of mitochondria permeability transition (MPT). In this study we examined the role of Ngb in MPT pore (mPTP) opening following oxygen-glucose deprivation (OGD) in primary cultured mouse cortical neurons. Co-immunoprecipitation (Co-IP) and immunocytochemistry showed that the binding between Ngb and VDAC was increased after OGD compared to normoxia, indicating the OGD-enhanced Ngb-VDAC interaction. Ngb overexpression protected primary mouse cortical neurons from OGD-induced neuronal death, to an extent comparable to mPTP opening inhibitor, cyclosporine A (CsA) pretreatment. We further measured the role of Ngb in OGD-induced mPTP opening using Ngb overexpression and knockdown approaches in primary cultured neurons, and recombinant Ngb exposure to isolated mitochondria. Same as CsA pretreatment, Ngb overexpression significantly reduced OGD-induced mPTP opening markers including mitochondria swelling, mitochondrial NAD(+) release, and cytochrome c (Cyt c) release in primary cultured neurons. Recombinant Ngb incubation significantly reduced OGD-induced NAD(+) release and Cyt c release from isolated mitochondria. In contrast, Ngb knockdown significantly increased OGD-induced neuron death, and increased OGD-induced mitochondrial NAD(+) release and Cyt c release as well, and these outcomes could be rescued by CsA pretreatment. In summary, our results demonstrated that Ngb overexpression can inhibit OGD-induced mPTP opening in primary cultured mouse cortical neurons, which may be one of the molecular mechanisms of Ngb's neuroprotection. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Cooperative transcription activation by Nurr1 and Pitx3 induces embryonic stem cell maturation to the midbrain dopamine neuron phenotype

    DEFF Research Database (Denmark)

    Martinat, Cecile; Bacci, Jean-Jacques; Leete, Thomas

    2006-01-01

    's disease. We sought to identify genes that can potentiate maturation of ES cell cultures to the midbrain DA neuron phenotype. A number of transcription factors have been implicated in the development of midbrain DA neurons by expression analyses and loss-of-function knockout mouse studies, including Nurr1......Midbrain dopamine (DA) neurons play a central role in the regulation of voluntary movement, and their degeneration is associated with Parkinson's disease. Cell replacement therapies, and in particular embryonic stem (ES) cell-derived DA neurons, offer a potential therapeutic venue for Parkinson......, Pitx3, Lmx1b, Engrailed-1, and Engrailed-2. However, none of these factors appear sufficient alone to induce the mature midbrain DA neuron phenotype in ES cell cultures in vitro, suggesting a more complex regulatory network. Here we show that Nurr1 and Pitx3 cooperatively promote terminal maturation...

  3. Therapeutic opportunities and challenges of induced pluripotent stem cells-derived motor neurons for treatment of amyotrophic lateral sclerosis and motor neuron disease

    Institute of Scientific and Technical Information of China (English)

    Manoj Kumar Jaiswal

    2017-01-01

    Amyotrophic lateral sclerosis (ALS) and motor neuron diseases (MNDs) are progressive neurodegenera-tive diseases that affect nerve cells in the brain affecting upper and lower motor neurons (UMNs/LMNs), brain stem and spinal cord.The clinical phenotype is characterized by loss of motor neurons (MNs), mus-cular weakness and atrophy eventually leading to paralysis and death due to respiratory failure within 3–5 years after disease onset. No effective treatment or cure is currently available that halts or reverses ALS and MND except FDA approved drug riluzole that only modestly slows the progression of ALS in some patients. Recent advances in human derived induced pluripotent stem cells have made it possible for the first time to obtain substantial amounts of human cells to recapitulate in vitro"disease in dish"and test some of the underlying pathogenetic mechanisms involved in ALS and MNDs. In this review, I discussed the opportunities and challenges of induced pluropotent stem cells-derived motor neurons for treatment of ALS and MND patients with special emphasis on their implications in finding a cure for ALS and MNDs.

  4. Therapeutic opportunities and challenges of induced pluripotent stem cells-derived motor neurons for treatment of amyotrophic lateral sclerosis and motor neuron disease.

    Science.gov (United States)

    Jaiswal, Manoj Kumar

    2017-05-01

    Amyotrophic lateral sclerosis (ALS) and motor neuron diseases (MNDs) are progressive neurodegenerative diseases that affect nerve cells in the brain affecting upper and lower motor neurons (UMNs/LMNs), brain stem and spinal cord. The clinical phenotype is characterized by loss of motor neurons (MNs), muscular weakness and atrophy eventually leading to paralysis and death due to respiratory failure within 3-5 years after disease onset. No effective treatment or cure is currently available that halts or reverses ALS and MND except FDA approved drug riluzole that only modestly slows the progression of ALS in some patients. Recent advances in human derived induced pluripotent stem cells have made it possible for the first time to obtain substantial amounts of human cells to recapitulate in vitro " disease in dish " and test some of the underlying pathogenetic mechanisms involved in ALS and MNDs. In this review, I discussed the opportunities and challenges of induced pluropotent stem cells-derived motor neurons for treatment of ALS and MND patients with special emphasis on their implications in finding a cure for ALS and MNDs.

  5. The Effect of Substrate Topography on Direct Reprogramming of Fibroblasts to Induced Neurons

    Science.gov (United States)

    Kulangara, Karina; Adler, Andrew F.; Wang, Hong; Chellappan, Malathi; Hammett, Ellen; Yasuda, Ryohei; Leong, Kam W.

    2014-01-01

    Cellular reprogramming holds tremendous potential for cell therapy and regenerative medicine. Recently, fibroblasts have been directly converted into induced neurons (iNs) by overexpression of the neuronal transcription factors Ascl1, Brn2 and Myt1L. Hypothesizing that cell-topography interactions could influence the fibroblast-to-neuron reprogramming process, we investigated the effects of various topographies on iNs produced by direct reprogramming. Final iN purity and conversion efficiency were increased on micrograting substrates. Neurite branching was increased on microposts and decreased on microgratings, with a simplified dendritic arbor characterized by the reduction of MAP2+ neurites. Neurite outgrowth increased significantly on various topographies. DNA microarray analysis detected 20 differentially expressed genes in iNs reprogrammed on smooth versus microgratings, and quantitative PCR (qPCR) confirmed the upregulation of Vip and downregulation of Thy1 and Bmp5 on microgratings. Electrophysiology and calcium imaging verified the functionality of these iNs. This study demonstrates the potential of applying topographical cues to optimize cellular reprogramming. PMID:24709523

  6. Lung inflammation induces IL-1β expression in hypoglossal neurons in rat brainstem

    Science.gov (United States)

    Jafri, Anjum; Belkadi, Abdelmadjid; Zaidi, Syed I. A.; Getsy, Paulina; Wilson, Christopher G.; Martin, Richard J.

    2013-01-01

    Perinatal inflammation is associated with respiratory morbidity. Immune modulation of brainstem respiratory control centers may provide a link for this pathobiology. We exposed 11-day old rats to intratracheal lipopolysaccharide (LPS, 0.5 µg/g) to test the hypothesis that intrapulmonary inflammation increases expression of the proinflammatory cytokine IL-1β within respiratory-related brainstem regions. Intratracheal LPS resulted in a 32% increase in IL-1β protein expression in the medulla oblongata. In situ hybridization showed increased intensity of IL-1β mRNA but no change in neuronal numbers. Co-localization experiments showed that hypoglossal neurons express IL-1β mRNA and immunostaining showed a 43% increase in IL-1β protein-expressing cells after LPS exposure. LPS treatment also significantly increased microglial cell numbers though they did not express IL-1β mRNA. LPS-induced brainstem expression of neuronal IL-1β mRNA and protein may have implications for our understanding of the vulnerability of neonatal respiratory control in response to a peripheral pro-inflammatory stimulus. PMID:23648475

  7. Neuroprotection with metformin and thymoquinone against ethanol-induced apoptotic neurodegeneration in prenatal rat cortical neurons

    Directory of Open Access Journals (Sweden)

    Ullah Ikram

    2012-01-01

    Full Text Available Abstract Background Exposure to ethanol during early development triggers severe neuronal death by activating multiple stress pathways and causes neurological disorders, such as fetal alcohol effects or fetal alcohol syndrome. This study investigated the effect of ethanol on intracellular events that predispose developing neurons for apoptosis via calcium-mediated signaling. Although the underlying molecular mechanisms of ethanol neurotoxicity are not completely determined, mitochondrial dysfunction, altered calcium homeostasis and apoptosis-related proteins have been implicated in ethanol neurotoxicity. The present study was designed to evaluate the neuroprotective mechanisms of metformin (Met and thymoquinone (TQ during ethanol toxicity in rat prenatal cortical neurons at gestational day (GD 17.5. Results We found that Met and TQ, separately and synergistically, increased cell viability after ethanol (100 mM exposure for 12 hours and attenuated the elevation of cytosolic free calcium [Ca2+]c. Furthermore, Met and TQ maintained normal physiological mitochondrial transmembrane potential (ΔψM, which is typically lowered by ethanol exposure. Increased cytosolic free [Ca2+]c and lowered mitochondrial transmembrane potential after ethanol exposure significantly decreased the expression of a key anti-apoptotic protein (Bcl-2, increased expression of Bax, and stimulated the release of cytochrome-c from mitochondria. Met and TQ treatment inhibited the apoptotic cascade by increasing Bcl-2 expression. These compounds also repressed the activation of caspase-9 and caspase-3 and reduced the cleavage of PARP-1. Morphological conformation of cell death was assessed by TUNEL, Fluoro-Jade-B, and PI staining. These staining methods demonstrated more cell death after ethanol treatment, while Met, TQ or Met plus TQ prevented ethanol-induced apoptotic cell death. Conclusion These findings suggested that Met and TQ are strong protective agents against ethanol-induced

  8. Late calcium EDTA rescues hippocampal CA1 neurons from global ischemia-induced death.

    Science.gov (United States)

    Calderone, Agata; Jover, Teresa; Mashiko, Toshihiro; Noh, Kyung-min; Tanaka, Hidenobu; Bennett, Michael V L; Zukin, R Suzanne

    2004-11-03

    Transient global ischemia induces a delayed rise in intracellular Zn2+, which may be mediated via glutamate receptor 2 (GluR2)-lacking AMPA receptors (AMPARs), and selective, delayed death of hippocampal CA1 neurons. The molecular mechanisms underlying Zn2+ toxicity in vivo are not well delineated. Here we show the striking finding that intraventricular injection of the high-affinity Zn2+ chelator calcium EDTA (CaEDTA) at 30 min before ischemia (early CaEDTA) or at 48-60 hr (late CaEDTA), but not 3-6 hr, after ischemia, afforded robust protection of CA1 neurons in approximately 50% (late CaEDTA) to 75% (early CaEDTA) of animals. We also show that Zn2+ acts via temporally distinct mechanisms to promote neuronal death. Early CaEDTA attenuated ischemia-induced GluR2 mRNA and protein downregulation (and, by inference, formation of Zn2+-permeable AMPARs), the delayed rise in Zn2+, and neuronal death. These findings suggest that Zn2+ acts at step(s) upstream from GluR2 gene downregulation and implicate Zn2+ in transcriptional regulation and/or GluR2 mRNA stability. Early CaEDTA also blocked mitochondrial release of cytochrome c and Smac/DIABLO (second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein-binding protein with low pI), caspase-3 activity (but not procaspase-3 cleavage), p75NTR induction, and DNA fragmentation. These findings indicate that CaEDTA preserves the functional integrity of the mitochondrial outer membrane and arrests the caspase death cascade. Late injection of CaEDTA at a time when GluR2 is downregulated and caspase is activated inhibited the delayed rise in Zn2+, p75NTR induction, DNA fragmentation, and cell death. The finding of neuroprotection by late CaEDTA administration has striking implications for intervention in the delayed neuronal death associated with global ischemia.

  9. Exercise-induced neuronal plasticity in central autonomic networks: role in cardiovascular control.

    Science.gov (United States)

    Michelini, Lisete C; Stern, Javier E

    2009-09-01

    more comprehensive studies aimed at understanding cellular and molecular mechanisms within CNS neuronal networks that contribute to exercise-induced neuroplasticity and cardiovascular adjustments.

  10. H2O2 INDUCES DELAYED HYPEREXCITABILITY IN NUCLEUS TRACTUS SOLITARII NEURONS

    Science.gov (United States)

    Ostrowski, Tim D.; Hasser, Eileen M.; Heesch, Cheryl M.; Kline, David D.

    2014-01-01

    Hydrogen peroxide (H2O2) is a stable reactive oxygen species and potent neuromodulator of cellular and synaptic activity. Centrally, endogenous H2O2 is elevated during bouts of hypoxia-reoxygenation, a variety of disease states, and aging. The nucleus tractus solitarii (nTS) is the central termination site of visceral afferents for homeostatic reflexes and contributes to reflex alterations during these conditions. We determined the extent to which H2O2 modulates synaptic and membrane properties in nTS neurons in rat brainstem slices. Stimulation of the tractus solitarii (which contains the sensory afferent fibers) evoked synaptic currents that were not altered by 10 – 500 μM H2O2. However, 500 μM H2O2 modulated several intrinsic membrane properties of nTS neurons, including a decrease in input resistance, hyperpolarization of resting membrane potential (RMP) and action potential (AP) threshold (THR), and an initial reduction in AP discharge to depolarizing current. H2O2 increased conductance of barium-sensitive potassium currents, and block of these currents ablated H2O2-induced changes in RMP, input resistance and AP discharge. Following washout of H2O2 AP discharge was enhanced due to depolarization of RMP and a partially maintained hyperpolarization of THR. Hyperexcitability persisted with repeated H2O2 exposure. H2O2 effects on RMP and THR were ablated by intracellular administration of the antioxidant catalase, which was immunohistochemically identified in neurons throughout the nTS. Thus, H2O2 initially reduces excitability of nTS neurons that is followed by sustained hyperexcitability, which may play a profound role in cardiorespiratory reflexes. PMID:24397952

  11. Different types of exercise induce differential effects on neuronal adaptations and memory performance.

    Science.gov (United States)

    Lin, Tzu-Wei; Chen, Shean-Jen; Huang, Tung-Yi; Chang, Chia-Yuan; Chuang, Jih-Ing; Wu, Fong-Sen; Kuo, Yu-Min; Jen, Chauying J

    2012-01-01

    Different exercise paradigms show differential effects on various forms of memory. We hypothesize that the differential effects of exercises on memory performance are caused by different neuroplasticity changes in relevant brain regions in response to different exercise trainings. We examined the effects of treadmill running (TR) and wheel running (WR) on the Pavlovian fear conditioning task that assesses learning and memory performance associated with the amygdala (cued conditioning) and both the amygdala and hippocampus (contextual conditioning). The skeletal muscle citrate synthase activity, an indicator of aerobic capacity, was elevated in rats received 4 w of TR, but not WR. While both TR and WR elevated the contextual conditional response, only TR facilitated the cued conditional response. Using a single-neuron labeling technique, we found that while both TR and MR enlarged the dendritic field and increased the spine density in hippocampal CA3 neurons, only TR showed these effects in basolateral amygdalar neurons. Moreover, both types of exercise upregulated synaptic proteins (i.e., TrkB and SNAP-25) in the hippocampus; however only TR showed similar effects in the amygdala. Injection of K252a, a TrkB kinase inhibitor, in the dorsal hippocampus or basolateral amygdala abolished the exercise-facilitated contextual or cued fear learning and memory performance, respectively, regardless of the types of exercise. In summary, our results supported that different types of exercise affect the performance of learning and memory via BDNF-TrkB signaling and neuroplasticity in specific brain regions. The brain region-specific neuronal adaptations are possibly induced by various levels of intensity/stress elicited by different types of exercise. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Adaptive behavior of neighboring neurons during adaptation-induced plasticity of orientation tuning in V1

    Directory of Open Access Journals (Sweden)

    Shumikhina Svetlana

    2009-12-01

    Full Text Available Abstract Background Sensory neurons display transient changes of their response properties following prolonged exposure to an appropriate stimulus (adaptation. In adult cat primary visual cortex, orientation-selective neurons shift their preferred orientation after being adapted to a non-preferred orientation. The direction of those shifts, towards (attractive or away (repulsive from the adapter depends mostly on adaptation duration. How the adaptive behavior of a neuron is related to that of its neighbors remains unclear. Results Here we show that in most cases (75%, cells shift their preferred orientation in the same direction as their neighbors. We also found that cells shifting preferred orientation differently from their neighbors (25% display three interesting properties: (i larger variance of absolute shift amplitude, (ii wider tuning bandwidth and (iii larger range of preferred orientations among the cluster of cells. Several response properties of V1 neurons depend on their location within the cortical orientation map. Our results suggest that recording sites with both attractive and repulsive shifts following adaptation may be located in close proximity to iso-orientation domain boundaries or pinwheel centers. Indeed, those regions have a more diverse orientation distribution of local inputs that could account for the three properties above. On the other hand, sites with all cells shifting their preferred orientation in the same direction could be located within iso-orientation domains. Conclusions Our results suggest that the direction and amplitude of orientation preference shifts in V1 depend on location within the orientation map. This anisotropy of adaptation-induced plasticity, comparable to that of the visual cortex itself, could have important implications for our understanding of visual adaptation at the psychophysical level.

  13. Regional differentiation of retinoic acid-induced human pluripotent embryonic carcinoma stem cell neurons.

    Directory of Open Access Journals (Sweden)

    Dennis E Coyle

    Full Text Available The NTERA2 cl D1 (NT2 cell line, derived from human teratocarcinoma, exhibits similar properties as embryonic stem (ES cells or very early neuroepithelial progenitors. NT2 cells can be induced to become postmitotic central nervous system neurons (NT2N with retinoic acid. Although neurons derived from pluripotent cells, such as NT2N, have been characterized for their neurotransmitter phenotypes, their potential suitability as a donor source for neural transplantation also depends on their ability to respond to localized environmental cues from a specific region of the CNS. Therefore, our study aimed to characterize the regional transcription factors that define the rostocaudal and dorsoventral identity of NT2N derived from a monolayer differentiation paradigm using quantitative PCR (qPCR. Purified NT2N mainly expressed both GABAergic and glutamatergic phenotypes and were electrically active but did not form functional synapses. The presence of immature astrocytes and possible radial glial cells was noted. The NT2N expressed a regional transcription factor code consistent with forebrain, hindbrain and spinal cord neural progenitors but showed minimal expression of midbrain phenotypes. In the dorsoventral plane NT2N expressed both dorsal and ventral neural progenitors. Of major interest was that even under the influence of retinoic acid, a known caudalization factor, the NT2N population maintained a rostral phenotype subpopulation which expressed cortical regional transcription factors. It is proposed that understanding the regional differentiation bias of neurons derived from pluripotent stem cells will facilitate their successful integration into existing neuronal networks within the CNS.

  14. Paraquat induces oxidative stress and neuronal cell death; neuroprotection by water-soluble Coenzyme Q10

    International Nuclear Information System (INIS)

    McCarthy, S.; Somayajulu, M.; Sikorska, M.; Borowy-Borowski, H.; Pandey, S.

    2004-01-01

    Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme Q 10 (CoQ 10 ) before paraquat exposure inhibited ROS generation. Pretreatment with CoQ 10 also significantly reduced the number of apoptotic cells and DNA fragmentation. We also analyzed the effect of paraquat and CoQ 10 on isolated mitochondria. Our results indicated that treatment with paraquat induced the generation of ROS from isolated mitochondria and depolarization of the inner mitochondrial membrane. Pretreatment with CoQ 10 was able to inhibit ROS generation from isolated mitochondria as well as the collapse of mitochondrial membrane potential. Our results indicate that water-soluble CoQ 10 can prevent oxidative stress and neuronal damage induced by paraquat and therefore, can be used for the prevention and therapy of neurodegenerative diseases caused by environmental toxins

  15. Blockade of store-operated calcium entry alleviates high glucose-induced neurotoxicity via inhibiting apoptosis in rat neurons.

    Science.gov (United States)

    Xu, Zhenkuan; Xu, Wenzhe; Song, Yan; Zhang, Bin; Li, Feng; Liu, Yuguang

    2016-07-25

    Altered store-operated calcium entry (SOCE) has been suggested to be involved in many diabetic complications. However, the association of altered SOCE and diabetic neuronal damage remains unclear. This study aimed to investigate the effects of altered SOCE on primary cultured rat neuron injury induced by high glucose. Our data demonstrated that high glucose increased rat neuron injury and upregulated the expression of store-operated calcium channel (SOC). Inhibition of SOCE by a pharmacological inhibitor and siRNA knockdown of stromal interaction molecule 1 weakened the intracellular calcium overload, restored mitochondrial membrane potential, downregulated cytochrome C release and inhibited cell apoptosis. As well, treatment with the calcium chelator BAPTA-AM prevented cell apoptosis by ameliorating the high glucose-increased intracellular calcium level. These findings suggest that SOCE blockade may alleviate high glucose-induced neuronal damage by inhibiting apoptosis. SOCE might be a promising therapeutic target in diabetic neurotoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Optimal autaptic and synaptic delays enhanced synchronization transitions induced by each other in Newman–Watts neuronal networks

    International Nuclear Information System (INIS)

    Wang, Baoying; Gong, Yubing; Xie, Huijuan; Wang, Qi

    2016-01-01

    Highlights: • Optimal autaptic delay enhanced synchronization transitions induced by synaptic delay in neuronal networks. • Optimal synaptic delay enhanced synchronization transitions induced by autaptic delay. • Optimal coupling strength enhanced synchronization transitions induced by autaptic or synaptic delay. - Abstract: In this paper, we numerically study the effect of electrical autaptic and synaptic delays on synchronization transitions induced by each other in Newman–Watts Hodgkin–Huxley neuronal networks. It is found that the synchronization transitions induced by synaptic delay vary with varying autaptic delay and become strongest when autaptic delay is optimal. Similarly, the synchronization transitions induced by autaptic delay vary with varying synaptic delay and become strongest at optimal synaptic delay. Also, there is optimal coupling strength by which the synchronization transitions induced by either synaptic or autaptic delay become strongest. These results show that electrical autaptic and synaptic delays can enhance synchronization transitions induced by each other in the neuronal networks. This implies that electrical autaptic and synaptic delays can cooperate with each other and more efficiently regulate the synchrony state of the neuronal networks. These findings could find potential implications for the information transmission in neural systems.

  17. Proliferating cell nuclear antigen binds DNA polymerase-β and mediates 1-methyl-4-phenylpyridinium-induced neuronal death.

    Directory of Open Access Journals (Sweden)

    Zhentao Zhang

    Full Text Available The mechanisms leading to dopaminergic neuronal loss in the substantia nigra of patients with Parkinson disease (PD remain poorly understood. We recently reported that aberrant DNA replication mediated by DNA polymerase-β (DNA pol-β plays a causal role in the death of postmitotic neurons in an in vitro model of PD. In the present study, we show that both proliferating cell nuclear antigen (PCNA and DNA pol-β are required for MPP(+-induced neuronal death. PCNA binds to the catalytic domain of DNA pol-β in MPP(+-treated neurons and in post-mortem brain tissues of PD patients. The PCNA-DNA pol-β complex is loaded into DNA replication forks and mediates DNA replication in postmitotic neurons. The aberrant DNA replication mediated by the PCNA-DNA pol-β complex induces p53-dependent neuronal cell death. Our results indicate that the interaction of PCNA and DNA pol-β contributes to neuronal death in PD.

  18. Pharmacological activation/inhibition of the cannabinoid system affects alcohol withdrawal-induced neuronal hypersensitivity to excitotoxic insults.

    Directory of Open Access Journals (Sweden)

    Marina Rubio

    Full Text Available Cessation of chronic ethanol consumption can increase the sensitivity of the brain to excitotoxic damages. Cannabinoids have been proposed as neuroprotectants in different models of neuronal injury, but their effect have never been investigated in a context of excitotoxicity after alcohol cessation. Here we examined the effects of the pharmacological activation/inhibition of the endocannabinoid system in an in vitro model of chronic ethanol exposure and withdrawal followed by an excitotoxic challenge. Ethanol withdrawal increased N-methyl-D-aspartate (NMDA-evoked neuronal death, probably by altering the ratio between GluN2A and GluN2B NMDA receptor subunits. The stimulation of the endocannabinoid system with the cannabinoid agonist HU-210 decreased NMDA-induced neuronal death exclusively in ethanol-withdrawn neurons. This neuroprotection could be explained by a decrease in NMDA-stimulated calcium influx after the administration of HU-210, found exclusively in ethanol-withdrawn neurons. By contrast, the inhibition of the cannabinoid system with the CB1 receptor antagonist rimonabant (SR141716 during ethanol withdrawal increased death of ethanol-withdrawn neurons without any modification of NMDA-stimulated calcium influx. Moreover, chronic administration of rimonabant increased NMDA-stimulated toxicity not only in withdrawn neurons, but also in control neurons. In summary, we show for the first time that the stimulation of the endocannabinoid system is protective against the hyperexcitability developed during alcohol withdrawal. By contrast, the blockade of the endocannabinoid system is highly counterproductive during alcohol withdrawal.

  19. The Marine Guanidine Alkaloid Crambescidin 816 Induces Calcium Influx and Cytotoxicity in Primary Cultures of Cortical Neurons through Glutamate Receptors.

    Science.gov (United States)

    Mendez, Aida G; Juncal, Andrea Boente; Silva, Siguara B L; Thomas, Olivier P; Martín Vázquez, Víctor; Alfonso, Amparo; Vieytes, Mercedes R; Vale, Carmen; Botana, Luís M

    2017-07-19

    Crambescidin 816 is a guanidine alkaloid produced by the sponge Crambe crambe with known antitumoral activity. While the information describing the effects of this alkaloid in central neurons is scarce, Cramb816 is known to block voltage dependent calcium channels being selective for L-type channels. Moreover, Cramb816 reduced neuronal viability through an unknown mechanism. Here, we aimed to describe the toxic activity of Cramb816 in cortical neurons. Since calcium influx is considered the main mechanism responsible for neuronal cell death, the effects of Cramb816 in the cytosolic calcium concentration of cortical neurons were studied. The alkaloid decreased neuronal viability and induced a dose-dependent increase in cytosolic calcium that was also related to the presence of calcium in the extracellular media. The increase in calcium influx was age dependent, being higher in younger neurons. Moreover, this effect was prevented by glutamate receptor antagonists, which did not fully block the cytotoxic effect of Cramb816 after 24 h of treatment but completely prevented Cramb816 cytotoxicity after 10 min exposure. Therefore, the findings presented herein provide new insights into the cytotoxic effect of Cramb816 in cortical neurons.

  20. Trigeminal ganglion neurons of mice show intracellular chloride accumulation and chloride-dependent amplification of capsaicin-induced responses.

    Directory of Open Access Journals (Sweden)

    Nicole Schöbel

    Full Text Available Intracellular Cl(- concentrations ([Cl(-](i of sensory neurons regulate signal transmission and signal amplification. In dorsal root ganglion (DRG and olfactory sensory neurons (OSNs, Cl(- is accumulated by the Na(+-K(+-2Cl(- cotransporter 1 (NKCC1, resulting in a [Cl(-](i above electrochemical equilibrium and a depolarizing Cl(- efflux upon Cl(- channel opening. Here, we investigate the [Cl(-](i and function of Cl(- in primary sensory neurons of trigeminal ganglia (TG of wild type (WT and NKCC1(-/- mice using pharmacological and imaging approaches, patch-clamping, as well as behavioral testing. The [Cl(-](i of WT TG neurons indicated active NKCC1-dependent Cl(- accumulation. Gamma-aminobutyric acid (GABA(A receptor activation induced a reduction of [Cl(-](i as well as Ca(2+ transients in a corresponding fraction of TG neurons. Ca(2+ transients were sensitive to inhibition of NKCC1 and voltage-gated Ca(2+ channels (VGCCs. Ca(2+ responses induced by capsaicin, a prototypical stimulus of transient receptor potential vanilloid subfamily member-1 (TRPV1 were diminished in NKCC1(-/- TG neurons, but elevated under conditions of a lowered [Cl(-](o suggesting a Cl(--dependent amplification of capsaicin-induced responses. Using next generation sequencing (NGS, we found expression of different Ca(2+-activated Cl(- channels (CaCCs in TGs of mice. Pharmacological inhibition of CaCCs reduced the amplitude of capsaicin-induced responses of TG neurons in Ca(2+ imaging and electrophysiological recordings. In a behavioral paradigm, NKCC1(-/- mice showed less avoidance of the aversive stimulus capsaicin. In summary, our results strongly argue for a Ca(2+-activated Cl(--dependent signal amplification mechanism in TG neurons that requires intracellular Cl(- accumulation by NKCC1 and the activation of CaCCs.

  1. Th17 Cells Induce Dopaminergic Neuronal Death via LFA-1/ICAM-1 Interaction in a Mouse Model of Parkinson's Disease.

    Science.gov (United States)

    Liu, Zhan; Huang, Yan; Cao, Bei-Bei; Qiu, Yi-Hua; Peng, Yu-Ping

    2017-12-01

    T helper (Th)17 cells, a subset of CD4 + T lymphocytes, have strong pro-inflammatory property and appear to be essential in the pathogenesis of many inflammatory diseases. However, the involvement of Th17 cells in Parkinson's disease (PD) that is characterized by a progressive degeneration of dopaminergic (DAergic) neurons in the nigrostriatal system is unclear. Here, we aimed to demonstrate that Th17 cells infiltrate into the brain parenchyma and induce neuroinflammation and DAergic neuronal death in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)- or 1-methyl-4-phenylpyridinium (MPP + )-induced PD models. Blood-brain barrier (BBB) disruption in the substantia nigra (SN) was assessed by the signal of FITC-labeled albumin that was injected into blood circulation via the ascending aorta. Live cell imaging system was used to observe a direct contact of Th17 cells with neurons by staining these cells using the two adhesion molecules, leukocyte function-associated antigen (LFA)-1 and intercellular adhesion molecule (ICAM)-1, respectively. Th17 cells invaded into the SN where BBB was disrupted in MPTP-induced PD mice. Th17 cells exacerbated DAergic neuronal loss and pro-inflammatory/neurotrophic factor disorders in MPP + -treated ventral mesencephalic (VM) cell cultures. A direct contact of LFA-1-stained Th17 cells with ICAM-1-stained VM neurons was dynamically captured. Either blocking LFA-1 in Th17 cells or blocking ICAM-1 in VM neurons with neutralizing antibodies abolished Th17-induced DAergic neuronal death. These results establish that Th17 cells infiltrate into the brain parenchyma of PD mice through lesioned BBB and exert neurotoxic property by promoting glial activation and importantly by a direct damage to neurons depending on LFA-1/ICAM-1 interaction.

  2. Iron-induced neuronal damage in a rat model of post-traumatic stress disorder.

    Science.gov (United States)

    Zhao, Ming; Yu, Zhibo; Zhang, Yang; Huang, Xueling; Hou, Jingming; Zhao, YanGang; Luo, Wei; Chen, Lin; Ou, Lan; Li, Haitao; Zhang, Jiqiang

    2016-08-25

    Previous studies have shown that iron redistribution and deposition in the brain occurs in some neurodegenerative diseases, and oxidative damage due to abnormal iron level is a primary cause of neuronal death. In the present study, we used the single prolonged stress (SPS) model to mimic post-traumatic stress disorder (PTSD), and examined whether iron was involved in the progression of PTSD. The anxiety-like behaviors of the SPS group were assessed by the elevated plus maze (EPM) and open field tests, and iron levels were measured by inductively coupled plasma optical emission spectrometer (ICP-OES). Expression of glucocorticoid receptors and transferrin receptor 1 (TfR1) and ferritin (Fn) was detected by Western blot and immunohistochemistry in selected brain areas; TfR1 and Fn mRNA expression were detected by quantitative-polymerase chain reaction (Q-PCR). Ultrastructures of the hippocampus were observed under a transmission electron microscope. Our results showed that SPS exposure induced anxiety-like symptoms and increased the level of serum cortisol and the concentration of iron in key brain areas such as the hippocampus, prefrontal cortex, and striatum. The stress induced region-specific changes in both protein and mRNA levels of TfR1 and Fn. Moreover, swelling mitochondria and cell apoptosis were observed in neurons in brain regions with iron accumulation. We concluded that SPS stress increased iron in some cognition-related brain regions and subsequently cause neuronal injury, indicating that the iron may function in the pathology of PTSD. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. Fear extinction induces mGluR5-mediated synaptic and intrinsic plasticity in infralimbic neurons.

    Science.gov (United States)

    Sepulveda-Orengo, Marian T; Lopez, Ana V; Soler-Cedeño, Omar; Porter, James T

    2013-04-24

    Studies suggest that plasticity in the infralimbic prefrontal cortex (IL) in rodents and its homolog in humans is necessary for inhibition of fear during the recall of fear extinction. The recall of extinction is impaired by locally blocking metabotropic glutamate receptor type 5 (mGluR5) activation in IL during extinction training. This finding suggests that mGluR5 stimulation may lead to IL plasticity needed for fear extinction. To test this hypothesis, we recorded AMPA and NMDA currents, AMPA receptor (AMPAR) rectification, and intrinsic excitability in IL pyramidal neurons in slices from trained rats using whole-cell patch-clamp recording. We observed that fear extinction increases the AMPA/NMDA ratio, consistent with insertion of AMPARs into IL synapses. In addition, extinction training increased inward rectification, suggesting that extinction induces the insertion of calcium-permeable (GluA2-lacking) AMPARs into IL synapses. Consistent with this, selectively blocking calcium-permeable AMPARs with Naspm reduced the AMPA EPSCs in IL neurons to a larger degree after extinction. Extinction-induced changes in AMPA/NMDA ratio, rectification, and intrinsic excitability were blocked with an mGluR5 antagonist. These findings suggest that mGluR5 activation leads to consolidation of fear extinction by regulating the intrinsic excitability of IL neurons and modifying the composition of AMPARs in IL synapses. Therefore, impaired mGluR5 activity in IL synapses could be one factor that causes inappropriate modulation of fear expression leading to anxiety disorders.

  4. Neuroprotective effect of ebselen against intracerebroventricular streptozotocin-induced neuronal apoptosis and oxidative stress in rats.

    Science.gov (United States)

    Unsal, Cuneyt; Oran, Mustafa; Albayrak, Yakup; Aktas, Cevat; Erboga, Mustafa; Topcu, Birol; Uygur, Ramazan; Tulubas, Feti; Yanartas, Omer; Ates, Ozkan; Ozen, Oguz Aslan

    2016-04-01

    The goal of this study was to examine the neuroprotective effect of ebselen against intracerebroventricular streptozotocin (ICV-STZ)-induced oxidative stress and neuronal apoptosis in rat brain. A total of 30 adult male Sprague-Dawley rats were randomly divided into 3 groups of 10 animals each: control, ICV-STZ, and ICV-STZ treated with ebselen. The ICV-STZ group rats were injected bilaterally with ICV-STZ (3 mg/kg) on days 1 and 3, and ebselen (10 mg/kg/day) was administered for 14 days starting from 1st day of ICV-STZ injection to day 14. Rats were killed at the end of the study and brain tissues were removed for biochemical and histopathological investigation. Our results demonstrated, for the first time, the neuroprotective effect of ebselen on Alzheimer's disease (AD) model in rats. Our present study, in ICV-STZ group, showed significant increase in tissue malondialdehyde levels and significant decrease in enzymatic antioxidants superoxide dismutase and glutathione peroxidase in the frontal cortex tissue. The histopathological studies in the brain of rats also supported that ebselen markedly reduced the ICV-STZ-induced histopathological changes and well preserved the normal histological architecture of the frontal cortex tissue. The number of apoptotic neurons was increased in frontal cortex tissue after ICV-STZ administration. Treatment of ebselen markedly reduced the number of degenerating apoptotic neurons. The study demonstrates the effectiveness of ebselen, as a powerful antioxidant, in preventing the oxidative damage and morphological changes caused by ICV-STZ in rats. Thus, ebselen may have a therapeutic value for the treatment of AD. © The Author(s) 2013.

  5. Pyruvate administration reduces recurrent/moderate hypoglycemia-induced cortical neuron death in diabetic rats.

    Directory of Open Access Journals (Sweden)

    Bo Young Choi

    Full Text Available Recurrent/moderate (R/M hypoglycemia is common in type 1 diabetes patients. Moderate hypoglycemia is not life-threatening, but if experienced recurrently it may present several clinical complications. Activated PARP-1 consumes cytosolic NAD, and because NAD is required for glycolysis, hypoglycemia-induced PARP-1 activation may render cells unable to use glucose even when glucose availability is restored. Pyruvate, however, can be metabolized in the absence of cytosolic NAD. We therefore hypothesized that pyruvate may be able to improve the outcome in diabetic rats subjected to insulin-induced R/M hypoglycemia by terminating hypoglycemia with glucose plus pyruvate, as compared with delivering just glucose alone. In an effort to mimic juvenile type 1 diabetes the experiments were conducted in one-month-old young rats that were rendered diabetic by streptozotocin (STZ, 50mg/kg, i.p. injection. One week after STZ injection, rats were subjected to moderate hypoglycemia by insulin injection (10 U/kg, i.p. without anesthesia for five consecutive days. Pyruvate (500 mg/kg was given by intraperitoneal injection after each R/M hypoglycemia. Three hours after last R/M hypoglycemia, zinc accumulation was evaluated. Three days after R/M hypoglycemia, neuronal death, oxidative stress, microglial activation and GSH concentrations in the cerebral cortex were analyzed. Sparse neuronal death was observed in the cortex. Zinc accumulation, oxidative injury, microglial activation and GSH loss in the cortex after R/M hypoglycemia were all reduced by pyruvate injection. These findings suggest that when delivered alongside glucose, pyruvate may significantly improve the outcome after R/M hypoglycemia by circumventing a sustained impairment in neuronal glucose utilization resulting from PARP-1 activation.

