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Sample records for cultured hippocampal slices

  1. Ethanol induces MAP2 changes in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Noraberg, J; Zimmer, J

    1998-01-01

    loss of CA3 pyramidal cells and moderate loss of dentate granule cells, as seen in vivo. The results indicate that brain slice cultures combined with immunostaining for cytoskeleton and neuronal markers can be used for studies of ethanol and organic solvent neurotoxicity.......Microtubule-associated protein 2 (MAP2) and neuron-specific protein (NeuN) immunostains were used to demonstrate neurotoxic effects in mature hippocampal slice cultures exposed to ethanol (50, 100, 200 mM) for 4 weeks. At the low dose the density of MAP2 immunostaining in the dentate molecular...... layer was 118% of the control cultures, with no detectable changes in CA1 and CA3. At 100 mM no changes were detected, while 200 mM ethanol significantly reduced the MAP2 density in both dentate (19%) and hippocampal dendritic fields (CA3, 52%; CA1, 55%). At this dose NeuN staining showed considerable...

  2. Trimethyltin (TMT) neurotoxicity in organotypic rat hippocampal slice cultures

    DEFF Research Database (Denmark)

    Noraberg, J; Gramsbergen, J B; Fonnum, F

    1998-01-01

    ) propidium iodide (PI) uptake, (b) lactate dehydrogenase (LDH) efflux into the culture medium, (c) cellular cobalt uptake as an index of calcium influx, (d) ordinary Nissl cell staining, and (e) immunohistochemical staining for microtubule-associated protein 2 (MAP-2). Cellular degeneration as assessed...... to in vivo cell stain observations of rats acutely exposed to TMT. The mean PI uptake of the cultures and the LDH efflux into the medium were highly correlated. The combined results obtained by the different markers indicate that the hippocampal slice culture method is a feasible model for further studies...

  3. Excitatory and inhibitory pathways modulate kainate excitotoxicity in hippocampal slice cultures

    DEFF Research Database (Denmark)

    Casaccia-Bonnefil, P; Benedikz, Eirikur; Rai, R

    1993-01-01

    In organotypic hippocampal slice cultures, kainate (KA) specifically induces cell loss in the CA3 region while N-methyl-D-aspartate induces cell loss in the CA1 region. The sensitivity of slice cultures to KA toxicity appears only after 2 weeks in vitro which parallels the appearance of mossy...... fibers. KA toxicity is potentiated by co-application with the GABA-A antagonist, picrotoxin. These data suggest that the excitotoxicity of KA in slice cultures is modulated by both excitatory and inhibitory synapses....

  4. Organotypic hippocampal slice culture from the adult mouse brain: a versatile tool for translational neuropsychopharmacology.

    Science.gov (United States)

    Kim, Hyunjeong; Kim, Eosu; Park, Minsun; Lee, Eun; Namkoong, Kee

    2013-03-05

    One of the most significant barriers towards translational neuropsychiatry would be an unavailability of living brain tissues. Although organotypic brain tissue culture could be a useful alternative enabling observation of temporal changes induced by various drugs in living brain tissues, a proper method to establish a stable organotypic brain slice culture system using adult (rather than neonatal) hippocampus has been still elusive. In this study, we evaluated our simple method using the serum-free culture medium for successful adult organotypic hippocampal slice culture. Several tens of hippocampal slices from a single adult mouse (3-5 months old) were cultured in serum-free versus serum-containing conventional culture medium for 30 days and underwent various experiments to validate the effects of the existence of serum in the culture medium. Neither the excessive regression of neuronal viability nor metabolic deficiency was observed in the serum-free medium culture in contrast to the serum-containing medium culture. Despite such viability, newly generated immature neurons were scarcely detected in the serum-free culture, suggesting that the original neurons in the brain slice persist rather than being replaced by neurogenesis. Key structural features of in vivo neural tissue constituting astrocytes, neural processes, and pre- and post-synapses were also well preserved in the serum-free culture. In conclusion, using the serum-free culture medium, the adult hippocampal slice culture system will serve as a promising ex vivo tool for various fields of neuroscience, especially for studies on aging-related neuropsychiatric disorders or for high throughput screening of potential agents working against such disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Organotypic hippocampal slice cultures for studies of brain damage, neuroprotection and neurorepair

    DEFF Research Database (Denmark)

    Noraberg, Jens; Poulsen, Frantz Rom; Blaabjerg, Morten

    2005-01-01

    Slices of developing brain tissue can be grown for several weeks as so-called organotypic slice cultures. Here we summarize and review studies using hippocampal slice cultures to investigate mechanisms and treatment strategies for the neurodegenerative disorders like stroke (cerebral ischemia......), Alzheimer's disease (AD) and epilepsia. Studies of non-excitotoxic neurotoxic compounds and the experimental use of slice cultures in studies of HIV neurotoxicity, traumatic brain injury (TBI) and neurogenesis are included. For cerebral ischemia, experimental models with oxygen-glucose deprivation (OGD......) and exposure to glutamate receptor agonists (excitotoxins) are reviewed. For epilepsia, focus is on induction of seizures with effects on neuronal loss, axonal sprouting and neurogenesis. For Alzheimer's disease, the review centers on the use of beta-amyloid (Abeta) in different models, while the section...

  6. GDNF and neublastin protect against NMDA-induced excitotoxicity in hippocampal slice cultures

    DEFF Research Database (Denmark)

    Bonde, C; Kristensen, B W; Blaabjerg, M

    2000-01-01

    -producing HiB5 cells, were added to slice cultures I h before exposure to 10 microM NMDA for 48h. Neuronal cell death was monitored, before and during the NMDA exposure, by densitometric measurements of propidium iodide (PI) uptake and loss of Nissl staining. Both the addition of rhGDNF and NBN......The potential neuroprotective effects of glial cell line-derived neurotrophic factor (GDNF) and neublastin (NBN) against NMDA-induced excitotoxicity were examined in hippocampal brain slice cultures. Recombinant human GDNF (25-100 ng/ ml) or NBN, in medium conditioned by growth of transfected, NBN...

  7. 3-nitropropionic acid neurotoxicity in hippocampal slice cultures

    DEFF Research Database (Denmark)

    Noer, Helle; Kristensen, Bjarne W; Noraberg, Jens

    2002-01-01

    : CA1 > CA3 > fascia dentata. In low glucose much lower concentrations of 3-NP (25 microM) triggered neurotoxicity. One-week-old cultures were less susceptible to 3-NP toxicity than 3-week-old cultures, but the dentate granule cells were relatively more affected in the immature cultures. We found...

  8. Methods to induce primary and secondary traumatic damage in organotypic hippocampal slice cultures.

    Science.gov (United States)

    Adamchik, Y; Frantseva, M V; Weisspapir, M; Carlen, P L; Perez Velazquez, J L

    2000-04-01

    Organotypic brain slice cultures have been used in a variety of studies on neurodegenerative processes [K.M. Abdel-Hamid, M. Tymianski, Mechanisms and effects of intracellular calcium buffering on neuronal survival in organotypic hippocampal cultures exposed to anoxia/aglycemia or to excitotoxins, J. Neurosci. 17, 1997, pp. 3538-3553; D.W. Newell, A. Barth, V. Papermaster, A.T. Malouf, Glutamate and non-glutamate receptor mediated toxicity caused by oxygen and glucose deprivation in organotypic hippocampal cultures, J. Neurosci. 15, 1995, pp. 7702-7711; J.L. Perez Velazquez, M.V. Frantseva, P.L. Carlen, In vitro ischemia promotes glutamate mediated free radical generation and intracellular calcium accumulation in pyramidal neurons of cultured hippocampal slices, J. Neurosci. 23, 1997, pp. 9085-9094; L. Stoppini, L.A. Buchs, D. Muller, A simple method for organotypic cultures of nervous tissue, J. Neurosci. Methods 37, 1991, pp. 173-182; R.C. Tasker, J.T. Coyle, J.J. Vornov, The regional vulnerability to hypoglycemia induced neurotoxicity in organotypic hippocampal culture: protection by early tetrodotoxin or delayed MK 801, J. Neurosci. 12, 1992, pp. 4298-4308.]. We describe two methods to induce traumatic cell damage in hippocampal organotypic cultures. Primary trauma injury was achieved by rolling a stainless steel cylinder (0.9 g) on the organotypic slices. Secondary injury was followed after dropping a weight (0.137 g) on a localised area of the organotypic slice, from a height of 2 mm. The time course and extent of cell death were determined by measuring the fluorescence of the viability indicator propidium iodide (PI) at several time points after the injury. The initial localised impact damage spread 24 and 67 h after injury, cell death being 25% and 54%, respectively, when slices were kept at 37 degrees C. To validate these methods as models to assess neuroprotective strategies, similar insults were applied to slices at relatively low temperatures (30

  9. Hyperexcitability and cell loss in kainate-treated hippocampal slice cultures

    DEFF Research Database (Denmark)

    Benedikz, Eirikur; Casaccia-Bonnefil, P; Stelzer, A

    1993-01-01

    Loss of hippocampal interneurons has been reported in patients with severe temporal lobe epilepsy and in animals treated with kainate. We investigated the relationship between KA induced epileptiform discharge and loss of interneurons in hippocampal slice cultures. Application of KA (1 micro......M) produced reversible epileptiform discharge without neurotoxicity. KA (5 microM), in contrast, produced irreversible epileptiform discharge and neurotoxicity, suggesting that the irreversible epileptiform discharge was required for the neuronal loss. Loss of CA3 pyramidal cells and parvalbumin......-like immunoreactive (PV-I) interneurons preceded loss of somatostatin-like immunoreactive (SS-I) interneurons suggesting a different time course of KA neurotoxicity in these subpopulations of interneurons....