  6. Dehydration-induced release of vasopressin involves activation of hypothalamic histaminergic neurons.

    Science.gov (United States)

    Kjaer, A; Knigge, U; Rouleau, A; Garbarg, M; Warberg, J

    1994-08-01

    The hypothalamic neurotransmitter histamine (HA) induces arginine vasopressin (AVP) release when administered centrally. We studied and characterized this effect of HA with respect to receptor involvement. In addition, we studied the possible role of hypothalamic histaminergic neurons in the mediation of a physiological stimulus (dehydration) for AVP secretion. Intracerebroventricular administration of HA, the H1-receptor agonists 2(3-bromophenyl)HA and 2-thiazolylethylamine, or the H2-receptor agonists amthamine or 4-methyl-HA stimulated AVP secretion. The stimulatory action of HA on AVP was inhibited by pretreatment with the H1-receptor antagonist mepyramine or the H2-receptor antagonist cimetidine. Twenty-four hours of dehydration elevated the plasma osmolality from 298 +/- 3 to 310 +/- 3 mmol/liter and increased the plasma AVP concentration 4-fold. The hypothalamic content of HA and its metabolite tele-methyl-HA was elevated in response to dehydration, indicating an increased synthesis and release of hypothalamic HA. Dehydration-induced AVP secretion was lowered when neuronal HA synthesis was inhibited by the administration of (S) alpha-fluoromethylhistidine or when the animals were pretreated with the H3-receptor agonist R(alpha)methylhistamine, which inhibits the release and synthesis of HA, the H1-receptor antagonists mepyramine and cetirizine, or the H2-receptor antagonists cimetidine and ranitidine. We conclude that HA, via activation of both H1- and H2-receptors, stimulates AVP release and that HA is a physiological regulator of AVP secretion.

  7. Nitro-Oxidative Stress after Neuronal Ischemia Induces Protein Nitrotyrosination and Cell Death

    Directory of Open Access Journals (Sweden)

    Marta Tajes

    2013-01-01

    Full Text Available Ischemic stroke is an acute vascular event that obstructs blood supply to the brain, producing irreversible damage that affects neurons but also glial and brain vessel cells. Immediately after the stroke, the ischemic tissue produces nitric oxide (NO to recover blood perfusion but also produces superoxide anion. These compounds interact, producing peroxynitrite, which irreversibly nitrates protein tyrosines. The present study measured NO production in a human neuroblastoma (SH-SY5Y, a murine glial (BV2, a human endothelial cell line (HUVEC, and in primary cultures of human cerebral myocytes (HC-VSMCs after experimental ischemia in vitro. Neuronal, endothelial, and inducible NO synthase (NOS expression was also studied up to 24 h after ischemia, showing a different time course depending on the NOS type and the cells studied. Finally, we carried out cell viability experiments on SH-SY5Y cells with H2O2, a prooxidant agent, and with a NO donor to mimic ischemic conditions. We found that both compounds were highly toxic when they interacted, producing peroxynitrite. We obtained similar results when all cells were challenged with peroxynitrite. Our data suggest that peroxynitrite induces cell death and is a very harmful agent in brain ischemia.

  8. 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.

  9. Agmatine induces Nrf2 and protects against corticosterone effects in hippocampal neuronal cell line.

    Science.gov (United States)

    Freitas, Andiara E; Egea, Javier; Buendía, Izaskun; Navarro, Elisa; Rada, Patricia; Cuadrado, Antonio; Rodrigues, Ana Lúcia S; López, Manuela G

    2015-01-01

    Hyperactivation of the hypothalamic-pituitary-adrenal axis is a common finding in major depression; this may lead to increased levels of cortisol, which are known to cause oxidative stress imbalance and apoptotic neuronal cell death, particularly in the hippocampus, a key region implicated in mood regulation. Agmatine, an endogenous metabolite of L-arginine, has been proposed for the treatment of major depression. Corticosterone induced apoptotic cell death and increased ROS production in cultured hippocampal neuronal cells, effects that were abolished in a concentration- and time-dependent manner by agmatine. Interestingly, the combination of sub-effective concentrations of agmatine with fluoxetine or imipramine afforded synergic protection. The neuroprotective effect of agmatine was abolished by yohimbine (α2-adrenoceptor antagonist), ketanserin (5-HT2A receptor antagonist), LY294002 (PI3K inhibitor), PD98059 (MEK1/2 inhibitor), SnPP (HO-1 inhibitor), and cycloheximide (protein synthesis inhibitor). Agmatine increased Akt and ERK phosphorylation and induced the transcription factor Nrf2 and the proteins HO-1 and GCLc; induction of these proteins was prevented by yohimbine, ketanserin, LY294002, and PD98059. In conclusion, agmatine affords neuroprotection against corticosterone effects by a mechanism that implicates Nrf2 induction via α2-adrenergic and 5-HT2A receptors, Akt and ERK pathways, and HO-1 and GCLc expression.

  10. PKA-induced internalization of slack KNa channels produces dorsal root ganglion neuron hyperexcitability.

    Science.gov (United States)

    Nuwer, Megan O; Picchione, Kelly E; Bhattacharjee, Arin

    2010-10-20

    Inflammatory mediators through the activation of the protein kinase A (PKA) pathway sensitize primary afferent nociceptors to mechanical, thermal, and osmotic stimuli. However, it is unclear which ion conductances are responsible for PKA-induced nociceptor hyperexcitability. We have previously shown the abundant expression of Slack sodium-activated potassium (K(Na)) channels in nociceptive dorsal root ganglion (DRG) neurons. Here we show using cultured DRG neurons, that of the total potassium current, I(K), the K(Na) current is predominantly inhibited by PKA. We demonstrate that PKA modulation of K(Na) channels does not happen at the level of channel gating but arises from the internal trafficking of Slack channels from DRG membranes. Furthermore, we found that knocking down the Slack subunit by RNA interference causes a loss of firing accommodation analogous to that observed during PKA activation. Our data suggest that the change in nociceptive firing occurring during inflammation is the result of PKA-induced Slack channel trafficking.

  11. Noradrenaline from Locus Coeruleus Neurons Acts on Pedunculo-Pontine Neurons to Prevent REM Sleep and Induces Its Loss-Associated Effects in Rats.

    Science.gov (United States)

    Khanday, Mudasir Ahmad; Somarajan, Bindu I; Mehta, Rachna; Mallick, Birendra Nath

    2016-01-01

    Normally, rapid eye movement sleep (REMS) does not appear during waking or non-REMS. Isolated, independent studies showed that elevated noradrenaline (NA) levels inhibit REMS and induce REMS loss-associated cytomolecular, cytomorphological, psychosomatic changes and associated symptoms. However, the source of NA and its target in the brain for REMS regulation and function in health and diseases remained to be confirmed in vivo . Using tyrosine hydroxylase (TH)-siRNA and virus-coated TH-shRNA in normal freely moving rats, we downregulated NA synthesis in locus coeruleus (LC) REM-OFF neurons in vivo . These TH-downregulated rats showed increased REMS, which was prevented by infusing NA into the pedunculo-pontine tegmentum (PPT), the site of REM-ON neurons, normal REMS returned after recovery. Moreover, unlike normal or control-siRNA- or shRNA-injected rats, upon REMS deprivation (REMSD) TH-downregulated rat brains did not show elevated Na-K ATPase (molecular changes) expression and activity. To the best of our knowledge, these are the first in vivo findings in an animal model confirming that NA from the LC REM-OFF neurons (1) acts on the PPT REM-ON neurons to prevent appearance of REMS, and (2) are responsible for inducing REMSD-associated molecular changes and symptoms. These observations clearly show neuro-physio-chemical mechanism of why normally REMS does not appear during waking. Also, that LC neurons are the primary source of NA, which in turn causes some, if not many, REMSD-associated symptoms and behavioral changes. The findings are proof-of-principle for the first time and hold potential to be exploited for confirmation toward treating REMS disorder and amelioration of REMS loss-associated symptoms in patients.

  12. Evaluation of the rotenone-induced activation of the Nrf2 pathway in a neuronal model derived from human induced pluripotent stem cells.

    Science.gov (United States)

    Zagoura, Dimitra; Canovas-Jorda, David; Pistollato, Francesca; Bremer-Hoffmann, Susanne; Bal-Price, Anna

    2017-06-01

    Human induced pluripotent stem cells (hiPSCs) are considered as a powerful tool for drug and chemical screening and development of new in vitro testing strategies in the field of toxicology, including neurotoxicity evaluation. These cells are able to expand and efficiently differentiate into different types of neuronal and glial cells as well as peripheral neurons. These human cells-based neuronal models serve as test systems for mechanistic studies on different pathways involved in neurotoxicity. One of the well-known mechanisms that are activated by chemically-induced oxidative stress is the Nrf2 signaling pathway. Therefore, in the current study, we evaluated whether Nrf2 signaling machinery is expressed in human induced pluripotent stem cells (hiPSCs)-derived mixed neuronal/glial culture and if so whether it becomes activated by rotenone-induced oxidative stress mediated by complex I inhibition of mitochondrial respiration. Rotenone was found to induce the activation of Nrf2 signaling particularly at the highest tested concentration (100 nM), as shown by Nrf2 nuclear translocation and the up-regulation of the Nrf2-downstream antioxidant enzymes, NQO1 and SRXN1. Interestingly, exposure to rotenone also increased the number of astroglial cells in which Nrf2 activation may play an important role in neuroprotection. Moreover, rotenone caused cell death of dopaminergic neurons since a decreased percentage of tyrosine hydroxylase (TH + ) cells was observed. The obtained results suggest that hiPSC-derived mixed neuronal/glial culture could be a valuable in vitro human model for the establishment of neuronal specific assays in order to link Nrf2 pathway activation (biomarker of oxidative stress) with additional neuronal specific readouts that could be applied to in vitro neurotoxicity evaluation. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Allopregnanolone-induced rise in intracellular calcium in embryonic hippocampal neurons parallels their proliferative potential

    Directory of Open Access Journals (Sweden)

    Brinton Roberta

    2008-12-01

    Full Text Available Abstract Background Factors that regulate intracellular calcium concentration are known to play a critical role in brain function and neural development, including neural plasticity and neurogenesis. We previously demonstrated that the neurosteroid allopregnanolone (APα; 5α-pregnan-3α-ol-20-one promotes neural progenitor proliferation in vitro in cultures of rodent hippocampal and human cortical neural progenitors, and in vivo in triple transgenic Alzheimer's disease mice dentate gyrus. We also found that APα-induced proliferation of neural progenitors is abolished by a calcium channel blocker, nifedipine, indicating a calcium dependent mechanism for the proliferation. Methods In the present study, we investigated the effect of APα on the regulation of intracellular calcium concentration in E18 rat hippocampal neurons using ratiometric Fura2-AM imaging. Results Results indicate that APα rapidly increased intracellular calcium concentration in a dose-dependent and developmentally regulated manner, with an EC50 of 110 ± 15 nM and a maximal response occurring at three days in vitro. The stereoisomers 3β-hydroxy-5α-hydroxy-pregnan-20-one, and 3β-hydroxy-5β-hydroxy-pregnan-20-one, as well as progesterone, were without significant effect. APα-induced intracellular calcium concentration increase was not observed in calcium depleted medium and was blocked in the presence of the broad spectrum calcium channel blocker La3+, or the L-type calcium channel blocker nifedipine. Furthermore, the GABAA receptor blockers bicuculline and picrotoxin abolished APα-induced intracellular calcium concentration rise. Conclusion Collectively, these data indicate that APα promotes a rapid, dose-dependent, stereo-specific, and developmentally regulated increase of intracellular calcium concentration in rat embryonic hippocampal neurons via a mechanism that requires both the GABAA receptor and L-type calcium channel. These data suggest that APα-induced

  14. Cyanidin-3-glucoside inhibits glutamate-induced Zn2+ signaling and neuronal cell death in cultured rat hippocampal neurons by inhibiting Ca2+-induced mitochondrial depolarization and formation of reactive oxygen species.

    Science.gov (United States)

    Yang, Ji Seon; Perveen, Shazia; Ha, Tae Joung; Kim, Seong Yun; Yoon, Shin Hee

    2015-05-05

    Cyanidin-3-glucoside (C3G), a member of the anthocyanin family, is a potent natural antioxidant. However, effects of C3G on glutamate-induced [Zn(2+)]i increase and neuronal cell death remain unknown. We studied the effects of C3G on glutamate-induced [Zn(2+)]i increase and cell death in cultured rat hippocampal neurons from embryonic day 17 maternal Sprague-Dawley rats using digital imaging methods for Zn(2+), Ca(2+), reactive oxygen species (ROS), mitochondrial membrane potential and a MTT assay for cell survival. Treatment with glutamate (100 µM) for 7 min induces reproducible [Zn(2+)]i increase at 35 min interval in cultured rat hippocampal neurons. The intracellular Zn(2+)-chelator TPEN markedly blocked glutamate-induced [Zn(2+)]i increase, but the extracellular Zn(2+) chelator CaEDTA did not affect glutamate-induced [Zn(2+)]i increase. C3G inhibited the glutamate-induced [Zn(2+)]i response in a concentration-dependent manner (IC50 of 14.1 ± 1.1 µg/ml). C3G also significantly inhibited glutamate-induced [Ca(2+)]i increase. Two antioxidants such as Trolox and DTT significantly inhibited the glutamate-induced [Zn(2+)]i response, but they did not affect the [Ca(2+)]i responses. C3G blocked glutamate-induced formation of ROS. Trolox and DTT also inhibited the formation of ROS. C3G significantly inhibited glutamate-induced mitochondrial depolarization. However, TPEN, Trolox and DTT did not affect the mitochondrial depolarization. C3G, Trolox and DTT attenuated glutamate-induced neuronal cell death in cultured rat hippocampal neurons, respectively. Taken together, all these results suggest that cyanidin-3-glucoside inhibits glutamate-induced [Zn(2+)]i increase through a release of Zn(2+) from intracellular sources in cultured rat hippocampal neurons by inhibiting Ca(2+)-induced mitochondrial depolarization and formation of ROS, which is involved in neuroprotection against glutamate-induced cell death. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Edaravone protects neurons in the rat substantia nigra against 6-hydroxydopamine-induced oxidative stress damage.

    Science.gov (United States)

    Liu, Xiqi; Shao, Rushing; Li, Meng; Yang, Guofeng

    2014-11-01

    To investigate the mechanism of the neuroprotective effect of edaravone in substantia nigra (SN) of the 6-OHDA-induced rat model of Parkinson's disease. Animal model of Parkinson's disease was induced in male Sprague-Dawley rats by injecting 6-OHDA into the left medial forebrain bundle. Subsequently, rats were intraperitoneally injected with 0.3, 1, or 3 mg/kg of edaravone for 14 days or with 3 mg/kg edaravone for 14 days followed by 14 days of no treatment. We evaluated the effect of edaravone on the rotational and normal behavior of the rats, and on the number of tyrosine hydroxylase (TH)-positive cells, the amount of Nissl bodies, and the levels of glutathione (GSH), and malondialdehyde (MDA) in the SN. Edaravone treatment at 3 mg/kg significantly reduced apomorphine-induced rotational behavior (P Edaravone exerted a long-term neuroprotective effects in 6-OHDA-induced PD animal model by attenuating changes in the levels of GSH and MDA in SN, caused by oxidative stress. Edaravone prevented 6-OHDA-induced behavioral changes and de-pigmentation of SN that results from the loss of dopaminergic neurons.

  16. Inflammation-induced reversible switch of the neuron-specific enolase promoter from Purkinje neurons to Bergmann glia.

    Science.gov (United States)

    Sawada, Yusuke; Konno, Ayumu; Nagaoka, Jun; Hirai, Hirokazu

    2016-06-13

    Neuron-specific enolase (NSE) is a glycolytic isoenzyme found in mature neurons and cells of neuronal origin. Injecting adeno-associated virus serotype 9 (AAV9) vectors carrying the NSE promoter into the cerebellar cortex is likely to cause the specific transduction of neuronal cells, such as Purkinje cells (PCs) and interneurons, but not Bergmann glia (BG). However, we found BG-predominant transduction without PC transduction along a traumatic needle tract for viral injection. The enhancement of neuroinflammation by the co-application of lipopolysaccharide (LPS) with AAV9 significantly expanded the BG-predominant area concurrently with the potentiated microglial activation. The BG-predominant transduction was gradually replaced by the PC-predominant transduction as the neuroinflammation dissipated. Experiments using glioma cell cultures revealed significant activation of the NSE promoter due to glucose deprivation, suggesting that intracellularly stored glycogen is metabolized through the glycolytic pathway for energy. Activation of the glycolytic enzyme promoter in BG concurrently with inactivation in PC may have pathophysiological significance for the production of lactate in activated BG and the utilization of lactate, which is provided by the BG-PC lactate shuttle, as a primary energy resource in injured PCs.

  17. 14,15-EET promotes mitochondrial biogenesis and protects cortical neurons against oxygen/glucose deprivation-induced apoptosis

    International Nuclear Information System (INIS)

    Wang, Lai; Chen, Man; Yuan, Lin; Xiang, Yuting; Zheng, Ruimao; Zhu, Shigong

    2014-01-01

    Highlights: • 14,15-EET inhibits OGD-induced apoptosis in cortical neurons. • Mitochondrial biogenesis of cortical neurons is promoted by 14,15-EET. • 14,15-EET preserves mitochondrial function of cortical neurons under OGD. • CREB mediates effect of 14,15-EET on mitochondrial biogenesis and function. - Abstract: 14,15-Epoxyeicosatrienoic acid (14,15-EET), a metabolite of arachidonic acid, is enriched in the brain cortex and exerts protective effect against neuronal apoptosis induced by ischemia/reperfusion. Although apoptosis has been well recognized to be closely associated with mitochondrial biogenesis and function, it is still unclear whether the neuroprotective effect of 14,15-EET is mediated by promotion of mitochondrial biogenesis and function in cortical neurons under the condition of oxygen–glucose deprivation (OGD). In this study, we found that 14,15-EET improved cell viability and inhibited apoptosis of cortical neurons. 14,15-EET significantly increased the mitochondrial mass and the ratio of mitochondrial DNA to nuclear DNA. Key makers of mitochondrial biogenesis, peroxisome proliferator activator receptor gamma-coactivator 1 alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), were elevated at both mRNA and protein levels in the cortical neurons treated with 14,15-EET. Moreover, 14,15-EET markedly attenuated the decline of mitochondrial membrane potential, reduced ROS, while increased ATP synthesis. Knockdown of cAMP-response element binding protein (CREB) by siRNA blunted the up-regulation of PGC-1α and NRF-1 stimulated by 14,15-EET, and consequently abolished the neuroprotective effect of 14,15-EET. Our results indicate that 14,15-EET protects neurons from OGD-induced apoptosis by promoting mitochondrial biogenesis and function through CREB mediated activation of PGC-1α and NRF-1

  18. Telomerase activity-independent function of telomerase reverse transcriptase is involved in acrylamide-induced neuron damage.

    Science.gov (United States)

    Zhang, P; Pan, H; Wang, J; Liu, X; Hu, X

    2014-07-01

    Polyacrylamide is used widely in industry, and its decomposition product, acrylamide (ACR), readily finds its way into commonly consumed cosmetics and baked and fried foods. ACR exerts potent neurotoxic effects in human and animal models. Telomerase reverse transcriptase (TERT), the catalytic subunit of telomerase, traditionally has been considered to play an important role in maintaining telomere length. Emerging evidence has shown, however, that TERT plays an important role in neuroprotection by inhibiting apoptosis and excitotoxicity, and by promoting angiogenesis, neuronal survival and neurogenesis, which are closely related to the telomere-independent functions of TERT. We investigated whether and how the TERT pathway is involved in ACR induced neurotoxicity in rat cortical neurons. We found that ACR 1) significantly reduced the viability of cortical neurons as measured by MTT assay, 2) induced neuron apoptosis as revealed by FITC-conjugated Annexin V/PI double staining and flow cytometry (FACS) analysis, 3) elevated expression of cleaved caspase-3, and 4) decreased bcl-2 expression of cortical neurons. ACR also increased intracellular ROS levels in cortical neurons, increased MDA levels and reduced GSH, SOD and GSH-Px levels in mitochondria in a dose-dependent manner. We found that TERT expression in mitochondria was increased by ACR at concentrations of 2.5 and 5.0 mM, but TERT expression was decreased by 10 mM ACR. Telomerase activity, however, was undetectable in rat cortical neurons. Our results suggest that the TERT pathway is involved in ACR induced apoptosis of cortical neurons. TERT also may exert its neuroprotective role in a telomerase activity-independent way, especially in mitochondria.

  19. Neuronal SIRT1 (Silent Information Regulator 2 Homologue 1) Regulates Glycolysis and Mediates Resveratrol-Induced Ischemic Tolerance.

    Science.gov (United States)

    Koronowski, Kevin B; Khoury, Nathalie; Saul, Isabel; Loris, Zachary B; Cohan, Charles H; Stradecki-Cohan, Holly M; Dave, Kunjan R; Young, Juan I; Perez-Pinzon, Miguel A

    2017-11-01

    Resveratrol, at least in part via SIRT1 (silent information regulator 2 homologue 1) activation, protects against cerebral ischemia when administered 2 days before injury. However, it remains unclear if SIRT1 activation must occur, and in which brain cell types, for the induction of neuroprotection. We hypothesized that neuronal SIRT1 is essential for resveratrol-induced ischemic tolerance and sought to characterize the metabolic pathways regulated by neuronal Sirt1 at the cellular level in the brain. We assessed infarct size and functional outcome after transient 60 minute middle cerebral artery occlusion in control and inducible, neuronal-specific SIRT1 knockout mice. Nontargeted primary metabolomics analysis identified putative SIRT1-regulated pathways in brain. Glycolytic function was evaluated in acute brain slices from adult mice and primary neuronal-enriched cultures under ischemic penumbra-like conditions. Resveratrol-induced neuroprotection from stroke was lost in neuronal Sirt1 knockout mice. Metabolomics analysis revealed alterations in glucose metabolism on deletion of neuronal Sirt1 , accompanied by transcriptional changes in glucose metabolism machinery. Furthermore, glycolytic ATP production was impaired in acute brain slices from neuronal Sirt1 knockout mice. Conversely, resveratrol increased glycolytic rate in a SIRT1-dependent manner and under ischemic penumbra-like conditions in vitro. Our data demonstrate that resveratrol requires neuronal SIRT1 to elicit ischemic tolerance and identify a novel role for SIRT1 in the regulation of glycolytic function in brain. Identification of robust neuroprotective mechanisms that underlie ischemia tolerance and the metabolic adaptations mediated by SIRT1 in brain are crucial for the translation of therapies in cerebral ischemia and other neurological disorders. © 2017 American Heart Association, Inc.

  20. 14,15-EET promotes mitochondrial biogenesis and protects cortical neurons against oxygen/glucose deprivation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lai; Chen, Man; Yuan, Lin; Xiang, Yuting [Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing (China); Zheng, Ruimao, E-mail: rmzheng@pku.edu.cn [Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing (China); Zhu, Shigong, E-mail: sgzhu@bjmu.edu.cn [Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing (China)

    2014-07-18

    Highlights: • 14,15-EET inhibits OGD-induced apoptosis in cortical neurons. • Mitochondrial biogenesis of cortical neurons is promoted by 14,15-EET. • 14,15-EET preserves mitochondrial function of cortical neurons under OGD. • CREB mediates effect of 14,15-EET on mitochondrial biogenesis and function. - Abstract: 14,15-Epoxyeicosatrienoic acid (14,15-EET), a metabolite of arachidonic acid, is enriched in the brain cortex and exerts protective effect against neuronal apoptosis induced by ischemia/reperfusion. Although apoptosis has been well recognized to be closely associated with mitochondrial biogenesis and function, it is still unclear whether the neuroprotective effect of 14,15-EET is mediated by promotion of mitochondrial biogenesis and function in cortical neurons under the condition of oxygen–glucose deprivation (OGD). In this study, we found that 14,15-EET improved cell viability and inhibited apoptosis of cortical neurons. 14,15-EET significantly increased the mitochondrial mass and the ratio of mitochondrial DNA to nuclear DNA. Key makers of mitochondrial biogenesis, peroxisome proliferator activator receptor gamma-coactivator 1 alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), were elevated at both mRNA and protein levels in the cortical neurons treated with 14,15-EET. Moreover, 14,15-EET markedly attenuated the decline of mitochondrial membrane potential, reduced ROS, while increased ATP synthesis. Knockdown of cAMP-response element binding protein (CREB) by siRNA blunted the up-regulation of PGC-1α and NRF-1 stimulated by 14,15-EET, and consequently abolished the neuroprotective effect of 14,15-EET. Our results indicate that 14,15-EET protects neurons from OGD-induced apoptosis by promoting mitochondrial biogenesis and function through CREB mediated activation of PGC-1α and NRF-1.

  1. The activation of autophagy protects neurons and astrocytes against bilirubin-induced cytotoxicity.

    Science.gov (United States)

    Qaisiya, Mohammed; Mardešić, Paula; Pastore, Beatrice; Tiribelli, Claudio; Bellarosa, Cristina

    2017-11-20

    Unconjugated bilirubin (UCB) neurotoxicity involves oxidative stress, calcium signaling and ER-stress. The same insults can also induce autophagy, a process of "self-eating", with both a pro-survival or a pro-apoptotic role. Our aim was to study the outcome of autophagy activation by UCB in the highly sensitive neuronal SH-SY5Y cells and in the resistant astrocytoma U87 cells. Upon treatment with a toxic dose of UCB, the conversion of LC3-I to LC3-II was detected in both cell lines. Inhibition of autophagy by E64d before UCB treatment increased SH-SY5Y cell mortality and made U87 cells sensitive to UCB. In SH-SY5Y autophagy related genes ATG8 (5 folds), ATG18 (5 folds), p62 (3 folds) and FAM 129A (4.5 folds) were induced 8h after UCB treatment while DDIT4 upregulation (13 folds) started at 4h. mTORC1 inactivation by UCB was confirmed by phosphorylation of 4EBP1. UCB induced LC3-II conversion was completely prevented by pretreating cells with the calcium chelator BAPTA and reduced by 65% using the ER-stress inhibitor 4-PBA. Pretreatment with the PKC inhibitor reduced LC3 mRNA by 70% as compared to cells exposed to UCB alone. Finally, autophagy induction by Trifluoroperazine (TFP) increased the cell viability of rat hippocampal primary neurons upon UCB treatment from 60% to 80%. In SH-SY5Y cells, TFP pretreatment blocked the UCB-induced cleaved caspase-3 protein expression, decreased LDH release from 50% to 23%, reduced the UCB-induction of HO1, CHOP and IL-8 mRNAs by 85%, 70% and 97%. Collectively these data indicate that the activation of autophagy protects neuronal cells from UCB cytotoxicity. The mechanisms of autophagy activation by UCB involves mTOR/ER-stress/PKC/calcium signaling. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A role for CaV1 and calcineurin signaling in depolarization-induced changes in neuronal DNA methylation.

    Science.gov (United States)

    Hannon, Eilis; Chand, Annisa N; Evans, Mark D; Wong, Chloe C Y; Grubb, Matthew S; Mill, Jonathan

    2015-07-01

    Direct manipulations of neuronal activity have been shown to induce changes in DNA methylation (DNAm), although little is known about the cellular signaling pathways involved. Using reduced representation bisulfite sequencing, we identify DNAm changes associated with moderate chronic depolarization in dissociated rat hippocampal cultures. Consistent with previous findings, these changes occurred primarily in the vicinity of loci implicated in neuronal function, being enriched in intergenic regions and underrepresented in CpG-rich promoter regulatory regions. We subsequently used 2 pharmacological interventions (nifedipine and FK-506) to test whether the identified changes depended on 2 interrelated signaling pathways known to mediate multiple forms of neuronal plasticity. Both pharmacological manipulations had notable effects on the extent and magnitude of depolarization-induced DNAm changes indicating that a high proportion of activity-induced changes are likely to be mediated by calcium entry through L-type Ca V 1 channels and/or downstream signaling via the calcium-dependent phosphatase calcineurin.

  3. Heart failure-induced changes of voltage-gated Ca2+ channels and cell excitability in rat cardiac postganglionic neurons.

    Science.gov (United States)

    Tu, Huiyin; Liu, Jinxu; Zhang, Dongze; Zheng, Hong; Patel, Kaushik P; Cornish, Kurtis G; Wang, Wei-Zhong; Muelleman, Robert L; Li, Yu-Long

    2014-01-15

    Chronic heart failure (CHF) is characterized by decreased cardiac parasympathetic and increased cardiac sympathetic nerve activity. This autonomic imbalance increases the risk of arrhythmias and sudden death in patients with CHF. We hypothesized that the molecular and cellular alterations of cardiac postganglionic parasympathetic (CPP) neurons located in the intracardiac ganglia and sympathetic (CPS) neurons located in the stellate ganglia (SG) possibly link to the cardiac autonomic imbalance in CHF. Rat CHF was induced by left coronary artery ligation. Single-cell real-time PCR and immunofluorescent data showed that L (Ca(v)1.2 and Ca(v)1.3), P/Q (Ca(v)2.1), N (Ca(v)2.2), and R (Ca(v)2.3) types of Ca2+ channels were expressed in CPP and CPS neurons, but CHF decreased the mRNA and protein expression of only the N-type Ca2+ channels in CPP neurons, and it did not affect mRNA and protein expression of all Ca2+ channel subtypes in the CPS neurons. Patch-clamp recording confirmed that CHF reduced N-type Ca2+ currents and cell excitability in the CPP neurons and enhanced N-type Ca2+ currents and cell excitability in the CPS neurons. N-type Ca2+ channel blocker (1 μM ω-conotoxin GVIA) lowered Ca2+ currents and cell excitability in the CPP and CPS neurons from sham-operated and CHF rats. These results suggest that CHF reduces the N-type Ca2+ channel currents and cell excitability in the CPP neurons and enhances the N-type Ca2+ currents and cell excitability in the CPS neurons, which may contribute to the cardiac autonomic imbalance in CHF.

  4. Potential protection of green tea polyphenols against 1800 MHz electromagnetic radiation-induced injury on rat cortical neurons.

    Science.gov (United States)

    Liu, Mei-Li; Wen, Jian-Qiang; Fan, Yu-Bo

    2011-10-01

    Radiofrequency electromagnetic fields (EMF) are harmful to public health, but the certain anti-irradiation mechanism is not clear yet. The present study was performed to investigate the possible protective effects of green tea polyphenols against electromagnetic radiation-induced injury in the cultured rat cortical neurons. In this study, green tea polyphenols were used in the cultured cortical neurons exposed to 1800 MHz EMFs by the mobile phone. We found that the mobile phone irradiation for 24 h induced marked neuronal cell death in the MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide) and TUNEL (TdT mediated biotin-dUTP nicked-end labeling) assay, and protective effects of green tea polyphenols on the injured cortical neurons were demonstrated by testing the content of Bcl-2 Assaciated X protein (Bax) in the immunoprecipitation assay and Western blot assay. In our study results, the mobile phone irradiation-induced increases in the content of active Bax were inhibited significantly by green tea polyphenols, while the contents of total Bax had no marked changes after the treatment of green tea polyphenols. Our results suggested a neuroprotective effect of green tea polyphenols against the mobile phone irradiation-induced injury on the cultured rat cortical neurons.

  5. Sox2-Mediated Conversion of NG2 Glia into Induced Neurons in the Injured Adult Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Christophe Heinrich

    2014-12-01

    Full Text Available The adult cerebral cortex lacks the capacity to replace degenerated neurons following traumatic injury. Conversion of nonneuronal cells into induced neurons has been proposed as an innovative strategy toward brain repair. Here, we show that retrovirus-mediated expression of the transcription factors Sox2 and Ascl1, but strikingly also Sox2 alone, can induce the conversion of genetically fate-mapped NG2 glia into induced doublecortin (DCX+ neurons in the adult mouse cerebral cortex following stab wound injury in vivo. In contrast, lentiviral expression of Sox2 in the unlesioned cortex failed to convert oligodendroglial and astroglial cells into DCX+ cells. Neurons induced following injury mature morphologically and some acquire NeuN while losing DCX. Patch-clamp recording of slices containing Sox2- and/or Ascl1-transduced cells revealed that a substantial fraction of these cells receive synaptic inputs from neurons neighboring the injury site. Thus, NG2 glia represent a potential target for reprogramming strategies toward cortical repair.

  6. Mechanisms underlying odorant-induced and spontaneous calcium signals in olfactory receptor neurons of spiny lobsters, Panulirus argus.

    Science.gov (United States)

    Tadesse, Tizeta; Derby, Charles D; Schmidt, Manfred

    2014-01-01

    We determined if a newly developed antennule slice preparation allows studying chemosensory properties of spiny lobster olfactory receptor neurons under in situ conditions with Ca(2+) imaging. We show that chemical stimuli reach the dendrites of olfactory receptor neurons but not their somata, and that odorant-induced Ca(2+) signals in the somata are sufficiently stable over time to allow stimulation with a substantial number of odorants. Pharmacological manipulations served to elucidate the source of odorant-induced Ca(2+) transients and spontaneous Ca(2+) oscillations in the somata of olfactory receptor neurons. Both Ca(2+) signals are primarily mediated by an influx of extracellular Ca(2+) through voltage-activated Ca(2+) channels that can be blocked by CoCl2 and the L-type Ca(2+) channel blocker verapamil. Intracellular Ca(2+) stores contribute little to odorant-induced Ca(2+) transients and spontaneous Ca(2+) oscillations. The odorant-induced Ca(2+) transients as well as the spontaneous Ca(2+) oscillations depend on action potentials mediated by Na(+) channels that are largely TTX-insensitive but blocked by the local anesthetics tetracaine and lidocaine. Collectively, these results corroborate the conclusion that odorant-induced Ca(2+) transients and spontaneous Ca(2+) oscillations in the somata of olfactory receptor neurons closely reflect action potential activity associated with odorant-induced phasic-tonic responses and spontaneous bursting, respectively. Therefore, both types of Ca(2+) signals represent experimentally accessible proxies of spiking.

  7. Phospholipase A2 is involved in galactosylsphingosine-induced astrocyte toxicity, neuronal damage and demyelination.

    Directory of Open Access Journals (Sweden)

    Cedric Misslin

    Full Text Available Krabbe disease is a fatal rare inherited lipid storage disorder affecting 1:100,000 births. This illness is caused by mutations in the galc gene encoding for the enzyme galactosylceramidase (GALC. Dysfunction of GALC has been linked to the toxic build-up of the galactolipid, galactosylsphingosine (psychosine, which induces cell death of oligodendrocytes. Previous studies show that phospholipase A2 (PLA2 may play a role in psychosine induce cell death. Here, we demonstrate that non-selective inhibition of cPLA2/sPLA2 and selective inhibition of cPLA2, but not sPLA2, also attenuates psychosine-induced cell death of human astrocytes. This study shows that extracellular calcium is required for psychosine induced cell death, but intracellular calcium release, reactive oxygen species or release of soluble factors are not involved. These findings suggest a cell autonomous effect, at least in human astrocytes. Supporting a role for PLA2 in psychosine-induced cell death of oligodendrocytes and astrocytes, the results show inhibition of PLA2 attenuates psychosine-induced decrease in the expression of astrocyte marker vimentin as well as myelin basic protein (MBP, myelin oligodendrocyte glycoprotein (MOG and the neuronal marker SMI-32 in organotypic slice cultures. These findings provide further mechanistic details of psychosine-induced death of glia and suggest a role for PLA2 in the process. This work also supports the proposal that novel drugs for Krabbe disease may require testing on astrocytes as well as oligodendrocytes for more holistic prediction of pre-clinical and clinical efficacy.

  8. Fibroblast growth factor 10 protects neuron against oxygen–glucose deprivation injury through inducing heme oxygenase-1

    International Nuclear Information System (INIS)

    Li, Yong-Hua; Yang, Li-Ye; Chen, Wei; Li, Ying-Ke; Yuan, Hong-Bin

    2015-01-01

    Highlights: • FGF10 attenuates OGD induced injury in cortical neuron. • FGF10 reduces OGD triggered ROS level in cortical neuron. • FGF10 induces HO-1 expression upon OGD stimuli in cortical neuron. • Knockdown of HO-1 impairs the neuroprotection of FGF10 in OGD model. - Abstract: Fibroblast growth factors (FGFs) are a family of structurally related heparin-binding proteins with diverse biological functions. FGFs participate in mitogenesis, angiogenesis, cell proliferation, development, differentiation and cell migration. Here, we investigated the potential effect of FGF10, a member of FGFs, on neuron survival in oxygen–glucose deprivation (OGD) model. In primary cultured mouse cortical neurons upon OGD, FGF10 treatment (100 and 1000 ng/ml) attenuated the decrease of cell viability and rescued the LDH release. Tuj-1 immunocytochemistry assay showed that FGF10 promoted neuronal survival. Apoptosis assay with Annexin V + PI by flow cytometry demonstrated that FGF10 treatment reduced apoptotic cell proportion. Moreover, immunoblotting showed that FGF10 alleviated the cleaved caspase-3 upregulation caused by OGD. FGF10 treatment also depressed the OGD-induced increase of caspase-3, -8 and -9 activities. At last, we found FGF10 triggered heme oxygenase-1 (HO-1) protein expression rather than hypoxia-inducible factor-1 (HIF-1), AMP-activated protein kinase (AMPK) signaling and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling. Knockdown of HO-1 by siRNA partly abolished the neuroprotection of FGF10 in OGD model. In summary, our observations provide the first evidence for the neuroprotective function of FGF10 against ischemic neuronal injury and suggest that FGF10 may be a promising agent for treatment of ischemic stroke

  9. Fibroblast growth factor 10 protects neuron against oxygen–glucose deprivation injury through inducing heme oxygenase-1

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yong-Hua; Yang, Li-Ye; Chen, Wei; Li, Ying-Ke, E-mail: liyingke6f@126.com; Yuan, Hong-Bin, E-mail: yuanhongbin6f@126.com

    2015-01-02

    Highlights: • FGF10 attenuates OGD induced injury in cortical neuron. • FGF10 reduces OGD triggered ROS level in cortical neuron. • FGF10 induces HO-1 expression upon OGD stimuli in cortical neuron. • Knockdown of HO-1 impairs the neuroprotection of FGF10 in OGD model. - Abstract: Fibroblast growth factors (FGFs) are a family of structurally related heparin-binding proteins with diverse biological functions. FGFs participate in mitogenesis, angiogenesis, cell proliferation, development, differentiation and cell migration. Here, we investigated the potential effect of FGF10, a member of FGFs, on neuron survival in oxygen–glucose deprivation (OGD) model. In primary cultured mouse cortical neurons upon OGD, FGF10 treatment (100 and 1000 ng/ml) attenuated the decrease of cell viability and rescued the LDH release. Tuj-1 immunocytochemistry assay showed that FGF10 promoted neuronal survival. Apoptosis assay with Annexin V + PI by flow cytometry demonstrated that FGF10 treatment reduced apoptotic cell proportion. Moreover, immunoblotting showed that FGF10 alleviated the cleaved caspase-3 upregulation caused by OGD. FGF10 treatment also depressed the OGD-induced increase of caspase-3, -8 and -9 activities. At last, we found FGF10 triggered heme oxygenase-1 (HO-1) protein expression rather than hypoxia-inducible factor-1 (HIF-1), AMP-activated protein kinase (AMPK) signaling and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling. Knockdown of HO-1 by siRNA partly abolished the neuroprotection of FGF10 in OGD model. In summary, our observations provide the first evidence for the neuroprotective function of FGF10 against ischemic neuronal injury and suggest that FGF10 may be a promising agent for treatment of ischemic stroke.

  10. Aging Enables Ca2+ Overload and Apoptosis Induced by Amyloid-β Oligomers in Rat Hippocampal Neurons: Neuroprotection by Non-Steroidal Anti-Inflammatory Drugs and R-Flurbiprofen in Aging Neurons.

    Science.gov (United States)

    Calvo-Rodríguez, María; García-Durillo, Mónica; Villalobos, Carlos; Núñez, Lucía

    2016-07-22

    The most important risk factor for Alzheimer's disease (AD) is aging. Neurotoxicity in AD has been linked to dyshomeostasis of intracellular Ca2+ induced by small aggregates of the amyloid-β peptide 1-42 (Aβ42 oligomers). However, how aging influences susceptibility to neurotoxicity induced by Aβ42 oligomers is unknown. In this study, we used long-term cultures of rat hippocampal neurons, a model of neuronal in vitro aging, to investigate the contribution of aging to Ca2+ dishomeostasis and neuron cell death induced by Aβ42 oligomers. In addition, we tested whether non-steroidal anti-inflammatory drugs (NSAIDs) and R-flurbiprofen prevent apoptosis acting on subcellular Ca2+ in aged neurons. We found that Aβ42 oligomers have no effect on young hippocampal neurons cultured for 2 days in vitro (2 DIV). However, they promoted apoptosis modestly in mature neurons (8 DIV) and these effects increased dramatically after 13 DIV, when neurons display many hallmarks of in vivo aging. Consistently, cytosolic and mitochondrial Ca2+ responses induced by Aβ42 oligomers increased dramatically with culture age. At low concentrations, NSAIDs and the enantiomer R-flurbiprofen lacking anti-inflammatory activity prevent Ca2+ overload and neuron cell death induced by Aβ42 oligomers in aged neurons. However, at high concentrations R-flurbiprofen induces apoptosis. Thus, Aβ42 oligomers promote Ca2+ overload and neuron cell death only in aged rat hippocampal neurons. These effects are prevented by low concentrations of NSAIDs and R-flurbiprofen acting on mitochondrial Ca2+ overload.

  11. Heart failure induces changes in acid-sensing ion channels in sensory neurons innervating skeletal muscle.

    Science.gov (United States)

    Gibbons, David D; Kutschke, William J; Weiss, Robert M; Benson, Christopher J

    2015-10-15

    Heart failure is associated with diminished exercise capacity, which is driven, in part, by alterations in exercise-induced autonomic reflexes triggered by skeletal muscle sensory neurons (afferents). These overactive reflexes may also contribute to the chronic state of sympathetic excitation, which is a major contributor to the morbidity and mortality of heart failure. Acid-sensing ion channels (ASICs) are highly expressed in muscle afferents where they sense metabolic changes associated with ischaemia and exercise, and contribute to the metabolic component of these reflexes. Therefore, we tested if ASICs within muscle afferents are altered in heart failure. We used whole-cell patch clamp to study the electrophysiological properties of acid-evoked currents in isolated, labelled muscle afferent neurons from control and heart failure (induced by myocardial infarction) mice. We found that the percentage of muscle afferents that displayed ASIC-like currents, the current amplitudes, and the pH dose-response relationships were not altered in mice with heart failure. On the other hand, the biophysical properties of ASIC-like currents were significantly different in a subpopulation of cells (40%) from heart failure mice. This population displayed diminished pH sensitivity, altered desensitization kinetics, and very fast recovery from desensitization. These unique properties define these channels within this subpopulation of muscle afferents as being heteromeric channels composed of ASIC2a and -3 subunits. Heart failure induced a shift in the subunit composition of ASICs within muscle afferents, which significantly altered their pH sensing characteristics. These results might, in part, contribute to the changes in exercise-mediated reflexes that are associated with heart failure. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  12. Leptin activates oxytocin neurons of the hypothalamic paraventricular nucleus in both control and diet-induced obese rodents.

    Directory of Open Access Journals (Sweden)

    Mario Perello

    Full Text Available The adipocyte-derived hormone leptin acts in the brain to reduce body weight and fat mass. Recent studies suggest that parvocellular oxytocin (OXT neurons of the hypothalamic paraventricular nucleus (PVN can mediate body weight reduction through inhibition of food intake and increased energy expenditure. However, the role of OXT neurons of the PVN as a primary target of leptin has not been investigated. Here, we studied the potential role of OXT neurons of the PVN in leptin-mediated effects on body weight regulation in fasted rats. We demonstrated that intracerebroventricular (ICV leptin activates STAT3 phosphorylation in OXT neurons of the PVN, showed that this occurs in a subpopulation of OXT neurons that innervate the nucleus of the solitary tract (NTS, and provided further evidence suggesting a role of OXT to mediate leptin's actions on body weight. In addition, our results indicated that OXT neurons are responsive to ICV leptin and mediate leptin effects on body weight in diet induced obese (DIO rats, which are resistant to the anorectic effects of the hormone. Thus, we conclude that leptin targets a specific subpopulation of parvocellular OXT neurons of the PVN, and that this action may be important for leptin's ability to reduce body weight in both control and obese rats.

  13. Neonatal hyperglycemia inhibits angiogenesis and induces inflammation and neuronal degeneration in the retina.

    Directory of Open Access Journals (Sweden)

    Elsa Kermorvant-Duchemin

    Full Text Available Recent evidence suggests that transient hyperglycemia in extremely low birth weight infants is strongly associated with the occurrence of retinopathy of prematurity (ROP. We propose a new model of Neonatal Hyperglycemia-induced Retinopathy (NHIR that mimics many aspects of retinopathy of prematurity. Hyperglycemia was induced in newborn rat pups by injection of streptozocine (STZ at post natal day one (P1. At various time points, animals were assessed for vascular abnormalities, neuronal cell death and accumulation and activation of microglial cells. We here report that streptozotocin induced a rapid and sustained increase of glycemia from P2/3 to P6 without affecting rat pups gain weight or necessitating insulin treatment. Retinal vascular area was significantly reduced in P6 hyperglycemic animals compared to control animals. Hyperglycemia was associated with (i CCL2 chemokine induction at P6, (ii a significant recruitment of inflammatory macrophages and an increase in total number of Iba+ macrophages/microglia cells in the inner nuclear layer (INL, and (iii excessive apoptosis in the INL. NHIR thereby reproduces several aspects of ischemic retinopathies, including ROP and diabetic retinopathies, and might be a useful model to decipher hyperglycemia-induced cellular and molecular mechanisms in the small rodent.

  14. Taurine Protected Against the Impairments of Neural Stem Cell Differentiated Neurons Induced by Oxygen-Glucose Deprivation.

    Science.gov (United States)

    Xiao, Bo; Liu, Huazhen; Gu, Zeyun; Liu, Sining; Ji, Cheng

    2015-11-01

    Cell transplantation of neural stem cells (NSCs) is a promising approach for neurological recovery both structurally and functionally. However, one big obstacle is to promote differentiation of NSCs into neurons and the followed maturation. In the present study, we aimed to investigate the protective effect of taurine on the differentiation of NSCs and subsequent maturation of their neuronal lineage, when exposed to oxygen-glucose deprivation (OGD). The results suggested that taurine (5-20 mM) promoted the viability and proliferation of NSCs, and it protected against 8 h of OGD induced impairments. Furthermore, 20 mM taurine promoted NSCs to differentiate into neurons after 7 days of culture, and it also protected against the suppressive impairments of 8 h of OGD. Consistently, taurine (20 mM) promoted the neurite sprouting and outgrowth of the NSC differentiated neurons after 14 days of differentiation, which were significantly inhibited by OGD (8 h). At D21, the mushroom spines and spine density were promoted or restored by 20 mM taurine. Taken together, the enhanced viability and proliferation of NSCs, more differentiated neurons and the promoted maturation of neurons by 20 mM taurine support its therapeutic application during stem cell therapy to enhance neurological recovery. Moreover, it protected against the impairments induced by OGD, which may highlight its role for a more direct therapeutic application especially in an ischemic stroke environment.

  15. Decreased spinal synaptic inputs to phrenic motor neurons elicit localized inactivity-induced phrenic motor facilitation

    Science.gov (United States)

    Streeter, K.A.; Baker-Herman, T.L.

    2014-01-01

    Phrenic motor neurons receive rhythmic synaptic inputs throughout life. Since even brief disruption in phrenic neural activity is detrimental to life, on-going neural activity may play a key role in shaping phrenic motor output. To test the hypothesis that spinal mechanisms sense and respond to reduced phrenic activity, anesthetized, ventilated rats received micro-injections of procaine in the C2 ventrolateral funiculus (VLF) to transiently (~30 min) block axon conduction in bulbospinal axons from medullary respiratory neurons that innervate one phrenic motor pool; during procaine injections, contralateral phrenic neural activity was maintained. Once axon conduction resumed, a prolonged increase in phrenic burst amplitude was observed in the ipsilateral phrenic nerve, demonstrating inactivity-induced phrenic motor facilitation (iPMF). Inhibition of tumor necrosis factor alpha (TNFα) and atypical PKC (aPKC) activity in spinal segments containing the phrenic motor nucleus impaired ipsilateral iPMF, suggesting a key role for spinal TNFα and aPKC in iPMF following unilateral axon conduction block. A small phrenic burst amplitude facilitation was also observed contralateral to axon conduction block, indicating crossed spinal phrenic motor facilitation (csPMF). csPMF was independent of spinal TNFα and aPKC. Ipsilateral iPMF and csPMF following unilateral withdrawal of phrenic synaptic inputs were associated with proportional increases in phrenic responses to chemoreceptor stimulation (hypercapnia), suggesting iPMF and csPMF increase phrenic dynamic range. These data suggest that local, spinal mechanisms sense and respond to reduced synaptic inputs to phrenic motor neurons. We hypothesize that iPMF and csPMF may represent compensatory mechanisms that assure adequate motor output is maintained in a physiological system in which prolonged inactivity ends life. PMID:24681155

  16. Decreased spinal synaptic inputs to phrenic motor neurons elicit localized inactivity-induced phrenic motor facilitation.

    Science.gov (United States)

    Streeter, K A; Baker-Herman, T L

    2014-06-01

    Phrenic motor neurons receive rhythmic synaptic inputs throughout life. Since even brief disruption in phrenic neural activity is detrimental to life, on-going neural activity may play a key role in shaping phrenic motor output. To test the hypothesis that spinal mechanisms sense and respond to reduced phrenic activity, anesthetized, ventilated rats received micro-injections of procaine in the C2 ventrolateral funiculus (VLF) to transiently (~30min) block axon conduction in bulbospinal axons from medullary respiratory neurons that innervate one phrenic motor pool; during procaine injections, contralateral phrenic neural activity was maintained. Once axon conduction resumed, a prolonged increase in phrenic burst amplitude was observed in the ipsilateral phrenic nerve, demonstrating inactivity-induced phrenic motor facilitation (iPMF). Inhibition of tumor necrosis factor alpha (TNFα) and atypical PKC (aPKC) activity in spinal segments containing the phrenic motor nucleus impaired ipsilateral iPMF, suggesting a key role for spinal TNFα and aPKC in iPMF following unilateral axon conduction block. A small phrenic burst amplitude facilitation was also observed contralateral to axon conduction block, indicating crossed spinal phrenic motor facilitation (csPMF). csPMF was independent of spinal TNFα and aPKC. Ipsilateral iPMF and csPMF following unilateral withdrawal of phrenic synaptic inputs were associated with proportional increases in phrenic responses to chemoreceptor stimulation (hypercapnia), suggesting iPMF and csPMF increase phrenic dynamic range. These data suggest that local, spinal mechanisms sense and respond to reduced synaptic inputs to phrenic motor neurons. We hypothesize that iPMF and csPMF may represent compensatory mechanisms that assure adequate motor output is maintained in a physiological system in which prolonged inactivity ends life. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Neurospheres induced from bone marrow stromal cells are multipotent for differentiation into neuron, astrocyte, and oligodendrocyte phenotypes

    International Nuclear Information System (INIS)

    Suzuki, Hidenori; Taguchi, Toshihiko; Tanaka, Hiroshi; Kataoka, Hideo; Li Zhenglin; Muramatsu, Keiichi; Gondo, Toshikazu; Kawai, Shinya

    2004-01-01

    Bone marrow stromal cells (MSCs) can be expanded rapidly in vitro and have the potential to be differentiated into neuronal, glial and endodermal cell types. However, induction for differentiation does not always have stable result. We present a new method for efficient induction and acquisition of neural progenitors, neuronal- and glial-like cells from MSCs. We demonstrate that rat MSCs can be induced to neurospheres and most cells are positive for nestin, which is an early marker of neuronal progenitors. In addition, we had success in proliferation of these neurospheres with undifferentiated characteristics and finally we could obtain large numbers of neuronal and glial phenotypes. Many of the cells expressed β-tubulin III when they were cultivated with our method. MSCs can become a valuable cell source as an autograft for clinical application involving regeneration of the central nervous system

  18. Ketogenic diet prevents neuronal firing increase within the substantia nigra during pentylenetetrazole-induced seizure in rats.

    Science.gov (United States)

    Viggiano, Andrea; Stoddard, Madison; Pisano, Simone; Operto, Francesca Felicia; Iovane, Valentina; Monda, Marcellino; Coppola, Giangennaro

    2016-07-01

    The mechanism responsible for the anti-seizure effect of ketogenic diets is poorly understood. Because the substantia nigra pars reticulata (SNr) is a "gate" center for seizures, the aim of the present experiment was to evaluate if a ketogenic diet modifies the neuronal response of this nucleus when a seizure-inducing drug is administered in rats. Two groups of rats were given a standard diet (group 1) or a ketogenic diet (group 2) for four weeks, then the threshold for seizure induction and the firing rate of putative GABAergic neurons within the SNr were evaluated with progressive infusion of pentylenetetrazole under general anesthesia. The results demonstrated that the ketogenic diet abolished the correlation between the firing rate response of SNr-neurons and the seizure-threshold. This result suggests that the anti-seizure effect of ketogenic diets can be due to a decrease in reactivity of GABAergic SNr-neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Transcriptional Elongation Factor Elongin A Regulates Retinoic Acid-Induced Gene Expression during Neuronal Differentiation

    Directory of Open Access Journals (Sweden)

    Takashi Yasukawa

    2012-11-01

    Full Text Available Elongin A increases the rate of RNA polymerase II (pol II transcript elongation by suppressing transient pausing by the enzyme. Elongin A also acts as a component of a cullin-RING ligase that can target stalled pol II for ubiquitylation and proteasome-dependent degradation. It is not known whether these activities of Elongin A are functionally interdependent in vivo. Here, we demonstrate that Elongin A-deficient (Elongin A−/− embryos exhibit abnormalities in the formation of both cranial and spinal nerves and that Elongin A−/− embryonic stem cells (ESCs show a markedly decreased capacity to differentiate into neurons. Moreover, we identify Elongin A mutations that selectively inactivate one or the other of the aforementioned activities and show that mutants that retain the elongation stimulatory, but not pol II ubiquitylation, activity of Elongin A rescue neuronal differentiation and support retinoic acid-induced upregulation of a subset of neurogenesis-related genes in Elongin A−/− ESCs.

  20. Gastrodin Protects Apoptotic Dopaminergic Neurons in a Toxin-Induced Parkinson’s Disease Model

    Directory of Open Access Journals (Sweden)

    Hemant Kumar

    2013-01-01

    Full Text Available Gastrodia elata (GE Blume is one of the most important traditional plants in Oriental countries and has been used for centuries to improve various conditions. The phenolic glucoside gastrodin is an active constituent of GE. The aim of this study was to investigate the neuroprotective role of gastrodin in 1-methyl-4-phenylpyridinium (MPP+/1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP induced human dopaminergic SH-SY5Y cells and mouse model of Parkinson’s disease (PD, respectively. Gastrodin significantly and dose dependently protected dopaminergic neurons against neurotoxicity through regulating free radicals, Bax/Bcl-2 mRNA, caspase-3, and cleaved poly(ADP-ribose polymerase (PARP in SH-SY5Y cells stressed with MPP+. Gastrodin also showed neuroprotective effects in the subchronic MPTP mouse PD model by ameliorating bradykinesia and motor impairment in the pole and rotarod tests, respectively. Consistent with this finding, gastrodin prevented dopamine depletion and reduced reactive astrogliosis caused by MPTP as assessed by immunohistochemistry and immunoblotting in the substantiae nigrae and striatata of mice. Moreover, gastrodin was also effective in preventing neuronal apoptosis by attenuating antioxidant and antiapoptotic activities in these brain areas. These results strongly suggest that gastrodin has protective effects in experimental PD models and that it may be developed as a clinical candidate to ameliorate PD symptoms.

  1. Neuronal Damage Induced by Perinatal Asphyxia Is Attenuated by Postinjury Glutaredoxin-2 Administration.

    Science.gov (United States)

    Romero, Juan Ignacio; Holubiec, Mariana Inés; Tornatore, Tamara Logica; Rivière, Stéphanie; Hanschmann, Eva-Maria; Kölliker-Frers, Rodolfo Alberto; Tau, Julia; Blanco, Eduardo; Galeano, Pablo; Rodríguez de Fonseca, Fernando; Lillig, Christopher Horst; Capani, Francisco

    2017-01-01

    The general disruption of redox signaling following an ischemia-reperfusion episode has been proposed as a crucial component in neuronal death and consequently brain damage. Thioredoxin (Trx) family proteins control redox reactions and ensure protein regulation via specific, oxidative posttranslational modifications as part of cellular signaling processes. Trx proteins function in the manifestation, progression, and recovery following hypoxic/ischemic damage. Here, we analyzed the neuroprotective effects of postinjury, exogenous administration of Grx2 and Trx1 in a neonatal hypoxia/ischemia model. P7 Sprague-Dawley rats were subjected to right common carotid ligation or sham surgery, followed by an exposure to nitrogen. 1 h later, animals were injected i.p. with saline solution, 10 mg/kg recombinant Grx2 or Trx1, and euthanized 72 h postinjury. Results showed that Grx2 administration, and to some extent Trx1, attenuated part of the neuronal damage associated with a perinatal hypoxic/ischemic damage, such as glutamate excitotoxicity, axonal integrity, and astrogliosis. Moreover, these treatments also prevented some of the consequences of the induced neural injury, such as the delay of neurobehavioral development. To our knowledge, this is the first study demonstrating neuroprotective effects of recombinant Trx proteins on the outcome of neonatal hypoxia/ischemia, implying clinical potential as neuroprotective agents that might counteract neonatal hypoxia/ischemia injury.

  2. Amyloid-Beta Induced Changes in Vesicular Transport of BDNF in Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Bianca Seifert

    2016-01-01

    Full Text Available The neurotrophin brain derived neurotrophic factor (BDNF is an important growth factor in the CNS. Deficits in transport of this secretory protein could underlie neurodegenerative diseases. Investigation of disease-related changes in BDNF transport might provide insights into the cellular mechanism underlying, for example, Alzheimer’s disease (AD. To analyze the role of BDNF transport in AD, live cell imaging of fluorescently labeled BDNF was performed in hippocampal neurons of different AD model systems. BDNF and APP colocalized with low incidence in vesicular structures. Anterograde as well as retrograde transport of BDNF vesicles was reduced and these effects were mediated by factors released from hippocampal neurons into the extracellular medium. Transport of BDNF was altered at a very early time point after onset of human APP expression or after acute amyloid-beta(1-42 treatment, while the activity-dependent release of BDNF remained unaffected. Taken together, extracellular cleavage products of APP induced rapid changes in anterograde and retrograde transport of BDNF-containing vesicles while release of BDNF was unaffected by transgenic expression of mutated APP. These early transport deficits might lead to permanently impaired brain functions in the adult brain.

  3. Effects of Bee Venom on Glutamate-Induced Toxicity in Neuronal and Glial Cells

    Directory of Open Access Journals (Sweden)

    Sang Min Lee

    2012-01-01

    Full Text Available Bee venom (BV, which is extracted from honeybees, is used in traditional Korean medical therapy. Several groups have demonstrated the anti-inflammatory effects of BV in osteoarthritis both in vivo and in vitro. Glutamate is the predominant excitatory neurotransmitter in the central nervous system (CNS. Changes in glutamate release and uptake due to alterations in the activity of glutamate transporters have been reported in many neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. To assess if BV can prevent glutamate-mediated neurotoxicity, we examined cell viability and signal transduction in glutamate-treated neuronal and microglial cells in the presence and absence of BV. We induced glutamatergic toxicity in neuronal cells and microglial cells and found that BV protected against cell death. Furthermore, BV significantly inhibited the cellular toxicity of glutamate, and pretreatment with BV altered MAP kinase activation (e.g., JNK, ERK, and p38 following exposure to glutamate. These findings suggest that treatment with BV may be helpful in reducing glutamatergic cell toxicity in neurodegenerative diseases.

  4. Neuronal Damage Induced by Perinatal Asphyxia Is Attenuated by Postinjury Glutaredoxin-2 Administration

    Directory of Open Access Journals (Sweden)

    Juan Ignacio Romero

    2017-01-01

    Full Text Available The general disruption of redox signaling following an ischemia-reperfusion episode has been proposed as a crucial component in neuronal death and consequently brain damage. Thioredoxin (Trx family proteins control redox reactions and ensure protein regulation via specific, oxidative posttranslational modifications as part of cellular signaling processes. Trx proteins function in the manifestation, progression, and recovery following hypoxic/ischemic damage. Here, we analyzed the neuroprotective effects of postinjury, exogenous administration of Grx2 and Trx1 in a neonatal hypoxia/ischemia model. P7 Sprague-Dawley rats were subjected to right common carotid ligation or sham surgery, followed by an exposure to nitrogen. 1 h later, animals were injected i.p. with saline solution, 10 mg/kg recombinant Grx2 or Trx1, and euthanized 72 h postinjury. Results showed that Grx2 administration, and to some extent Trx1, attenuated part of the neuronal damage associated with a perinatal hypoxic/ischemic damage, such as glutamate excitotoxicity, axonal integrity, and astrogliosis. Moreover, these treatments also prevented some of the consequences of the induced neural injury, such as the delay of neurobehavioral development. To our knowledge, this is the first study demonstrating neuroprotective effects of recombinant Trx proteins on the outcome of neonatal hypoxia/ischemia, implying clinical potential as neuroprotective agents that might counteract neonatal hypoxia/ischemia injury.

  5. Inducing repetitive action potential firing in neurons via synthesized photoresponsive nanoscale cellular prostheses.

    Science.gov (United States)

    Lu, Siyuan; Madhukar, Anupam

    2013-02-01

    Recently we reported an analysis that examined the potential of synthesized photovoltaic functional abiotic nanosystems (PVFANs) to modulate membrane potential and activate action potential firing in neurons. Here we extend the analysis to delineate the requirements on the electronic energy levels and the attendant photophysical properties of the PVFANs to induce repetitive action potential under continuous light, a capability essential for the proposed potential application of PVFANs as retinal cellular prostheses to compensate for loss of photoreceptors. We find that repetitive action potential firing demands two basic characteristics in the electronic response of the PVFANs: an exponential dependence of the PVFAN excited state decay rate on the membrane potential and a three-state system such that, following photon absorption, the electron decay from the excited state to the ground state is via intermediate state(s) whose lifetime is comparable to the refractory time following an action potential. In this study, the potential of synthetic photovoltaic functional abiotic nanosystems (PVFANs) is examined under continuous light to modulate membrane potential and activate action potential firing in neurons with the proposed potential application of PVFANs as retinal cellular prostheses. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. The Fas/Fas ligand death receptor pathway contributes to phenylalanine-induced apoptosis in cortical neurons.

    Directory of Open Access Journals (Sweden)

    Xiaodong Huang

    Full Text Available Phenylketonuria (PKU, an autosomal recessive disorder of amino acid metabolism caused by mutations in the phenylalanine hydroxylase (PAH gene, leads to childhood mental retardation by exposing neurons to cytotoxic levels of phenylalanine (Phe. A recent study showed that the mitochondria-mediated (intrinsic apoptotic pathway is involved in Phe-induced apoptosis in cultured cortical neurons, but it is not known if the death receptor (extrinsic apoptotic pathway and endoplasmic reticulum (ER stress-associated apoptosis also contribute to neurodegeneration in PKU. To answer this question, we used specific inhibitors to block each apoptotic pathway in cortical neurons under neurotoxic levels of Phe. The caspase-8 inhibitor Z-IETD-FMK strongly attenuated apoptosis in Phe-treated neurons (0.9 mM, 18 h, suggesting involvement of the Fas receptor (FasR-mediated cell death receptor pathway in Phe toxicity. In addition, Phe significantly increased cell surface Fas expression and formation of the Fas/FasL complex. Blocking Fas/FasL signaling using an anti-Fas antibody markedly inhibited apoptosis caused by Phe. In contrast, blocking the ER stress-induced cell death pathway with salubrinal had no effect on apoptosis in Phe-treated cortical neurons. These experiments demonstrate that the Fas death receptor pathway contributes to Phe-induced apoptosis and suggest that inhibition of the death receptor pathway may be a novel target for neuroprotection in PKU patients.

  7. The role of MAC1 in diesel exhaust particle-induced microglial activation and loss of dopaminergic neuron function.

    Science.gov (United States)

    Levesque, Shannon; Taetzsch, Thomas; Lull, Melinda E; Johnson, Jo Anne; McGraw, Constance; Block, Michelle L

    2013-06-01

    Increasing reports support that air pollution causes neuroinflammation and is linked to central nervous system (CNS) disease/damage. Diesel exhaust particles (DEP) are a major component of urban air pollution, which has been linked to microglial activation and Parkinson's disease-like pathology. To begin to address how DEP may exert CNS effects, microglia and neuron-glia cultures were treated with either nanometer-sized DEP (neuron function was assessed. All three treatments showed enhanced ameboid microglia morphology, increased H2 O2 production, and decreased DA uptake. Mechanistic inquiry revealed that the scavenger receptor inhibitor fucoidan blocked DEP internalization in microglia, but failed to alter DEP-induced H2 O2 production in microglia. However, pre-treatment with the MAC1/CD11b inhibitor antibody blocked microglial H2 O2 production in response to DEP. MAC1(-/-) mesencephalic neuron-glia cultures were protected from DEP-induced loss of DA neuron function, as measured by DA uptake. These findings support that DEP may activate microglia through multiple mechanisms, where scavenger receptors regulate internalization of DEP and the MAC1 receptor is mandatory for both DEP-induced microglial H2 O2 production and loss of DA neuron function. © 2013 International Society for Neurochemistry.

  8. Pivotal roles of p53 transcription-dependent and -independent pathways in manganese-induced mitochondrial dysfunction and neuronal apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Chunhua [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226019 Jiangsu (China); Ma, Xa; Shi, Shangshi [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Zhao, Jianya; Nie, Xiaoke [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Han, Jingling; Xiao, Jing; Wang, Xiaoke [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiang, Shengyang [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226019 Jiangsu (China); Jiang, Junkang, E-mail: Jiang_junkang@163.com [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226019 Jiangsu (China)

    2014-12-15

    Chronic exposure to excessive manganese (Mn) has been known to lead to neuronal loss and a clinical syndrome resembling idiopathic Parkinson's disease (IPD). p53 plays an integral role in the development of various human diseases, including neurodegenerative disorders. However, the role of p53 in Mn-induced neuronal apoptosis and neurological deficits remains obscure. In the present study, we showed that p53 was critically involved in Mn-induced neuronal apoptosis in rat striatum through both transcription-dependent and -independent mechanisms. Western blot and immunohistochemistrical analyses revealed that p53 was remarkably upregulated in the striatum of rats following Mn exposure. Coincidentally, increased level of cleaved PARP, a hallmark of apoptosis, was observed. Furthermore, using nerve growth factor (NGF)-differentiated PC12 cells as a neuronal cell model, we showed that Mn exposure decreased cell viability and induced apparent apoptosis. Importantly, p53 was progressively upregulated, and accumulated in both the nucleus and the cytoplasm. The cytoplasmic p53 had a remarkable distribution in mitochondria, suggesting an involvement of p53 mitochondrial translocation in Mn-induced neuronal apoptosis. In addition, Mn-induced impairment of mitochondrial membrane potential (ΔΨm) could be partially rescued by pretreatment with inhibitors of p53 transcriptional activity and p53 mitochondrial translocation, Pifithrin-α (PFT-α) and Pifithrin-μ (PFT-μ), respectively. Moreover, blockage of p53 activities with PFT-α and PFT-μ significantly attenuated Mn-induced reactive oxidative stress (ROS) generation and mitochondrial H{sub 2}O{sub 2} production. Finally, we observed that pretreatment with PFT-α and PFT-μ ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings implicate that p53 transcription-dependent and -independent pathways may play crucial roles in the regulation of Mn-induced neuronal death. - Highlights: • p53 is

  9. Pivotal roles of p53 transcription-dependent and -independent pathways in manganese-induced mitochondrial dysfunction and neuronal apoptosis

    International Nuclear Information System (INIS)

    Wan, Chunhua; Ma, Xa; Shi, Shangshi; Zhao, Jianya; Nie, Xiaoke; Han, Jingling; Xiao, Jing; Wang, Xiaoke; Jiang, Shengyang; Jiang, Junkang

    2014-01-01

    Chronic exposure to excessive manganese (Mn) has been known to lead to neuronal loss and a clinical syndrome resembling idiopathic Parkinson's disease (IPD). p53 plays an integral role in the development of various human diseases, including neurodegenerative disorders. However, the role of p53 in Mn-induced neuronal apoptosis and neurological deficits remains obscure. In the present study, we showed that p53 was critically involved in Mn-induced neuronal apoptosis in rat striatum through both transcription-dependent and -independent mechanisms. Western blot and immunohistochemistrical analyses revealed that p53 was remarkably upregulated in the striatum of rats following Mn exposure. Coincidentally, increased level of cleaved PARP, a hallmark of apoptosis, was observed. Furthermore, using nerve growth factor (NGF)-differentiated PC12 cells as a neuronal cell model, we showed that Mn exposure decreased cell viability and induced apparent apoptosis. Importantly, p53 was progressively upregulated, and accumulated in both the nucleus and the cytoplasm. The cytoplasmic p53 had a remarkable distribution in mitochondria, suggesting an involvement of p53 mitochondrial translocation in Mn-induced neuronal apoptosis. In addition, Mn-induced impairment of mitochondrial membrane potential (ΔΨm) could be partially rescued by pretreatment with inhibitors of p53 transcriptional activity and p53 mitochondrial translocation, Pifithrin-α (PFT-α) and Pifithrin-μ (PFT-μ), respectively. Moreover, blockage of p53 activities with PFT-α and PFT-μ significantly attenuated Mn-induced reactive oxidative stress (ROS) generation and mitochondrial H 2 O 2 production. Finally, we observed that pretreatment with PFT-α and PFT-μ ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings implicate that p53 transcription-dependent and -independent pathways may play crucial roles in the regulation of Mn-induced neuronal death. - Highlights: • p53 is robustly

  10. Phospho-Rb mediating cell cycle reentry induces early apoptosis following oxygen-glucose deprivation in rat cortical neurons.

    Science.gov (United States)

    Yu, Ying; Ren, Qing-Guo; Zhang, Zhao-Hui; Zhou, Ke; Yu, Zhi-Yuan; Luo, Xiang; Wang, Wei

    2012-03-01

    The aim of this study was to investigate the relationship between cell cycle reentry and apoptosis in cultured cortical neurons following oxygen-glucose deprivation (OGD). We found that the percentage of neurons with BrdU uptake, TUNEL staining, and colocalized BrdU uptake and TUNEL staining was increased relative to control 6, 12 and 24 h after 1 h of OGD. The number of neurons with colocalized BrdU and TUNEL staining was decreased relative to the number of TUNEL-positive neurons at 24 h. The expression of phosphorylated retinoblastoma protein (phospho-Rb) was significantly increased 6, 12 and 24 h after OGD, parallel with the changes in BrdU uptake. Phospho-Rb and TUNEL staining were colocalized in neurons 6 and 12 h after OGD. This colocalization was strikingly decreased 24 h after OGD. Treatment with the cyclin-dependent kinase inhibitor roscovitine (100 μM) decreased the expression of phospho-Rb and reduced neuronal apoptosis in vitro. These results demonstrated that attempted cell cycle reentry with phosphorylation of Rb induce early apoptosis in neurons after OGD and there must be other mechanisms involved in the later stages of neuronal apoptosis besides cell cycle reentry. Phosphoralated Rb may be an important factor which closely associates aberrant cell cycle reentry with the early stages of neuronal apoptosis following ischemia/hypoxia in vitro, and pharmacological interventions for neuroprotection may be useful directed at this keypoint.

  11. Long-lasting novelty-induced neuronal reverberation during slow-wave sleep in multiple forebrain areas.

    Directory of Open Access Journals (Sweden)

    Sidarta Ribeiro

    2004-01-01

    Full Text Available The discovery of experience-dependent brain reactivation during both slow-wave (SW and rapid eye-movement (REM sleep led to the notion that the consolidation of recently acquired memory traces requires neural replay during sleep. To date, however, several observations continue to undermine this hypothesis. To address some of these objections, we investigated the effects of a transient novel experience on the long-term evolution of ongoing neuronal activity in the rat forebrain. We observed that spatiotemporal patterns of neuronal ensemble activity originally produced by the tactile exploration of novel objects recurred for up to 48 h in the cerebral cortex, hippocampus, putamen, and thalamus. This novelty-induced recurrence was characterized by low but significant correlations values. Nearly identical results were found for neuronal activity sampled when animals were moving between objects without touching them. In contrast, negligible recurrence was observed for neuronal patterns obtained when animals explored a familiar environment. While the reverberation of past patterns of neuronal activity was strongest during SW sleep, waking was correlated with a decrease of neuronal reverberation. REM sleep showed more variable results across animals. In contrast with data from hippocampal place cells, we found no evidence of time compression or expansion of neuronal reverberation in any of the sampled forebrain areas. Our results indicate that persistent experience-dependent neuronal reverberation is a general property of multiple forebrain structures. It does not consist of an exact replay of previous activity, but instead it defines a mild and consistent bias towards salient neural ensemble firing patterns. These results are compatible with a slow and progressive process of memory consolidation, reflecting novelty-related neuronal ensemble relationships that seem to be context- rather than stimulus-specific. Based on our current and previous results

  12. NDRG2 promoted secreted miR-375 in microvesicles shed from M1 microglia, which induced neuron damage.

    Science.gov (United States)

    Tang, Li-li; Wu, Yuan-bo; Fang, Chuan-qin; Qu, Ping; Gao, Zong-liang

    2016-01-15

    Microglia microvesicles (MVs) has shown to have significant biological functions under normal conditions. A diversity of miRNAs is involved in neuronal development, survival, function, and plasticity, but the exact functional role of NDRG2 and secreted miR-375 in MVs in neuron damage is poorly understood. We investigated the effect of NDRG2 and secreted miR-375 in MVs shed from M1 microglia on neuron damage. Expression of Nos2, Arg-1, miR-375, syntaxin-1A, NDRG2 and Pdk 1 were evaluated using RT-PCR or western blotting. Cell viability of N2A neuron was quantified by a MTT assay. Microglia can be polarized into different functional phenotypes. Expression of NDRG2 and Nos2 were significantly increased by LPS treatment on N9 cells, whereas treatment with IL-4 dramatically suppressed the expression of NDRG2 and remarkably elevated expression of Arg-1. Besides, MVs shed from LPS-treated N9 microglia significantly inhibited cell viability of N2A neurons and expression of syntaxin-1A, and NDRG2 interference reversed the up-regulated miR-375 in LPS-treated N9 microglia and MVs shed from LPS-treated N9 cells. Furthermore, NDRG2 could modulate miR-375 expression in N9 microglia and MVs. And miR-375 inhibitor remarkably elevated Pdk1 expression in N2A neurons. Finally, miR-375 inhibitor could reverse suppression effect of NDRG2 overexpression on cell viability of N2A neurons and expression of syntaxin-1A. Our results demonstrated that NDRG2 promoted secreted miR-375 in microvesicles shed from M1 microglia, which induced neuron damage. The suppression of NDRG2 and secreted miR-375 in MVs shed from M1 microglia may be potential targets for alleviation of neuron damage. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. 7, 8, 3′-Trihydroxyflavone Promotes Neurite Outgrowth and Protects Against Bupivacaine-Induced Neurotoxicity in Mouse Dorsal Root Ganglion Neurons

    Science.gov (United States)

    Shi, Haohong; Luo, Xingjing

    2016-01-01

    Background 7, 8, 3′-trihydroxyflavone (THF) is a novel pro-neuronal small molecule that acts as a TrkB agonist. In this study, we examined the effect of THF on promoting neuronal growth and protecting anesthetics-induced neurotoxicity in dorsal root ganglion (DRG) neurons in vitro. Material/Methods Neonatal mouse DRG neurons were cultured in vitro and treated with various concentrations of THF. The effect of THF on neuronal growth was investigated by neurite outgrowth assay and Western blot. In addition, the protective effects of THF on bupivacaine-induced neurotoxicity were investigated by apoptosis TUNEL assay, neurite outgrowth assay, and Western blot, respectively. Results THF promoted neurite outgrowth of DRG neurons in dose-dependent manner, with an EC50 concentration of 67.4 nM. Western blot analysis showed THF activated TrkB signaling pathway by inducing TrkB phosphorylation. THF also rescued bupivacaine-induced neurotoxicity by reducing apoptosis and protecting neurite retraction in DRG neurons. Furthermore, the protection of THF in bupivacaine-injured neurotoxicity was directly associated with TrkB phosphorylation in a concentration-dependent manner in DRG neurons. Conclusions THF has pro-neuronal effect on DRG neurons by promoting neurite growth and protecting against bupivacaine-induced neurotoxicity, likely through TrkB activation. PMID:27371503

  14. CREB activity in dopamine D1 receptor expressing neurons regulates cocaine-induced behavioral effects

    Science.gov (United States)

    Bilbao, Ainhoa; Rieker, Claus; Cannella, Nazzareno; Parlato, Rosanna; Golda, Slawomir; Piechota, Marcin; Korostynski, Michal; Engblom, David; Przewlocki, Ryszard; Schütz, Günther; Spanagel, Rainer; Parkitna, Jan R.