  10. Pilocarpine-induced seizure-like activity with increased BNDF and neuropeptide Y expression in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Poulsen, Frantz Rom; Jahnsen, Henrik; Blaabjerg, Morten

    2002-01-01

    Organotypic hippocampal slice cultures were treated with the muscarinic agonist pilocarpine to study induced seizure-like activity and changes in neurotrophin and neuropeptide expression. For establishment of a seizure-inducing protocol, 2-week-old cultures derived from 6-8-day-old rats were...

  11. The GABAA receptor agonist THIP is neuroprotective in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Kristensen, Bjarne Winther; Noraberg, Jens; Zimmer, Jens

    2003-01-01

    The potential neuroprotective effects of the GABA(A) receptor agonists THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) and muscimol, and the selective GluR5 kainate receptor agonist ATPA ((RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid), which activates GABAergic interneu......The potential neuroprotective effects of the GABA(A) receptor agonists THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) and muscimol, and the selective GluR5 kainate receptor agonist ATPA ((RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid), which activates GABAergic...... interneurons, were examined in hippocampal slice cultures exposed to N-methyl-D-aspartate (NMDA). The NMDA-induced excitotoxicity was quantified by densitometric measurements of propidium iodide (PI) uptake. THIP (100-1000 microM) was neuroprotective in slice cultures co-exposed to NMDA (10 microM) for 48 h......, while muscimol (100-1000 microM) and ATPA (1-3 microM) were without effect. The results demonstrate that direct GABA(A) agonism can mediate neuroprotection in the hippocampus in vitro as previously suggested in vivo....

  12. Biocompatibility of silicon-based arrays of electrodes coupled to organotypic hippocampal brain slice cultures

    DEFF Research Database (Denmark)

    Kristensen, Bjarne Winther; Noraberg, J; Thiébaud, P

    2001-01-01

    by Nissl staining, Timm sulphide silver-staining, microtubule-associated protein 2 (MAP2) and glial fibrillary acidic protein (GFAP) immunostaining, the slice cultures grown on chips did not differ from conventionally grown slice cultures. Neither were there any signs of astrogliosis or neurodegeneration...

  13. Conversion of Synthetic Aβ to In Vivo Active Seeds and Amyloid Plaque Formation in a Hippocampal Slice Culture Model.

    Science.gov (United States)

    Novotny, Renata; Langer, Franziska; Mahler, Jasmin; Skodras, Angelos; Vlachos, Andreas; Wegenast-Braun, Bettina M; Kaeser, Stephan A; Neher, Jonas J; Eisele, Yvonne S; Pietrowski, Marie J; Nilsson, K Peter R; Deller, Thomas; Staufenbiel, Matthias; Heimrich, Bernd; Jucker, Mathias

    2016-05-04

    The aggregation of amyloid-β peptide (Aβ) in brain is an early event and hallmark of Alzheimer's disease (AD). We combined the advantages of in vitro and in vivo approaches to study cerebral β-amyloidosis by establishing a long-term hippocampal slice culture (HSC) model. While no Aβ deposition was noted in untreated HSCs of postnatal Aβ precursor protein transgenic (APP tg) mice, Aβ deposition emerged in HSCs when cultures were treated once with brain extract from aged APP tg mice and the culture medium was continuously supplemented with synthetic Aβ. Seeded Aβ deposition was also observed under the same conditions in HSCs derived from wild-type or App-null mice but in no comparable way when HSCs were fixed before cultivation. Both the nature of the brain extract and the synthetic Aβ species determined the conformational characteristics of HSC Aβ deposition. HSC Aβ deposits induced a microglia response, spine loss, and neuritic dystrophy but no obvious neuron loss. Remarkably, in contrast to in vitro aggregated synthetic Aβ, homogenates of Aβ deposits containing HSCs induced cerebral β-amyloidosis upon intracerebral inoculation into young APP tg mice. Our results demonstrate that a living cellular environment promotes the seeded conversion of synthetic Aβ into a potent in vivo seeding-active form. In this study, we report the seeded induction of Aβ aggregation and deposition in long-term hippocampal slice cultures. Remarkably, we find that the biological activities of the largely synthetic Aβ aggregates in the culture are very similar to those observed in vivo This observation is the first to show that potent in vivo seeding-active Aβ aggregates can be obtained by seeded conversion of synthetic Aβ in a living (wild-type) cellular environment. Copyright © 2016 the authors 0270-6474/16/365084-10$15.00/0.

  14. Local establishment of repetitive long-term potentiation-induced synaptic enhancement in cultured hippocampal slices with divided input pathways.

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    Oe, Yuki; Tominaga-Yoshino, Keiko; Ogura, Akihiko

    2011-09-01

    Long-term potentiation (LTP) in the rodent hippocampus is a popular model for synaptic plasticity, which is considered the cellular basis for brain memory. Because most LTP analysis involves acutely prepared brain slices, however, the longevity of single LTP has not been well documented. Using stable hippocampal slice cultures for long-term examination, we previously found that single LTP disappeared within 1 day. In contrast, repeated induction of LTP led to the development of a distinct type of plasticity that lasted for more than 3 weeks and was accompanied by the formation of new synapses. Naming this novel plastic phenomenon repetitive LTP-induced synaptic enhancement (RISE), we proposed it as a model for the cellular processes involved in long-term memory formation. However, because in those experiments LTP was induced pharmacologically in the whole slice, it is not known whether RISE has input-pathway specificity, an essential property for memory. In this study, we divided the input pathway of CA1 pyramidal neurons by a knife cut and induced LTP three times, the third by tetanic stimulation in one of the divided pathways to express RISE specifically. Voltage-sensitive dye imaging and Golgi-staining performed 2 weeks after the three LTP inductions revealed both enhanced synaptic strength and increased dendritic spine density confined to the tetanized region. These results demonstrate that RISE is a feasible cellular model for long-term memory. Copyright © 2011 Wiley-Liss, Inc.

  15. Oxygen Glucose Deprivation in Rat Hippocampal Slice Cultures Results in Alterations in Carnitine Homeostasis and Mitochondrial Dysfunction

    Science.gov (United States)

    Rau, Thomas F.; Lu, Qing; Sharma, Shruti; Sun, Xutong; Leary, Gregory; Beckman, Matthew L.; Hou, Yali; Wainwright, Mark S.; Kavanaugh, Michael; Poulsen, David J.; Black, Stephen M.

    2012-01-01

    Mitochondrial dysfunction characterized by depolarization of mitochondrial membranes and the initiation of mitochondrial-mediated apoptosis are pathological responses to hypoxia-ischemia (HI) in the neonatal brain. Carnitine metabolism directly supports mitochondrial metabolism by shuttling long chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Our previous studies have shown that HI disrupts carnitine homeostasis in neonatal rats and that L-carnitine can be neuroprotective. Thus, this study was undertaken to elucidate the molecular mechanisms by which HI alters carnitine metabolism and to begin to elucidate the mechanism underlying the neuroprotective effect of L-carnitine (LCAR) supplementation. Utilizing neonatal rat hippocampal slice cultures we found that oxygen glucose deprivation (OGD) decreased the levels of free carnitines (FC) and increased the acylcarnitine (AC): FC ratio. These changes in carnitine homeostasis correlated with decreases in the protein levels of carnitine palmitoyl transferase (CPT) 1 and 2. LCAR supplementation prevented the decrease in CPT1 and CPT2, enhanced both FC and the AC∶FC ratio and increased slice culture metabolic viability, the mitochondrial membrane potential prior to OGD and prevented the subsequent loss of neurons during later stages of reperfusion through a reduction in apoptotic cell death. Finally, we found that LCAR supplementation preserved the structural integrity and synaptic transmission within the hippocampus after OGD. Thus, we conclude that LCAR supplementation preserves the key enzymes responsible for maintaining carnitine homeostasis and preserves both cell viability and synaptic transmission after OGD. PMID:22984394

  16. Trafficking of astrocytic vesicles in hippocampal slices

    International Nuclear Information System (INIS)