    2014-01-01

    It is suggested that striatal cAMP responsive element binding protein (CREB) regulates sensitivity to psychostimulants. To test the cell-specificity of this hypothesis we examined the effects of a dominant-negative CREB protein variant expressed in dopamine receptor D1 (D1R) neurons on cocaine-induced behaviors. A transgenic mouse strain was generated by pronuclear injection of a BAC-derived transgene harboring the A-CREB sequence under the control of the D1R gene promoter. Compared to wild-type, drug-naïve mutants showed moderate alterations in gene expression, especially a reduction in basal levels of activity-regulated transcripts such as Arc and Egr2. The behavioral responses to cocaine were elevated in mutant mice. Locomotor activity after acute treatment, psychomotor sensitization after intermittent drug injections and the conditioned locomotion after saline treatment were increased compared to wild-type littermates. Transgenic mice had significantly higher cocaine conditioned place preference, displayed normal extinction of the conditioned preference, but showed an augmented cocaine-seeking response following priming-induced reinstatement. This enhanced cocaine-seeking response was associated with increased levels of activity-regulated transcripts and prodynorphin. The primary reinforcing effects of cocaine were not altered in the mutant mice as they did not differ from wild-type in cocaine self-administration under a fixed ratio schedule at the training dose. Collectively, our data indicate that expression of a dominant-negative CREB variant exclusively in neurons expressing D1R is sufficient to recapitulate the previously reported behavioral phenotypes associated with virally expressed dominant-negative CREB. PMID:24966820

  15. Learning tasks as a possible treatment for DNA lesions induced by oxidative stress in hippocampal neurons

    Institute of Scientific and Technical Information of China (English)

    DragoCrneci; Radu Silaghi-Dumitrescu

    2013-01-01

    Reactive oxygen species have been implicated in conditions ranging from cardiovascular dysfunc-tion, arthritis, cancer, to aging and age-related disorders. The organism developed several path-ways to counteract these effects, with base excision repair being responsible for repairing one of the major base lesions (8-oxoG) in al organisms. Epidemiological evidence suggests that cognitive stimulation makes the brain more resilient to damage or degeneration. Recent studies have linked enriched environment to reduction of oxidative stressin neurons of mice with Alzheimer’s dis-ease-like disease, but given its complexity it is not clear what specific aspect of enriched environ-ment has therapeutic effects. Studies from molecular biology have shown that the protein p300, which is a transcription co-activator required for consolidation of memories during specific learning tasks, is at the same time involved in DNA replication and repair, playing a central role in the long-patch pathway of base excision repair. Based on the evidence, we propose that learning tasks such as novel object recognition could be tested as possible methods of base excision repair faci-litation, hence inducing DNA repair in the hippocampal neurons. If this method proves to be effective, it could be the start for designing similar tasks for humans, as a behavioral therapeutic complement to the classical drug-based therapy in treating neurodegenerative disorders. This review presents the current status of therapeutic methods used in treating neurodegenerative diseases induced by reactive oxygen species and proposes a new approach based on existing data.

  16. Early Transcriptional Changes Induced by Wnt/β-Catenin Signaling in Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Eduardo Pérez-Palma

    2016-01-01

    Full Text Available Wnt/β-catenin signaling modulates brain development and function and its deregulation underlies pathological changes occurring in neurodegenerative and neurodevelopmental disorders. Since one of the main effects of Wnt/β-catenin signaling is the modulation of target genes, in the present work we examined global transcriptional changes induced by short-term Wnt3a treatment (4 h in primary cultures of rat hippocampal neurons. RNAseq experiments allowed the identification of 170 differentially expressed genes, including known Wnt/β-catenin target genes such as Notum, Axin2, and Lef1, as well as novel potential candidates Fam84a, Stk32a, and Itga9. Main biological processes enriched with differentially expressed genes included neural precursor (GO:0061364, p-adjusted = 2.5 × 10−7, forebrain development (GO:0030900, p-adjusted = 7.3 × 10−7, and stem cell differentiation (GO:0048863 p-adjusted = 7.3 × 10−7. Likewise, following activation of the signaling cascade, the expression of a significant number of genes with transcription factor activity (GO:0043565, p-adjusted = 4.1 × 10−6 was induced. We also studied molecular networks enriched upon Wnt3a activation and detected three highly significant expression modules involved in glycerolipid metabolic process (GO:0046486, p-adjusted = 4.5 × 10−19, learning or memory (GO:0007611, p-adjusted = 4.0 × 10−5, and neurotransmitter secretion (GO:0007269, p-adjusted = 5.3 × 10−12. Our results indicate that Wnt/β-catenin mediated transcription controls multiple biological processes related to neuronal structure and activity that are affected in synaptic dysfunction disorders.

  17. Phrenic motor neuron TrkB expression is necessary for acute intermittent hypoxia-induced phrenic long-term facilitation.

    Science.gov (United States)

    Dale, Erica A; Fields, Daryl P; Devinney, Michael J; Mitchell, Gordon S

    2017-01-01

    Phrenic long-term facilitation (pLTF) is a form of hypoxia-induced spinal respiratory motor plasticity that requires new synthesis of brain derived neurotrophic factor (BDNF) and activation of its high-affinity receptor, tropomyosin receptor kinase B (TrkB). Since the cellular location of relevant TrkB receptors is not known, we utilized intrapleural siRNA injections to selectively knock down TrkB receptor protein within phrenic motor neurons. TrkB receptors within phrenic motor neurons are necessary for BDNF-dependent acute intermittent hypoxia-induced pLTF, demonstrating that phrenic motor neurons are a critical site of respiratory motor plasticity. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. The neuronal nitric oxide synthase inhibitor, 7-nitroindazole, protects against methamphetamine-induced neurotoxicity in vivo.

    Science.gov (United States)

    Itzhak, Y; Ali, S F

    1996-10-01

    The present study was undertaken to investigate whether the relatively selective neuronal nitric oxide synthase (NOS) inhibitor, 7-nitroindazole (7-NI), protects against methamphetamine (METH)-induced neurotoxicity. Male Swiss Webster mice received the following treatments (i.p.; q 3 h x 3): (a) vehicle/saline, (b) 7-NI (25 mg/kg)/saline, (c) vehicle/METH (5 mg/kg), and (d) 7-NI (25 mg/kg)/METH (5 mg/kg). On the second day, groups (a) and (b) received two vehicle injections, and groups (c) and (d) received two 7-NI injections (25 mg/kg, each). Administration of vehicle/METH resulted in 68, 44, and 55% decreases in the concentration of dopamine, 3,4-dihydroxyphenylacetic acid, and homovanillic acid, respectively, and a 48% decrease in the number of [3H]mazindol binding sites in the striatum compared with control values. Treatment with 7-NI (group d) provided full protection against the depletion of dopamine and its metabolites and the loss of dopamine transporter binding sites. Administration of 7-NI/saline (group b) affected neither the tissue concentration of dopamine and its metabolites nor the binding parameters of [3H] mazindol compared with control values. 7-NI had no significant effect on animals' body temperature, and it did not affect METH-induced hyperthermia. These findings indicate a role for nitric oxide in methamphetamine-induced neurotoxicity and also suggest that blockade of NOS may be beneficial for the management of Parkinson's disease.

  19. O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling.

    Science.gov (United States)

    Shi, Jianhua; Gu, Jin-hua; Dai, Chun-ling; Gu, Jianlan; Jin, Xiaoxia; Sun, Jianming; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

    2015-09-28

    Apoptosis plays an important role in neural development and neurological disorders. In this study, we found that O-GlcNAcylation, a unique protein posttranslational modification with O-linked β-N-acetylglucosamine (GlcNAc), promoted apoptosis through attenuating phosphorylation/activation of AKT and Bad. By using co-immunoprecipitation and mutagenesis techniques, we identified O-GlcNAc modification at both Thr308 and Ser473 of AKT. O-GlcNAcylation-induced apoptosis was attenuated by over-expression of AKT. We also found a dynamic elevation of protein O-GlcNAcylation during the first four hours of cerebral ischemia, followed by continuous decline after middle cerebral artery occlusion (MCAO) in the mouse brain. The elevation of O-GlcNAcylation coincided with activation of cell apoptosis. Finally, we found a negative correlation between AKT phosphorylation and O-GlcNAcylation in ischemic brain tissue. These results indicate that cerebral ischemia induces a rapid increase of O-GlcNAcylation that promotes apoptosis through down-regulation of AKT activity. These findings provide a novel mechanism through which O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling.

  20. Inflammatory responses are not sufficient to cause delayed neuronal death in ATP-induced acute brain injury.

    Directory of Open Access Journals (Sweden)

    Hey-Kyeong Jeong

    Full Text Available BACKGROUND: Brain inflammation is accompanied by brain injury. However, it is controversial whether inflammatory responses are harmful or beneficial to neurons. Because many studies have been performed using cultured microglia and neurons, it has not been possible to assess the influence of multiple cell types and diverse factors that dynamically and continuously change in vivo. Furthermore, behavior of microglia and other inflammatory cells could have been overlooked since most studies have focused on neuronal death. Therefore, it is essential to analyze the precise roles of microglia and brain inflammation in the injured brain, and determine their contribution to neuronal damage in vivo from the onset of injury. METHODS AND FINDINGS: Acute neuronal damage was induced by stereotaxic injection of ATP into the substantia nigra pars compacta (SNpc and the cortex of the rat brain. Inflammatory responses and their effects on neuronal damage were investigated by immunohistochemistry, electron microscopy, quantitative RT-PCR, and stereological counting, etc. ATP acutely caused death of microglia as well as neurons in a similar area within 3 h. We defined as the core region the area where both TH(+ and Iba-1(+ cells acutely died, and as the penumbra the area surrounding the core where Iba-1(+ cells showed activated morphology. In the penumbra region, morphologically activated microglia arranged around the injury sites. Monocytes filled the damaged core after neurons and microglia died. Interestingly, neither activated microglia nor monocytes expressed iNOS, a major neurotoxic inflammatory mediator. Monocytes rather expressed CD68, a marker of phagocytic activity. Importantly, the total number of dopaminergic neurons in the SNpc at 3 h (∼80% of that in the contralateral side did not decrease further at 7 d. Similarly, in the cortex, ATP-induced neuron-damage area detected at 3 h did not increase for up to 7 d. CONCLUSIONS: Different cellular

  1. Effect of inhibition of fatty acid amide hydrolase on MPTP-induced dopaminergic neuronal damage.

    Science.gov (United States)

    Viveros-Paredes, J M; Gonzalez-Castañeda, R E; Escalante-Castañeda, A; Tejeda-Martínez, A R; Castañeda-Achutiguí, F; Flores-Soto, M E

    2017-01-16

    Parkinson's disease (PD) is a neurodegenerative disorder characterised by balance problems, muscle rigidity, and slow movement due to low dopamine levels and loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). The endocannabinoid system is known to modulate the nigrostriatal pathway through endogenous ligands such as anandamide (AEA), which is hydrolysed by fatty acid amide hydrolase (FAAH). The purpose of this study was to increase AEA levels using FAAH inhibitor URB597 to evaluate the modulatory effect of AEA on dopaminergic neuronal death induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Our study included 4 experimental groups (n = 6 mice per group): a control group receiving no treatment, a group receiving URB597 (0.2mg/kg) every 3 days for 30 days, a group treated with MPTP (30mg/kg) for 5 days, and a group receiving URB597 and subsequently MPTP injections. Three days after the last dose, we conducted a series of behavioural tests (beam test, pole test, and stride length test) to compare motor coordination between groups. We subsequently analysed immunoreactivity of dopaminergic cells and microglia in the SNpc and striatum. Mice treated with URB597 plus MPTP were found to perform better on behavioural tests than mice receiving MPTP only. According to the immunohistochemistry study, mice receiving MPTP showed fewer dopaminergic cells and fibres in the SNpc and striatum. Animals treated with URB597 plus MPTP displayed increased tyrosine hydroxylase immunoreactivity compared to those treated with MPTP only. Regarding microglial immunoreactivity, the group receiving MPTP showed higher Iba1 immunoreactivity in the striatum and SNpc than did the group treated with URB597 plus MPTP. Our results show that URB597 exerts a protective effect since it inhibits dopaminergic neuronal death, decreases microglial immunoreactivity, and improves MPTP-induced motor alterations. Copyright © 2016 Sociedad Española de Neurología. Publicado

  2. Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death.

    Science.gov (United States)

    Guida, Natascia; Laudati, Giusy; Anzilotti, Serenella; Secondo, Agnese; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M T; Formisano, Luigi

    2015-11-01

    Resveratrol (3,5,4'-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Preemptive, but not reactive, spinal cord stimulation mitigates transient ischemia-induced myocardial infarction via cardiac adrenergic neurons

    NARCIS (Netherlands)

    Southerland, E. M.; Milhorn, D. M.; Foreman, R. D.; Linderoth, B.; DeJongste, M. J. L.; Armour, J. A.; Subramanian, V.; Singh, M.; Singh, K.; Ardell, J. L.

    2007-01-01

    Our objective was to determine whether electrical neuromodulation using spinal cord stimulation ( SCS) mitigates transient ischemia-induced ventricular infarction and, if so, whether adrenergic neurons are involved in such cardioprotection. The hearts of anesthetized rabbits, subjected to 30 min of

  4. Role of GluR2 expression in AMPA-induced toxicity in cultured murine cerebral cortical neurons

    DEFF Research Database (Denmark)

    Jensen, Jette Bisgaard; Lund, Trine Meldgaard; Timmermann, Daniel B.

    2001-01-01

    of the Mg(2+) block of the NMDA receptor on AMPA-R stimulation. The involvement of Ca(2+) influx through AMPA-R was also examined. The number of neurons possessing Ca(2+)-permeable AMPA-R increased during culture development, concurrently with an increasing susceptibility for AMPA-induced toxicity during...

  5. Endogenous Opioid-Induced Neuroplasticity of Dopaminergic Neurons in the Ventral Tegmental Area Influences Natural and Opiate Reward

    NARCIS (Netherlands)

    Pitchers, Kyle K.; Coppens, Caroline M.; Beloate, Lauren N.; Fuller, Jonathan; Van, Sandy; Frohmader, Karla S.; Laviolette, Steven R.; Lehman, Michael N.; Coolen, Lique M.

    2014-01-01

    Natural reward and drugs of abuse converge on the mesolimbic pathway and activate common mechanism of neural plasticity in the nucleus accumbens. Chronic exposure to opiates induces plasticity in dopaminergic neurons of the ventral tegmental area (VTA), which regulates morphine reward tolerance.

  6. N-acetylcysteine prevents ketamine-induced adverse effects on development, heart rate and monoaminergic neurons in zebrafish.

    Science.gov (United States)

    Robinson, Bonnie; Dumas, Melanie; Gu, Qiang; Kanungo, Jyotshna

    2018-06-08

    N-acetylcysteine, a precursor molecule of glutathione, is an antioxidant. Ketamine, a pediatric anesthetic, has been implicated in cardiotoxicity and neurotoxicity including modulation of monoaminergic systems in mammals and zebrafish. Here, we show that N-acetylcysteine prevents ketamine's adverse effects on development and monoaminergic neurons in zebrafish embryos. The effects of ketamine and N-acetylcysteine alone or in combination were measured on the heart rate, body length, brain serotonergic neurons and tyrosine hydroxylase-immunoreactive (TH-IR) neurons. In the absence of N-acetylcysteine, a concentration of ketamine that produces an internal embryo exposure level comparable to human anesthetic plasma concentrations significantly reduced heart rate and body length and those effects were prevented by N-acetylcysteine co-treatment. Ketamine also reduced the areas occupied by serotonergic neurons in the brain, whereas N-acetylcysteine co-exposure counteracted this effect. TH-IR neurons in the embryo brain and TH-IR cells in the trunk were significantly reduced with ketamine treatment, but not in the presence of N-acetylcysteine. In our continued search for compounds that can prevent ketamine toxicity, this study using specific endpoints of developmental toxicity, cardiotoxicity and neurotoxicity, demonstrates protective effects of N-acetylcysteine against ketamine's adverse effects. This is the first study that shows the protective effects of N-acetylcysteine on ketamine-induced developmental defects of monoaminergic neurons as observed in a whole organism. Published by Elsevier B.V.

  7. 3-Hydroxybutyrate regulates energy metabolism and induces BDNF expression in cerebral cortical neurons

    DEFF Research Database (Denmark)

    Marosi, Krisztina; Kim, Sang Woo; Moehl, Keelin

    2016-01-01

    During fasting and vigorous exercise, a shift of brain cell energy substrate utilization from glucose to the ketone 3-hydroxybutyrate (3OHB) occurs. Studies have shown that 3OHB can protect neurons against excitotoxicity and oxidative stress, but the underlying mechanisms remain unclear. Neurons ...... suggest cellular signaling mechanisms by which 3OHB may mediate adaptive responses of neurons to fasting, exercise, and ketogenic diets....

  8. Synthesis of N-(Methoxycarbonylthienylmethylthioureas and Evaluation of Their Interaction with Inducible and Neuronal Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    Michael D. Threadgill

    2010-04-01

    Full Text Available Two isomeric N-(methoxycarbonylthienylmethylthioureas were synthesised by a sequence of radical bromination of methylthiophenecarboxylic esters, substitution with trifluoroacetamide anion, deprotection, formation of the corresponding isothiocyanates and addition of ammonia. The interaction of these new thiophene-based thioureas with inducible and neuronal nitric oxide synthase was evaluauted. These novel thienylmethylthioureas stimulated the activity of inducible Nitric Oxide Synthase (iNOS.

  9. Ghrelin receptors mediate ghrelin-induced excitation of agouti-related protein/neuropeptide Y but not pro-opiomelanocortin neurons.

    Science.gov (United States)

    Chen, Shao-Rui; Chen, Hong; Zhou, Jing-Jing; Pradhan, Geetali; Sun, Yuxiang; Pan, Hui-Lin; Li, De-Pei

    2017-08-01

    Ghrelin increases food intake and body weight by stimulating orexigenic agouti-related protein (AgRP)/neuropeptide Y (NPY) neurons and inhibiting anorexic pro-opiomelanocortin (POMC) neurons in the hypothalamus. Growth hormone secretagogue receptor (Ghsr) mediates the effect of ghrelin on feeding behavior and energy homeostasis. However, the role of Ghsr in the ghrelin effect on these two populations of neurons is unclear. We hypothesized that Ghsr mediates the effect of ghrelin on AgRP and POMC neurons. In this study, we determined whether Ghsr similarly mediates the effects of ghrelin on AgRP/NPY and POMC neurons using cell type-specific Ghsr-knockout mice. Perforated whole-cell recordings were performed on green fluorescent protein-tagged AgRP/NPY and POMC neurons in the arcuate nucleus in hypothalamic slices. In Ghsr +/+ mice, ghrelin (100 nM) significantly increased the firing activity of AgRP/NPY neurons but inhibited the firing activity of POMC neurons. In Ghsr -/- mice, the excitatory effect of ghrelin on AgRP/NPY neurons was abolished. Ablation of Ghsr also eliminated ghrelin-induced increases in the frequency of GABAergic inhibitory postsynaptic currents of POMC neurons. Strikingly, ablation of Ghsr converted the ghrelin effect on POMC neurons from inhibition to excitation. Des-acylated ghrelin had no such effect on POMC neurons in Ghsr -/- mice. In both Ghsr +/+ and Ghsr -/- mice, blocking GABA A receptors with gabazine increased the basal firing activity of POMC neurons, and ghrelin further increased the firing activity of POMC neurons in the presence of gabazine. Our findings provide unequivocal evidence that Ghsr is essential for ghrelin-induced excitation of AgRP/NPY neurons. However, ghrelin excites POMC neurons through an unidentified mechanism that is distinct from conventional Ghsr. © 2017 International Society for Neurochemistry.

  10. Trypanosomiasis-induced megacolon illustrates how myenteric neurons modulate the risk for colon cancer in rats and humans.

    Directory of Open Access Journals (Sweden)

    Vinicius Kannen

    2015-04-01

    Full Text Available Trypanosomiasis induces a remarkable myenteric neuronal degeneration leading to megacolon. Very little is known about the risk for colon cancer in chagasic megacolon patients. To clarify whether chagasic megacolon impacts on colon carcinogenesis, we investigated the risk for colon cancer in Trypanosoma cruzi (T. cruzi infected patients and rats.Colon samples from T. cruzi-infected and uninfected patients and rats were histopathologically investigated with colon cancer biomarkers. An experimental model for chemical myenteric denervation was also performed to verify the myenteric neuronal effects on colon carcinogenesis. All experiments complied the guidelines and approval of ethical institutional review boards.No colon tumors were found in chagasic megacolon samples. A significant myenteric neuronal denervation was observed. Epithelial cell proliferation and hyperplasia were found increased in chagasic megacolon. Analyzing the argyrophilic nucleolar organiser regions within the cryptal bottom revealed reduced risk for colon cancer in Chagas' megacolon patients. T. cruzi-infected rats showed a significant myenteric neuronal denervation and decreased numbers of colon preneoplastic lesions. In chemical myenteric denervated rats preneoplastic lesions were reduced from the 2nd wk onward, which ensued having the colon myenteric denervation significantly induced.Our data suggest that the trypanosomiasis-related myenteric neuronal degeneration protects the colon tissue from carcinogenic events. Current findings highlight potential mechanisms in tropical diseases and cancer research.

  11. Fingolimod phosphate attenuates oligomeric amyloid β-induced neurotoxicity via increased brain-derived neurotrophic factor expression in neurons.

    Directory of Open Access Journals (Sweden)

    Yukiko Doi

    Full Text Available The neurodegenerative processes that underlie Alzheimer's disease are mediated, in part, by soluble oligomeric amyloid β, a neurotoxic protein that inhibits hippocampal long-term potentiation, disrupts synaptic plasticity, and induces the production of reactive oxygen species. Here we show that the sphingosine-1-phosphate (S1P receptor (S1PR agonist fingolimod phosphate (FTY720-P-a new oral drug for multiple sclerosis-protects neurons against oligomeric amyloid β-induced neurotoxicity. We confirmed that primary mouse cortical neurons express all of the S1P receptor subtypes and FTY720-P directly affects the neurons. Treatment with FTY720-P enhanced the expression of brain-derived neurotrophic factor (BDNF in neurons. Moreover, blocking BDNF-TrkB signaling with a BDNF scavenger, TrkB inhibitor, or ERK1/2 inhibitor almost completely ablated these neuroprotective effects. These results suggested that the neuroprotective effects of FTY720-P are mediated by upregulated neuronal BDNF levels. Therefore, FTY720-P may be a promising therapeutic agent for neurodegenerative diseases, such as Alzheimer's disease.

  12. Menthol Enhances Nicotine Reward-Related Behavior by Potentiating Nicotine-Induced Changes in nAChR Function, nAChR Upregulation, and DA Neuron Excitability.

    Science.gov (United States)

    Henderson, Brandon J; Wall, Teagan R; Henley, Beverley M; Kim, Charlene H; McKinney, Sheri; Lester, Henry A

    2017-11-01

    Understanding why the quit rate among smokers of menthol cigarettes is lower than non-menthol smokers requires identifying the neurons that are altered by nicotine, menthol, and acetylcholine. Dopaminergic (DA) neurons in the ventral tegmental area (VTA) mediate the positive reinforcing effects of nicotine. Using mouse models, we show that menthol enhances nicotine-induced changes in nicotinic acetylcholine receptors (nAChRs) expressed on midbrain DA neurons. Menthol plus nicotine upregulates nAChR number and function on midbrain DA neurons more than nicotine alone. Menthol also enhances nicotine-induced changes in DA neuron excitability. In a conditioned place preference (CPP) assay, we observed that menthol plus nicotine produces greater reward-related behavior than nicotine alone. Our results connect changes in midbrain DA neurons to menthol-induced enhancements of nicotine reward-related behavior and may help explain how smokers of menthol cigarettes exhibit reduced cessation rates.

  13. Metformin Protects Neurons against Oxygen-Glucose Deprivation/Reoxygenation -Induced Injury by Down-Regulating MAD2B.

    Science.gov (United States)

    Meng, Xianfang; Chu, Guangpin; Yang, Zhihua; Qiu, Ping; Hu, Yue; Chen, Xiaohe; Peng, Wenpeng; Ye, Chen; He, Fang-Fang; Zhang, Chun

    2016-01-01

    Metformin, the common medication for type II diabetes, has protective effects on cerebral ischemia. However, the molecular mechanisms are far from clear. Mitotic arrest deficient 2-like protein 2 (MAD2B), an inhibitor of the anaphase-promoting complex (APC), is widely expressed in hippocampal and cortical neurons and plays an important role in mediating high glucose-induced neurotoxicity. The present study investigated whether metformin modifies the expression of MAD2B and to exert its neuroprotective effects in primary cultured cortical neurons during oxygen-glucose deprivation/reoxygenation (OGD/R), a widely used in vitro model of ischemia/reperfusion. Primary cortical neurons were cultured, deprived of oxygen-glucose for 1 h, and then recovered with oxygen-glucose for 12 h and 24 h. Cell viability was measured by detecting the levels of lactate dehydrogenase (LDH) in culture medium. The levels of MAD2B, cyclin B and p-histone 3 were measured by Western blot. Cell viability of neurons was reduced under oxygen-glucose deprivation/reoxygenation (OGD/R). The expression of MAD2B was increased under OGD/R. The levels of cyclin B1, which is a substrate of APC, were also increased. Moreover, OGD/R up-regulated the phosphorylation levels of histone 3, which is the induction of aberrant re-entry of post-mitotic neurons. However, pretreatment of neurons with metformin alleviated OGD/R-induced injury. Metformin further decreased the expression of MAD2B, cyclin B1 and phosphorylation levels of histone 3. Metformin exerts its neuroprotective effect through regulating the expression of MAD2B in neurons under OGD/R. © 2016 The Author(s) Published by S. Karger AG, Basel.

  14. Lemon Odor Reduces Stress-induced Neuronal Activation in the Emotion Expression System: An Animal Model Study

    Science.gov (United States)

    Sanada, Kazue; Sugimoto, Koji; Shutoh, Fumihiro; Hisano, Setsuji

    Perception of particular sensory stimuli from the surroundings can influence emotion in individuals. In an uncomfortable situation, humans protect themselves from some aversive stimulus by acutely evoking a stress response. Animal model studies have contributed to an understanding of neuronal mechanisms underlying the stress response in humans. To study a possible anti-stressful effect of lemon odor, an excitation of neurons secreting corticotropin-releasing hormone (CRH) as a primary factor of the hypothalamic-pituitary-adrenal axis (HPA) was analyzed in animal model experiments, in which rats are restrained in the presence or absence of the odor. The effect was evaluated by measuring expression of c-Fos (an excited neuron marker) in the hypothalamic paraventricular nucleus (PVN), a key structure of the HPA in the brain. We prepared 3 animal groups: Groups S, L and I. Groups S and L were restrained for 30 minutes while being blown by air and being exposed to the lemon odor, respectively. Group I was intact without any treatment. Two hours later of the onset of experiments, brains of all groups were sampled and processed for microscopic examination. Brain sections were processed for c-Fos immunostaining and/or in situ hybridization for CRH. In Group S but not in Group I, c-Fos expression was found in the PVN. A combined in situ hybridization-immunohistochemical dual labeling revealed that CRH mRNA-expressing neurons express c-Fos. In computer-assisted automatic counting, the incidence of c-Fos-expressing neurons in the entire PVN was statistically lower in Group L than in Group S. Detailed analysis of PVN subregions demonstrated that c-Fos-expressing neurons are fewer in Group L than in Group S in the dorsal part of the medial parvocellular subregion. These results may suggest that lemon odor attenuates the restraint stress-induced neuronal activation including CRH neurons, presumably mimicking an aspect of stress responses in humans.

  15. Neuroprotective effects of ginsenoside Rb1 on high glucose-induced neurotoxicity in primary cultured rat hippocampal neurons.

    Science.gov (United States)

    Liu, Di; Zhang, Hong; Gu, Wenjuan; Liu, Yuqin; Zhang, Mengren

    2013-01-01

    Ginsenoside Rb1 is one of the main active principles in traditional herb ginseng and has been reported to have a wide variety of neuroprotective effects. Endoplasmic reticulum (ER) stress has been implicated in neurodegenerative diseases, so the present study aimed to observe the effects of ginsenoside Rb1 on ER stress signaling pathways in high glucose-treated hippocampal neurons. The results from MTT, TUNEL labeling and Annexin V-FITC/PI/Hoechst assays showed that incubating neurons with 50 mM high glucose for 72 h decreased cell viability and increased the number of apoptotic cells whereas treating neurons with 1 μM Rb1 for 72 h protected the neurons against high glucose-induced cell damage. Further molecular mechanism study demonstrated that Rb1 suppressed the activation of ER stress-associated proteins including protein kinase RNA (PKR)-like ER kinase (PERK) and C/EBP homology protein (CHOP) and downregulation of Bcl-2 induced by high glucose. Moreover, Rb1 inhibited both the elevation of intracellular reactive oxygen species (ROS) and the disruption of mitochondrial membrane potential induced by high glucose. In addition, the high glucose-induced cell apoptosis, activation of ER stress, ROS accumulation and mitochondrial dysfunction can also be attenuated by the inhibitor of ER stress 4-phenylbutyric acid (4-PBA) and anti-oxidant N-acetylcysteine(NAC). In conclusion, these results suggest that Rb1 may protect neurons against high glucose-induced cell injury through inhibiting CHOP signaling pathway as well as oxidative stress and mitochondrial dysfunction.

  16. Alkaloids from piper longum protect dopaminergic neurons against inflammation-mediated damage induced by intranigral injection of lipopolysaccharide.

    Science.gov (United States)

    He, Huan; Guo, Wei-Wei; Xu, Rong-Rong; Chen, Xiao-Qing; Zhang, Nan; Wu, Xia; Wang, Xiao-Min

    2016-10-24

    Alkaloids from Piper longum (PLA), extracted from P. longum, have potent anti-inflammatory effects. The aim of this study was to investigate whether PLA could protect dopaminergic neurons against inflammation-mediated damage by inhibiting microglial activation using a lipopolysaccharide (LPS)-induced dopaminergic neuronal damage rat model. The animal behaviors of rotational behavior, rotarod test and open-field test were investigated. The survival ratio of dopaminergic neurons and microglial activation were examined. The dopamine (DA) and its metabolite were detected by high performance liquid chromatography (HPLC). The effects of PLA on the expression of interleukin (IL)-6, interleukin (IL)-1β and tumor necrosis factor (TNF)-α were detected by enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) and nitric oxide (NO) were also estimated. We showed that the survival ratio of tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the substantia nigra pars compacta (SNpc) and DA content in the striatum were reduced after a single intranigral dose of LPS (10 μg) treatment. The survival rate of TH-ir neurons in the SNpc and DA levels in the striatum were significantly improved after treatment with PLA for 6 weeks. The over-activated microglial cells were suppressed by PLA treatment. We also observed that the levels of inflammatory cytokines, including TNF-α, IL-6 and IL-1β were decreased and the excessive production of ROS and NO were abolished after PLA treatment. Therefore, the behavioral dysfunctions induced by LPS were improved after PLA treatment. This study suggests that PLA plays a significant role in protecting dopaminergic neurons against inflammatory reaction induced damage.

  17. Treadmill exercise ameliorates social isolation-induced depression through neuronal generation in rat pups.

    Science.gov (United States)

    Cho, Jung-Wan; Jung, Sun-Young; Lee, Sang-Won; Lee, Sam-Jun; Seo, Tae-Beom; Kim, Young-Pyo; Kim, Dae-Young

    2017-12-01

    Social isolation is known to induce emotional and behavioral changes in animals and humans. The effect of treadmill exercise on depression was investigated using social isolated rat pups. The rat pups in the social isolation groups were housed individually. The rat pups in the exercise groups were forced to run on treadmill for 30 min once a day from postnatal day 21 to postnatal day 34. In order to evaluate depression state of rat pups, forced swimming test was performed. Newly generated cells in the hippocampal dentate gyrus were determined by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. We examined the expression of 5-hydroxytryptamine (5-HT) and tryptophan hydroxylase (TPH) in the dorsal raphe using immunofluorescence. The expression of brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) was detected by Western blot analysis. The present results demonstrated that social isolation increased resting time and decreased mobility time. Expression of 5-HT and TPH in the dorsal raphe and expression of BDNF and TrkB in the hippocampus were decreased by social isolation. The number of BrdU-positive cells in the hippocampal dentate gyrus was suppressed by social isolation. Treadmill exercise decreased resting time and increased mobility in the social isolated rat pups. Expression of 5-HT, TPH, BDNF, and TrkB was increased by treadmill exercise. The present results suggested that treadmill exercise may ameliorates social isolation-induced depression through increasing neuronal generation.

  18. Neural stem cells was induced to differentiate into cholinergic neurons in vitro

    International Nuclear Information System (INIS)

    Chang Yan; Xu Yilong; Pan Jingkun; Tian Lei; Gao Yuhong; Guo Shuilong

    2004-01-01

    The cholinergic-inducing effect of BMP4 on isolated and cultivated rat's cerebral neural stem cells (NSCs) was examined. NSCs which were isolated from two month's old rat's brain region like hippocampus and striatum were cultivated in a medium containing EGF and bFGF, and were identified with morphological character by microscope and nestin immunocytochemistry test. After 24 hours, half NSCs were cultivated with a BMP4-added medium as a experimental group instead of the primary medium, while the an other half NSCs being cultivated with the primary medium as a control group. After 8 days the expression of choline acetyltransferase (ChAT) of the cultivated cells was observated by indirect immunofluorescence test. Results showed that more positive cells were found in the experimental group, and the fluorescence intensity were stronger; while less positive cells were found in the control group, and the fluorescence intensity was weaker. The differentiational efficiency of the NSCs was examined by FITC-labelled Flow Cytometry. The results showed that about 16% cells of the experimental group appeared ChAT-positive, while that of control group only 7%. So BMP4 may have the function of inducing NSCs to differentiate into neurons with cholinergic characteristic. (authors)

  19. [Effect of Shouwu Shudi Yin on dopaminegic neurons in MPTP induced Parkinson's disease mouse model].

    Science.gov (United States)

    Tunje, Reginachizi; Ye, Yang-Lie; Sonauddin, Ahmed; Hansraj, Bhugun; Ngawang, Sangye; Shivani, Sharma; Zhang, Xiong; Zhu, Jian-Hong; Liu, Rong-Pei

    2016-09-01

    In order to investigate the effect of Shouwu Shudi Yin on dopaminegic neurons in MPTP induced Parkinson's disease mouse model and the possible mechamism, the experimental mice were randomly divided into 4 groups: control, Shouwu Shudi Yin, MPTP and the treatment (MPTP+Shouwu Shudi Yin) groups. The number of tyrosine hydroxylase (TH) positive cells in the substantia nigra was measured by immunohistochemistry, and mRNA expression of TH and glutathione peroxidase (GPX) were detected by PCR. The results showed that the number of TH positive cells and mRNA expression of TH were significantly reduced in MPTP group compared with the control (PYin didn't show protective effect. Compared to MPTP group, the mRNA expression of four subtypes of GPX were increased in various degrees in the treatment group pretreated with Shouwu Shudi Yin, although the difference was not statistically significant. These indicated that the preventive medication of Shouwu Shudi Yin don't have protective effect on the mice with Parkinson' s disease induced by MPTP, but it may enhance the antioxidant capacity through increasing the expression of GPX. Copyright© by the Chinese Pharmaceutical Association.