    Potokar, Maja; Kreft, Marko; Lee, So-Young; Takano, Hajime; Haydon, Philip G.; Zorec, Robert

    2009-01-01

    The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

  17. Neuroprotective Effects of α-Tocotrienol on Kainic Acid-Induced Neurotoxicity in Organotypic Hippocampal Slice Cultures

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    Bae Hwan Lee

    2013-09-01

    Full Text Available Vitamin E, such as alpha-tocopherol (ATPH and alpha-tocotrienol (ATTN, is a chain-breaking antioxidant that prevents the chain propagation step during lipid peroxidation. In the present study, we investigated the effects of ATTN on KA-induced neuronal death using organotypic hippocampal slice culture (OHSC and compared the neuroprotective effects of ATTN and ATPH. After 15 h KA (5 µM treatment, delayed neuronal death was detected in the CA3 region and reactive oxygen species (ROS formation and lipid peroxidation were also increased. Both co-treatment and post-treatment of ATPH (100 µM or ATTN (100 µM significantly increased the cell survival and reduced the number of TUNEL-positive cells in the CA3 region. Increased dichlorofluorescein (DCF fluorescence and levels of thiobarbiturate reactive substances (TBARS were decreased by ATPH and ATTN treatment. These data suggest that ATPH and ATTN treatment have protective effects on KA-induced cell death in OHSC. ATTN treatment tended to be more effective than ATPH treatment, even though there was no significant difference between ATPH and ATTN in co-treatment or post-treatment.

  18. Neuroprotective effects of the AMPA antagonist PNQX in oxygen-glucose deprivation in mouse hippocampal slice cultures and global cerebral ischemia in gerbils

    DEFF Research Database (Denmark)

    Montero, Maria; Nielsen, Marianne; Rønn, Lars Christian B

    2007-01-01

    PNQX (9-methyl-amino-6-nitro-hexahydro-benzo(F)quinoxalinedione) is a selective AMPA antagonist with demonstrated neuroprotective effects in focal ischemia in rats. Here we report corresponding effects in mouse hippocampal slice cultures subjected to oxygen and glucose deprivation (OGD) and in tr......PNQX (9-methyl-amino-6-nitro-hexahydro-benzo(F)quinoxalinedione) is a selective AMPA antagonist with demonstrated neuroprotective effects in focal ischemia in rats. Here we report corresponding effects in mouse hippocampal slice cultures subjected to oxygen and glucose deprivation (OGD......) and in transient global cerebral ischemia in gerbils. For in vitro studies, hippocampal slice cultures derived from 7-day-old mice and grown for 14 days, were submersed in oxygen-glucose deprived medium for 30 min and exposed to PNQX for 24 h, starting together with OGD, immediately after OGD, or 2 h after OGD...... stained for the neurodegeneration marker Fluoro-Jade B and immunostained for the astroglial marker glial fibrillary acidic protein revealed a significant PNQX-induced decrease in neuronal cell death and astroglial activation. We conclude that, PNQX provided neuroprotection against both global cerebral...

  19. Comparison of excitotoxic profiles of ATPA, AMPA, KA and NMDA in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Kristensen, Bjarne Winther; Noraberg, J; Zimmer, J

    2001-01-01

    ) values was found after 2 days of exposure: AMPA (3.7 mM)>NMDA (11 mM)=KA (13 mM)>ATPA (33 mM). Exposed to 30 microM ATPA, 3 microM AMPA and 10 microM NMDA, CA1 was the most susceptible subfield followed by fascia dentata and CA3. Using 8 microM KA, CA3 was the most susceptible subfield, followed...... by fascia dentata and CA1. In 100 microM concentrations, all four agonists induced the same, maximal PI uptake in all hippocampal subfields, corresponding to total neuronal degeneration. Using glutamate receptor antagonists, like GYKI 52466, NBQX and MK-801, inhibition data revealed that AMPA excitotoxicity...

  20. Palmitoylethanolamide exerts neuroprotective effects in mixed neuroglial cultures and organotypic hippocampal slices via peroxisome proliferator-activated receptor-α

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    Scuderi Caterina

    2012-03-01

    Full Text Available Abstract Background In addition to cytotoxic mechanisms directly impacting neurons, β-amyloid (Aβ-induced glial activation also promotes release of proinflammatory molecules that may self-perpetuate reactive gliosis and damage neighbouring neurons, thus amplifying neuropathological lesions occurring in Alzheimer's disease (AD. Palmitoylethanolamide (PEA has been studied extensively for its anti-inflammatory, analgesic, antiepileptic and neuroprotective effects. PEA is a lipid messenger isolated from mammalian and vegetable tissues that mimics several endocannabinoid-driven actions, even though it does not bind to cannabinoid receptors. Some of its pharmacological properties are considered to be dependent on the expression of peroxisome proliferator-activated receptors-α (PPARα. Findings In the present study, we evaluated the effect of PEA on astrocyte activation and neuronal loss in models of Aβ neurotoxicity. To this purpose, primary rat mixed neuroglial co-cultures and organotypic hippocampal slices were challenged with Aβ1-42 and treated with PEA in the presence or absence of MK886 or GW9662, which are selective PPARα and PPARγ antagonists, respectively. The results indicate that PEA is able to blunt Aβ-induced astrocyte activation and, subsequently, to improve neuronal survival through selective PPARα activation. The data from organotypic cultures confirm that PEA anti-inflammatory properties implicate PPARα mediation and reveal that the reduction of reactive gliosis subsequently induces a marked rebound neuroprotective effect on neurons. Conclusions In line with our previous observations, the results of this study show that PEA treatment results in decreased numbers of infiltrating astrocytes during Aβ challenge, resulting in significant neuroprotection. PEA could thus represent a promising pharmacological tool because it is able to reduce Aβ-evoked neuroinflammation and attenuate its neurodegenerative consequences.

  1. Glutamate receptor antagonists and growth factors modulate dentate granule cell neurogenesis in organotypic, rat hippocampal slice cultures

    DEFF Research Database (Denmark)

    Poulsen, Frantz Rom; Blaabjerg, Morten; Montero, Maria

    2005-01-01

    facing CA1 and the immediate subgranular zone, exposure for 3 days to the NMDA receptor blocking agents MK-801 (10 microM) or APV (25 microM) in the culture medium, increased the number of TOAD-64/Ulip/CRMP-4 (TUC-4)-positive cells as counted in the slice cultures at the end of the 3-day treatment period...

  2. Comparison of neuroprotective effects of erythropoietin (EPO) and carbamylerythropoietin (CEPO) against ischemia-like oxygen-glucose deprivation (OGD) and NMDA excitotoxicity in mouse hippocampal slice cultures

    DEFF Research Database (Denmark)

    Montero, Maria; Rom Poulsen, Frantz; Noraberg, Jens

    2007-01-01

    of hematopoietic bioactivity, is the chemically modified, EPO-derivative carbamylerythropoietin (CEPO). For comparison of the neuroprotective effects of CEPO and EPO, we subjected organotypic hippocampal slice cultures to oxygen-glucose deprivation (OGD) or N-methyl-d-aspartate (NMDA) excitotoxicity. Hippocampal...... slice cultures were pretreated for 24 h with 100 IU/ml EPO (=26 nM) or 26 nM CEPO before OGD or NMDA lesioning. Exposure to EPO and CEPO continued during OGD and for the next 24 h until histology, as well as during the 24 h exposure to NMDA. Neuronal cell death was quantified by cellular uptake...... of propidium iodide (PI), recorded before the start of OGD and NMDA exposure and 24 h after. In cultures exposed to OGD or NMDA, CEPO reduced PI uptake by 49+/-3 or 35+/-8%, respectively, compared to lesion-only controls. EPO reduced PI uptake by 33+/-5 and 15+/-8%, respectively, in the OGD and NMDA exposed...

  3. The developmental expression of fluorescent proteins in organotypic hippocampal slice cultures from transgenic mice and its use in the determination of excitotoxic neurodegeneration

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    Noraberg, Jens; Jensen, Carsten V; Bonde, Christian

    2007-01-01

    Transgenic mice, expressing fluorescent proteins in neurons and glia, provide new opportunities for real-time microscopic monitoring of degenerative and regenerative structural changes. We have previously validated and compared a number of quantifiable markers for neuronal damage and cell death...... changes, as well as the opportunity to monitor reversible changes or long-term effects in the event of minor damage. As a first step, we present: a) the developmental expression in organotypic hippocampal brain slice cultures of transgenic fluorescent proteins, useful for the visualisation of neuronal...... transgenic mouse strains which express fluorescent proteins in their neurons and/or astroglial cells. From the time of explantation, and subsequently for up to nine weeks in culture, the transgenic neuronal fluorescence displayed the expected characteristics of a developmental, in vivo-like increase...

  4. Long-term, repeated dose in vitro neurotoxicity of the glutamate receptor antagonist L-AP3, demonstrated in rat hippocampal slice cultures by using continuous propidium iodide incubation.