  20. Curcumin Protects Neuron against Cerebral Ischemia-Induced Inflammation through Improving PPAR-Gamma Function

    Directory of Open Access Journals (Sweden)

    Zun-Jing Liu

    2013-01-01

    Full Text Available Cerebral ischemia is the most common cerebrovascular disease worldwide. Recent studies have demonstrated that curcumin had beneficial effect to attenuate cerebral ischemic injury. However, it is unclear how curcumin protects against cerebral ischemic injury. In the present study, using rat middle cerebral artery occlusion model, we found that curcumin was a potent PPARγ agonist in that it upregulated PPARγ expression and PPARγ-PPRE binding activity. Administration of curcumin markedly decreased the infarct volume, improved neurological deficits, and reduced neuronal damage of rats. In addition, curcumin suppressed neuroinflammatory response by decreasing inflammatory mediators, such as IL-1β, TNF-α, PGE2, NO, COX-2, and iNOS induced by cerebral ischemia of rats. Furthermore, curcumin suppressed IκB degradation that was caused by cerebral ischemia. The present data also showed that PPARγ interacted with NF-κB-p65 and thus inhibited NF-κB activation. All the above protective effects of curcumin on cerebral ischemic injury were markedly attenuated by GW9662, an inhibitor of PPARγ. Our results as described above suggested that PPARγ induced by curcumin may play a critical role in protecting against brain injury through suppression of inflammatory response. It also highlights the potential of curcumin as a therapeutic agent against cerebral ischemia.

  1. Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death

    Energy Technology Data Exchange (ETDEWEB)

    Guida, Natascia [IRCSS SDN, Naples 80131 (Italy); Laudati, Giusy [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Anzilotti, Serenella [IRCSS SDN, Naples 80131 (Italy); Secondo, Agnese [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Montuori, Paolo [Department of Public Health, ‘Federico II’ University of Naples, Naples (Italy); Di Renzo, Gianfranco [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Canzoniero, Lorella M.T. [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy); Formisano, Luigi, E-mail: cformisa@unisannio.it [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy)

    2015-11-01

    Resveratrol (3,5,4′-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. - Highlights: • Resveratrol via SIRT1/c-Jun downregulates REST mRNA and protein in SH-SY5Y cells. • Non-dioxin-like (NDL) PCB-95 is cytotoxic to

  2. Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death

    International Nuclear Information System (INIS)

    Guida, Natascia; Laudati, Giusy; Anzilotti, Serenella; Secondo, Agnese; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M.T.; Formisano, Luigi

    2015-01-01

    Resveratrol (3,5,4′-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. - Highlights: • Resveratrol via SIRT1/c-Jun downregulates REST mRNA and protein in SH-SY5Y cells. • Non-dioxin-like (NDL) PCB-95 is cytotoxic to

  3. Unraveling the biology of bipolar disorder using induced pluripotent stem-derived neurons.

    Science.gov (United States)

    Miller, Nathaniel D; Kelsoe, John R

    2017-11-01

    Bipolar disorder has been studied from numerous angles, from pathological studies to large-scale genomic studies, overall making moderate gains toward an understanding of the disorder. With the advancement of induced pluripotent stem (iPS) cell technology, in vitro models based on patient samples are now available that inherently incorporate the complex genetic variants that largely are the basis for this disorder. A number of groups are starting to apply iPS technology to the study of bipolar disorder. We selectively reviewed the literature related to understanding bipolar disorder based on using neurons derived from iPS cells. So far, most work has used the prototypical iPS cells. However, others have been able to transdifferentiate fibroblasts directly to neurons. Others still have utilized olfactory epithelium tissue as a source of neural-like cells that do not need reprogramming. In general, iPS and related cells can be used for studies of disease pathology, drug discovery, or stem cell therapy. Published studies have primarily focused on understanding bipolar disorder pathology, but initial work is also being done to use iPS technology for drug discovery. In terms of disease pathology, some evidence is pointing toward a differentiation defect with more ventral cell types being prominent. Additionally, there is evidence for a calcium signaling defect, a finding that builds on the genome-wide association study results. Continued work with iPS cells will certainly help us understand bipolar disorder and provide a way forward for improved treatments. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Lipopolysaccharide-induced neuronal activation in the paraventricular and dorsomedial hypothalamus depends on ambient temperature.

    Directory of Open Access Journals (Sweden)

    Samuel P Wanner

    Full Text Available Systemic inflammatory response syndrome is associated with either fever or hypothermia, but the mechanisms responsible for switching from one to the other are unknown. In experimental animals, systemic inflammation is often induced by bacterial lipopolysaccharide (LPS. To identify the diencephalic and brainstem structures involved in the fever-hypothermia switch, we studied the expression of c-Fos protein, a marker of neuronal activation, in rats treated with the same high dose of LPS (0.5 mg/kg, intravenously either in a thermoneutral (30 °C or cool (24 °C environment. At 30 °C, LPS caused fever; at 24 °C, the same dose caused profound hypothermia. Both fever and hypothermia were associated with the induction of c-Fos in many brain areas, including several structures of the anterior preoptic, paraventricular, lateral, and dorsal hypothalamus, the bed nucleus of the stria terminalis, the posterior pretectal nucleus, ventrolateral periaqueductal gray, lateral parabrachial nucleus, area postrema, and nucleus of the solitary tract. Every brain area studied showed a comparable response to LPS at the two different ambient temperatures used, with the exception of two areas: the dorsomedial hypothalamic nucleus (DMH, which we studied together with the adjacent dorsal hypothalamic area (DA, and the paraventricular hypothalamic nucleus (PVH. Both structures had much stronger c-Fos expression during LPS hypothermia than during fever. We propose that PVH and DMH/DA neurons are involved in a circuit, which - depending on the ambient temperature - determines whether the thermoregulatory response to bacterial LPS will be fever or hypothermia.

  5. Phrenic motor neuron TrkB expression is necessary for acute intermittent hypoxia-induced phrenic long-term facilitation

    OpenAIRE

    Dale, Erica A.; Fields, Daryl P.; Devinney, Michael J.; Mitchell, Gordon S.

    2016-01-01

    Phrenic long-term facilitation (pLTF) is a form of hypoxia-induced spinal respiratory motor plasticity that requires new synthesis of brain derived neurotrophic factor (BDNF) and activation of its high-affinity receptor, tropomyosin receptor kinase B (TrkB). Since the cellular location of relevant TrkB receptors is not known, we utilized intrapleural siRNA injections to selectively knock down TrkB receptor protein within phrenic motor neurons. TrkB receptors within phrenic motor neurons are n...

  6. Role of Serotonin Neurons in L-DOPA- and Graft-Induced Dyskinesia in a Rat Model of Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Eunju Shin

    2012-01-01

    Full Text Available L-DOPA, the most effective drug to treat motor symptoms of Parkinson's disease, causes abnormal involuntary movements, limiting its use in advanced stages of the disease. An increasing body of evidence points to the serotonin system as a key player in the appearance of L-DOPA-induced dyskinesia (LID. In fact, exogenously administered L-DOPA can be taken up by serotonin neurons, converted to dopamine and released as a false transmitter, contributing to pulsatile stimulation of striatal dopamine receptors. Accordingly, destruction of serotonin fibers or silencing serotonin neurons by serotonin agonists could counteract LID in animal models. Recent clinical work has also shown that serotonin neurons are present in the caudate/putamen of patients grafted with embryonic ventral mesencephalic cells, producing intense serotonin hyperinnervation. These patients experience graft-induced dyskinesia (GID, a type of dyskinesia phenotypically similar to the one induced by L-DOPA but independent from its administration. Interestingly, the 5-HT1A receptor agonist buspirone has been shown to suppress GID in these patients, suggesting that serotonin neurons might be involved in the etiology of GID as for LID. In this paper we will discuss the experimental and clinical evidence supporting the involvement of the serotonin system in both LID and GID.

  7. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    Directory of Open Access Journals (Sweden)

    Nevzat Selim Gokay

    2016-01-01

    Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  8. Bilobalide induces neuronal differentiation of P19 embryonic carcinoma cells via activating Wnt/β-catenin pathway.

    Science.gov (United States)

    Liu, Mei; Guo, Jingjing; Wang, Juan; Zhang, Luyong; Pang, Tao; Liao, Hong

    2014-08-01

    Bilobalide, a natural product extracted from Ginkgo biloba leaf, is known to exhibit a number of pharmacological activities. So far, whether it could affect embryonic stem cell differentiation is still unknown. The main aim of this study was to investigate the effect of bilobalide on P19 embryonic carcinoma cells differentiation and the underlying mechanisms. Our results showed that bilobalide induced P19 cells differentiation into neurons in a concentration- and time-dependent manner. We also found that bilobalide promoted neuronal differentiation through activation of Wnt/β-catenin signaling pathway. Exposure to bilobalide increased inactive GSK-3β phosphorylation, further induced the nuclear accumulation of β-catenin, and also up-regulated the expression of Wnt ligands Wnt1 and Wnt7a. Neuronal differentiation induced by bilobalide was totally abolished by XAV939, an inhibitor of Wnt/β-catenin pathway. These results revealed a novel role of bilobalide in neuronal differentiation from P19 embryonic cells acting through Wnt/β-catenin signaling pathway, which would provide a better insight into the beneficial effects of bilobalide in brain diseases.

  9. Protein misfolding cyclic amplification induces the conversion of recombinant prion protein to PrP oligomers causing neuronal apoptosis.

    Science.gov (United States)

    Yuan, Zhen; Yang, Lifeng; Chen, Baian; Zhu, Ting; Hassan, Mohammad Farooque; Yin, Xiaomin; Zhou, Xiangmei; Zhao, Deming

    2015-06-01

    The formation of neurotoxic prion protein (PrP) oligomers is thought to be a key step in the development of prion diseases. Recently, it was determined that the sonication and shaking of recombinant PrP can convert PrP monomers into β-state oligomers. Herein, we demonstrate that β-state oligomeric PrP can be generated through protein misfolding cyclic amplification from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP, and that these oligomers can be used for subsequent research into the mechanisms of PrP-induced neurotoxicity. We have characterized protein misfolding cyclic amplification-induced monomer-to-oligomer conversion of PrP from three species using western blotting, circular dichroism, size-exclusion chromatography, and resistance to proteinase K (PK) digestion. We have further shown that all of the resulting β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, whereas the corresponding monomeric PrP were not toxic. In addition, we found that this toxicity is the result of oligomer-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3 in both wild-type and PrP(-/-) cortical neurons. It is our hope that these results may contribute to our understanding of prion transformation within the brain. We found that β-state oligomeric PrPs can be generated through protein misfolding cyclic amplification (PMCA) from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP. β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, while the corresponding monomeric PrPs were not toxic. This toxicity is the result of oligomers-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3. These results may contribute to our understanding of prion transformation within the brain. © 2015 International Society for Neurochemistry.

  10. Shp-1 dephosphorylates TRPV1 in dorsal root ganglion neurons and alleviates CFA-induced inflammatory pain in rats.

    Science.gov (United States)

    Xiao, Xing; Zhao, Xiao-Tao; Xu, Ling-Chi; Yue, Lu-Peng; Liu, Feng-Yu; Cai, Jie; Liao, Fei-Fei; Kong, Jin-Ge; Xing, Guo-Gang; Yi, Ming; Wan, You

    2015-04-01

    Transient receptor potential vanilloid 1 (TRPV1) receptors are expressed in nociceptive neurons of rat dorsal root ganglions (DRGs) and mediate inflammatory pain. Nonspecific inhibition of protein-tyrosine phosphatases (PTPs) increases the tyrosine phosphorylation of TRPV1 and sensitizes TRPV1. However, less is known about tyrosine phosphorylation's implication in inflammatory pain, compared with that of serine/threonine phosphorylation. Src homology 2 domain-containing tyrosine phosphatase 1 (Shp-1) is a key phosphatase dephosphorylating TRPV1. In this study, we reported that Shp-1 colocalized with and bound to TRPV1 in nociceptive DRG neurons. Shp-1 inhibitors, including sodium stibogluconate and PTP inhibitor III, sensitized TRPV1 in cultured DRG neurons. In naive rats, intrathecal injection of Shp-1 inhibitors increased both TRPV1 and tyrosine-phosphorylated TRPV1 in DRGs and induced thermal hyperalgesia, which was abolished by pretreatment with TRPV1 antagonists capsazepine, BCTC, or AMG9810. Complete Freund's adjuvant (CFA)-induced inflammatory pain in rats significantly increased the expression of Shp-1, TRPV1, and tyrosine-phosphorylated TRPV1, as well as the colocalization of Shp-1 and TRPV1 in DRGs. Intrathecal injection of sodium stibogluconate aggravated CFA-induced inflammatory pain, whereas Shp-1 overexpression in DRG neurons alleviated it. These results suggested that Shp-1 dephosphorylated and inhibited TRPV1 in DRG neurons, contributing to maintain thermal nociceptive thresholds in normal rats, and as a compensatory mechanism, Shp-1 increased in DRGs of rats with CFA-induced inflammatory pain, which was involved in protecting against excessive thermal hyperalgesia.

  11. Docosahexaenoic acid prevents paraquat-induced reactive oxygen species production in dopaminergic neurons via enhancement of glutathione homeostasis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyoung Jun; Han, Jeongsu; Jang, Yunseon; Kim, Soo Jeong; Park, Ji Hoon; Seo, Kang Sik [Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon (Korea, Republic of); Jeong, Soyeon; Shin, Soyeon; Lim, Kyu [Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon (Korea, Republic of); Infection Signaling Network Research Center, Chungnam National University, Daejeon (Korea, Republic of); Heo, Jun Young, E-mail: junyoung3@gmail.com [Brainscience Institute, Chungnam National University, Daejeon (Korea, Republic of); Kweon, Gi Ryang, E-mail: mitochondria@cnu.ac.kr [Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon (Korea, Republic of); Infection Signaling Network Research Center, Chungnam National University, Daejeon (Korea, Republic of)

    2015-01-30

    Highlights: • DHA prevents PQ-induced dopaminergic neuronal loss via decreasing of excessive ROS. • DHA increases GR and GCLm derivate GSH pool by enhancement of Nrf2 expression. • Protective mechanism is removal of PQ-induced ROS via DHA-dependent GSH pool. • DHA may be a good preventive strategy for Parkinson’s disease (PD) therapy. - Abstract: Omega-3 polyunsaturated fatty acid levels are reduced in the substantia nigra area in Parkinson’s disease patients and animal models, implicating docosahexaenoic acid (DHA) as a potential treatment for preventing Parkinson’s disease and suggesting the need for investigations into how DHA might protect against neurotoxin-induced dopaminergic neuron loss. The herbicide paraquat (PQ) induces dopaminergic neuron loss through the excessive production of reactive oxygen species (ROS). We found that treatment of dopaminergic SN4741 cells with PQ reduced cell viability in a dose-dependent manner, but pretreatment with DHA ameliorated the toxic effect of PQ. To determine the toxic mechanism of PQ, we measured intracellular ROS content in different organelles with specific dyes. As expected, all types of ROS were increased by PQ treatment, but DHA pretreatment selectively decreased cytosolic hydrogen peroxide content. Furthermore, DHA treatment-induced increases in glutathione reductase and glutamate cysteine ligase modifier subunit (GCLm) mRNA expression were positively correlated with glutathione (GSH) content. Consistent with this increase in GCLm mRNA levels, Western blot analysis revealed that DHA pretreatment increased nuclear factor-erythroid 2 related factor 2 (Nrf2) protein levels. These findings indicate that DHA prevents PQ-induced neuronal cell loss by enhancing Nrf2-regulated GSH homeostasis.

  12. Docosahexaenoic acid prevents paraquat-induced reactive oxygen species production in dopaminergic neurons via enhancement of glutathione homeostasis

    International Nuclear Information System (INIS)

    Lee, Hyoung Jun; Han, Jeongsu; Jang, Yunseon; Kim, Soo Jeong; Park, Ji Hoon; Seo, Kang Sik; Jeong, Soyeon; Shin, Soyeon; Lim, Kyu; Heo, Jun Young; Kweon, Gi Ryang

    2015-01-01

    Highlights: • DHA prevents PQ-induced dopaminergic neuronal loss via decreasing of excessive ROS. • DHA increases GR and GCLm derivate GSH pool by enhancement of Nrf2 expression. • Protective mechanism is removal of PQ-induced ROS via DHA-dependent GSH pool. • DHA may be a good preventive strategy for Parkinson’s disease (PD) therapy. - Abstract: Omega-3 polyunsaturated fatty acid levels are reduced in the substantia nigra area in Parkinson’s disease patients and animal models, implicating docosahexaenoic acid (DHA) as a potential treatment for preventing Parkinson’s disease and suggesting the need for investigations into how DHA might protect against neurotoxin-induced dopaminergic neuron loss. The herbicide paraquat (PQ) induces dopaminergic neuron loss through the excessive production of reactive oxygen species (ROS). We found that treatment of dopaminergic SN4741 cells with PQ reduced cell viability in a dose-dependent manner, but pretreatment with DHA ameliorated the toxic effect of PQ. To determine the toxic mechanism of PQ, we measured intracellular ROS content in different organelles with specific dyes. As expected, all types of ROS were increased by PQ treatment, but DHA pretreatment selectively decreased cytosolic hydrogen peroxide content. Furthermore, DHA treatment-induced increases in glutathione reductase and glutamate cysteine ligase modifier subunit (GCLm) mRNA expression were positively correlated with glutathione (GSH) content. Consistent with this increase in GCLm mRNA levels, Western blot analysis revealed that DHA pretreatment increased nuclear factor-erythroid 2 related factor 2 (Nrf2) protein levels. These findings indicate that DHA prevents PQ-induced neuronal cell loss by enhancing Nrf2-regulated GSH homeostasis

  13. Electromagnetized gold nanoparticles mediate direct lineage reprogramming into induced dopamine neurons in vivo for Parkinson's disease therapy

    Science.gov (United States)

    Yoo, Junsang; Lee, Euiyeon; Kim, Hee Young; Youn, Dong-Ho; Jung, Junghyun; Kim, Hongwon; Chang, Yujung; Lee, Wonwoong; Shin, Jaein; Baek, Soonbong; Jang, Wonhee; Jun, Won; Kim, Soochan; Hong, Jongki; Park, Hi-Joon; Lengner, Christopher J.; Moh, Sang Hyun; Kwon, Youngeun; Kim, Jongpil

    2017-10-01

    Electromagnetic fields (EMF) are physical energy fields generated by electrically charged objects, and specific ranges of EMF can influence numerous biological processes, which include the control of cell fate and plasticity. In this study, we show that electromagnetized gold nanoparticles (AuNPs) in the presence of specific EMF conditions facilitate an efficient direct lineage reprogramming to induced dopamine neurons in vitro and in vivo. Remarkably, electromagnetic stimulation leads to a specific activation of the histone acetyltransferase Brd2, which results in histone H3K27 acetylation and a robust activation of neuron-specific genes. In vivo dopaminergic neuron reprogramming by EMF stimulation of AuNPs efficiently and non-invasively alleviated symptoms in mouse Parkinson's disease models. This study provides a proof of principle for EMF-based in vivo lineage conversion as a potentially viable and safe therapeutic strategy for the treatment of neurodegenerative disorders.

  14. Progressive neurodegenerative and behavioural changes induced by AAV-mediated overexpression of α-synuclein in midbrain dopamine neurons

    DEFF Research Database (Denmark)

    Decressac, M; Mattsson, Bente; Lundblad, M

    2012-01-01

    -synuclein, we have now been able to achieve increased levels of α-synuclein in the transduced midbrain dopamine neurons sufficient to induce profound deficits in motor function, accompanied by reduced expression of proteins involved in dopamine neurotransmission and a time-dependent loss of nigral dopamine......Parkinson's disease (PD) is characterised by the progressive loss of nigral dopamine neurons and the presence of synucleinopathy. Overexpression of α-synuclein in vivo using viral vectors has opened interesting possibilities to model PD-like pathology in rodents. However, the attempts made so far...... have failed to show a consistent behavioural phenotype and pronounced dopamine neurodegeneration. Using a more efficient adeno-associated viral (AAV) vector construct, which includes a WPRE enhancer element and uses the neuron-specific synapsin-1 promoter to drive the expression of human wild-type α...

  15. Depolarization-induced release of [(3)H]D-aspartate from GABAergic neurons caused by reversal of glutamate transporters

    DEFF Research Database (Denmark)

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

    2000-01-01

    if glutamate in addition to gamma-aminobutyric acid (GABA) could be released from these cultures. The neurons were preloaded with [(3)H]D-aspartate and subsequently its release was followed during depolarization induced by a high potassium concentration or the alpha-amino-3-hydroxy-5-methyl-4......-isoxazolepropionic acid (AMPA) receptor agonists, AMPA and kainate. Depolarization of the neurons with 55 mM potassium increased the release of [(3)H]D-aspartate by more than 10-fold. When the non-specific calcium-channel blockers cobalt or lanthanum were included in the stimulation buffer with potassium......, the release of [(3)H]D-aspartate was decreased by about 40%. These results indicated that some of the released [(3)H]D-aspartate might originate from a vesicular pool. When AMPA was applied to the neurons, the release of [(3)H]D-aspartate was increased 2-fold and could not be prevented or decreased...

  16. Speaking with a mirror: engagement of mirror neurons via choral speech and its derivatives induces stuttering inhibition.

    Science.gov (United States)

    Kalinowski, Joseph; Saltuklaroglu, Tim

    2003-04-01

    'Choral speech', 'unison speech', or 'imitation speech' has long been known to immediately induce reflexive, spontaneous, and natural sounding fluency, even the most severe cases of stuttering. Unlike typical post-therapeutic speech, a hallmark characteristic of choral speech is the sense of 'invulnerability' to stuttering, regardless of phonetic context, situational environment, or audience size. We suggest that choral speech immediately inhibits stuttering by engaging mirror systems of neurons, innate primitive neuronal substrates that dominate the initial phases of language development due to their predisposition to reflexively imitate gestural action sequences in a fluent manner. Since mirror systems are primordial in nature, they take precedence over the much later developing stuttering pathology. We suggest that stuttering may best be ameliorated by reengaging mirror neurons via choral speech or one of its derivatives (using digital signal processing technology) to provide gestural mirrors, that are nature's way of immediately overriding the central stuttering block. Copyright 2003 Elsevier Science Ltd.

  17. GnRH Neuron Activity and Pituitary Response in Estradiol-Induced vs Proestrous Luteinizing Hormone Surges in Female Mice.

    Science.gov (United States)

    Silveira, Marina A; Burger, Laura L; DeFazio, R Anthony; Wagenmaker, Elizabeth R; Moenter, Suzanne M

    2017-02-01

    During the female reproductive cycle, estradiol exerts negative and positive feedback at both the central level to alter gonadotropin-releasing hormone (GnRH) release and at the pituitary to affect response to GnRH. Many studies of the neurobiologic mechanisms underlying estradiol feedback have been done on ovariectomized, estradiol-replaced (OVX+E) mice. In this model, GnRH neuron activity depends on estradiol and time of day, increasing in estradiol-treated mice in the late afternoon, coincident with a daily luteinizing hormone (LH) surge. Amplitude of this surge appears lower than in proestrous mice, perhaps because other ovarian factors are not replaced. We hypothesized GnRH neuron activity is greater during the proestrous-preovulatory surge than the estradiol-induced surge. GnRH neuron activity was monitored by extracellular recordings from fluorescently tagged GnRH neurons in brain slices in the late afternoon from diestrous, proestrous, and OVX+E mice. Mean GnRH neuron firing rate was low on diestrus; firing rate was similarly increased in proestrous and OVX+E mice. Bursts of action potentials have been associated with hormone release in neuroendocrine systems. Examination of the patterning of action potentials revealed a shift toward longer burst duration in proestrous mice, whereas intervals between spikes were shorter in OVX+E mice. LH response to an early afternoon injection of GnRH was greater in proestrous than diestrous or OVX+E mice. These observations suggest the lower LH surge amplitude observed in the OVX+E model is likely not attributable to altered mean GnRH neuron activity, but because of reduced pituitary sensitivity, subtle shifts in action potential pattern, and/or excitation-secretion coupling in GnRH neurons. Copyright © 2017 by the Endocrine Society.

  18. Catalpol ameliorates beta amyloid-induced degeneration of cholinergic neurons by elevating brain-derived neurotrophic factors.

    Science.gov (United States)

    Wang, Z; Liu, Q; Zhang, R; Liu, S; Xia, Z; Hu, Y

    2009-11-10

    The purpose of this work is to study the effect of catalpol, an iridoid from Rehmannia glutinosa on neurodegenerative changes induced by beta-amyloid peptide Abeta(25-35) or Abeta(25-35)+ibotenic acid and the underlying mechanism. Results showed that catalpol significantly improved the memory deficits in the neurodegenerative mouse model produced by injection of Abeta(25-35)+ibotenic acid to the nucleus magnocellularis basalis, yet it is neither a cholinesterase inhibitor nor a muscarinic (M) receptor agonist. Instead, the choline acetyl transferase (ChAT) activity and the M receptor density in brain were significantly decreased in the model mice and catalpol could significantly elevate their levels. Furthermore, the brain-derived neurotrophic factor (BDNF) content in brain was significantly decreased in the model mice and catalpol elevated it to normal level (83%+/-3% and 102%+/-2% of normal respectively). There is a significant positive correlation between BDNF content and memory. Primary culture of forebrain neurons revealed that aggregated Abeta(25-35) induced significant decrease of ChAT positive neuron number, neurite outgrowth length, and M receptor density, while catalpol added to the culture medium 2 h prior to Abeta addition showed significant dose dependent protective effect. Notably, 24 h and 48 h after the addition of Abeta to the cultured cells, the BDNF mRNA level in the neurons decreased to 76%+/-7% and 66%+/-3% of control without catalpol treatment, but became 128%+/-17% and 131%+/-23% of control with catalpol treatment. When the action of BDNF was inhibited by k252a in the cultured neurons, the protective effect of catalpol was completely (neurite outgrowth length) or partially (ChAT positive neuron number and the M receptor density) abolished. Taken together, catalpol improves memory and protects the forebrain neurons from neurodegeneration through increasing BDNF expression. Whether catalpol could reverse the neurodegenerative changes already

  19. Water deprivation increases Fos expression in hypothalamic corticotropin-releasing factor neurons induced by right atrial distension in awake rats.

    Science.gov (United States)

    Benedetti, Mauricio; Rorato, Rodrigo; Castro, Margaret; Machado, Benedito H; Antunes-Rodrigues, Jose; Elias, Lucila L K

    2008-11-01

    Atrial mechanoreceptors, sensitive to stretch, contribute in regulating heart rate and intravascular volume. The information from those receptors reaches the nucleus tractus solitarius and then the paraventricular nucleus (PVN), known to have a crucial role in the regulation of cardiovascular function. Neurons in the PVN synthesize CRF, AVP, and oxytocin (OT). Stimulation of atrial mechanoreceptors was performed in awake rats implanted with a balloon at the junction of the superior vena cava and right atrium. Plasma ACTH, AVP, and OT concentrations and Fos, CRF, AVP, and OT immunolabeling in the PVN were determined after balloon inflation in hydrated and water-deprived rats. The distension of the balloon increased the plasma ACTH concentrations, which were higher in water-deprived than in hydrated rats (P neurons in the parvocellular PVN, which was higher in the water-deprived than in the hydrated group (P neurons after distension in hydrated and water-deprived groups, compared with respective controls. In conclusion, parvocellular CRF neurons showed an increase of Fos expression induced by stimulation of right atrial mechanoreceptors, suggesting that CRF participates in the cardiovascular reflex adjustments elicited by volume loading. Activation of CRF neurons in the PVN by cardiovascular reflex is affected by osmotic stimulation.

  20. αν and β1 Integrins mediate Aβ-induced neurotoxicity in hippocampal neurons via the FAK signaling pathway.

    Directory of Open Access Journals (Sweden)

    Hai-Yan Han

    Full Text Available αν and β1 integrins mediate Aβ-induced neurotoxicity in primary hippocampal neurons. We treated hippocampal neurons with 2.5 µg/mL 17E6 and 5 µg/mL ab58524, which are specific αν and β1 integrin antagonists, respectively, for 42 h prior to 10 µM Aβ treatment. Next, we employed small interfering RNA (siRNA to silence focal adhesion kinase (FAK, a downstream target gene of integrins. The siRNAs were designed with a target sequence, an MOI of 10 and the addition of 5 µg/mL polybrene. Under these conditions, the neurons were transfected and the apoptosis of different cell types was detected. Moreover, we used real-time PCR and Western blotting analyses to detect the expression of FAK and ρFAK genes in different cell types and investigated the underlying mechanism and signal pathway by which αν and β1 integrins mediate Aβ-induced neurotoxicity in hippocampal neurons. An MTT assay showed that both 17E6 and ab58524 significantly increased cell viability compared with the Aβ-treated neurons (P<0.01 and P<0.05, respectively. However, this protective effect was markedly attenuated after transfection with silencing FAK (siFAK. Moreover, TUNEL immunostaining and flow cytometry indicated that both 17E6 and ab58524 significantly protected hippocampal neurons against apoptosis induced by Aβ (P<0.05 compared with the Aβ-treated cells. However, this protective effect was reversed with siFAK treatment. Both the gene and protein expression of FAK increased after Aβ treatment. Interestingly, as the gene and protein levels of FAK decreased, the ρFAK protein expression markedly increased. Furthermore, both the gene and protein expression of FAK and ρFAK were significantly diminished. Thus, we concluded that both αν and β1 integrins interfered with Aβ-induced neurotoxicity in hippocampal neurons and that this mechanism partially contributes to the activation of the Integrin-FAK signaling pathway.

  1. Dislocation Coupling-Induced Transition of Synchronization in Two-Layer Neuronal Networks

    International Nuclear Information System (INIS)

    Qin Hui-Xin; Ma Jun; Wang Chun-Ni; Jin Wu-Yin

    2014-01-01

    The mutual coupling between neurons in a realistic neuronal system is much complex, and a two-layer neuronal network is designed to investigate the transition of electric activities of neurons. The Hindmarsh—Rose neuron model is used to describe the local dynamics of each neuron, and neurons in the two-layer networks are coupled in dislocated type. The coupling intensity between two-layer networks, and the coupling ratio (Pro), which defines the percentage involved in the coupling in each layer, are changed to observe the synchronization transition of collective behaviors in the two-layer networks. It is found that the two-layer networks of neurons becomes synchronized with increasing the coupling intensity and coupling ratio (Pro) beyond certain thresholds. An ordered wave in the first layer is useful to wake up the rest state in the second layer, or suppress the spatiotemporal state in the second layer under coupling by generating target wave or spiral waves. And the scheme of dislocation coupling can be used to suppress spatiotemporal chaos and excite quiescent neurons. (interdisciplinary physics and related areas of science and technology)

  2. Persistent attenuation and enhancement of the earthworm main muscle contraction generator response induced by repeated stimulation of a peripheral neuron

    Directory of Open Access Journals (Sweden)

    Y.C. Chang

    1998-10-01

    Full Text Available Responses evoked in the earthworm, Amynthas hawayanus, main muscle contraction generator M-2 (postsynaptic mechanical-stimulus-sensitive neuron by threshold mechanical stimuli in 2-s intertrial intervals (ITI were used as the control or unconditioned responses (UR. Their attenuation induced by decreasing these intervals in non-associative conditioning and their enhancement induced by associating the unconditioned stimuli (US to a train of short (0.1 s hyperpolarizing electrical substitutive conditioning stimuli (SCS in the Peri-Kästchen (PK neuron were measured in four parameters, i.e., peak numbers (N and amplitude (averaged from 120 responses, sum of these amplitudes (SAMP and the highest peak amplitude (V over a period of 4 min. Persistent attenuation similar to habituation was induced by decreasing the control ITI to 0.5 s and 2.0 s in non-associative conditioning within less than 4 min. Dishabituation was induced by randomly pairing one of these habituated US to an electrical stimulus in the PK neuron. All four parameters of the UR were enhanced by forward (SCS-US, but not backward (US-SCS, association of the US with 25, 100 and 250-Hz trains of SCS with 40-ms interstimulus intervals (ISI for 4 min and persisted for another 4 min after turning off the SCS. The enhancement of these parameters was proportional to the SCS frequencies in the train. No UR was evoked by the SCS when the US was turned off after 4 min of classical conditioning.

  3. Y2 receptor signalling in NPY neurons controls bone formation and fasting induced feeding but not spontaneous feeding.

    Science.gov (United States)

    Qi, Yue; Fu, Melissa; Herzog, Herbert

    2016-02-01

    Y2 receptors have been implicated in the development of obesity and are a potential target for obesity treatment due to their known role of inhibiting neuropeptide Y (NPY) induced feeding responses. However, the precise neuronal population on which Y2 receptors act to fulfil this role is less clear. Here we utilise a novel inducible, postnatal onset NPY neurons specific deletion model to investigate the functional consequences of loss of Y2 signalling in this population of neurons on feeding and energy homeostasis regulation. While the consequences of lack of Y2 signalling in NPY neurons are confirmed in terms of the uncoupling of suppression/increasing of NPY and pro-opiomelanocortin (POMC) mRNA expression in the arcuate nuclei (Arc), respectively, this lack of Y2 signalling surprisingly does not have any significant effect on spontaneous food intake. Fasting induced food intake, however, is strongly increased but only in the first 1h after re-feeding. Consequently no significant changes in body weight are being observed although body weight gain is increased in male mice after postnatal onset Y2 deletion. Importantly, another known function of central Y2 receptor signalling, the suppression of bone formation is conserved in this conditional model with whole body bone mineral content being decreased. Taken together this model confirms the critical role of Y2 signalling to control NPY and associated POMC expression in the Arc, but also highlights the possibility that others, non-NPY neuronal Y2 receptors, are also involved in controlling feeding and energy homeostasis regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. High and low frequency stimulation of the subthalamic nucleus induce prolonged changes in subthalamic and globus pallidus neurons

    Directory of Open Access Journals (Sweden)

    Hagar eLavian

    2013-12-01

    Full Text Available High frequency stimulation (HFS of the subthalamic nucleus (STN is widely used to treat the symptoms of Parkinson’s disease but the mechanism of this therapy is unclear. Using a rat brain slice preparation maintaining the connectivity between the STN and one of its target nuclei, the globus pallidus (GP, we investigated the effects of high and low frequency stimulation (HFS 100 Hz, LFS 10 Hz on activity of single neurons in the STN and GP. Both HFS and LFS caused changes in firing frequency and pattern of subthalamic and pallidal neurons. These changes were of synaptic origin, as they were abolished by glutamate and GABA antagonists. Both HFS and LFS also induced a long-lasting reduction in firing frequency in STN neurons possibly contending a direct causal link between HFS and the outcome DBS. In the GP both HFS and LFS induced either a long-lasting depression, or less frequently, a long-lasting excitation. Thus, in addition to the intrinsic activation of the stimulated neurons, long-lasting stimulation of the STN may trigger prolonged biochemical processes.

  5. A neuroprotective astrocyte state is induced by neuronal signal EphB1 but fails in ALS models.

    Science.gov (United States)

    Tyzack, Giulia E; Hall, Claire E; Sibley, Christopher R; Cymes, Tomasz; Forostyak, Serhiy; Carlino, Giulia; Meyer, Ione F; Schiavo, Giampietro; Zhang, Su-Chun; Gibbons, George M; Newcombe, Jia; Patani, Rickie; Lakatos, András

    2017-10-27

    Astrocyte responses to neuronal injury may be beneficial or detrimental to neuronal recovery, but the mechanisms that determine these different responses are poorly understood. Here we show that ephrin type-B receptor 1 (EphB1) is upregulated in injured motor neurons, which in turn can activate astrocytes through ephrin-B1-mediated stimulation of signal transducer and activator of transcription-3 (STAT3). Transcriptional analysis shows that EphB1 induces a protective and anti-inflammatory signature in astrocytes, partially linked to the STAT3 network. This is distinct from the response evoked by interleukin (IL)-6 that is known to induce both pro inflammatory and anti-inflammatory processes. Finally, we demonstrate that the EphB1-ephrin-B1 pathway is disrupted in human stem cell derived astrocyte and mouse models of amyotrophic lateral sclerosis (ALS). Our work identifies an early neuronal help-me signal that activates a neuroprotective astrocytic response, which fails in ALS, and therefore represents an attractive therapeutic target.

  6. 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.

  7. Murine model of acute myocarditis and cerebral cortical neuron edema induced by coxsackievirus B4

    Directory of Open Access Journals (Sweden)

    Zhao-Peng Dong

    2018-01-01

    Full Text Available Globally, coxsackievirus B4 (CV-B4 has been continuously isolated and evidence suggests an association with the development of pancreatitis and type I diabetes. In addition, CV-B4 is also associated with myocarditis and severe central nervous system (CNS complications, which remain poorly studied and understood. In the present study, we established an ICR mouse model of CV-B4 infection and examined whether CV-B4 infection resulted in a predisposition to myocarditis and CNS infection. We found high survival in both the treatment and control group, with no significant differences in clinical outcomes observed. However, pathological lesions were evident in both brain and heart tissue of the CV-B4-infected mice. In addition, high viral loads were found in the neural and cardiac tissues as early as 2 d postinfection. Expressions of IFN-γ and IL-6 in sera were significantly higher in CV-B4-infected mice compared to uninfected negative controls, suggesting the involvement of these cytokines in the development of histopathological lesions. Our murine model successfully reproduced the acute myocarditis and cerebral cortical neuron edema induced by CV-B4, and may be useful for the evaluation of vaccine candidates and potential antivirals against CV-B4 infection.

  8. Effect of low potassium concentration on cadmium induced epileptiform activity of leech retzius neurons

    Directory of Open Access Journals (Sweden)

    Milićević Nebojša

    2016-01-01

    Full Text Available Epilepsies have a large significance and require detailed investigation of cellular mechanisms that lead to this disorder. Environmental, especially industrial, toxins are having increasingly more prominent role in these investigations. The aim of our research was to investigate the significance of Cd2+ in generation of epileptiform electrical activity of neurons, and the role of Na+/K+ pump in mechanisms that lead to cessation of this activity. Experiments were performed on Retzius nerve cells of the leech Haemopis sanguisuga. Intracellularly placed microelectrodes were used to measure membrane potential changes upon administration of Cd2+ (100 µmol/l, and the same concentration of Cd2+ in low K+ (1 mmol/l solution. In our experiments Cd2+ led to generation of rhythmic repetitive oscillatory activity. This activity closely resembles paroxysmal depolarizing shifts (PDS which represent the cellular basis of epilepsy. Cd2+ induced epileptiform activity had the following characteristics: frequency of 3.9±0.8 PDS/minute, PDS duration of 4.0±0.3 s, and PDS amplitude of 8.1±0.7 mV. Cd2+ induces effects similar to those of Ni2+ and Co2+, but in 30 times smaller concentration. Application of Cd2+ in low K+ solution led to a significant reduction of PDS frequency (by 2.34±0.55 PDS/minute, p<0.05, Student's t-test, highly significant increase in PDS duration (by 2.84±0.23 s, p<0.01, Student's t-test and highly significant reduction in PDS amplitude (by 1.91±0.33 mV, p=0.01, Student's t-test. Our results show that Cd2+ is a potent initiator of epileptiform activity, and that Na+/K+ pump significantly affects this activity and has a potentially important role in mechanisms that lead to its cessation.

  9. Inhibiting cholesterol degradation induces neuronal sclerosis and epileptic activity in mouse hippocampus

    Science.gov (United States)

    Chali, Farah; Djelti, Fathia; Eugene, Emmanuel; Valderrama, Mario; Marquer, Catherine; Aubourg, Patrick; Duykaerts, Charles; Miles, Richard; Cartier, Nathalie; Navarro, Vincent

    2015-01-01

    Elevations in neuronal cholesterol have been associated with several degenerative diseases. An enhanced excitability and synchronous firing in surviving neurons are among the sequels of neuronal death in these diseases and also in some epileptic syndromes. Here, we attempted to increase neuronal cholesterol levels, using a short hairpin RNA (shRNA) to suppress expression of the enzyme CYP46A1. This protein hydroxylates cholesterol and so facilitates trans-membrane extrusion. A sh-RNA CYP46A1construction coupled to an adeno-associated virus (AAV5) was injected focally and unilaterally into mouse hippocampus. It was selectively expressed first in neurons of the CA3a region. Cytoplasmic and membrane cholesterol increased, neuronal soma volume increased and then decreased before pyramidal cells died. As CA3a pyramidal cells died, inter-ictal EEG events occurred during exploration and non-REM sleep. With time, neuronal death spread to involve pyramidal cells and interneurons of the CA1 region. CA1 neuronal death was correlated with a delayed local expression of phosphorylated tau. Astrocytes were activated throughout the hippocampus and microglial activation was specific to regions of neuronal death. CA1 neuronal death was correlated with distinct aberrant EEG activity. During exploratory behaviour and rapid eye movement sleep, EEG oscillations at 7-10 Hz (theta) could accelerate to 14-21 Hz (beta) waves. They were accompanied by low amplitude, high-frequency oscillations of peak power at ~300Hz and a range of 250-350 Hz. While episodes of EEG acceleration were not correlated with changes in exploratory behaviour, they were followed in some animals by structured seizure-like discharges. These data strengthen links between increased cholesterol, neuronal sclerosis and epileptic behavior PMID:25847620

  10. [Neuroprotective effect of erigeron breviscapus (vant) hand-mazz on NMDA-induced retinal neuron injury in the rats].

    Science.gov (United States)

    Shi, Jingming; Jiag, Youqin; Liu, Xuyang

    2004-07-01

    To investigate if Erigeron Breviscapus (vant) Hand-Mazz (EBHM) has a neuroprotective effect against NMDA-induced neuron death in retinal ganglion cell layer (RGCL). Sixty healthy SD rats were randomly divided into four groups. 6 animals were in normal control group (group A). The others were divided as group B (EBHM group), group C (normal saline+NMDA group), group D (EBHM+NMDA group). Each group has 18 rats. 10 nmol NMDA was chosen for intravitreal injection to cause partial damage of the neurons in RGCL in the right eyes of Groups C and D. Same volume PBS was intravitreal injected in the left eyes as self-control. Groups B and D were pre-treated intraperitoneally with 6% EBHM solution at a dose of 15 mg x 100 g(-1) x d(-1) seven days before and after NMDA treatment. Group C were administrated intraperitoneally with 0.9% normal saline at the same time of EBHM injection. Rats were sacrificed in 4, 7, 14 days after NMDA treatment. Flat preparation of whole retinas were stained with 0.5% cresyl violet and neuron counting in RGCL from both eyes. Each subgroup has 6 rats. There was no significant difference between the right eye and the left eye of neuron counting from RGCL in normal control group (group A) (P=0.200). There was no significant difference between normal control group and EBHM group either in the right eyes or in the left eye in 4 days, 7 days and 14 days respectively after intravitreal injection of 10 nmol NMDA in group C and group D. (P=0.636, P=0.193). Neuron counting from RGCL of group C and group D were significant decreased in the NMDA-treated eyes in 4 days, 7 days and 14 days after intravitreal injection (P 0.05). Neuron counting was significantly higher in the EBHM+NMDA group than normal saline+NMDA group at 14 days after intraviteal injection (P=0.044). However,it is obvious that the difference was still significant between normal control group and EBHM+NMDA group (P < 0.05). EBHM has no effect on neuron counting of RGCL when administered alone

  11. Chronic wheel running reduces maladaptive patterns of methamphetamine intake: regulation by attenuation of methamphetamine-induced neuronal nitric oxide synthase

    Science.gov (United States)

    Engelmann, Alexander J.; Aparicio, Mark B.; Kim, Airee; Sobieraj, Jeffery C.; Yuan, Clara J.; Grant, Yanabel

    2013-01-01

    We investigated whether prior exposure to chronic wheel running (WR) alters maladaptive patterns of excessive and escalating methamphetamine intake under extended access conditions, and intravenous methamphetamine self-administration-induced neurotoxicity. Adult rats were given access to WR or no wheel (sedentary) in their home cage for 6 weeks. A set of WR rats were injected with 5-bromo-2′-deoxyuridine (BrdU) to determine WR-induced changes in proliferation (2-h old) and survival (28-day old) of hippocampal progenitors. Another set of WR rats were withdrawn (WRw) or continued (WRc) to have access to running wheels in their home cages during self-administration days. Following self-administration [6 h/day], rats were tested on the progressive ratio (PR) schedule. Following PR, BrdU was injected to determine levels of proliferating progenitors (2-h old). WRc rats self-administered significantly less methamphetamine than sedentary rats during acquisition and escalation sessions, and demonstrated reduced motivation for methamphetamine seeking. Methamphetamine reduced daily running activity of WRc rats compared with that of pre-methamphetamine days. WRw rats self-administered significantly more methamphetamine than sedentary rats during acquisition, an effect that was not observed during escalation and PR sessions. WR-induced beneficial effects on methamphetamine self-administration were not attributable to neuroplasticity effects in the hippocampus and medial prefrontal cortex, but were attributable to WR-induced inhibition of methamphetamine-induced increases in the number of neuronal nitric oxide synthase expressing neurons and apoptosis in the nucleus accumbens shell. Our results demonstrate that WR prevents methamphetamine-induced damage to forebrain neurons to provide a beneficial effect on drug-taking behavior. Importantly, WR-induced neuroprotective effects are transient and continued WR activity is necessary to prevent compulsive methamphetamine intake

  12. Inhibition of polymerases-alpha and -beta completely blocks DNA repair induced by UV irradiation in cultured mouse neuronal cells

    International Nuclear Information System (INIS)

    Licastro, F.; Sarafian, T.; Verity, A.M.; Walford, R.L.

    1985-01-01

    The effects of hydroxyurea, aphidicolin and dideoxythymidine on UV-induced DNA repair of mouse neuronal granular cells were studied. Aphidicolin, which is considered a specific inhibitor of polymerase-alpha, decreased spontaneous DNA synthesis by 93% and totally suppressed DNA repair. Dideoxythymidine, an inhibitor of polymerase-beta, was more potent in decreasing scheduled DNA synthesis than aphidicolin, and also completely blocked the UV-induced DNA repair. Hydroxyurea, a specific inhibitor of ribonucleotide reductase, inhibited scheduled DNA synthesis, but unscheduled DNA synthesis after UV irradiation was always well detectable. Our data suggest that in neuronal cells from 5 to 10 days old mice both polymerases-alpha and -beta are required for both DNA synthesis and repair. These two enzymes may act jointly in filling up the gaps along the DNA molecule and elongating the DNA chain

  13. Intranasal insulin protects against substantia nigra dopaminergic neuronal loss and alleviates motor deficits induced by 6-OHDA in rats.

    Science.gov (United States)

    Pang, Y; Lin, S; Wright, C; Shen, J; Carter, K; Bhatt, A; Fan, L-W

    2016-03-24

    Protection of substantia nigra (SN) dopaminergic (DA) neurons by neurotrophic factors (NTFs) is one of the promising strategies in Parkinson's disease (PD) therapy. A major clinical challenge for NTF-based therapy is that NTFs need to be delivered into the brain via invasive means, which often shows limited delivery efficiency. The nose to brain pathway is a non-invasive brain drug delivery approach developed in recent years. Of particular interest is the finding that intranasal insulin improves cognitive functions in Alzheimer's patients. In vitro, insulin has been shown to protect neurons against various insults. Therefore, the current study was designed to test whether intranasal insulin could afford neuroprotection in the 6-hydroxydopamine (6-OHDA)-based rat PD model. 6-OHDA was injected into the right side of striatum to induce a progressive DA neuronal lesion in the ipsilateral SN pars compact (SNc). Recombinant human insulin was applied intranasally to rats starting from 24h post lesion, once per day, for 2 weeks. A battery of motor behavioral tests was conducted on day 8 and 15. The number of DA neurons in the SNc was estimated by stereological counting. Our results showed that 6-OHDA injection led to significant motor deficits and 53% of DA neuron loss in the ipsilateral side of injection. Treatment with insulin significantly ameliorated 6-OHDA-induced motor impairments, as shown by improved locomotor activity, tapered/ledged beam-walking performance, vibrissa-elicited forelimb-placing, initial steps, as well as methamphetamine-induced rotational behavior. Consistent with behavioral improvements, insulin treatment provided a potent protection of DA neurons in the SNc against 6-OHDA neurotoxicity, as shown by a 74.8% increase in tyrosine hydroxylase (TH)-positive neurons compared to the vehicle group. Intranasal insulin treatment did not affect body weight and blood glucose levels. In conclusion, our study showed that intranasal insulin provided strong

  14. Protective effects of antioxidants and anti-inflammatory agents against manganese-induced oxidative damage and neuronal injury

    Energy Technology Data Exchange (ETDEWEB)

    Milatovic, Dejan, E-mail: dejan.milatovic@vanderbilt.edu [Vanderbilt University School of Medicine, Department of Pediatrics, Nashville, TN (United States); Gupta, Ramesh C. [Murray State University, Breathitt Veterinary Center, Hopkinsville, KY (United States); Yu, Yingchun; Zaja-Milatovic, Snjezana [Vanderbilt University School of Medicine, Department of Pediatrics, Nashville, TN (United States); Aschner, Michael [Vanderbilt University School of Medicine, Department of Pediatrics, Nashville, TN (United States); Pharmacology and the Kennedy Center for Research on Human Development, Nashville, TN (United States)

    2011-11-15

    Exposure to excessive manganese (Mn) levels leads to neurotoxicity, referred to as manganism, which resembles Parkinson's disease (PD). Manganism is caused by neuronal injury in both cortical and subcortical regions, particularly in the basal ganglia. The basis for the selective neurotoxicity of Mn is not yet fully understood. However, several studies suggest that oxidative damage and inflammatory processes play prominent roles in the degeneration of dopamine-containing neurons. In the present study, we assessed the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates and associated neuronal dysfunctions both in vitro and in vivo. Results from our in vitro study showed a significant (p < 0.01) increase in biomarkers of oxidative damage, F{sub 2}-isoprostanes (F{sub 2}-IsoPs), as well as the depletion of ATP in primary rat cortical neurons following exposure to Mn (500 {mu}M) for 2 h. These effects were protected when neurons were pretreated for 30 min with 100 of an antioxidant, the hydrophilic vitamin E analog, trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), or an anti-inflammatory agent, indomethacin. Results from our in vivo study confirmed a significant increase in F{sub 2}-IsoPs levels in conjunction with the progressive spine degeneration and dendritic damage of the striatal medium spiny neurons (MSNs) of mice exposed to Mn (100 mg/kg, s.c.) 24 h. Additionally, pretreatment with vitamin E (100 mg/kg, i.p.) or ibuprofen (140 {mu}g/ml in the drinking water for two weeks) attenuated the Mn-induced increase in cerebral F{sub 2}-IsoPs? and protected the MSNs from dendritic atrophy and dendritic spine loss. Our findings suggest that the mediation of oxidative stress/mitochondrial dysfunction and the control of alterations in biomarkers of oxidative injury, neuroinflammation and synaptodendritic degeneration may provide an effective, multi-pronged therapeutic strategy for protecting dysfunctional

  15. Protective effects of antioxidants and anti-inflammatory agents against manganese-induced oxidative damage and neuronal injury

    International Nuclear Information System (INIS)

    Milatovic, Dejan; Gupta, Ramesh C.; Yu, Yingchun; Zaja-Milatovic, Snjezana; Aschner, Michael

    2011-01-01

    Exposure to excessive manganese (Mn) levels leads to neurotoxicity, referred to as manganism, which resembles Parkinson's disease (PD). Manganism is caused by neuronal injury in both cortical and subcortical regions, particularly in the basal ganglia. The basis for the selective neurotoxicity of Mn is not yet fully understood. However, several studies suggest that oxidative damage and inflammatory processes play prominent roles in the degeneration of dopamine-containing neurons. In the present study, we assessed the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates and associated neuronal dysfunctions both in vitro and in vivo. Results from our in vitro study showed a significant (p 2 -isoprostanes (F 2 -IsoPs), as well as the depletion of ATP in primary rat cortical neurons following exposure to Mn (500 μM) for 2 h. These effects were protected when neurons were pretreated for 30 min with 100 of an antioxidant, the hydrophilic vitamin E analog, trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), or an anti-inflammatory agent, indomethacin. Results from our in vivo study confirmed a significant increase in F 2 -IsoPs levels in conjunction with the progressive spine degeneration and dendritic damage of the striatal medium spiny neurons (MSNs) of mice exposed to Mn (100 mg/kg, s.c.) 24 h. Additionally, pretreatment with vitamin E (100 mg/kg, i.p.) or ibuprofen (140 μg/ml in the drinking water for two weeks) attenuated the Mn-induced increase in cerebral F 2 -IsoPs? and protected the MSNs from dendritic atrophy and dendritic spine loss. Our findings suggest that the mediation of oxidative stress/mitochondrial dysfunction and the control of alterations in biomarkers of oxidative injury, neuroinflammation and synaptodendritic degeneration may provide an effective, multi-pronged therapeutic strategy for protecting dysfunctional dopaminergic transmission and slowing of the progression of Mn-induced neurodegenerative

  16. Dual Inhibition of Activin/Nodal/TGF-β and BMP Signaling Pathways by SB431542 and Dorsomorphin Induces Neuronal Differentiation of Human Adipose Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Vedavathi Madhu

    2016-01-01

    Full Text Available Damage to the nervous system can cause devastating diseases or musculoskeletal dysfunctions and transplantation of progenitor stem cells can be an excellent treatment option in this regard. Preclinical studies demonstrate that untreated stem cells, unlike stem cells activated to differentiate into neuronal lineage, do not survive in the neuronal tissues. Conventional methods of inducing neuronal differentiation of stem cells are complex and expensive. We therefore sought to determine if a simple, one-step, and cost effective method, previously reported to induce neuronal differentiation of embryonic stem cells and induced-pluripotent stem cells, can be applied to adult stem cells. Indeed, dual inhibition of activin/nodal/TGF-β and BMP pathways using SB431542 and dorsomorphin, respectively, induced neuronal differentiation of human adipose derived stem cells (hADSCs as evidenced by formation of neurite extensions, protein expression of neuron-specific gamma enolase, and mRNA expression of neuron-specific transcription factors Sox1 and Pax6 and matured neuronal marker NF200. This process correlated with enhanced phosphorylation of p38, Erk1/2, PI3K, and Akt1/3. Additionally, in vitro subcutaneous implants of SB431542 and dorsomorphin treated hADSCs displayed significantly higher expression of active-axonal-growth-specific marker GAP43. Our data offers novel insights into cell-based therapies for the nervous system repair.

  17. Nerve growth factor alters microtubule targeting agent-induced neurotransmitter release but not MTA-induced neurite retraction in sensory neurons.

    Science.gov (United States)

    Pittman, Sherry K; Gracias, Neilia G; Fehrenbacher, Jill C

    2016-05-01

    Peripheral neuropathy is a dose-limiting side effect of anticancer treatment with the microtubule-targeted agents (MTAs), paclitaxel and epothilone B (EpoB); however, the mechanisms by which the MTAs alter neuronal function and morphology are unknown. We previously demonstrated that paclitaxel alters neuronal sensitivity, in vitro, in the presence of nerve growth factor (NGF). Evidence in the literature suggests that NGF may modulate the neurotoxic effects of paclitaxel. Here, we examine whether NGF modulates changes in neuronal sensitivity and morphology induced by paclitaxel and EpoB. Neuronal sensitivity was assessed using the stimulated release of calcitonin gene-related peptide (CGRP), whereas morphology of established neurites was evaluated using a high content screening system. Dorsal root ganglion cultures, maintained in the absence or presence of NGF, were treated from day 7 to day 12 in culture with paclitaxel (300nM) or EpoB (30nM). Following treatment, the release of CGRP was stimulated using capsaicin or high extracellular potassium. In the presence of NGF, EpoB mimicked the effects of paclitaxel: capsaicin-stimulated release was attenuated, potassium-stimulated release was slightly enhanced and the total peptide content was unchanged. In the absence of NGF, both paclitaxel and EpoB decreased capsaicin- and potassium-stimulated release and the total peptide content, suggesting that NGF may reverse MTA-induced hyposensitivity. Paclitaxel and EpoB both decreased neurite length and branching, and this attenuation was unaffected by NGF in the growth media. These differential effects of NGF on neuronal sensitivity and morphology suggest that neurite retraction is not a causative factor to alter neuronal sensitivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Mechanism Governing Human Kappa-Opioid Receptor Expression under Desferrioxamine-Induced Hypoxic Mimic Condition in Neuronal NMB Cells

    Directory of Open Access Journals (Sweden)

    Jennifer Babcock

    2017-01-01

    Full Text Available Cellular adaptation to hypoxia is a protective mechanism for neurons and relevant to cancer. Treatment with desferrioxamine (DFO to induce hypoxia reduced the viability of human neuronal NMB cells. Surviving/attached cells exhibited profound increases of expression of the human kappa-opioid receptor (hKOR and hypoxia inducible factor-1α (HIF-1α. The functional relationship between hKOR and HIF-1α was investigated using RT-PCR, Western blot, luciferase reporter, mutagenesis, siRNA and receptor-ligand binding assays. In surviving neurons, DFO increased HIF-1α expression and its amount in the nucleus. DFO also dramatically increased hKOR expression. Two (designated as HIFC and D out of four potential HIF response elements of the hKOR gene (HIFA–D synergistically mediated the DFO response. Mutation of both elements completely abolished the DFO-induced effect. The CD11 plasmid (containing HIFC and D with an 11 bp spacing produced greater augmentation than that of the CD17 plasmid (HIFC and D with a 17 bp-spacing, suggesting that a proper topological interaction of these elements synergistically enhanced the promoter activity. HIF-1α siRNA knocked down the increase of endogenous HIF-1α messages and diminished the DFO-induced increase of hKOR expression. Increased hKOR expression resulted in the up-regulation of hKOR protein. In conclusion, the adaptation of neuronal hKOR under hypoxia was governed by HIF-1, revealing a new mechanism of hKOR regulation.

  19. Isothiocyanate from Moringa oleifera seeds mitigates hydrogen peroxide-induced cytotoxicity and preserved morphological features of human neuronal cells.

    Directory of Open Access Journals (Sweden)

    Mohammed Sani Jaafaru

    Full Text Available Reactive oxygen species are well known for induction of oxidative stress conditions through oxidation of vital biomarkers leading to cellular death via apoptosis and other process, thereby causing devastative effects on the host organs. This effect is believed to be linked with pathological alterations seen in several neurodegenerative disease conditions. Many phytochemical compounds proved to have robust antioxidant activities that deterred cells against cytotoxic stress environment, thus protect apoptotic cell death. In view of that we studied the potential of glucomoringin-isothiocyanate (GMG-ITC or moringin to mitigate the process that lead to neurodegeneration in various ways. Neuroprotective effect of GMG-ITC was performed on retinoic acid (RA induced differentiated neuroblastoma cells (SHSY5Y via cell viability assay, flow cytometry analysis and fluorescence microscopy by means of acridine orange and propidium iodide double staining, to evaluate the anti-apoptotic activity and morphology conservation ability of the compound. Additionally, neurite surface integrity and ultrastructural analysis were carried out by means of scanning and transmission electron microscopy to assess the orientation of surface and internal features of the treated neuronal cells. GMG-ITC pre-treated neuron cells showed significant resistance to H2O2-induced apoptotic cell death, revealing high level of protection by the compound. Increase of intracellular oxidative stress induced by H2O2 was mitigated by GMG-ITC. Thus, pre-treatment with the compound conferred significant protection to cytoskeleton and cytoplasmic inclusion coupled with conservation of surface morphological features and general integrity of neuronal cells. Therefore, the collective findings in the presence study indicated the potentials of GMG-ITC to protect the integrity of neuron cells against induced oxidative-stress related cytotoxic processes, the hallmark of neurodegenerative diseases.

  20. PELATIHAN MIRROR NEURON SYSTEM SAMA DENGAN PELATIHAN CONSTRAINT INDUCED MOVEMENT THERAPY DALAM MENINGKATKAN KEMAMPUAN FUNGSIONAL ANGGOTA GERAK ATAS PASIEN STROKE

    Directory of Open Access Journals (Sweden)

    Abdul chalik meidian

    2014-03-01

    Full Text Available Stroke is an interruption of blood vasculature system in the brain that causes suddenly neurological dysfunction, resulted in clinically brain tissue damage in a relatively long time period, decreased physical mobility and functional ability impaired of upper limb. The purpose of this study is to know an increasing in upper limb functional ability among stroke patients after mirror neuron system exercise and constraint induced movement therapy exercise and to know the comparison of both exercise. This study uses an experimental research with pre-test and post-test control group design. Number of samples of the first group is 13 patients given mirror neuron system exercise for 30-60 minutes , while the second group 13 patients were given constraint induced movement therapy exercise for 30-60 minutes. The research was conducted in 2 month period time. Each patient is taught a variety of upper limb functional ability in accordance with the operational concept guidance and patients were asked to repeat the exercise independently at home as directed. Measuring test of upper limb functional ability is using the wolf motor function test instruments. The result is an increase the upper limb functional ability of 21.7% in the mirror neuron system exercise group and proved a significant difference (p<0.05 and an increase in the upper limb functional ability of 17.1% in the constraint induced movement therapy exercise group and proved a significant difference (p<0.05 while the difference of increasing of upper limb functional ability of the two groups showed no significant difference (p>0,05. It was concluded that the mirror neuron system exercise is similar with constraint induced movement therapy exercise in increasing the upper limb functional ability among stroke patients.

  1. The GluN2B subunit represents a major functional determinant of NMDA receptors in human induced pluripotent stem cell-derived cortical neurons

    Directory of Open Access Journals (Sweden)

    Ioana Neagoe

    2018-04-01

    Full Text Available Abnormal signaling pathways mediated by N-methyl-d-aspartate receptors (NMDARs have been implicated in the pathogenesis of various CNS disorders and have been long considered as promising points of therapeutic intervention. However, few efforts have been previously described concerning evaluation of therapeutic modulators of NMDARs and their downstream pathways in human neurons with endogenous expression of NMDARs. In the present study, we assessed expression, functionality, and subunit composition of endogenous NMDARs in human induced pluripotent stem cell (hiPSC-derived cortical neurons (iCell Neurons and iCell GlutaNeurons. We initially confirmed the expected pharmacological response of iCell Neurons and iCell GlutaNeurons to NMDA by patch-clamp recordings. Subsequent pharmacological interrogation using GluN2 subunit-selective antagonists revealed the predominance of GluN2B in both iCell Neurons and iCell GlutaNeurons. This observation was also supported by qRT-PCR and Western blot analyses of GluN2 subunit expression as well as pharmacological experiments using positive allosteric modulators with distinct GluN2 subunit selectivity. We conclude that iCell Neurons and iCell GlutaNeurons express functional GluN2B-containing NMDARs and could serve as a valuable system for development and validation of GluN2B-modulating pharmaceutical agents. Keywords: Human induced pluripotent stem cell-derived neurons, iCell Neurons, iCell GlutaNeurons, NMDA receptors, GluN2B, Positive allosteric modulators

  2. Functionalizing Ascl1 with Novel Intracellular Protein Delivery Technology for Promoting Neuronal Differentiation of Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Robinson, Meghan; Chapani, Parv; Styan, Tara; Vaidyanathan, Ranjani; Willerth, Stephanie Michelle

    2016-08-01

    Pluripotent stem cells can become any cell type found in the body. Accordingly, one of the major challenges when working with pluripotent stem cells is producing a highly homogenous population of differentiated cells, which can then be used for downstream applications such as cell therapies or drug screening. The transcription factor Ascl1 plays a key role in neural development and previous work has shown that Ascl1 overexpression using viral vectors can reprogram fibroblasts directly into neurons. Here we report on how a recombinant version of the Ascl1 protein functionalized with intracellular protein delivery technology (Ascl1-IPTD) can be used to rapidly differentiate human induced pluripotent stem cells (hiPSCs) into neurons. We first evaluated a range of Ascl1-IPTD concentrations to determine the most effective amount for generating neurons from hiPSCs cultured in serum free media. Next, we looked at the frequency of Ascl1-IPTD supplementation in the media on differentiation and found that one time supplementation is sufficient enough to trigger the neural differentiation process. Ascl1-IPTD was efficiently taken up by the hiPSCs and enabled rapid differentiation into TUJ1-positive and NeuN-positive populations with neuronal morphology after 8 days. After 12 days of culture, hiPSC-derived neurons produced by Ascl1-IPTD treatment exhibited greater neurite length and higher numbers of branch points compared to neurons derived using a standard neural progenitor differentiation protocol. This work validates Ascl1-IPTD as a powerful tool for engineering neural tissue from pluripotent stem cells.

  3. Oleate induces KATP channel-dependent hyperpolarization in mouse hypothalamic glucose-excited neurons without altering cellular energy charge.

    Science.gov (United States)

    Dadak, Selma; Beall, Craig; Vlachaki Walker, Julia M; Soutar, Marc P M; McCrimmon, Rory J; Ashford, Michael L J

    2017-03-27

    The unsaturated fatty acid, oleate exhibits anorexigenic properties reducing food intake and hepatic glucose output. However, its mechanism of action in the hypothalamus has not been fully determined. This study investigated the effects of oleate and glucose on GT1-7 mouse hypothalamic cells (a model of glucose-excited (GE) neurons) and mouse arcuate nucleus (ARC) neurons. Whole-cell and perforated patch-clamp recordings, immunoblotting and cell energy status measures were used to investigate oleate- and glucose-sensing properties of mouse hypothalamic neurons. Oleate or lowered glucose concentration caused hyperpolarization and inhibition of firing of GT1-7 cells by the activation of ATP-sensitive K + channels (K ATP ). This effect of oleate was not dependent on fatty acid oxidation or raised AMP-activated protein kinase activity or prevented by the presence of the UCP2 inhibitor genipin. Oleate did not alter intracellular calcium, indicating that CD36/fatty acid translocase may not play a role. However, oleate activation of K ATP may require ATP metabolism. The short-chain fatty acid octanoate was unable to replicate the actions of oleate on GT1-7 cells. Although oleate decreased GT1-7 cell mitochondrial membrane potential there was no change in total cellular ATP or ATP/ADP ratios. Perforated patch and whole-cell recordings from mouse hypothalamic slices demonstrated that oleate hyperpolarized a subpopulation of ARC GE neurons by K ATP activation. Additionally, in a separate small population of ARC neurons, oleate application or lowered glucose concentration caused membrane depolarization. In conclusion, oleate induces K ATP- dependent hyperpolarization and inhibition of firing of a subgroup of GE hypothalamic neurons without altering cellular energy charge. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. In vitro evidence of glucose-induced toxicity in GnRH secreting neurons: high glucose concentrations influence GnRH secretion, impair cell viability, and induce apoptosis in the GT1-1 neuronal cell line.

    Science.gov (United States)

    Pal, Lubna; Chu, Hsiao-Pai; Shu, Jun; Topalli, Ilir; Santoro, Nanette; Karkanias, George

    2007-10-01

    To evaluate for direct toxic effects of high glucose concentrations on cellular physiology in GnRH secreting immortalized GT1-1 neurons. Prospective experimental design. In vitro experimental model using a cell culture system. GT1-1 cells were cultured in replicates in media with two different glucose concentrations (450 mg/dL and 100 mg/dL, respectively) for varying time intervals (24, 48, and 72 hours). Effects of glucose concentrations on GnRH secretion by the GT1-1 neurons were evaluated using a static culture model. Cell viability, cellular apoptosis, and cell cycle events in GT1-1 neurons maintained in two different glucose concentrations were assessed by flow cytometry (fluorescence-activated cell sorter) using Annexin V-PI staining. Adverse influences of high glucose concentrations on GnRH secretion and cell viability were noted in cultures maintained in high glucose concentration (450 mg/dL) culture medium for varying time intervals. A significantly higher percentage of cells maintained in high glucose concentration medium demonstrated evidence of apoptosis by a fluorescence-activated cell sorter. We provide in vitro evidence of glucose-induced cellular toxicity in GnRH secreting GT1-1 neurons. Significant alterations in GnRH secretion, reduced cell viability, and a higher percentage of apoptotic cells were observed in GT1-1 cells maintained in high (450 mg/dL) compared with low (100 mg/dL) glucose concentration culture medium.

  5. Levodopa-Induced Dyskinesia Is Related to Indirect Pathway Medium Spiny Neuron Excitotoxicity: A Hypothesis Based on an Unexpected Finding

    Directory of Open Access Journals (Sweden)

    Svetlana A. Ivanova

    2016-01-01

    Full Text Available A serendipitous pharmacogenetic finding links the vulnerability to developing levodopa-induced dyskinesia to the age of onset of Huntington’s disease. Huntington’s disease is caused by a polyglutamate expansion of the protein huntingtin. Aberrant huntingtin is less capable of binding to a member of membrane-associated guanylate kinase family (MAGUKs: postsynaptic density- (PSD- 95. This leaves more PSD-95 available to stabilize NR2B subunit carrying NMDA receptors in the synaptic membrane. This results in increased excitotoxicity for which particularly striatal medium spiny neurons from the indirect extrapyramidal pathway are sensitive. In Parkinson’s disease the sensitivity for excitotoxicity is related to increased oxidative stress due to genetically determined abnormal metabolism of dopamine or related products. This probably also increases the sensitivity of medium spiny neurons for exogenous levodopa. Particularly the combination of increased oxidative stress due to aberrant dopamine metabolism, increased vulnerability to NMDA induced excitotoxicity, and the particular sensitivity of indirect pathway medium spiny neurons for this excitotoxicity may explain the observed increased prevalence of levodopa-induced dyskinesia.

  6. A role for CaV1 and calcineurin signaling in depolarization-induced changes in neuronal DNA methylation

    Directory of Open Access Journals (Sweden)

    Eilis Hannon

    2015-07-01

    Full Text Available Direct manipulations of neuronal activity have been shown to induce changes in DNA methylation (DNAm, although little is known about the cellular signaling pathways involved. Using reduced representation bisulfite sequencing, we identify DNAm changes associated with moderate chronic depolarization in dissociated rat hippocampal cultures. Consistent with previous findings, these changes occurred primarily in the vicinity of loci implicated in neuronal function, being enriched in intergenic regions and underrepresented in CpG-rich promoter regulatory regions. We subsequently used 2 pharmacological interventions (nifedipine and FK-506 to test whether the identified changes depended on 2 interrelated signaling pathways known to mediate multiple forms of neuronal plasticity. Both pharmacological manipulations had notable effects on the extent and magnitude of depolarization-induced DNAm changes indicating that a high proportion of activity-induced changes are likely to be mediated by calcium entry through L-type CaV1 channels and/or downstream signaling via the calcium-dependent phosphatase calcineurin.

  7. Estrogen induces rapid decrease in dendritic thorns of CA3 pyramidal neurons in adult male rat hippocampus

    International Nuclear Information System (INIS)

    Tsurugizawa, Tomokazu; Mukai, Hideo

    2005-01-01

    Modulation of hippocampal synaptic plasticity by estrogen has been attracting much attention. Thorns of thorny excrescences of CA3 hippocampal neurons are post-synaptic regions whose presynaptic partners are mossy fiber terminals. Here we demonstrated the rapid effect of estradiol on the density of thorns of thorny excrescences, by imaging Lucifer Yellow-injected CA3 neurons in adult male rat hippocampal slices. The application of 1 nM estradiol induced rapid decrease in the density of thorns on pyramidal neurons within 2 h. The estradiol-mediated decrease in the density of thorns was blocked by CNQX (AMPA receptor antagonist) and PD98059 (MAP kinase inhibitor), but not by MK-801 (NMDA receptor antagonist). ERα agonist PPT induced the same suppressive effect as that induced by estradiol on the density of thorns, but ERβ agonist DPN did not affect the density of thorns. Note that a 1 nM estradiol treatment did not affect the density of spines in the stratum radiatum and stratum oriens. A search for synaptic ERα was performed using purified RC-19 antibody. The localization of ERα (67 kDa) in the CA3 mossy fiber terminals and thorns was demonstrated using immunogold electron microscopy. These results imply that estradiol drives the signaling pathway including ERα and MAP kinase

  8. Resistance of neuronal nitric oxide synthase-deficient mice to methamphetamine-induced dopaminergic neurotoxicity.

    Science.gov (United States)

    Itzhak, Y; Gandia, C; Huang, P L; Ali, S F

    1998-03-01

    Methamphetamine (METH) is a powerful psychostimulant that produces dopaminergic neurotoxicity manifested by a decrease in the levels of dopamine, tyrosine hydroxylase activity and dopamine transporter (DAT) binding sites in the nigrostriatal system. We have recently reported that blockade of the neuronal nitric oxide synthase (nNOS) isoform by 7-nitroindazole provides protection against METH-induced neurotoxicity in Swiss Webster mice. The present study was undertaken to investigate the effect of a neurotoxic dose of METH on mutant mice lacking the nNOS gene [nNOS(-/-)] and wild-type controls. In addition, we sought to investigate the behavioral outcome of exposure to a neurotoxic dose of METH. Homozygote nNOS(-/-), heterozygote nNOS(+/-) and wild-type animals were administered either saline or METH (5 mg/kg x 3). Dopamine, DOPAC and HVA levels, as well as DAT binding site levels, were determined in striatal tissue derived 72 h after the last METH injection. This regimen of METH given to nNOS(-/-) mice affected neither the tissue content of dopamine and its metabolites nor the number of DAT binding sites. Although a moderate reduction in the levels of dopamine (35%) and DAT binding sites (32%) occurred in striatum of heterozygote nNOS(+/-) mice, a more profound depletion of the dopaminergic markers (up to 68%) was observed in the wild-type animals. METH-induced hyperthermia was observed in all animal strains examined except the nNOS(-/-) mice. Investigation of the animals' spontaneous locomotor activity before and after administration of the neurotoxic dose of METH (5 mg/kg x 3) revealed no differences. A low dose of METH (1.0 mg/kg) administered to naive animals (nNOS(-/-) and wild-type) resulted in a similar intensity of locomotor stimulation. However, 68 to 72 h after exposure to the high-dose METH regimen, a marked sensitized responses to a challenge METH injection was observed in the wild-type mice but not in the nNOS(-/-) mice. Taken together, these results

  9. Electrophysiological characterization of spinal neurons in different models of diabetes type 1- and type 2-induced neuropathy in rats.

    Science.gov (United States)

    Schuelert, N; Gorodetskaya, N; Just, S; Doods, H; Corradini, L

    2015-04-16

    Diabetic polyneuropathy (DPN) is a devastating complication of diabetes. The underlying pathogenesis of DPN is still elusive and an effective treatment devoid of side effects presents a challenge. There is evidence that in type-1 and -2 diabetes, metabolic and morphological changes lead to peripheral nerve damage and altered central nociceptive transmission, which may contribute to neuropathic pain symptoms. We characterized the electrophysiological response properties of spinal wide dynamic range (WDR) neurons in three diabetic models. The streptozotocin (STZ) model was used as a drug-induced model of type-1 diabetes, and the BioBreeding/Worcester (BB/Wor) and Zucker diabetic fatty (ZDF) rat models were used for genetic DPN models. Data were compared to the respective control group (BB/Wor diabetic-resistant, Zucker lean (ZL) and saline-injected Wistar rat). Response properties of WDR neurons to mechanical stimulation and spontaneous activity were assessed. We found abnormal response properties of spinal WDR neurons in all diabetic rats but not controls. Profound differences between models were observed. In BB/Wor diabetic rats evoked responses were increased, while in ZDF rats spontaneous activity was increased and in STZ rats mainly after discharges were increased. The abnormal response properties of neurons might indicate differential pathological, diabetes-induced, changes in spinal neuronal transmission. This study shows for the first time that specific electrophysiological response properties are characteristic for certain models of DPN and that these might reflect the diverse and complex symptomatology of DPN in the clinic. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Neuroprotective role of nanoencapsulated quercetin in combating ischemia-reperfusion induced neuronal damage in young and aged rats.