    Science.gov (United States)

    Kristensen, Bjarne W; Blaabjerg, Morten; Noraberg, Jens; Zimmer, Jens

    2007-05-01

    Most in vitro models are only used to assess short-term effects of test compounds. However, as demonstrated here, hippocampal slice cultures can be used for long-term studies. The test compound used was the metabotropic glutamate receptor antagonist, L(+)-2-amino-3-phosphonopropionic acid (L-AP3), which is known to be toxic in vivo after subchronic, but not acute, administration. Degenerative effects were monitored by measuring the cellular uptake of propidium iodide (PI; continuously present in the medium) and lactate dehydrogenase (LDH) leakage, and by using a panel of histological stains. Hippocampal slices, derived from 2-3 day old rats and grown for 3 weeks, were subsequently exposed for the next 3 weeks to 0, 10 or 100microM L-AP3, with PI (2microM) in the culture medium. Exposure to 100microM L-AP3 induced severe toxicity after 4-6 days, shown by massive PI uptake, LDH leakage, changes in MAP2 and GFAP immunostaining, and in Nissl and Timm staining. In contrast, 10microM L-AP3 did not induce detectable neuronal degeneration. Treatment with the NMDA receptor antagonist, MK-801, or the AMPA/KA receptor antagonist NBQX, together with 100microM L-AP3, reduced neurodegeneration down to close to control values. It is concluded that continuous incubation of hippocampal slice cultures with PI is technically feasible for use in studies of inducible neuronal degeneration over time.

  5. Characterization of the in vitro propagation of epileptiform electrophysiological activity in organotypic hippocampal slice cultures coupled to 3D microelectrode arrays.

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    Pisciotta, Marzia; Morgavi, Giovanna; Jahnsen, Henrik

    2010-10-28

    Dynamic aspects of the propagation of epileptiform activity have so far received little attention. With the aim of providing new insights about the spatial features of the propagation of epileptic seizures in the nervous system, we studied in vitro the initiation and propagation of traveling epileptiform waves of electrophysiological activity in the hippocampus by means of substrate three-dimensional microelectrode arrays (MEAs) for extracellular measurements. Pharmacologically disinhibited hippocampal slices spontaneously generate epileptiform bursts mostly originating in CA3 and propagating to CA1. Our study specifically addressed the activity-dependent changes of the propagation of traveling electrophysiological waves in organotypic hippocampal slices during epileptiform discharge and in particular our question is: what happens to the epileptic signals during their propagation through the slice? Multichannel data analysis enabled us to quantify an activity-dependent increase in the propagation velocity of spontaneous bursts. Moreover, through the evaluation of the coherence of the signals, it was possible to point out that only the lower-frequency components (propagation of electrophysiological activity becomes ineffective for those firing rates exceeding an upper bound or that some noise of neuronal origin was added to the signal during propagation. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Electrical coupling between hippocampal astrocytes in rat brain slices.

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    Meme, William; Vandecasteele, Marie; Giaume, Christian; Venance, Laurent

    2009-04-01

    Gap junctions in astrocytes play a crucial role in intercellular communication by supporting both biochemical and electrical coupling between adjacent cells. Despite the critical role of electrical coupling in the network organization of these glial cells, the electrophysiological properties of gap junctions have been characterized in cultures while no direct evidence has been sought in situ. In the present study, gap-junctional currents were investigated using simultaneous dual whole-cell patch-clamp recordings between astrocytes from rat hippocampal slices. Bidirectional electrotonic coupling was observed in 82% of the cell pairs with an average coupling coefficient of 5.1%. Double patch-clamp analysis indicated that junctional currents were independent of the transjunctional voltage over a range from -100 to +110 mV. Interestingly, astrocytic electrical coupling displayed weak low-pass filtering properties compared to neuronal electrical synapses. Finally, during uncoupling processes triggered by either the gap-junction inhibitor carbenoxolone or endothelin-1, an increase in the input resistance in the injected cell paralleled the decrease in the coupling coefficient. Altogether, these results demonstrate that hippocampal astrocytes are electrically coupled through gap-junction channels characterized by properties that are distinct from those of electrical synapses between neurons. In addition, gap-junctional communication is efficiently regulated by endogenous compounds. This is taken to represent a mode of communication that may have important implications for the functional role of astrocyte networks in situ.

  7. Central Administration of Lipopolysaccharide Induces Depressive-like Behavior in Vivo and Activates Brain Indoleamine 2,3 Dioxygenase In Murine Organotypic Hippocampal Slice Cultures

    Directory of Open Access Journals (Sweden)

    Kavelaars Annemieke

    2010-08-01

    Full Text Available Abstract Background Transient stimulation of the innate immune system by an intraperitoneal injection of lipopolysaccharide (LPS activates peripheral and central expression of the tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO which mediates depressive-like behavior. It is unknown whether direct activation of the brain with LPS is sufficient to activate IDO and induce depressive-like behavior. Methods Sickness and depressive-like behavior in C57BL/6J mice were assessed by social exploration and the forced swim test, respectively. Expression of cytokines and IDO mRNA was measured by real-time RT-PCR and cytokine protein was measured by enzyme-linked immunosorbent assays (ELISAs. Enzymatic activity of IDO was estimated as the amount of kynurenine produced from tryptophan as determined by high pressure liquid chromatography (HPLC with electrochemical detection. Results Intracerebroventricular (i.c.v. administration of LPS (100 ng increased steady-state transcripts of TNFα, IL-6 and the inducible isoform of nitric oxide synthase (iNOS in the hippocampus in the absence of any change in IFNγ mRNA. LPS also increased IDO expression and induced depressive-like behavior, as measured by increased duration of immobility in the forced swim test. The regulation of IDO expression was investigated using in situ organotypic hippocampal slice cultures (OHSCs derived from brains of newborn C57BL/6J mice. In accordance with the in vivo data, addition of LPS (10 ng/ml to the medium of OHSCs induced steady-state expression of mRNA transcripts for IDO that peaked at 6 h and translated into increased IDO enzymatic activity within 8 h post-LPS. This activation of IDO by direct application of LPS was preceded by synthesis and secretion of TNFα and IL-6 protein and activation of iNOS while IFNγ expression was undetectable. Conclusion These data establish that activation of the innate immune system in the brain is sufficient to activate IDO and induce

  8. Characterization of the in vitro propagation of epileptiform electrophysiological activity in organotypic hippocampal slice cultures coupled to 3D microelectrode arrays

    DEFF Research Database (Denmark)

    Pisciotta, Marzia; Morgavi, Giovanna; Jahnsen, Henrik

    2010-01-01

    Dynamic aspects of the propagation of epileptiform activity have so far received little attention. With the aim of providing new insights about the spatial features of the propagation of epileptic seizures in the nervous system, we studied in vitro the initiation and propagation of traveling...... activity are completely coherent with respect to the activity originating in the CA3, while components at higher frequencies lose the coherence, possibly suggesting that the cellular mechanism mediating propagation of electrophysiological activity becomes ineffective for those firing rates exceeding...... epileptiform waves of electrophysiological activity in the hippocampus by means of substrate three-dimensional microelectrode arrays (MEAs) for extracellular measurements. Pharmacologically disinhibited hippocampal slices spontaneously generate epileptiform bursts mostly originating in CA3 and propagating...

  9. Adaptation of Microplate-based Respirometry for Hippocampal Slices and Analysis of Respiratory Capacity

    Science.gov (United States)

    Schuh, Rosemary A.; Clerc, Pascaline; Hwang, Hyehyun; Mehrabian, Zara; Bittman, Kevin; Chen, Hegang; Polster, Brian M.

    2011-01-01

    Multiple neurodegenerative disorders are associated with altered mitochondrial bioenergetics. Although mitochondrial O2 consumption is frequently measured in isolated mitochondria, isolated synaptic nerve terminals (synaptosomes), or cultured cells, the absence of mature brain circuitry is a remaining limitation. Here we describe the development of a method that adapts the Seahorse Extracellular Flux Analyzer (XF24) for the microplate-based measurement of hippocampal slice O2 consumption. As a first evaluation of the technique, we compared whole slice bioenergetics to previous measurements made with synaptosomes or cultured neurons. We found that mitochondrial respiratory capacity and O2 consumption coupled to ATP synthesis could be estimated in cultured or acute hippocampal slices with preserved neural architecture. Mouse organotypic hippocampal slices oxidizing glucose displayed mitochondrial O2 consumption that was well-coupled, as determined by the sensitivity to the ATP synthase inhibitor oligomycin. However stimulation of respiration by uncoupler was modest (<120% of basal respiration) compared to previous measurements in cells or synaptosomes, although enhanced slightly (to ~150% of basal respiration) by the acute addition of the mitochondrial complex I-linked substrate pyruvate. These findings suggest a high basal utilization of respiratory capacity in slices and a limitation of glucose-derived substrate for maximal respiration. The improved throughput of microplate-based hippocampal respirometry over traditional O2 electrode-based methods is conducive to neuroprotective drug screening. When coupled with cell type-specific pharmacology or genetic manipulations, the ability to efficiently measure O2 consumption from whole slices should advance our understanding of mitochondrial roles in physiology and neuropathology. PMID:21520220

  10. Stimulation of estradiol biosynthesis by tributyltin in rat hippocampal slices.

    Science.gov (United States)

    Munetsuna, Eiji; Hattori, Minoru; Yamazaki, Takeshi

    2014-01-01

    Hippocampal functions are influenced by steroid hormones, such as testosterone and estradiol. It has been demonstrated that hippocampus-derived steroid hormones play important roles in neuronal protection and synapse formation. Our research groups have demonstrated that estradiol is de novo synthesized in the rat hippocampus. However, the mechanism(s) regulating this synthesis remains unclear. It has been reported that tributyltin, an environmental pollutant, binds to the retinoid X receptor (RXR) and modifies estrogen synthesis in human granulosa-like tumor cells. This compound can penetrate the blood brain barrier, and tends to accumulate in the brain. Based on these facts, we hypothesized that tributyltin could influence the hippocampal estradiol synthesis. A concentration of 0.1 μM tributyltin induced an increase in the mRNA content of P450(17α) and P450arom in hippocampal slices, as determined using real-time PCR. The transcript levels of other steroidogenic enzymes and a steroidogenic acute regulatory protein were not affected. The estradiol level in rat hippocampal slices was subsequently determined using a radioimmunoassay. We found that the estradiol synthesis was stimulated by ∼2-fold following a 48-h treatment with 0.1 μM tributyltin, and this was accompanied by transcriptional activation of P450(17α) and P450arom. Tributyltin stimulated de novo hippocampal estradiol synthesis by modifying the transcription of specific steroidogenic enzymes.

  11. Rosiglitazone Suppresses In Vitro Seizures in Hippocampal Slice by Inhibiting Presynaptic Glutamate Release in a Model of Temporal Lobe Epilepsy.

    Directory of Open Access Journals (Sweden)

    Shi-Bing Wong

    Full Text Available Peroxisomal proliferator-activated receptor gamma (PPARγ is a nuclear hormone receptor whose agonist, rosiglitazone has a neuroprotective effect to hippocampal neurons in pilocarpine-induced seizures. Hippocampal slice preparations treated in Mg2+ free medium can induce ictal and interictal-like epileptiform discharges, which is regarded as an in vitro model of N-methyl-D-aspartate (NMDA receptor-mediated temporal lobe epilepsy (TLE. We applied rosiglitazone in hippocampal slices treated in Mg2+ free medium. The effects of rosiglitazone on hippocampal CA1-Schaffer collateral synaptic transmission were tested. We also examined the neuroprotective effect of rosiglitazone toward NMDA excitotoxicity on cultured hippocampal slices. Application of 10 μM rosiglitazone significantly suppressed amplitude and frequency of epileptiform discharges in CA1 neurons. Pretreatment with the PPARγ antagonist GW9662 did not block the effect of rosiglitazone on suppressing discharge frequency, but reverse the effect on suppressing discharge amplitude. Application of rosiglitazone suppressed synaptic transmission in the CA1-Schaffer collateral pathway. By miniature excitatory-potential synaptic current (mEPSC analysis, rosiglitazone significantly suppressed presynaptic neurotransmitter release. This phenomenon can be reversed by pretreating PPARγ antagonist GW9662. Also, rosiglitazone protected cultured hippocampal slices from NMDA-induced excitotoxicity. The protective effect of 10 μM rosiglitazone was partially antagonized by concomitant high dose GW9662 treatment, indicating that this effect is partially mediated by PPARγ receptors. In conclusion, rosiglitazone suppressed NMDA receptor-mediated epileptiform discharges by inhibition of presynaptic neurotransmitter release. Rosiglitazone protected hippocampal slice from NMDA excitotoxicity partially by PPARγ activation. We suggest that rosiglitazone could be a potential agent to treat patients with TLE.

  12. Long-term, repeated dose in vitro neurotoxicity of the glutamate receptor antagonist L-AP3, demonstrated in rat hippocampal slice cultures by using continuous propidium iodide incubation

    DEFF Research Database (Denmark)

    Kristensen, Bjarne W; Blaabjerg, Morten; Noraberg, Jens

    2007-01-01

    ), which is known to be toxic in vivo after subchronic, but not acute, administration. Degenerative effects were monitored by measuring the cellular uptake of propidium iodide (PI; continuously present in the medium) and lactate dehydrogenase (LDH) leakage, and by using a panel of histological stains....... Hippocampal slices, derived from 2-3 day old rats and grown for 3 weeks, were subsequently exposed for the next 3 weeks to 0, 10 or 100microM L-AP3, with PI (2microM) in the culture medium. Exposure to 100microM L-AP3 induced severe toxicity after 4-6 days, shown by massive PI uptake, LDH leakage, changes...... in MAP2 and GFAP immunostaining, and in Nissl and Timm staining. In contrast, 10microM L-AP3 did not induce detectable neuronal degeneration. Treatment with the NMDA receptor antagonist, MK-801, or the AMPA/KA receptor antagonist NBQX, together with 100microM L-AP3, reduced neurodegeneration down...

  13. Fluidic system for long-term in vitro culturing and monitoring of organotypic brain slices

    DEFF Research Database (Denmark)

    Bakmand, Tanya; Troels-Smith, Ane R.; Dimaki, Maria

    2015-01-01

    Brain slice preparations cultured in vitro have long been used as a simplified model for studying brain development, electrophysiology, neurodegeneration and neuroprotection. In this paper an open fluidic system developed for improved long term culturing of organotypic brain slices is presented....... The positive effect of continuous flow of growth medium, and thus stability of the glucose concentration and waste removal, is simulated and compared to the effect of stagnant medium that is most often used in tissue culturing. Furthermore, placement of the tissue slices in the developed device was studied...... by numerical simulations in order to optimize the nutrient distribution. The device was tested by culturing transverse hippocampal slices from 7 days old NMRI mice for a duration of 14 days. The slices were inspected visually and the slices cultured in the fluidic system appeared to have preserved...

  14. Microfluidic culture chamber for the long-term perfusion and precise chemical stimulation of organotypic brain tissue slices

    DEFF Research Database (Denmark)

    Caicedo, H. H.; Vignes, M.; Brugg, B.

    2010-01-01

    We have developed a microfluidic perfusion-based culture system to study long-term in-vitro responses of organo-typic brain slices exposed to localized neurochemical stimulation. Using this microperfusion chamber we show that hip-pocampal organotypic brain slices cultures grown on nitrocellulose ...

  15. The metabotropic glutamate receptor agonist 1S,3R-ACPD stimulates and modulates NMDA receptor mediated excitotoxicity in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Blaabjerg, M; Kristensen, Bjarne Winther; Bonde, C

    2001-01-01

    the PI uptake in both CA1 and CA3, compared to cultures exposed to 10 microM NMDA only. Adding the 300 microM ACPD as pretreatment for 30 min followed by a 30 min wash in normal medium before the ACPD/NMDA co-exposure, eliminated the potentiation of NMDA toxicity. The potentiation was also blocked...

  16. Modulator effects of interleukin-1beta and tumor necrosis factor-alpha on AMPA-induced excitotoxicity in mouse organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Bernardino, Liliana; Xapelli, Sara; Silva, Ana P

    2005-01-01

    The inflammatory cytokines interleukin-1beta and tumor necrosis factor-alpha (TNF-alpha) have been identified as mediators of several forms of neurodegeneration in the brain. However, they can produce either deleterious or beneficial effects on neuronal function. We investigated the effects...... of mouse recombinant TNF-alpha (10 ng/ml) enhanced excitotoxicity when the cultures were simultaneously exposed to AMPA and to this cytokine. Decreasing the concentration of TNF-alpha to 1 ng/ml resulted in neuroprotection against AMPA-induced neuronal death independently on the application protocol....... By using TNF-alpha receptor (TNFR) knock-out mice, we demonstrated that the potentiation of AMPA-induced toxicity by TNF-alpha involves TNF receptor-1, whereas the neuroprotective effect is mediated by TNF receptor-2. AMPA exposure was associated with activation and proliferation of microglia as assessed...

  17. Alkaloid fraction of Uncaria rhynchophylla protects against N-methyl-D-aspartate-induced apoptosis in rat hippocampal slices.