    Directory of Open Access Journals (Sweden)

    Aparajita Ghosh

    Full Text Available Cerebral stroke is the leading cause of death and permanent disability among elderly people. In both humans and animals, cerebral ischemia damages the nerve cells in vulnerable regions of the brain, viz., hippocampus, cerebral cortex, cerebellum, and hypothalamus. The present study was conducted to evaluate the therapeutic efficacy of nanoencapsulated quercetin (QC in combating ischemia-reperfusion-induced neuronal damage in young and aged Swiss Albino rats. Cerebral ischemia was induced by occlusion of the common carotid arteries of both young and aged rats followed by reperfusion. Nanoencapsulated quercetin (2.7 mg/kg b wt was administered to both groups of animals via oral gavage two hours prior to ischemic insults as well as post-operation till day 3. Cerebral ischemia and 30 min consecutive reperfusion caused a substantial increase in lipid peroxidation, decreased antioxidant enzyme activities and tissue osmolality in different brain regions of both groups of animals. It also decreased mitochondrial membrane microviscosity and increased reactive oxygen species (ROS generation in different brain regions of young and aged rats. Among the brain regions studied, the hippocampus appeared to be the worst affected region showing increased upregulation of iNOS and caspase-3 activity with decreased neuronal count in the CA1 and CA3 subfields of both young and aged rats. Furthermore, three days of continuous reperfusion after ischemia caused massive damage to neuronal cells. However, it was observed that oral treatment of nanoencapsulated quercetin (2.7 mg/kg b wt resulted in downregulation of iNOS and caspase-3 activities and improved neuronal count in the hippocampal subfields even 3 days after reperfusion. Moreover, the nanoformulation imparted a significant level of protection in the antioxidant status in different brain regions, thus contributing to a better understanding of the given pathophysiological processes causing ischemic neuronal damage.

  11. A Bivalent Securinine Compound SN3-L6 Induces Neuronal Differentiation via Translational Upregulation of Neurogenic Transcription Factors

    Directory of Open Access Journals (Sweden)

    Yumei Liao

    2018-04-01

    Full Text Available Developing therapeutic approaches that target neuronal differentiation will be greatly beneficial for the regeneration of neurons and synaptic networks in neurological diseases. Protein synthesis (mRNA translation has recently been shown to regulate neurogenesis of neural stem/progenitor cells (NSPCs. However, it has remained unknown whether engineering translational machinery is a valid approach for manipulating neuronal differentiation. The present study identifies that a bivalent securinine compound SN3-L6, previously designed and synthesized by our group, induces potent neuronal differentiation through a novel translation-dependent mechanism. An isobaric tag for relative and absolute quantitation (iTRAQ-based proteomic analysis in Neuro-2a progenitor cells revealed that SN3-L6 upregulated a group of neurogenic transcription regulators, and also upregulated proteins involved in RNA processing, translation, and protein metabolism. Notably, puromycylation and metabolic labeling of newly synthesized proteins demonstrated that SN3-L6 induced rapid and robust activation of general mRNA translation. Importantly, mRNAs of the proneural transcription factors Foxp1, Foxp4, Hsf1, and Erf were among the targets that were translationally upregulated by SN3-L6. Either inhibition of translation or knockdown of these transcription factors blocked SN3-L6 activity. We finally confirmed that protein synthesis of a same set of transcription factors was upregulated in primary cortical NPCs. These findings together identify a new compound for translational activation and neuronal differentiation, and provide compelling evidence that reprogramming transcriptional regulation network at translational levels is a promising strategy for engineering NSPCs.

  12. Protective effects of antioxidants and anti-inflammatory agents against manganese-induced oxidative damage and neuronal injury.

    Science.gov (United States)

    Milatovic, Dejan; Gupta, Ramesh C; Yu, Yingchun; Zaja-Milatovic, Snjezana; Aschner, Michael

    2011-11-01

    Exposure to excessive manganese (Mn) levels leads to neurotoxicity, referred to as manganism, which resembles Parkinson's disease (PD). Manganism is caused by neuronal injury in both cortical and subcortical regions, particularly in the basal ganglia. The basis for the selective neurotoxicity of Mn is not yet fully understood. However, several studies suggest that oxidative damage and inflammatory processes play prominent roles in the degeneration of dopamine-containing neurons. In the present study, we assessed the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates and associated neuronal dysfunctions both in vitro and in vivo. Results from our in vitro study showed a significant (pprotected when neurons were pretreated for 30 min with 100 of an antioxidant, the hydrophilic vitamin E analog, trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), or an anti-inflammatory agent, indomethacin. Results from our in vivo study confirmed a significant increase in F(2)-IsoPs levels in conjunction with the progressive spine degeneration and dendritic damage of the striatal medium spiny neurons (MSNs) of mice exposed to Mn (100mg/kg, s.c.) 24h. Additionally, pretreatment with vitamin E (100mg/kg, i.p.) or ibuprofen (140 μg/ml in the drinking water for two weeks) attenuated the Mn-induced increase in cerebral F(2)-IsoPs? and protected the MSNs from dendritic atrophy and dendritic spine loss. Our findings suggest that the mediation of oxidative stress/mitochondrial dysfunction and the control of alterations in biomarkers of oxidative injury, neuroinflammation and synaptodendritic degeneration may provide an effective, multi-pronged therapeutic strategy for protecting dysfunctional dopaminergic transmission and slowing of the progression of Mn-induced neurodegenerative processes. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. The mast cell stabilizer sodium cromoglycate reduces histamine release and status epilepticus-induced neuronal damage in the rat hippocampus.

    Science.gov (United States)

    Valle-Dorado, María Guadalupe; Santana-Gómez, César Emmanuel; Orozco-Suárez, Sandra Adela; Rocha, Luisa

    2015-05-01

    Experiments were designed to evaluate changes in the histamine release, mast cell number and neuronal damage in hippocampus induced by status epilepticus. We also evaluated if sodium cromoglycate, a stabilizer of mast cells with a possible stabilizing effect on the membrane of neurons, was able to prevent the release of histamine, γ-aminobutyric acid (GABA) and glutamate during the status epilepticus. During microdialysis experiments, rats were treated with saline (SS-SE) or sodium cromoglycate (CG-SE) and 30 min later received the administration of pilocarpine to induce status epilepticus. Twenty-four hours after the status epilepticus, the brains were used to determine the neuronal damage and the number of mast cells in hippocampus. During the status epilepticus, SS-SE group showed an enhanced release of histamine (138.5%, p = 0.005), GABA (331 ± 91%, p ≤ 0.001) and glutamate (467%, p ≤ 0.001), even after diazepam administration. One day after the status epilepticus, SS-SE group demonstrated increased number of mast cells in Stratum pyramidale of CA1 (88%, p status epilepticus (p = 0.048), absence of wet-dog shakes, reduced histamine (but not GABA and glutamate) release, lower number of mast cells (p = 0.008) and reduced neuronal damage in hippocampus. Our data revealed that histamine, possibly from mast cells, is released in hippocampus during the status epilepticus. This effect may be involved in the subsequent neuronal damage and is diminished with sodium cromoglycate pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. 14,15-EET promotes mitochondrial biogenesis and protects cortical neurons against oxygen/glucose deprivation-induced apoptosis.

    Science.gov (United States)

    Wang, Lai; Chen, Man; Yuan, Lin; Xiang, Yuting; Zheng, Ruimao; Zhu, Shigong

    2014-07-18

    14,15-Epoxyeicosatrienoic acid (14,15-EET), a metabolite of arachidonic acid, is enriched in the brain cortex and exerts protective effect against neuronal apoptosis induced by ischemia/reperfusion. Although apoptosis has been well recognized to be closely associated with mitochondrial biogenesis and function, it is still unclear whether the neuroprotective effect of 14,15-EET is mediated by promotion of mitochondrial biogenesis and function in cortical neurons under the condition of oxygen-glucose deprivation (OGD). In this study, we found that 14,15-EET improved cell viability and inhibited apoptosis of cortical neurons. 14,15-EET significantly increased the mitochondrial mass and the ratio of mitochondrial DNA to nuclear DNA. Key makers of mitochondrial biogenesis, peroxisome proliferator activator receptor gamma-coactivator 1 alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), were elevated at both mRNA and protein levels in the cortical neurons treated with 14,15-EET. Moreover, 14,15-EET markedly attenuated the decline of mitochondrial membrane potential, reduced ROS, while increased ATP synthesis. Knockdown of cAMP-response element binding protein (CREB) by siRNA blunted the up-regulation of PGC-1α and NRF-1 stimulated by 14,15-EET, and consequently abolished the neuroprotective effect of 14,15-EET. Our results indicate that 14,15-EET protects neurons from OGD-induced apoptosis by promoting mitochondrial biogenesis and function through CREB mediated activation of PGC-1α and NRF-1. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. 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.

  16. Dendrobium nobile Lindl alkaloid, a novel autophagy inducer, protects against axonal degeneration induced by Aβ25-35 in hippocampus neurons in vitro.

    Science.gov (United States)

    Li, Li-Sheng; Lu, Yan-Liu; Nie, Jing; Xu, Yun-Yan; Zhang, Wei; Yang, Wen-Jin; Gong, Qi-Hai; Lu, Yuan-Fu; Lu, Yang; Shi, Jing-Shan

    2017-04-01

    Axonal degeneration is a pathological symbol in the early stage of Alzheimer's disease (AD), which can be triggered by amyloid-β (Aβ) peptide deposition. Growing evidence indicates that deficit of autophagy eventually leads to the axonal degeneration. Our previous studies have shown that Dendrobium nobile Lindl alkaloid (DNLA) had protective effect on neuron impairment in vivo and in vitro; however, the underlying mechanisms is still unclear. We exposed cultured hippocampus neurons to Aβ 25-35 to investigate the effect of DNLA in vitro. Axonal degeneration was evaluated by immunofluorescence staining and MTT assay. Neurons overexpressing GFP-LC3B were used to measure the formation of autophagosome. Autophagosome-lysosome fusion, the lysosomal pH, and cathepsin activity were assessed to reflect autophagy process. Proteins of interest were analyzed by Western blot. DNLA pretreatment significantly inhibited axonal degeneration induced by Aβ 25-35 peptide in vitro. Further studies revealed DNLA treatment increased autophagic flux through promoting formation and degradation of autophagosome in hippocampus neurons. Moreover, enhancement of autophagic flux was responsible for the protective effects of DNLA on axonal degeneration. DNLA prevents Aβ 25-35 -induced axonal degeneration via activation of autophagy process and could be a novel therapeutic target. © 2017 John Wiley & Sons Ltd.

  17. Co-induction of p75(NTR) and the associated death executor NADE in degenerating hippocampal neurons after kainate-induced seizures in the rat.

    Science.gov (United States)

    Yi, Jung-Sun; Lee, Soon-Keum; Sato, Taka-Aki; Koh, Jae-Young

    2003-08-21

    Zinc induces in cultured cortical neurons both p75(NTR) and p75(NTR)-associated death executor (NADE), which together contribute to caspase-dependent neuronal apoptosis. Since zinc neurotoxicity may contribute to neuronal death following seizures, we examined whether p75(NTR) and NADE are co-induced also in rat hippocampal neurons degenerating after seizures. Staining of brain sections with a zinc-specific fluorescent dye (N-(6-methoxy-8-quinolyl)-p-carboxybenzoylsulphonamide) and acid fuchsin revealed zinc accumulation in degenerating neuronal cell bodies in CA1 and CA3 of hippocampus 24 h after kainate injection. Both anti-p75(NTR) and anti-NADE immunoreactivities appeared in zinc-accumulating/degenerating neurons in both areas. Intraventricular injection of CaEDTA, without altering the severity or time course of kainate-induced seizures, markedly attenuated the induction of p75(NTR)/NADE in hippocampus, which correlated with the decrease of caspase-3 activation and zinc accumulation/cell death. The present study has demonstrated that p75(NTR) and NADE are co-induced in neurons degenerating after kainate-induced seizures in rats, likely in a zinc-dependent manner.

  18. Microelectrode array-induced neuronal alignment directs neurite outgrowth: analysis using a fast Fourier transform (FFT).

    Science.gov (United States)

    Radotić, Viktorija; Braeken, Dries; Kovačić, Damir

    2017-12-01

    Many studies have shown that the topography of the substrate on which neurons are cultured can promote neuronal adhesion and guide neurite outgrowth in the same direction as the underlying topography. To investigate this effect, isotropic substrate-complementary metal-oxide-semiconductor (CMOS) chips were used as one example of microelectrode arrays (MEAs) for directing neurite growth of spiral ganglion neurons. Neurons were isolated from 5 to 7-day-old rat pups, cultured 1 day in vitro (DIV) and 4 DIV, and then fixed with 4% paraformaldehyde. For analysis of neurite alignment and orientation, fast Fourier transformation (FFT) was used. Results revealed that on the micro-patterned surface of a CMOS chip, neurons orient their neurites along three directional axes at 30, 90, and 150° and that neurites aligned in straight lines between adjacent pillars and mostly followed a single direction while occasionally branching perpendicularly. We conclude that the CMOS substrate guides neurites towards electrodes by means of their structured pillar organization and can produce electrical stimulation of aligned neurons as well as monitoring their neural activities once neurites are in the vicinity of electrodes. These findings are of particular interest for neural tissue engineering with the ultimate goal of developing a new generation of MEA essential for improved electrical stimulation of auditory neurons.

  19. THYROID HORMONE TREATED ASTROCYTES INDUCE MATURATION OF CEREBRAL CORTICAL NEURONS THROUGH MODULATION OF PROTEOGLYCAN LEVELS

    Directory of Open Access Journals (Sweden)

    Romulo Sperduto Dezonne

    2013-08-01

    Full Text Available Proper brain neuronal circuitry formation and synapse development is dependent on specific cues, either genetic or epigenetic, provided by the surrounding neural environment. Within these signals, thyroid hormones (T3 and T4 play crucial role in several steps of brain morphogenesis including proliferation of progenitor cells, neuronal differentiation, maturation, migration, and synapse formation. The lack of thyroid hormones during childhood is associated with several impair neuronal connections, cognitive deficits, and mental disorders. Many of the thyroid hormones effects are mediated by astrocytes, although the mechanisms underlying these events are still unknown. In this work, we investigated the effect of 3, 5, 3’-triiodothyronine-treated (T3-treated astrocytes on cerebral cortex neuronal differentiation. Culture of neural progenitors from embryonic cerebral cortex mice onto T3-treated astrocyte monolayers yielded an increment in neuronal population, followed by enhancement of neuronal maturation, arborization and neurite outgrowth. In addition, real time PCR assays revealed an increase in the levels of the heparan sulfate proteoglycans, Glypican 1 (GPC-1 and Syndecans 3 e 4 (SDC-3 e SDC-4, followed by a decrease in the levels of the chondroitin sulfate proteoglycan, Versican. Disruption of glycosaminoglycan chains by chondroitinase AC or heparanase III completely abolished the effects of T3-treated astrocytes on neuronal morphogenesis. Our work provides evidence that astrocytes are key mediators of T3 actions on cerebral cortex neuronal development and identified potential molecules and pathways involved in neurite extension; which might eventually contribute to a better understanding of axonal regeneration, synapse formation and neuronal circuitry recover.

  20. Am80 induces neuronal differentiation via increased tropomyosin-related kinase B expression in a human neuroblastoma SH-SY5Y cell line.

    Science.gov (United States)

    Shiohira, Hideo; Kitaoka, Akira; Enjoji, Munechika; Uno, Tsukasa; Nakashima, Manabu

    2012-01-01

    Am80, a synthetic retinoid, has been used in differentiation therapy for acute promyelocytic leukemia (APL). All-trans retinoic acid (ATRA) as one of natural retinoid has been also used to treat APL. ATRA treatment causes neuronal differentiation by inducing tropomyosin-related kinase B (TrkB) expression and increasing the sensitivity to brain-derived neurotrophic factor (BDNF), a TrkB ligand. In the present study, we investigated the effects of Am80 on neuronal differentiation, BDNF sensitivity and TrkB expression in human neuroblastoma SH-SY5Y cells. Treatment with Am80 induced morphological differentiation of neurite outgrowth and increased the expression of GAP43 mRNA, a neuronal differentiation marker. Additionally, TrkB protein was also increased, and exogenous BDNF stimulation after treatment with Am80 induced greater neurite outgrowth than without BDNF treatment. These results suggest that Am80 induced neuronal differentiation by increasing TrkB expression and BDNF sensitivity.

  1. 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.

  2. Molecular mechanisms of Ca(2+) signaling in neurons induced by the S100A4 protein

    DEFF Research Database (Denmark)

    Kiryushko, Darya; Novitskaya, Vera; Soroka, Vladislav

    2006-01-01

    The S100A4 protein belongs to the S100 family of vertebrate-specific proteins possessing both intra- and extracellular functions. In the nervous system, high levels of S100A4 expression are observed at sites of neurogenesis and lesions, suggesting a role of the protein in neuronal plasticity. Ext...... at the cell surface. Thus, glycosaminoglycans may act as coreceptors of S100 proteins in neurons. This may provide a mechanism by which S100 proteins could locally regulate neuronal plasticity in connection with brain lesions and neurological disorders....

  3. (3H)-dihydrotestosterone in catecholamine neurons of rat brain stem: combined localization by autoradiography and formaldehyde-induced fluorescence

    International Nuclear Information System (INIS)

    Heritage, A.S.; Stumpf, W.E.; Sar, M.; Grant, L.D.

    1981-01-01

    A combined formaldehyde-induced fluorescence (FIF)-autoradiography procedure was used to determine how and where the androgen, dihydrotestosterone (DHT), is associated with catecholamine systems in the rat brain. With this dual localization method, ( 3 H)-DHT target sites can be visualized in relation to catecholamine perikarya and terminals. In the hindbrain, catecholamine neurons adjacent to the fourth ventricle (group A4), the nucleus (n.) olivaris superior (group A5), the n. parabranchialis medialis (group A7), and in the locus coeruleus (group A6) and subcoeruleal regions, as well as in the substantia grisea centralis, concentrate ( 3 H)-DHT in their nuclei. ( 3 H)-DHT target neurons appear to be innervated by numerous catecholamine terminals in the following hindbrain regions: n. motorius dorsalis nervi vagi, n. tractus solitarii, n. commissuralis, n. raphe pallidus, n. olivaris inferior, the ventrolateral portion of the substantia grisea centralis, n. cuneiformis, and the ventrolateral reticular formation in the caudal mesencephalon. In the forebrain, ( 3 H)-DHT concentrates in nuclei of catecholamine neurons located in the n. arcuatus and n. periventricularis (group A12). In addition, ( 3 H)-DHT target neurons appear to be innervated by numerous catecholamine terminals in the following forebrain regions: n. periventricularis rotundocellularis, n. paraventricularis, n. dorsomedialis, n. periventricularis, area retrochiasmatica, n. interstititalis striae terminalis (ventral portion), and n. amygdaloideus centralis. The disclosure of a morphologic association between ( 3 H)-DHT target sites and certain brain catecholamine systems suggests a close functional interdependence between androgens and catecholamines

  4. Ceramides in Alzheimer’s Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and Aβ Accumulation

    Directory of Open Access Journals (Sweden)

    Maja Jazvinšćak Jembrek

    2015-01-01

    Full Text Available Alzheimer’s disease (AD, the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloid β-peptides (Aβ and intracellular deposits of hyperphosphorylated tau (phospho-tau protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβ generation. Enhanced levels of ceramides directly increase Aβ through stabilization of β-secretase, the key enzyme in the amyloidogenic processing of Aβ precursor protein (APP. As a positive feedback loop, the generated oligomeric and fibrillar Aβ induces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS, cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs. This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβ in the cascade of events ending in neuronal degeneration.

  5. Restoration of Progranulin Expression Rescues Cortical Neuron Generation in an Induced Pluripotent Stem Cell Model of Frontotemporal Dementia

    Directory of Open Access Journals (Sweden)

    Susanna Raitano

    2015-01-01

    Full Text Available To understand how haploinsufficiency of progranulin (PGRN causes frontotemporal dementia (FTD, we created induced pluripotent stem cells (iPSCs from patients carrying the GRNIVS1+5G > C mutation (FTD-iPSCs. FTD-iPSCs were fated to cortical neurons, the cells most affected in FTD. Although generation of neuroprogenitors was unaffected, their further differentiation into CTIP2-, FOXP2-, or TBR1-TUJ1 double-positive cortical neurons, but not motorneurons, was significantly decreased in FTD-neural progeny. Zinc finger nuclease-mediated introduction of GRN cDNA into the AAVS1 locus corrected defects in cortical neurogenesis, demonstrating that PGRN haploinsufficiency causes inefficient cortical neuron generation. RNA sequencing analysis confirmed reversal of the altered gene expression profile following genetic correction. We identified the Wnt signaling pathway as one of the top defective pathways in FTD-iPSC-derived neurons, which was reversed following genetic correction. Differentiation of FTD-iPSCs in the presence of a WNT inhibitor mitigated defective corticogenesis. Therefore, we demonstrate that PGRN haploinsufficiency hampers corticogenesis in vitro.

  6. Toll-like receptor 4 signaling in neurons of trigeminal ganglion contributes to nociception induced by acute pulpitis in rats.

    Science.gov (United States)

    Lin, Jia-Ji; Du, Yi; Cai, Wen-Ke; Kuang, Rong; Chang, Ting; Zhang, Zhuo; Yang, Yong-Xiang; Sun, Chao; Li, Zhu-Yi; Kuang, Fang

    2015-07-30

    Pain caused by acute pulpitis (AP) is a common symptom in clinical settings. However, its underlying mechanisms have largely remained unknown. Using AP model, we demonstrated that dental injury caused severe pulp inflammation with up-regulated serum IL-1β. Assessment from head-withdrawal reflex thresholds (HWTs) and open-field test demonstrated nociceptive response at 1 day post injury. A consistent up-regulation of Toll-like receptor 4 (TLR4) in the trigeminal ganglion (TG) ipsilateral to the injured pulp was found; and downstream signaling components of TLR4, including MyD88, TRIF and NF-κB, and cytokines such as TNF-α and IL-1β, were also increased. Retrograde labeling indicated that most TLR4 positve neuron in the TG innnervated the pulp and TLR4 immunoreactivity was mainly in the medium and small neurons. Double labeling showed that the TLR4 expressing neurons in the ipsilateral TG were TRPV1 and CGRP positive, but IB4 negative. Furthermore, blocking TLR4 by eritoran (TLR4 antagonist) in TGs of the AP model significantly down-regulated MyD88, TRIF, NF-κB, TNF-α and IL-1β production and behavior of nociceptive response. Our findings suggest that TLR4 signaling in TG cells, particularly the peptidergic TRPV1 neurons, plays a key role in AP-induced nociception, and indicate that TLR4 signaling could be a potential therapeutic target for orofacial pain.

  7. Leptomeninges-Derived Induced Pluripotent Stem Cells and Directly Converted Neurons From Autopsy Cases With Varying Neuropathologic Backgrounds.

    Science.gov (United States)

    Rose, Shannon E; Frankowski, Harald; Knupp, Allison; Berry, Bonnie J; Martinez, Refugio; Dinh, Stephanie Q; Bruner, Lauren T; Willis, Sherry L; Crane, Paul K; Larson, Eric B; Grabowski, Thomas; Darvas, Martin; Keene, C Dirk; Young, Jessica E

    2018-05-01

    Patient-specific stem cell technology from skin and other biopsy sources has transformed in vitro models of neurodegenerative disease, permitting interrogation of the effects of complex human genetics on neurotoxicity. However, the neuropathologic changes that underlie cognitive and behavioral phenotypes can only be determined at autopsy. To better correlate the biology of derived neurons with age-related and neurodegenerative changes, we generated leptomeningeal cell lines from well-characterized research subjects that have undergone comprehensive postmortem neuropathologic examinations. In a series of proof of principle experiments, we reprogrammed autopsy leptomeningeal cell lines to human-induced pluripotent stem cells (hiPSCs) and differentiated these into neurons. We show that leptomeningeal-derived hiPSC lines can be generated from fresh and frozen leptomeninges, are pluripotent, and retain the karyotype of the starting cell population. Additionally, neurons differentiated from these hiPSCs are functional and produce measurable Alzheimer disease-relevant analytes (Aβ and Tau). Finally, we used direct conversion protocols to transdifferentiate leptomeningeal cells to neurons. These resources allow the generation of in vitro models to test mechanistic hypotheses as well as diagnostic and therapeutic strategies in association with neuropathology, clinical and cognitive data, and biomarker studies, aiding in the study of late-onset Alzheimer disease and other age-related neurodegenerative diseases.

  8. [Effects of perinatal exposure to bisphenol A inducing dopaminergic neuronal cell to apoptosis happening in midbrain of male rat offspring].

    Science.gov (United States)

    Lin, Yong; Zhang, Hao; Wang, Wen-dong; Wu, De-sheng; Jiang, Song-hui; Qu, Wei-dong

    2006-07-01

    To investigate the mechanism and effect of rat perinatal exposure to bisphenol A (BPA) resulting in midbrain dopaminergic neuronal cell apoptosis and tyrosine hydroxylase expression of male offspring. Rat dams were randomLy divided into 4 groups on gestational day(GD) 10 and given orally the bisphenol A doses as 0, 0.5, 5, 50 mg/kg x d from GD10 to weaning. The brains of male offspring were obtained for detecting, with immunohistochemistry protocol, the Caspase-3, Bcl-2 and tyrosine hydroxylase expression in the midbrain on postnatal day 21 or 30 respectively, and the midbrain apoptotic neuronal cell were detected by TUNEL on PND21. The expression of Caspase-3 in the midbrain of rat male offspring were increased but bcl-2 were decreased on PND21 and 30, respectively. On PND21, apoptotic neuronal cell were found in the midbrain of high and medium doses groups. TH protein expression was decreased. Perinatal exposure to bisphenol A can induce the apoptosis of midbrain dopaminergic neuron in the male rat offspring even after weaning, and concomitantly decrease the midbrain TH immunoreactivity, this may cause the abnormal function of dopaminergic pathway of rat male offspring.

  9. GPER1 mediates estrogen-induced neuroprotection against oxygen-glucose deprivation in the primary hippocampal neurons.

    Science.gov (United States)

    Zhao, Tian-Zhi; Shi, Fei; Hu, Jun; He, Shi-Ming; Ding, Qian; Ma, Lian-Ting

    2016-07-22

    It is well-known that the neuroprotective effects of estrogen have potential in the prevention and amelioration of ischemic and degenerative neurological disorders, while the underlying mechanisms for estrogen actions are undefined. As an important mediator for the non-genomic functions of estrogen, GPER1 (G Protein-coupled Estrogen Receptor 1) has been suggested to involve in the beneficial roles of estrogen in neural cells. Here our studies on primary hippocampal neurons have focused on GPER1 in an in vitro model of ischemia using oxygen-glucose deprivation (OGD). GPER1 expression in the primary hippocampal neurons was stimulated by the OGD treatments. Both E2 (estradiol) and E2-BSA (membrane impermeable estradiol by covalent conjugation of bovine serum albumin) attenuated OGD-induced cell death in primary cultures of hippocampal neurons. Importantly, this membrane-mediated estrogen function requires GPER1 protein. Knocking down of GPER1 diminished, while overexpression of GPER1 potentiated, the protective roles of E2/E2-BSA following OGD. Additionally, the downstream mechanisms employed by membrane-associated estrogen signaling were found to include PI3K/Akt-dependent Ask1 inhibition in the primary hippocampal neurons. Overall, these research results could enhance our understanding of the neuroprotective actions for estrogen, and provide a new therapeutic target for improving stroke outcome and ameliorating degenerative neurological diseases. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Neuroprotective effects of α-iso-cubebene against glutamate-induced damage in the HT22 hippocampal neuronal cell line.

    Science.gov (United States)

    Park, Sun Young; Jung, Won Jung; Kang, Jum Soon; Kim, Cheol-Min; Park, Geuntae; Choi, Young-Whan

    2015-02-01

    Since oxidative stress is critically involved in excitotoxic damage, we sought to determine whether the activation of the transcription factors, cAMP-responsive element binding protein (CREB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2, also known as NFE2L2), by α-iso-cubebene is involved in its protective effects against glutamate-induced neuronal cell death. Pre-treatment with α-iso-cubebene significantly attenuated glutamate-induced cytotoxicity in mouse hippocampus-derived neuronal cells. α-iso-cubebene also reduced the glutamate-induced generation of reactive oxygen species and calcium influx, thus preventing apoptotic cell death. α-iso-cubebene inhibited glutamate-induced mitochondrial membrane depolarization and, consequently, inhibited the release of the apoptosis-inducing factor from the mitochondria. Immunoblot anlaysis revealed that the phosphorylation of extracellular signal-regulated kinase (ERK) by glutamate was reduced in the presence of α-iso-cubebene. α-iso-cubebene activated protein kinase A (PKA), CREB and Nrf2, which mediate the expression of the antioxidant enzymes, heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO1), involved in neuroprotection. In addition, α-iso-cubebene induced the expression of antioxidant responsive element and CRE transcriptional activity, thus conferring neuroprotection against glutamate-induced oxidative injury. α-iso-cubebene also induced the expression of Nrf2-dependent genes encoding HO-1 and NQO1. Furthermore, the knockdown of CREB and Nrf2 by small interfering RNA attenuated the neuroprotective effects of α-iso-cubebene. Taken together, our results indicate that α-iso-cubebene protects HT22 cells from glutamate-induced oxidative damage through the activation of Nrf2/HO-1/NQO-1, as well as through the PKA and CREB signaling pathways.

  11. Participation of neuronal nitric oxide synthase in experimental neuropathic pain induced by sciatic nerve transection

    Directory of Open Access Journals (Sweden)

    M. Chacur

    2010-04-01

    Full Text Available Nerve injury leads to a neuropathic pain state that results from central sensitization. This phenomenom is mediated by NMDA receptors and may involve the production of nitric oxide (NO. In this study, we investigated the expression of the neuronal isoform of NO synthase (nNOS in the spinal cord of 3-month-old male, Wistar rats after sciatic nerve transection (SNT. Our attention was focused on the dorsal part of L3-L5 segments receiving sensory inputs from the sciatic nerve. SNT resulted in the development of neuropathic pain symptoms confirmed by evaluating mechanical hyperalgesia (Randall and Selitto test and allodynia (von Frey hair test. Control animals did not present any alteration (sham-animals. The selective inhibitor of nNOS, 7-nitroindazole (0.2 and 2 µg in 50 µL, blocked hyperalgesia and allodynia induced by SNT. Immunohistochemical analysis showed that nNOS was increased (48% by day 30 in the lumbar spinal cord after SNT. This increase was observed near the central canal (Rexed’s lamina X and also in lamina I-IV of the dorsal horn. Real-time PCR results indicated an increase of nNOS mRNA detected from 1 to 30 days after SNT, with the highest increase observed 1 day after injury (1469%. Immunoblotting confirmed the increase of nNOS in the spinal cord between 1 and 15 days post-lesion (20%, reaching the greatest increase (60% 30 days after surgery. The present findings demonstrate an increase of nNOS after peripheral nerve injury that may contribute to the increase of NO production observed after peripheral neuropathy.

  12. PROTECTIVE EFFECTS OF HYPOTHALAMIC BETA-ENDORPHIN NEURONS AGAINST ALCOHOL-INDUCED LIVER INJURIES AND LIVER CANCERS IN RAT ANIMAL MODELS

    Science.gov (United States)

    Murugan, Sengottuvelan; Boyadjieva, Nadka; Sarkar, Dipak K.

    2014-01-01

    Background Recently, retrograde tracing has provided evidence for an influence of hypothalamic β-endorphin (BEP) neurons on the liver, but functions of these neurons are not known. We evaluated the effect of BEP neuronal activation on alcohol-induced liver injury and hepatocellular cancer. Methods Male rats received either BEP neuron transplants or control transplants in the hypothalamus and randomly assigned to feeding alcohol-containing liquid diet or control liquid diet for 8 weeks or to treatment of a carcinogen diethylnitrosamine (DEN). Liver tissues of these animals were analyzed histochemically and biochemically for tissue injuries or cancer. Results Alcohol-feeding increased liver weight and induced several histopathological changes such as prominent microvesicular steatosis and hepatic fibrosis. Alcohol feeding also increased protein levels of triglyceride, hepatic stellate cell activation factors and catecholamines in the liver and endotoxin levels in the plasma. However, these effects of alcohol on the liver were reduced in animals with BEP neuron transplants. BEP neuron transplants also suppressed carcinogen-induced liver histopathologies such as extensive fibrosis, large focus of inflammatory infiltration, hepatocelluar carcinoma, collagen deposition, numbers of preneoplastic foci, levels of hepatic stellate cell activation factors and catecholamines, as well as inflammatory milieu and the levels of NK cell cytotoxic factors in the liver. Conclusion These findings are the first evidence for a role of hypothalamic BEP neurons in influencing liver functions. Additionally, the data identify that BEP neuron transplantation prevents hepatocellular injury and hepatocellular carcinoma formation possibly via influencing the immune function. PMID:25581653

  13. Lysine and arginine reduce the effects of cerebral ischemic insults and inhibit glutamate-induced neuronal activity in rats

    Directory of Open Access Journals (Sweden)

    Takashi Kondoh

    2010-06-01

    Full Text Available Intravenous administration of arginine was shown to be protective against cerebral ischemic insults via nitric oxide production and possibly via additional mechanisms. The present study aimed at evaluating the neuroprotective effects of oral administration of lysine (a basic amino acid, arginine, and their combination on ischemic insults (cerebral edema and infarction and hemispheric brain swelling induced by transient middle cerebral artery occlusion/reperfusion in rats. Magnetic resonance imaging and 2,3,5-triphenyltetrazolium chloride staining were performed two days after ischemia induction. In control animals, the major edematous areas were observed in the cerebral cortex and striatum. The volumes associated with cortical edema were significantly reduced by lysine (2.0 g/kg, arginine (0.6 g/kg, or their combined administration (0.6 g/kg each. Protective effects of these amino acids on infarction were comparable to the inhibitory effects on edema formation. Interestingly, these amino acids, even at low dose (0.6 g/kg, were effective to reduce hemispheric brain swelling. Additionally, the effects of in vivo microiontophoretic (juxtaneuronal applications of these amino acids on glutamate-evoked neuronal activity in the ventromedial hypothalamus were investigated in awake rats. Glutamate-induced neuronal activity was robustly inhibited by microiontophoretic applications of lysine or arginine onto neuronal membranes. Taken together, our results demonstrate the neuroprotective effects of oral ingestion of lysine and arginine against ischemic insults (cerebral edema and infarction, especially in the cerebral cortex, and suggest that suppression of glutamate-induced neuronal activity might be the primary mechanism associated with these neuroprotective effects.

  14. Gold nanoparticle-mediated laser stimulation induces a complex stress response in neuronal cells.

    Science.gov (United States)

    Johannsmeier, Sonja; Heeger, Patrick; Terakawa, Mitsuhiro; Kalies, Stefan; Heisterkamp, Alexander; Ripken, Tammo; Heinemann, Dag

    2018-04-25

    Stimulation of neuronal cells generally resorts to electric signals. Recent advances in laser-based stimulation methods could present an alternative with superior spatiotemporal resolution. The avoidance of electronic crosstalk makes these methods attractive for in vivo therapeutic application. In particular, nano-mediators, such as gold nanoparticles, can be used to transfer the energy from a laser pulse to the cell membrane and subsequently activate excitable cells. Although the underlying mechanisms of neuronal activation have been widely unraveled, the overall effect on the targeted cell is not understood. Little is known about the physiological and pathophysiological impact of a laser pulse targeted onto nanoabsorbers on the cell membrane. Here, we analyzed the reaction of the neuronal murine cell line Neuro-2A and murine primary cortical neurons to gold nanoparticle mediated laser stimulation. Our study reveals a severe, complex and cell-type independent stress response after laser irradiation, emphasizing the need for a thorough assessment of this approach's efficacy and safety.

  15. Naoxintong Protects Primary Neurons from Oxygen-Glucose Deprivation/Reoxygenation Induced Injury through PI3K-Akt Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Yan Ma

    2016-01-01

    Full Text Available Naoxintong capsule (NXT, developed from Buyang Huanwu Decoction, has shown the neuroprotective effects in cerebrovascular diseases, but the neuroprotection mechanisms of NXT on ischemia/reperfusion injured neurons have not yet been well known. In this study, we established the oxygen-glucose deprivation/reoxygenation (OGD/R induced neurons injury model and treat the neurons with cerebrospinal fluid containing NXT (BNC to investigate the effects of NXT on OGD/R induced neurons injury and potential mechanisms. BNC improved neuron viability and decreased apoptotic rate induced by OGD/R. BNC attenuated OGD/R induced cytosolic and mitochondrial Ca2+ overload, ROS generation, intracellular NO levels and nNOS mRNA increase, and cytochrome-c release when compared with OGD/R group. BNC significantly inhibited both mPTP opening and ΔΨm depolarization. BNC increased Bcl-2 expression and decreased Bax expression, upregulated the Bcl-2/Bax ratio, downregulated caspase-3 mRNA and caspase-9 mRNA expression, and decreased cleaved caspase-3 expression and caspase-3 activity. BNC increased phosphorylation of Akt following OGD/R, while LY294002 attenuated BNC induced increase of phosphorylated Akt expression. Our study demonstrated that NXT protected primary neurons from OGD/R induced injury by inhibiting calcium overload and ROS generation, protecting mitochondria, and inhibiting mitochondrial apoptotic pathway which was mediated partially by PI3K-Akt signaling pathway activation.