    Science.gov (United States)

    Lee, Jongseok; Son, Dongwook; Lee, Pyeongjae; Kim, Sun-Yeou; Kim, Hocheol; Kim, Chang-Ju; Lim, Eunhee

    2003-09-04

    Uncaria rhynchophylla is a medicinal herb which has sedative and anticonvulsive effects and has been applied in the treatment of epilepsy in Oriental medicine. In this study, the effect of alkaloid fraction of U. rhynchophylla against N-methyl-D-aspartate (NMDA)-induced neuronal cell death was investigated. Pretreatment with an alkaloid fraction of U. rhynchophylla for 1 h decreased the degree of neuronal damage induced by NMDA exposure in cultured hippocampal slices and also inhibited NMDA-induced enhanced expressions of apoptosis-related genes such as c-jun, p53, and bax. In the present study, the alkaloid fraction of U. rhynchophylla was shown to have a protective property against NMDA-induced cytotoxicity by suppressing the NMDA-induced apoptosis in rat hippocampal slices.

  18. Multiple single-unit long-term tracking on organotypic hippocampal slices using high-density microelectrode arrays

    Directory of Open Access Journals (Sweden)

    Wei Gong

    2016-11-01

    Full Text Available A novel system to cultivate and record from organotypic brain slices directly on high-density microelectrode arrays (HD-MEA was developed. This system allows for continuous recording of electrical activity of specific individual neurons at high spatial resolution while monitoring at the same time, neuronal network activity. For the first time, the electrical activity patterns of single neurons and the corresponding neuronal network in an organotypic hippocampal slice culture were studied during several consecutive weeks at daily intervals. An unsupervised iterative spike-sorting algorithm, based on PCA and k-means clustering, was developed to assign the activities to the single units. Spike-triggered average extracellular waveforms of an action potential recorded across neighboring electrodes, termed ‘footprints’ of single-units were generated and tracked over weeks. The developed system offers the potential to study chronic impacts of drugs or genetic modifications on individual neurons in slice preparations over extended times.

  19. Prolonged life of human acute hippocampal slices from temporal lobe epilepsy surgery

    DEFF Research Database (Denmark)

    Wickham, J; Brödjegård, N G; Vighagen, R

    2018-01-01

    Resected hippocampal tissue from patients with drug-resistant epilepsy presents a unique possibility to test novel treatment strategies directly in target tissue. The post-resection time for testing and analysis however is normally limited. Acute tissue slices allow for electrophysiological...... granule whole-cell recordings, can be consistently induced in these slices, underlying the usefulness of this methodology for testing and/or validating novel treatment strategies for epilepsy....

  20. Atorvastatin and Fluoxetine Prevent Oxidative Stress and Mitochondrial Dysfunction Evoked by Glutamate Toxicity in Hippocampal Slices.

    Science.gov (United States)

    Ludka, Fabiana K; Dal-Cim, Tharine; Binder, Luisa Bandeira; Constantino, Leandra Celso; Massari, Caio; Tasca, Carla I

    2017-07-01

    Atorvastatin has been shown to exert a neuroprotective action by counteracting glutamatergic toxicity. Recently, we have shown atorvastatin also exerts an antidepressant-like effect that depends on both glutamatergic and serotonergic systems modulation. Excitotoxicity is involved in several brain disorders including depression; thus, it is suggested that antidepressants may target glutamatergic system as a final common pathway. In this study, a comparison of the mechanisms involved in the putative neuroprotective effect of a repetitive atorvastatin or fluoxetine treatment against glutamate toxicity in hippocampal slices was performed. Adult Swiss mice were treated with atorvastatin (10 mg/kg, p.o.) or fluoxetine (10 mg/kg, p.o.), once a day during seven consecutive days. On the eighth day, animals were killed and hippocampal slices were obtained and subjected to an in vitro protocol of glutamate toxicity. An acute treatment of atorvastatin or fluoxetine was not neuroprotective; however, the repeated atorvastatin or fluoxetine treatment prevented the decrease in cellular viability induced by glutamate in hippocampal slices. The loss of cellular viability induced by glutamate was accompanied by increased D-aspartate release, increased reactive oxygen species (ROS) and nitric oxide (NO) production, and impaired mitochondrial membrane potential. Atorvastatin or fluoxetine repeated treatment also presented an antidepressant-like effect in the tail suspension test. Atorvastatin or fluoxetine treatment was effective in protecting mice hippocampal slices from glutamate toxicity by preventing the oxidative stress and mitochondrial dysfunction.

  1. Endogenous 24S-hydroxycholesterol modulates NMDAR-mediated function in hippocampal slices.

    Science.gov (United States)

    Sun, Min-Yu; Izumi, Yukitoshi; Benz, Ann; Zorumski, Charles F; Mennerick, Steven

    2016-03-01

    N-methyl-D-aspartate receptors (NMDARs), a major subtype of glutamate receptors mediating excitatory transmission throughout the central nervous system (CNS), play critical roles in governing brain function and cognition. Because NMDAR dysfunction contributes to the etiology of neurological and psychiatric disorders including stroke and schizophrenia, NMDAR modulators are potential drug candidates. Our group recently demonstrated that the major brain cholesterol metabolite, 24S-hydroxycholesterol (24S-HC), positively modulates NMDARs when exogenously administered. Here, we studied whether endogenous 24S-HC regulates NMDAR activity in hippocampal slices. In CYP46A1(-/-) (knockout; KO) slices where endogenous 24S-HC is greatly reduced, NMDAR tone, measured as NMDAR-to-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) excitatory postsynaptic current (EPSC) ratio, was reduced. This difference translated into more NMDAR-driven spiking in wild-type (WT) slices compared with KO slices. Application of SGE-301, a 24S-HC analog, had comparable potentiating effects on NMDAR EPSCs in both WT and KO slices, suggesting that endogenous 24S-HC does not saturate its NMDAR modulatory site in ex vivo slices. KO slices did not differ from WT slices in either spontaneous neurotransmission or in neuronal intrinsic excitability, and exhibited LTP indistinguishable from WT slices. However, KO slices exhibited higher resistance to persistent NMDAR-dependent depression of synaptic transmission induced by oxygen-glucose deprivation (OGD), an effect restored by SGE-301. Together, our results suggest that loss of positive NMDAR tone does not elicit compensatory changes in excitability or transmission, but it protects transmission against NMDAR-mediated dysfunction. We expect that manipulating this endogenous NMDAR modulator may offer new treatment strategies for neuropsychiatric dysfunction. Copyright © 2016 the American Physiological Society.

  2. Tumor Slice Culture: A New Avatar in Personalized Oncology

    Science.gov (United States)

    2017-09-01

    AWARD NUMBER: W81XWH-16-1-0149 TITLE: Tumor Slice Culture: A New Avatar in Personalized Oncology PRINCIPAL INVESTIGATOR: Raymond Yeung...CONTRACT NUMBER Tumor Slice Culture: A New Avatar in Personalized Oncology 5b. GRANT NUMBER W81XWH-16-1-0149 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...10 Annual Report 2017: Tumor Slice Culture: A new avatar for personalized oncology 1. INTRODUCTION: The goal of this research is to advance our

  3. Parkia biglobosa Improves Mitochondrial Functioning and Protects against Neurotoxic Agents in Rat Brain Hippocampal Slices

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    Kayode Komolafe

    2014-01-01

    Full Text Available Objective. Methanolic leaf extracts of Parkia biglobosa, PBE, and one of its major polyphenolic constituents, catechin, were investigated for their protective effects against neurotoxicity induced by different agents on rat brain hippocampal slices and isolated mitochondria. Methods. Hippocampal slices were preincubated with PBE (25, 50, 100, or 200 µg/mL or catechin (1, 5, or 10 µg/mL for 30 min followed by further incubation with 300 µM H2O2, 300 µM SNP, or 200 µM PbCl2 for 1 h. Effects of PBE and catechin on SNP- or CaCl2-induced brain mitochondrial ROS formation and mitochondrial membrane potential (ΔΨm were also determined. Results. PBE and catechin decreased basal ROS generation in slices and blunted the prooxidant effects of neurotoxicants on membrane lipid peroxidation and nonprotein thiol contents. PBE rescued hippocampal cellular viability from SNP damage and caused a significant boost in hippocampus Na+, K+-ATPase activity but with no effect on the acetylcholinesterase activity. Both PBE and catechin also mitigated SNP- or CaCl2-dependent mitochondrial ROS generation. Measurement by safranine fluorescence however showed that the mild depolarization of the ΔΨm by PBE was independent of catechin. Conclusion. The results suggest that the neuroprotective effect of PBE is dependent on its constituent antioxidants and mild mitochondrial depolarization propensity.

  4. Effects of metal ions on agonist-stimulated accumulation of inositol phosphates in hippocampal and cortical slices

    International Nuclear Information System (INIS)

    Bonner, M.J.; Tilson, H.A.

    1990-01-01

    [ 3 H]-inositol was incorporated into rat hippocampal or cortical slices. Zinc chloride and three different forms of inorganic lead compounds, lead chloride, lead nitrate, and lead acetate were used to stimulate PI metabolism at concentrations between 10 -15 and 10 -9 M. At these concentrations, these metal ions did not produce any significant stimulation of IP release. In birth hippocampal and cortical slices, carbachol produced equal levels of IP release. Norepinephrine (NE) produced a 10-15% higher stimulation than carbachol. When the metal ions were added to hippocampal slices together with the agonists, there was a general suppression of carbachol- or NE-induced IP release. This general suppression was not observed in cortical slices. These data suggest that the trace metals used inhibit agonist-induced second messenger release in the hippocampus

  5. Long-term potentiation protects rat hippocampal slices from the effects of acute hypoxia.

    Science.gov (United States)

    Youssef, F F; Addae, J I; McRae, A; Stone, T W

    2001-07-13

    We have previously shown that long-term potentiation (LTP) decreases the sensitivity of glutamate receptors in the rat hippocampal CA1 region to exogenously applied glutamate agonists. Since the pathophysiology of hypoxia/ischemia involves increased concentration of endogenous glutamate, we tested the hypothesis that LTP could reduce the effects of hypoxia in the hippocampal slice. The effects of LTP on hypoxia were measured by the changes in population spike potentials (PS) or field excitatory post-synaptic potentials (fepsps). Hypoxia was induced by perfusing the slice with (i) artificial CSF which had been pre-gassed with 95%N2/5% CO2; (ii) artificial CSF which had not been pre-gassed with 95% O2/5% CO2; or (iii) an oxygen-glucose deprived (OGD) medium which was similar to (ii) and in which the glucose had been replaced with sucrose. Exposure of a slice to a hypoxic medium for 1.5-3.0 min led to a decrease in the PS or fepsps; the potentials recovered to control levels within 3-5 min. Repeat exposure, 45 min later, of the same slice to the same hypoxic medium for the same duration as the first exposure caused a reduction in the potentials again; there were no significant differences between the degree of reduction caused by the first or second exposure for all three types of hypoxic media (P>0.05; paired t-test). In some of the slices, two episodes of LTP were induced 25 and 35 min after the first hypoxic exposure; this caused inhibition of reduction in potentials caused by the second hypoxic insult which was given at 45 min after the first; the differences in reduction in potentials were highly significant for all the hypoxic media used (Peffects of LTP were not prevented by cyclothiazide or inhibitors of NO synthetase compounds that have been shown to be effective in blocking the effects of LTP on the actions of exogenously applied AMPA and NMDA, respectively. The neuroprotective effects of LTP were similar to those of propentofylline, a known neuroprotective

  6. Long-lasting desynchronization in rat hippocampal slice induced by coordinated reset stimulation

    International Nuclear Information System (INIS)

    Tass, P. A.; Barnikol, U. B.; Silchenko, A. N.; Hauptmann, C.; Speckmann, E.-J.

    2009-01-01

    In computational models it has been shown that appropriate stimulation protocols may reshape the connectivity pattern of neural or oscillator networks with synaptic plasticity in a way that the network learns or unlearns strong synchronization. The underlying mechanism is that a network is shifted from one attractor to another, so that long-lasting stimulation effects are caused which persist after the cessation of stimulation. Here we study long-lasting effects of multisite electrical stimulation in a rat hippocampal slice rendered epileptic by magnesium withdrawal. We show that desynchronizing coordinated reset stimulation causes a long-lasting desynchronization between hippocampal neuronal populations together with a widespread decrease in the amplitude of the epileptiform activity. In contrast, periodic stimulation induces a long-lasting increase in both synchronization and amplitude.

  7. Metabolic therapy for temporal lobe epilepsy in a dish: investigating mechanisms of ketogenic diet using electrophysiological recordings in hippocampal slices

    Directory of Open Access Journals (Sweden)

    Masahito Kawamura

    2016-11-01

    Full Text Available The hippocampus is prone to epileptic seizures and is a key brain region and experimental platform for investigating mechanisms associated with the abnormal neuronal excitability that characterizes a seizure. Accordingly, the hippocampal slice is a common in vitro model to study treatments that may prevent or reduce seizure activity. The ketogenic diet is a metabolic therapy used to treat epilepsy in adults and children for nearly 100 years; it can reduce or eliminate even severe or refractory seizures. New insights into its underlying mechanisms have been revealed by diverse types of electrophysiological recordings in hippocampal slices. Here we review these reports and their relevant mechanistic findings. We acknowledge that a major difficulty in using hippocampal slices is the inability to reproduce precisely the in vivo condition of ketogenic diet feeding in any in vitro preparation, and progress has been made in this in vivo/in vitro transition. Thus far at least three different approaches are reported to reproduce relevant diet effects in the hippocampal slices: (1 direct application of ketone bodies, (2 mimicking the ketogenic diet condition during a whole-cell patch-clamp technique, and (3 reduced glucose incubation of hippocampal slices from ketogenic diet–fed animals. Significant results have been found with each of these methods and provide options for further study into short- and long-term mechanisms including ATP-sensitive potassium channels, vesicular glutamate transporter, pannexin channels and adenosine receptors underlying ketogenic diet and other forms of metabolic therapy.

  8. Metabolic Therapy for Temporal Lobe Epilepsy in a Dish: Investigating Mechanisms of Ketogenic Diet using Electrophysiological Recordings in Hippocampal Slices

    Science.gov (United States)

    Kawamura, Masahito Jr.; Ruskin, David N.; Masino, Susan A.

    2016-01-01

    The hippocampus is prone to epileptic seizures and is a key brain region and experimental platform for investigating mechanisms associated with the abnormal neuronal excitability that characterizes a seizure. Accordingly, the hippocampal slice is a common in vitro model to study treatments that may prevent or reduce seizure activity. The ketogenic diet is a metabolic therapy used to treat epilepsy in adults and children for nearly 100 years; it can reduce or eliminate even severe or refractory seizures. New insights into its underlying mechanisms have been revealed by diverse types of electrophysiological recordings in hippocampal slices. Here we review these reports and their relevant mechanistic findings. We acknowledge that a major difficulty in using hippocampal slices is the inability to reproduce precisely the in vivo condition of ketogenic diet feeding in any in vitro preparation, and progress has been made in this in vivo/in vitro transition. Thus far at least three different approaches are reported to reproduce relevant diet effects in the hippocampal slices: (1) direct application of ketone bodies; (2) mimicking the ketogenic diet condition during a whole-cell patch-clamp technique; and (3) reduced glucose incubation of hippocampal slices from ketogenic diet–fed animals. Significant results have been found with each of these methods and provide options for further study into short- and long-term mechanisms including Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels, vesicular glutamate transporter (VGLUT), pannexin channels and adenosine receptors underlying ketogenic diet and other forms of metabolic therapy. PMID:27847463

  9. Muscarinic agonists and phorbol esters increase tyrosine phosphorylation of a 40-kilodalton protein in hippocampal slices

    International Nuclear Information System (INIS)

    Stratton, K.R.; Worley, P.F.; Huganir, R.L.; Baraban, J.M.

    1989-01-01

    The authors have used the hippocampal slice preparation to investigate the regulation of protein tyrosine phosphorylation in brain. After pharmacological treatment of intact slices, proteins were separated by electrophoresis, and levels of protein tyrosine phosphorylation were assessed by immunoblotting with specific anti-phosphotyrosine antibodies. Phorbol esters, activators of the serine- and threonine-phosphorylating enzyme protein kinase C, selectively increase tyrosine phosphorylation of a soluble protein with an apparent molecular mass of approximately 40 kilodaltons. Muscarinic agonists such as carbachol and oxotremorine M that strongly activate the inositol phospholipid system also increase tyrosine phosphorylation of this protein. Neurotransmitter activation of the inositol phospholipid system and protein kinase C appears to trigger a cascade leading to increased tyrosine phosphorylation

  10. Age-dependent changes of presynaptic neuromodulation via A1-adenosine receptors in rat hippocampal slices.

    Science.gov (United States)

    Sperlágh, B; Zsilla, G; Baranyi, M; Kékes-Szabó, A; Vizi, E S

    1997-10-01

    The presynaptic neuromodulation of stimulation-evoked release of [3H]-acetylcholine by endogenous adenosine, via A1-adenosine receptors, was studied in superfused hippocampal slices taken from 4-, 12- and 24-month-old rats. 8-Cyclopentyl-1,3-dimethylxanthine (0.25 microM), a selective A1-receptor antagonist, increased significantly the electrical field stimulation-induced release of [3H]-acetylcholine in slices prepared from 4- and 12-month-old rats, showing a tonic inhibitory action of endogenous adenosine via stimulation of presynaptic A1-adenosine receptors. In contrast, 8-cyclopentyl-1,3-dimethylxanthine had no effect in 24-month-old rats. 2-Chloroadenosine (10 microM), an adenosine receptor agonist decreased the release of [3H]-acetylcholine in slices taken from 4- and 12-month-old rats, and no significant change was observed in slices taken from 24-month-old rats. In order to show whether the number/or affinity of the A1-receptors was affected in aged rats, [3H]-8-cyclopentyl-1,3-dimethylxanthine binding was studied in hippocampal membranes prepared from rats of different ages. Whereas the Bmax value was significantly lower in 2-year-old rats than in younger counterparts, the dissociation constant (Kd) was not affected by aging, indicating that the density rather than the affinity of adenosine receptors was altered. Endogenous adenosine levels present in the extracellular space were also measured in the superfusate by high performance liquid chromatography (HPLC) coupled with ultraviolet detection, and an age-related increase in the adenosine level was found. In summary, our results indicate that during aging the level of adenosine in the extracellular fluid is increased in the hippocampus. There is a downregulation and reduced responsiveness of presynaptic adenosine A1-receptors, and it seems likely that these changes are due to the enhanced adenosine level in the extracellular space.