  16. Phrenic long-term facilitation following intrapleural CTB-SAP-induced respiratory motor neuron death.

    Science.gov (United States)

    Nichols, Nicole L; Craig, Taylor A; Tanner, Miles A

    2017-08-16

    Amyotrophic lateral sclerosis (ALS) is a devastating disease leading to progressive motor neuron degeneration and death by ventilatory failure. In a rat model of ALS (SOD1 G93A ), phrenic long-term facilitation (pLTF) following acute intermittent hypoxia (AIH) is enhanced greater than expected at disease end-stage but the mechanism is unknown. We suggest that one trigger for this enhancement is motor neuron death itself. Intrapleural injections of cholera toxin B fragment conjugated to saporin (CTB-SAP) selectively kill respiratory motor neurons and mimic motor neuron death observed in SOD1 G93A rats. This CTB-SAP model allows us to study the impact of respiratory motor neuron death on breathing without many complications attendant to ALS. Here, we tested the hypothesis that phrenic motor neuron death is sufficient to enhance pLTF. pLTF was assessed in anesthetized, paralyzed and ventilated Sprague Dawley rats 7 and 28days following bilateral intrapleural injections of: 1) CTB-SAP (25μg), or 2) un-conjugated CTB and SAP (control). CTB-SAP enhanced pLTF at 7 (CTB-SAP: 162±18%, n=8 vs. 63±3%; n=8; pSAP: 64±10%, n=10 vs. 60±13; n=8; p>0.05). Thus, pLTF at 7 (not 28) days post-CTB-SAP closely resembles pLTF in end-stage ALS rats, suggesting that processes unique to the early period of motor neuron death enhance pLTF. This project increases our understanding of respiratory plasticity and its implications for breathing in motor neuron disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Naked mole-rat cortical neurons are resistant to acid-induced cell death

    OpenAIRE

    Husson, Zoé; Smith, Ewan S

    2018-01-01

    Abstract Regulation of brain pH is a critical homeostatic process and changes in brain pH modulate various ion channels and receptors and thus neuronal excitability. Tissue acidosis, resulting from hypoxia or hypercapnia, can activate various proteins and ion channels, among which acid-sensing ion channels (ASICs) a family of primarily Na+ permeable ion channels, which alongside classical excitotoxicity causes neuronal death. Naked mole-rats (NMRs, Heterocephalus glaber) are ...

  18. Human endothelial progenitor cells rescue cortical neurons from oxygen-glucose deprivation induced death.

    Science.gov (United States)

    Bacigaluppi, Susanna; Donzelli, Elisabetta; De Cristofaro, Valentina; Bragazzi, Nicola Luigi; D'Amico, Giovanna; Scuteri, Arianna; Tredici, Giovanni

    2016-09-19

    Cerebral ischemia is characterized by both acute and delayed neuronal injuries. Neuro-protection is a major issue that should be properly addressed from a pharmacological point of view, and cell-based treatment approaches are of interest due to their potential pleiotropic effects. Endothelial progenitor cells have the advantage of being mobilized from the bone marrow into the circulation, but have been less studied than other stem cells, such as mesenchymal stem cells. Therefore, the comparison between human endothelial progenitor cells (hEPC) and human mesenchymal progenitor cells (hMSC) in terms of efficacy in rescuing neurons from cell death after transitory ischemia is the aim of the current study, in the effort to address further directions. In vitro model of oxygen-glucose deprivation (OGD) on a primary culture of rodent cortical neurons was set up with different durations of exposure: 1, 2 and 3hrs with assessment of neuron survival. The 2hrs OGD was chosen for the subsequent experiments. After 2hrs OGD neurons were either placed in indirect co-culture with hMSC or hEPC or cultured in hMSC or hEPC conditioned medium and cell viability was evaluated by MTT assay. At day 2 after 2hrs OGD exposure, mean neuronal survival was 47.9±24.2%. In contrast, after treatment with hEPC and hMSC indirect co-culture was 74.1±27.3%; and 69.4±18.8%, respectively. In contrast, treatment with conditioned medium did not provide any advantage in terms of survival to OGD neurons The study shows the efficacy of hEPC in indirect co-culture to rescue neurons from cell death after OGD, comparable to that of hMSC. hEPC deserve further studies given their potential interest for ischemia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Caloric Restriction Protects against Lactacystin-Induced Degeneration of Dopamine Neurons Independent of the Ghrelin Receptor

    Directory of Open Access Journals (Sweden)

    Jessica Coppens

    2017-03-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative disorder, characterized by a loss of dopamine (DA neurons in the substantia nigra pars compacta (SNc. Caloric restriction (CR has been shown to exert ghrelin-dependent neuroprotective effects in the 1-methyl-4-phenyl-1,2,3,6-tetrathydropyridine (MPTP-based animal model for PD. We here investigated whether CR is neuroprotective in the lactacystin (LAC mouse model for PD, in which proteasome disruption leads to the destruction of the DA neurons of the SNc, and whether this effect is mediated via the ghrelin receptor. Adult male ghrelin receptor wildtype (WT and knockout (KO mice were maintained on an ad libitum (AL diet or on a 30% CR regimen. After 3 weeks, LAC was injected unilaterally into the SNc, and the degree of DA neuron degeneration was evaluated 1 week later. In AL mice, LAC injection significanty reduced the number of DA neurons and striatal DA concentrations. CR protected against DA neuron degeneration following LAC injection. However, no differences were observed between ghrelin receptor WT and KO mice. These results indicate that CR can protect the nigral DA neurons from toxicity related to proteasome disruption; however, the ghrelin receptor is not involved in this effect.

  20. 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.

  1. Wnts enhance neurotrophin-induced neuronal differentiation in adult bone-marrow-derived mesenchymal stem cells via canonical and noncanonical signaling pathways.

    Directory of Open Access Journals (Sweden)

    Hung-Li Tsai

    Full Text Available Wnts were previously shown to regulate the neurogenesis of neural stem or progenitor cells. Here, we explored the underlying molecular mechanisms through which Wnt signaling regulates neurotrophins (NTs in the NT-induced neuronal differentiation of human mesenchymal stem cells (hMSCs. NTs can increase the expression of Wnt1 and Wnt7a in hMSCs. However, only Wnt7a enables the expression of synapsin-1, a synaptic marker in mature neurons, to be induced and triggers the formation of cholinergic and dopaminergic neurons. Human recombinant (hrWnt7a and general neuron makers were positively correlated in a dose- and time-dependent manner. In addition, the expression of synaptic markers and neurites was induced by Wnt7a and lithium, a glycogen synthase kinase-3β inhibitor, in the NT-induced hMSCs via the canonical/β-catenin pathway, but was inhibited by Wnt inhibitors and frizzled-5 (Frz5 blocking antibodies. In addition, hrWnt7a triggered the formation of cholinergic and dopaminergic neurons via the non-canonical/c-jun N-terminal kinase (JNK pathway, and the formation of these neurons was inhibited by a JNK inhibitor and Frz9 blocking antibodies. In conclusion, hrWnt7a enhances the synthesis of synapse and facilitates neuronal differentiation in hMSCS through various Frz receptors. These mechanisms may be employed widely in the transdifferentiation of other adult stem cells.

  2. Curcumin protects neuronal cells against status-epilepticus-induced hippocampal damage through induction of autophagy and inhibition of necroptosis.

    Science.gov (United States)

    Wang, Jin; Liu, Yuan; Li, Xiao-Hui; Zeng, Xiang-Chang; Li, Jian; Zhou, Jun; Xiao, Bo; Hu, Kai

    2017-05-01

    Status epilepticus, the most severe form of epilepsy, is characterized by progressive functional and structural damage in the hippocampus, ultimately leading to the development and clinical appearance of spontaneous, recurrent seizures. Although the pathogenesis underlying epileptogenesis processes remains unclear, a substantial body of evidence has shown that status epilepticus acts as an important initial factor in triggering epileptogenesis. Notably, besides classical cell death mechanisms such as apoptosis and necrosis, 2 novel regulators of cell fate known as necroptosis and autophagy, are demonstrated to be involved in neuronal damage in various neurodegenerative and neuropsychiatric disorders. However, whether necroptosis and autophagy play a role in post-status-epilepticus rat hippocampus and other epilepsy mechanisms deserves further research effort. In addition, research is needed to determine whether compounds from traditional Chinese herbs possess antiepileptic effects through the modulation of necroptosis and autophagy. In this study, we found that curcumin, a polyphenolic phytochemical extracted from the Curcuma longa plant, protects neuronal cells against status-epilepticus-induced hippocampal neuronal damage in the lithium-pilocarpine-induced status epilepticus rat model through induction of autophagy and inhibition of necroptosis.

  3. Effects of 4-phenyl butyric acid on high glucose-induced alterations in dorsal root ganglion neurons.

    Science.gov (United States)

    Sharma, Dilip; Singh, Jitendra Narain; Sharma, Shyam S

    2016-12-02

    Mechanisms and pathways involving in diabetic neuropathy are still not fully understood but can be unified by the process of overproduction of reactive oxygen species (ROS) such as superoxide, endoplasmic reticulum (ER) stress, downstream intracellular signaling pathways and their modulation. Susceptibility of dorsal root ganglion (DRG) to internal/external hyperglycemic environment stress contributes to the pathogenesis and progression of diabetic neuropathy. ER stress leads to abnormal ion channel function, gene expression, transcriptional regulation, metabolism and protein folding. 4-phenyl butyric acid (4-PBA) is a potent and selective chemical chaperone; which may inhibit ER stress. It may be hypothesized that 4-PBA could attenuate via channels in DRG in diabetic neuropathy. Effects of 4-PBA were determined by applying different parameters of oxidative stress, cell viability, apoptosis assays and channel expression in cultured DRG neurons. Hyperglycemia-induced apoptosis in the DRG neuron was inhibited by 4-PBA. Cell viability of DRG neurons was not altered by 4-PBA. Oxidative stress was significantly blocked by the 4-PBA. Sodium channel expression was not altered by the 4-PBA. Our data provide evidence that the hyperglycemia-induced alteration may be reduced by the 4-PBA without altering the sodium channel expression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Fucoxanthin prevents H2O2-induced neuronal apoptosis via concurrently activating the PI3-K/Akt cascade and inhibiting the ERK pathway.

    Science.gov (United States)

    Yu, Jie; Lin, Jia-Jia; Yu, Rui; He, Shan; Wang, Qin-Wen; Cui, Wei; Zhang, Jin-Rong

    2017-01-01

    Background : As a natural carotenoid abundant in chloroplasts of edible brown algae, fucoxanthin possesses various health benefits, including anti-oxidative activity in particular. Objective : In the present study, we studied whether fucoxanthin protected against hydrogen peroxide (H 2 O 2 )-induced neuronal apoptosis. Design : The neuroprotective effects of fucoxanthin on H 2 O 2 -induced toxicity were studied in both SH-SY5Y cells and primary cerebellar granule neurons. Results : Fucoxanthin significantly protected against H 2 O 2 -induced neuronal apoptosis and intracellular reactive oxygen species. H 2 O 2 treatment led to the reduced activity of phosphoinositide 3-kinase (PI3-K)/Akt cascade and the increased activity of extracellular signal-regulated kinase (ERK) pathway in SH-SY5Y cells. Moreover, fucoxanthin significantly restored the altered activities of PI3-K/Akt and ERK pathways induced by H 2 O 2 . Both specific inhibitors of glycogen synthase kinase 3β (GSK3β) and mitogen-activated protein kinase kinase (MEK) significantly protected against H 2 O 2 -induced neuronal death. Furthermore, the neuroprotective effects of fucoxanthin against H 2 O 2 -induced neuronal death were abolished by specific PI3-K inhibitors. Conclusions : Our data strongly revealed that fucoxanthin protected against H 2 O 2 -induced neurotoxicity via concurrently activating the PI3-K/Akt cascade and inhibiting the ERK pathway, providing support for the use of fucoxanthin to treat neurodegenerative disorders induced by oxidative stress.

  5. Protective Actions of 17β-Estradiol and Progesterone on Oxidative Neuronal Injury Induced by Organometallic Compounds

    Directory of Open Access Journals (Sweden)

    Yasuhiro Ishihara

    2015-01-01

    Full Text Available Steroid hormones synthesized in and secreted from peripheral endocrine glands pass through the blood-brain barrier and play a role in the central nervous system. In addition, the brain possesses an inherent endocrine system and synthesizes steroid hormones known as neurosteroids. Increasing evidence shows that neuroactive steroids protect the central nervous system from various harmful stimuli. Reports show that the neuroprotective actions of steroid hormones attenuate oxidative stress. In this review, we summarize the antioxidative effects of neuroactive steroids, especially 17β-estradiol and progesterone, on neuronal injury in the central nervous system under various pathological conditions, and then describe our recent findings concerning the neuroprotective actions of 17β-estradiol and progesterone on oxidative neuronal injury induced by organometallic compounds, tributyltin, and methylmercury.

  6. Selective neuronal differentiation of neural stem cells induced by nanosecond microplasma agitation.

    Science.gov (United States)

    Xiong, Z; Zhao, S; Mao, X; Lu, X; He, G; Yang, G; Chen, M; Ishaq, M; Ostrikov, K

    2014-03-01

    An essential step for therapeutic and research applications of stem cells is their ability to differentiate into specific cell types. Neuronal cells are of great interest for medical treatment of neurodegenerative diseases and traumatic injuries of central nervous system (CNS), but efforts to produce these cells have been met with only modest success. In an attempt of finding new approaches, atmospheric-pressure room-temperature microplasma jets (MPJs) are shown to effectively direct in vitro differentiation of neural stem cells (NSCs) predominantly into neuronal lineage. Murine neural stem cells (C17.2-NSCs) treated with MPJs exhibit rapid proliferation and differentiation with longer neurites and cell bodies eventually forming neuronal networks. MPJs regulate ~75% of NSCs to differentiate into neurons, which is a higher efficiency compared to common protein- and growth factors-based differentiation. NSCs exposure to quantized and transient (~150 ns) micro-plasma bullets up-regulates expression of different cell lineage markers as β-Tubulin III (for neurons) and O4 (for oligodendrocytes), while the expression of GFAP (for astrocytes) remains unchanged, as evidenced by quantitative PCR, immunofluorescence microscopy and Western Blot assay. It is shown that the plasma-increased nitric oxide (NO) production is a factor in the fate choice and differentiation of NSCs followed by axonal growth. The differentiated NSC cells matured and produced mostly cholinergic and motor neuronal progeny. It is also demonstrated that exposure of primary rat NSCs to the microplasma leads to quite similar differentiation effects. This suggests that the observed effect may potentially be generic and applicable to other types of neural progenitor cells. The application of this new in vitro strategy to selectively differentiate NSCs into neurons represents a step towards reproducible and efficient production of the desired NSC derivatives. Published by Elsevier B.V.

  7. Selective neuronal differentiation of neural stem cells induced by nanosecond microplasma agitation

    Directory of Open Access Journals (Sweden)

    Z. Xiong

    2014-03-01

    Full Text Available An essential step for therapeutic and research applications of stem cells is their ability to differentiate into specific cell types. Neuronal cells are of great interest for medical treatment of neurodegenerative diseases and traumatic injuries of central nervous system (CNS, but efforts to produce these cells have been met with only modest success. In an attempt of finding new approaches, atmospheric-pressure room-temperature microplasma jets (MPJs are shown to effectively direct in vitro differentiation of neural stem cells (NSCs predominantly into neuronal lineage. Murine neural stem cells (C17.2-NSCs treated with MPJs exhibit rapid proliferation and differentiation with longer neurites and cell bodies eventually forming neuronal networks. MPJs regulate ~75% of NSCs to differentiate into neurons, which is a higher efficiency compared to common protein- and growth factors-based differentiation. NSCs exposure to quantized and transient (~150 ns micro-plasma bullets up-regulates expression of different cell lineage markers as β-Tubulin III (for neurons and O4 (for oligodendrocytes, while the expression of GFAP (for astrocytes remains unchanged, as evidenced by quantitative PCR, immunofluorescence microscopy and Western Blot assay. It is shown that the plasma-increased nitric oxide (NO production is a factor in the fate choice and differentiation of NSCs followed by axonal growth. The differentiated NSC cells matured and produced mostly cholinergic and motor neuronal progeny. It is also demonstrated that exposure of primary rat NSCs to the microplasma leads to quite similar differentiation effects. This suggests that the observed effect may potentially be generic and applicable to other types of neural progenitor cells. The application of this new in vitro strategy to selectively differentiate NSCs into neurons represents a step towards reproducible and efficient production of the desired NSC derivatives.

  8. 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

  9. Vagus nerve stimulation mitigates intrinsic cardiac neuronal remodeling and cardiac hypertrophy induced by chronic pressure overload in guinea pig

    Science.gov (United States)

    Beaumont, Eric; Wright, Gary L.; Southerland, Elizabeth M.; Li, Ying; Chui, Ray; KenKnight, Bruce H.; Armour, J. Andrew

    2016-01-01

    Our objective was to determine whether chronic vagus nerve stimulation (VNS) mitigates pressure overload (PO)-induced remodeling of the cardioneural interface. Guinea pigs (n = 48) were randomized to right or left cervical vagus (RCV or LCV) implant. After 2 wk, chronic left ventricular PO was induced by partial (15–20%) aortic constriction. Of the 31 animals surviving PO induction, 10 were randomized to RCV VNS, 9 to LCV VNS, and 12 to sham VNS. VNS was delivered at 20 Hz and 1.14 ± 0.03 mA at a 22% duty cycle. VNS commenced 10 days after PO induction and was maintained for 40 days. Time-matched controls (n = 9) were evaluated concurrently. Echocardiograms were obtained before and 50 days after PO. At termination, intracellular current-clamp recordings of intrinsic cardiac (IC) neurons were studied in vitro to determine effects of therapy on soma characteristics. Ventricular cardiomyocyte sizes were assessed with histology along with immunoblot analysis of selected proteins in myocardial tissue extracts. In sham-treated animals, PO increased cardiac output (34%, P < 0.004), as well as systolic (114%, P < 0.04) and diastolic (49%, P < 0.002) left ventricular volumes, a hemodynamic response prevented by VNS. PO-induced enhancements of IC synaptic efficacy and muscarinic sensitivity of IC neurons were mitigated by chronic VNS. Increased myocyte size, which doubled in PO (P < 0.05), was mitigated by RCV. PO hypertrophic myocardium displayed decreased glycogen synthase (GS) protein levels and accumulation of the phosphorylated (inactive) form of GS. These PO-induced changes in GS were moderated by left VNS. Chronic VNS targets IC neurons accompanying PO to obtund associated adverse cardiomyocyte remodeling. PMID:26993230

  10. Effect of environmental enrichment exposure on neuronal morphology of streptozotocin-induced diabetic and stressed rat hippocampus

    Directory of Open Access Journals (Sweden)

    Narendra Pamidi

    2014-08-01

    Full Text Available Background: Environmental enrichment (EE exposure is known to influence the structural changes in the neuronal network of hippocampus. In the present study, we evaluated the effects of EE exposure on the streptozotocin (STZ-induced diabetic and stressed rat hippocampus. Methods: Male albino rats of Wistar strain (4-5 weeks old were grouped into normal control (NC, vehicle control (VC, diabetes (DI, diabetes + stress (DI + S, diabetes + EE (DI + E, and diabetes + stress + EE (DI + S + E groups (n = 8 in each group. Rats were exposed to stress and EE after inducing diabetes with STZ (40 mg/kg. Rats were sacrificed on Day 30 and brain sections were processed for cresyl violet staining to quantify the number of surviving neurons in the CA1, CA3, and dentate hilus (DH regions of hippocampus. Results: A significant (p < 0.001 decrease in the number of survived neurons was noticed in DI (CA1, 34.06 ± 3.2; CA3, 36.1 ± 3.62; DH, 9.83 ± 2.02 as well as DI + S (CA1, 14.03 ± 3.12; CA3, 20.27 ± 4.09; DH, 6.4 ± 1.21 group rats compared to NC rats (CA1, 53.64 ± 2.96; CA3, 62.1 ± 3.34; DH, 21.11 ± 1.03. A significant (p < 0.001 increase in the number of survived neurons was observed in DI + E (CA1, 42.3 ± 3.66; CA3, 46.73 ± 4.74; DH, 17.03 ± 2.19 and DI + S + E (CA1, 29.69 ± 4.47; CA3, 36.73 ± 3.89; DH, 12.23 ± 2.36 group rats compared to DI and DI + S groups, respectively. Conclusions: EE exposure significantly reduced the amount of neuronal damage caused by complications of diabetes and stress to the neurons of hippocampus.

  11. Memory retrieval-induced activation of adult-born neurons generated in response to damage to the dentate gyrus.

    Science.gov (United States)

    Aguilar-Arredondo, Andrea; Zepeda, Angélica

    2018-04-16

    The dentate gyrus (DG) is a neurogenic structure that exhibits functional and structural reorganization after injury. Neurogenesis and functional recovery occur after brain damage, and the possible relation between both processes is a matter of study. We explored whether neurogenesis and the activation of new neurons correlated with DG recovery over time. We induced a DG lesion in young adult rats through the intrahippocampal injection of kainic acid and analyzed functional recovery and the activation of new neurons after animals performed a contextual fear memory task (CFM) or a control spatial exploratory task. We analyzed the number of BrdU+ cells that co-localized with doublecortin (DCX) or with NeuN within the damaged DG and evaluated the number of cells in each population that were labelled with the activity marker c-fos after either task. At 10 days post-lesion (dpl), a region of the granular cell layer was devoid of cells, evidencing the damaged area, whereas at 30 dpl this region was significantly smaller. At 10 dpl, the number of BrdU+/DCX+/c-fos positive cells was increased compared to the sham-lesion group, but CFM was impaired. At 30 dpl, a significantly greater number of BrdU+/NeuN+/c-fos positive cells was observed than at 10 dpl, and activation correlated with CFM recovery. Performance in the spatial exploratory task induced marginal c-fos immunoreactivity in the BrdU+/NeuN+ population. We demonstrate that neurons born after the DG was damaged survive and are activated in a time- and task-dependent manner and that activation of new neurons occurs along functional recovery.

  12. IGF-1-Involved Negative Feedback of NR2B NMDA Subunits Protects Cultured Hippocampal Neurons Against NMDA-Induced Excitotoxicity.

    Science.gov (United States)

    Li, Yun; Sun, Wei; Han, Song; Li, Jianing; Ding, Shu; Wang, Wei; Yin, Yanling

    2017-01-01

    Insulin-like growth factor 1 (IGF-1) is a multifunctional protein involved in neuronal polarity and axonal guidance. In our previous study, it was discovered that IGF-1 alleviated 50-μM NMDA-induced excitotoxicity against neuronal autophagy via depression of NR2B p-Ser1303 activation. However, it was found that NMDA at a higher dose did not cause neuronal autophagy. And, the performance of IGF-1 under severe excitotoxicity still needs to be clarified. In this study, we observed that IGF-1 can salvage the hippocampal neurons in an autophagy-independent manner after 150-μM NMDA exposure using thiazolyl blue tetrazolium bromide (MTT), lactate dehydrogenase (LDH), Western blot assay, and transmission electron microscopy. In addition, over-activation of post-synaptic NMDARs was found with the whole-cell patch clamp recording method. In order to explore whether there is a positive feedback way for post-synaptic NMDARs and the different pathway caused by 150 μM NMDA, the phosphorylation level of Fyn and the phosphorylation site of NR2B were investigated. It was observed that NR2B p-Tyr1472 was increased by the activation of Fyn after 150-μM NMDA exposure. When the neutralizing antibody against NR2B p-Ser1303 was added into the medium, both the activations of Fyn and NR2B p-Tyr1472 were blocked, suggesting NR2B p-Ser1303 may be the initial step of NMDA-induced excitotoxicity. In addition, since IGF-1 can block the initial step of NR2B activation, its effect is concluded to continue with the development of excitotoxicity. Overall, this study strongly indicates that the relationship between different phosphorylation sites of NR2B should be laid more emphasis on, which may be a vital target for the NR2B-involved excitotoxicity.

  13. Methyl Salicylate Lactoside Protects Neurons Ameliorating Cognitive Disorder Through Inhibiting Amyloid Beta-Induced Neuroinflammatory Response in Alzheimer's Disease.

    Science.gov (United States)

    Li, Jinze; Ma, Xiaowei; Wang, Yu; Chen, Chengjuan; Hu, Min; Wang, Linlin; Fu, Junmin; Shi, Gaona; Zhang, Dongming; Zhang, Tiantai

    2018-01-01

    Neuroinflammatory reactions mediated by microglia and astrocytes have been shown to play a key role in early progression of Alzheimer's disease (AD). Increased evidences have demonstrated that neurons exacerbate local inflammatory reactions by producing inflammatory mediators and act as an important participant in the pathogenesis of AD. Methyl salicylate lactoside (MSL) is an isolated natural product that is part of a class of novel non-steroidal anti-inflammatory drugs (NSAID). In our previous studies, we demonstrated that MSL exhibited therapeutic effects on arthritis-induced mice and suppressed the activation of glial cells. In the current study, we investigated the effects of MSL on cognitive function and neuronal protection induced by amyloid-beta peptides (Aβ) and explored potential underlying mechanisms involved. Amyloid precursor protein (APP) and presenilin 1 (PS1) double transgenic mice were used to evaluate the effects of MSL through behavioral testing and neuronal degenerative changes. In addition, copper-injured APP Swedish mutation overexpressing SH-SY5Y cells were used to determine the transduction of cyclooxygenase (COX) and mitogen-activated protein kinase (MAPK) pathways. Our results indicated that at an early stage, MSL treatment ameliorated cognitive impairment and neurodegeneration in APP/PS1 mice. Moreover, in an in vitro AD model, MSL treatment protected injured cells by increasing cell viability, improving mitochondrial dysfunction, and decreasing oxidative damage. In addition, MSL inhibited the phosphorylated level of c-Jun N-terminal kinase (JNK) and p38 MAPK, and suppressed the expression of COX-1/2. As a novel NSAIDs and used for the treatment in early stage of AD, MSL clearly demonstrated cognitive preservation by protecting neurons via a pleiotropic anti-inflammatory effect in the context of AD-associated deficits. Therefore, early treatment of anti-inflammatory therapy may be an effective strategy for treating AD.

  14. Glucose Induces Slow-Wave Sleep by Exciting the Sleep-Promoting Neurons in the Ventrolateral Preoptic Nucleus: A New Link between Sleep and Metabolism.

    Science.gov (United States)

    Varin, Christophe; Rancillac, Armelle; Geoffroy, Hélène; Arthaud, Sébastien; Fort, Patrice; Gallopin, Thierry

    2015-07-08

    Sleep-active neurons located in the ventrolateral preoptic nucleus (VLPO) play a crucial role in the induction and maintenance of slow-wave sleep (SWS). However, the cellular and molecular mechanisms responsible for their activation at sleep onset remain poorly understood. Here, we test the hypothesis that a rise in extracellular glucose concentration in the VLPO can promote sleep by increasing the activity of sleep-promoting VLPO neurons. We find that infusion of a glucose concentration into the VLPO of mice promotes SWS and increases the density of c-Fos-labeled neurons selectively in the VLPO. Moreover, we show in patch-clamp recordings from brain slices that VLPO neurons exhibiting properties of sleep-promoting neurons are selectively excited by glucose within physiological range. This glucose-induced excitation implies the catabolism of glucose, leading to a closure of ATP-sensitive potassium (KATP) channels. The extracellular glucose concentration monitors the gating of KATP channels of sleep-promoting neurons, highlighting that these neurons can adapt their excitability according to the extracellular energy status. Together, these results provide evidence that glucose may participate in the mechanisms of SWS promotion and/or consolidation. Although the brain circuitry underlying vigilance states is well described, the molecular mechanisms responsible for sleep onset remain largely unknown. Combining in vitro and in vivo experiments, we demonstrate that glucose likely contributes to sleep onset facilitation by increasing the excitability of sleep-promoting neurons in the ventrolateral preoptic nucleus (VLPO). We find here that these neurons integrate energetic signals such as ambient glucose directly to regulate vigilance states accordingly. Glucose-induced excitation of sleep-promoting VLPO neurons should therefore be involved in the drowsiness that one feels after a high-sugar meal. This novel mechanism regulating the activity of VLPO neurons reinforces the

  15. The influence of single neuron dynamics and network topology on time delay-induced multiple synchronous behaviors in inhibitory coupled network

    International Nuclear Information System (INIS)

    Zhao, Zhiguo; Gu, Huaguang

    2015-01-01

    Highlights: • Time delay-induced multiple synchronous behaviors was simulated in neuronal networks. • Multiple behaviors appear at time delays shorter than a bursting period of neurons. • The more spikes per burst of bursting, the more synchronous regions of time delay. • From regular to random via small-world networks, synchronous degree becomes weak. • An interpretation of the multiple behaviors and the influence of network are provided. - Abstract: Time delay induced-multiple synchronous behaviors are simulated in neuronal network composed of many inhibitory neurons and appear at different time delays shorter than a period of endogenous bursting of individual neurons. It is different from previous investigations wherein only one of multiple synchronous behaviors appears at time delay shorter than a period of endogenous firing and others appear at time delay longer than the period duration. The bursting patterns of the synchronous behaviors are identified based on the dynamics of an individual neuron stimulated by a signal similar to the inhibitory coupling current, which is applied at the decaying branch of a spike and suitable phase within the quiescent state of the endogenous bursting. If a burst of endogenous bursting contains more spikes, the synchronous behaviors appear at more regions of time delay. As the coupling strength increases, the multiple synchronous behaviors appear in a sequence because the different threshold of coupling current or strength is needed to achieve synchronous behaviors. From regular, to small-world, and to random networks, synchronous degree of the multiple synchronous behaviors becomes weak, and synchronous bursting patterns with lower spikes per burst disappear, which is properly interpreted by the difference of coupling current between neurons induced by different degree and the high threshold of coupling current to achieve synchronization for the absent synchronous bursting patterns. The results of the influence of

  16. Superior Cervical Ganglia Neurons Induce Foxp3+ Regulatory T Cells via Calcitonin Gene-Related Peptide.

    Science.gov (United States)

    Szklany, Kirsten; Ruiter, Evelyn; Mian, Firoz; Kunze, Wolfgang; Bienenstock, John; Forsythe, Paul; Karimi, Khalil

    2016-01-01

    The nervous and immune systems communicate bidirectionally, utilizing diverse molecular signals including cytokines and neurotransmitters to provide an integrated response to changes in the body's internal and external environment. Although, neuro-immune interactions are becoming better understood under inflammatory circumstances and it has been evidenced that interaction between neurons and T cells results in the conversion of encephalitogenic T cells to T regulatory cells, relatively little is known about the communication between neurons and naïve T cells. Here, we demonstrate that following co-culture of naïve CD4+ T cells with superior cervical ganglion neurons, the percentage of Foxp3 expressing CD4+CD25+ cells significantly increased. This was mediated in part by immune-regulatory cytokines TGF-β and IL-10, as well as the neuropeptide calcitonin gene-related peptide while vasoactive intestinal peptide was shown to play no role in generation of T regulatory cells. Additionally, T cells co-cultured with neurons showed a decrease in the levels of pro-inflammatory cytokine IFN-γ released upon in vitro stimulation. These findings suggest that the generation of Tregs may be promoted by naïve CD4+ T cell: neuron interaction through the release of neuropeptide CGRP.

  17. 2-Iminobiotin Superimposed on Hypothermia Protects Human Neuronal Cells from Hypoxia-Induced Cell Damage: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Karina Zitta

    2018-01-01

    Full Text Available Perinatal asphyxia represents one of the major causes of neonatal morbidity and mortality. Hypothermia is currently the only established treatment for hypoxic-ischemic encephalopathy (HIE, but additional pharmacological strategies are being explored to further reduce the damage after perinatal asphyxia. The aim of this study was to evaluate whether 2-iminobiotin (2-IB superimposed on hypothermia has the potential to attenuate hypoxia-induced injury of neuronal cells. In vitro hypoxia was induced for 7 h in neuronal IMR-32 cell cultures. Afterwards, all cultures were subjected to 25 h of hypothermia (33.5°C, and incubated with vehicle or 2-IB (10, 30, 50, 100, and 300 ng/ml. Cell morphology was evaluated by brightfield microscopy. Cell damage was analyzed by LDH assays. Production of reactive oxygen species (ROS was measured using fluorometric assays. Western blotting for PARP, Caspase-3, and the phosphorylated forms of akt and erk1/2 was conducted. To evaluate early apoptotic events and signaling, cell protein was isolated 4 h post-hypoxia and human apoptosis proteome profiler arrays were performed. Twenty-five hour after the hypoxic insult, clear morphological signs of cell damage were visible and significant LDH release as well as ROS production were observed even under hypothermic conditions. Post-hypoxic application of 2-IB (10 and 30 ng/ml reduced the hypoxia-induced LDH release but not ROS production. Phosphorylation of erk1/2 was significantly increased after hypoxia, while phosphorylation of akt, protein expression of Caspase-3 and cleavage of PARP were only slightly increased. Addition of 2-IB did not affect any of the investigated proteins. Apoptosis proteome profiler arrays performed with cellular protein obtained 4 h after hypoxia revealed that post-hypoxic application of 2-IB resulted in a ≥ 25% down regulation of 10/35 apoptosis-related proteins: Bad, Bax, Bcl-2, cleaved Caspase-3, TRAILR1, TRAILR2, PON2, p21, p27, and phospho

  18. Impacts of clustering on noise-induced spiking regularity in the excitatory neuronal networks of subnetworks.

    Science.gov (United States)

    Li, Huiyan; Sun, Xiaojuan; Xiao, Jinghua

    2015-01-01

    In this paper, we investigate how clustering factors influent spiking regularity of the neuronal network of subnetworks. In order to do so, we fix the averaged coupling probability and the averaged coupling strength, and take the cluster number M, the ratio of intra-connection probability and inter-connection probability R, the ratio of intra-coupling strength and inter-coupling strength S as controlled parameters. With the obtained simulation results, we find that spiking regularity of the neuronal networks has little variations with changing of R and S when M is fixed. However, cluster number M could reduce the spiking regularity to low level when the uniform neuronal network's spiking regularity is at high level. Combined the obtained results, we can see that clustering factors have little influences on the spiking regularity when the entire energy is fixed, which could be controlled by the averaged coupling strength and the averaged connection probability.

  19. Effect of morphine-induced antinociception is altered by AF64A-induced lesions on cholinergic neurons in rat nucleus raphe magnus.

    Science.gov (United States)

    Abe, Kenji; Ishida, Kota; Kato, Masatoshi; Shigenaga, Toshiro; Taguchi, Kyoji; Miyatake, Tadashi

    2002-11-01

    To examine the role of cholinergic neurons in the nucleus raphe magnus (NRM) in noxious heat stimulation and in the effects of morphine-induced antinociception by rats. After the cholinergic neuron selective toxin, AF64A, was microinjected into the NRM, we examined changes in the antinociceptive threshold and effects of morphine (5 mg/kg, ip) using the hot-plate (HP) and tail-flick (TF) tests. Systemic administration of morphine inhibited HP and TF responses in control rats. Microinjection of AF64A (2 nmol/site) into the NRM significantly decreased the threshold of HP response after 14 d, whereas the TF response was not affected. Morphine-induced antinociception was significantly attenuated in rats administered AF64A. Extracellular acetylcholine was attenuated after 14 d to below detectable levels in rats given AF64A. Naloxone (1 microg/site) microinjected into control rat NRM also antagonized the antinociceptive effect of systemic morphine. These findings suggest that cholinergic neuron activation in the NRM modulates the antinociceptive effect of morphine simultaneously with the opiate system.

  20. TRPA1 channels: expression in non-neuronal murine lung tissues and dispensability for hyperoxia-induced alveolar epithelial hyperplasia.

    Science.gov (United States)

    Kannler, Martina; Lüling, Robin; Yildirim, Ali Önder; Gudermann, Thomas; Steinritz, Dirk; Dietrich, Alexander

    2018-05-12

    Transient receptor potential A1 (TRPA1) channels were originally characterized in neuronal tissues but also identified in lung epithelium by staining with fluorescently coupled TRPA1 antibodies. Its exact function in non-neuronal tissues, however, is elusive. TRPA1 is activated in vitro by hypoxia and hyperoxia and is therefore a promising TRP candidate for sensing hyperoxia in pulmonary epithelial cells and for inducing alveolar epithelial hyperplasia. Here, we isolated tracheal, bronchial, and alveolar epithelial cells and show low but detectable TRPA1 mRNA levels in all these cells as well as TRPA1 protein by Western blotting in alveolar type II (AT II) cells. We quantified changes in intracellular Ca 2+ ([Ca 2+ ] i ) levels induced by application of hyperoxic solutions in primary tracheal epithelial, bronchial epithelial, and AT II cells isolated from wild-type (WT) and TRPA1-deficient (TRPA1-/-) mouse lungs. In all cell types, we detected hyperoxia-induced rises in [Ca 2+ ] i levels, which were not significantly different in TRPA1-deficient cells compared to WT cells. We also tested TRPA1 function in a mouse model for hyperoxia-induced alveolar epithelial hyperplasia. A characteristic significant increase in thickening of alveolar tissues was detected in mouse lungs after exposure to hyperoxia, but not in normoxic WT and TRPA1-/- controls. Quantification of changes in lung morphology in hyperoxic WT and TRPA1-/- mice, however, again revealed no significant changes. Therefore, TRPA1 expression does neither appear to be a key player for hyperoxia-induced changes in [Ca 2+ ] i levels in primary lung epithelial cells, nor being essential for the development of hyperoxia-induced alveolar epithelial hyperplasia.