  11. Effects of Administration of Perinatal Bupropion on the Population Spike Amplitude in Neonatal Rat Hippocampal Slice

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    Soomaayeh Heysieat-talab

    2010-09-01

    Full Text Available Objective(sBupropion is an atypical antidepressant that is widely used in smoke cessation under FDA approval. The study of synaptic effects of bupropion can help to finding out its mechanism(s for stopping nicotine dependence. In this study the effects of perinatal bupropion on the population spike (PS amplitude of neonates were investigated. Materials and Methods Hippocampal slices were prepared from 18-25 days old rat pups. The experimental groups included control and bupropion-treated. Bupropion (40 mg/Kg, i.p. was applied daily in perinatal period as pre-treatment. Due to the studying acute effects, bupropion was also added to the perfusion medium (10, 50, 200 μM for 30 min. The evoked PS was recorded from pyramidal layer of CA1 area, following stimulation of Schaffer collaterals. ResultsA concentration of 10 μM bupropion had no significant effects on the PS amplitude. The 50 μM concentration of bupropion reduced the amplitude of responses in 50% of the studied cases. At a concentration of 200 μM, the recorded PS amplitudes were reduced in all slices (n= 22. Amplitude was completely abolished in 8 out of the 22 slices. The decrease of the PS amplitude was found to be more in the non-pre-treated slices than in the pre-treated slices when both were perfused with 200 μM bupropion.Conclusion The results showed the perinatal exposure to bupropion and its acute effects while indicating that at concentrations of 50 and 200 μM bupropion reduced the PS amplitude. It was also found that there was evidence of synaptic adaptation in comparison of bupropion-treated and non-treated slices whereas they were both perfused with 200 µM.

  12. A simple method for multiday imaging of slice cultures.

    Science.gov (United States)

    Seidl, Armin H; Rubel, Edwin W

    2010-01-01

    The organotypic slice culture (Stoppini et al. A simple method for organotypic cultures of nervous tissue. 1991;37:173-182) has become the method of choice to answer a variety of questions in neuroscience. For many experiments, however, it would be beneficial to image or manipulate a slice culture repeatedly, for example, over the course of many days. We prepared organotypic slice cultures of the auditory brainstem of P3 and P4 mice and kept them in vitro for up to 4 weeks. Single cells in the auditory brainstem were transfected with plasmids expressing fluorescent proteins by way of electroporation (Haas et al. Single-cell electroporation for gene transfer in vivo. 2001;29:583-591). The culture was then placed in a chamber perfused with oxygenated ACSF and the labeled cell imaged with an inverted wide-field microscope repeatedly for multiple days, recording several time-points per day, before returning the slice to the incubator. We describe a simple method to image a slice culture preparation during the course of multiple days and over many continuous hours, without noticeable damage to the tissue or photobleaching. Our method uses a simple, inexpensive custom-built insulator constructed around the microscope to maintain controlled temperature and uses a perfusion chamber as used for in vitro slice recordings. (c) 2009 Wiley-Liss, Inc.

  13. Long-term brain slice culturing in a microfluidic platform

    DEFF Research Database (Denmark)

    Vedarethinam, Indumathi; Avaliani, N.; Tønnesen, J.

    2011-01-01

    In this work, we present the development of a transparent poly(methyl methacrylate) (PMMA) based microfluidic culture system for handling long-term brain slice cultures independent of an incubator. The different stages of system development have been validated by culturing GFP producing brain sli...

  14. Novel culturing platform for brain slices and neuronal cells

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  15. A pilot study of planar coil based magnetic stimulation using acute hippocampal slice in mice.

    Science.gov (United States)

    Park, H J; Kang, H K; Wang, M; Jo, J; Chung, E; Kim, S

    2017-07-01

    Micromagnetic stimulation using small-sized implantable coils has recently been studied. The main advantage of this method is that it can provide sustainable stimulation performance even if a fibrotic encapsulation layer is formed around the implanted coil by inflammation response, because indirectly induced currents are used to induce neural responses. In previous research, we optimized the geometrical and control parameters used in implantable magnetic stimulation. Based on those results, we fabricated the planar coil and studied the LTP effect in the hippocampal slice by two different magnetic stimulation protocols using the quadripulse stimulation (QPS) pattern. We found that direct magnetic stimulation (DMS) induced insignificant LTP effect and priming magnetic stimulation (PMS) occluded LTP effect after tetanic stimulation, when QPS patterned magnetic stimulation with 1 A current pulse was applied to the planar coil.

  16. Lindane blocks GABAA-mediated inhibition and modulates pyramidal cell excitability in the rat hippocampal slice.

    Science.gov (United States)

    Joy, R M; Walby, W F; Stark, L G; Albertson, T E

    1995-01-01

    An in vitro paired-pulse orthodromic stimulation technique was used to examine the effects of lindane on excitatory afferent terminals, CA1 pyramidal cells and recurrent collateral evoked inhibition in the rat hippocampal slice. This was done to establish simultaneous effects on a simple neural network and to develop procedures for more detailed analyses of the effects of lindane. Hippocampal slices 400 microns thick were perfused with oxygenated artificial cerebrospinal fluid. Electrodes were placed in the CA1 region to record extracellular population spike (PS) or excitatory postsynaptic potential (EPSP) responses to stimulation of Schaffer collateral/commissural (SC/C) fibers. Gamma-aminobutyric acid (GABA)-mediated recurrent inhibition was measured using a paired-pulse technique. Perfusion with lindane produced both time and dose dependent changes in a number of the responses measured. The most striking effect produced by lindane was the loss of GABAA-mediated recurrent collateral inhibition. This tended to occur rapidly, often before changes in EPSP or PS responses could be detected. With longer exposures to lindane, repetitive discharge of pyramidal cells developed resulting in multiple PSs to single stimuli. Lindane (50 microM) also completely reversed the effects of the injectable anesthetic, propofol, a compound known to potentiate GABAA-mediated inhibition via a direct action on the GABAA receptor-chloride channel complex. An analysis of input/output relationships at varying stimulus intensities showed that lindane increased EPSP and PS response amplitudes at any given stimulus intensity resulting in a leftward shift in the EPSP amplitude/stimulus intensity, PS amplitude/stimulus intensity and PS amplitude/EPSP amplitude relationships. This effect was most noticeable with low intensity stimuli and became progressively less so as stimulus intensities approached those yielding maximal responses. In addition lindane significantly increased paired pulse

  17. Metabolic Characterization of Acutely Isolated Hippocampal and Cerebral Cortical Slices Using [U-(13)C]Glucose and [1,2-(13)C]Acetate as Substrates

    DEFF Research Database (Denmark)

    McNair, Laura F; Kornfelt, Rasmus; Walls, Anne B

    2017-01-01

    Brain slice preparations from rats, mice and guinea pigs have served as important tools for studies of neurotransmission and metabolism. While hippocampal slices routinely have been used for electrophysiology studies, metabolic processes have mostly been studied in cerebral cortical slices. Few...

  18. Identification and two-photon imaging of oligodendrocyte in CA1 region of hippocampal slices

    International Nuclear Information System (INIS)

    Zhou Wei; Ge Wooping; Zeng Shaoqun; Duan Shumin; Luo Qingming

    2007-01-01

    Oligodendrocyte (OL) plays a critical role in myelination and axon maintenance in central nervous system. Recent studies show that OL can also express NMDA receptors in development and pathological situations in white matter. There is still lack of studies about OL properties and function in gray matter of brain. Here we reported that some glial cells in CA1 region of rat hippocampal slices (P15-23) had distinct electrophysiological characteristics from the other glia cells in this region, while they displayed uniform properties with OL from white matter in previous report; therefore, they were considered as OL in hippocampus. By loading dye in recording pipette and imaging with two-photon laser scanning microscopy, we acquired the high spatial resolution, three-dimension images of these special cells in live slices. The OL in hippocampus shows a complex process-bearing shape and the distribution of several processes is parallel to Schaffer fiber in CA1 region. When stimulating Schaffer fiber, OL displays a long duration depolarization mediated by inward rectifier potassium channel. This suggested that the OL in CA1 region could sense the neuronal activity and contribute to potassium clearance

  19. Hypo-and hyperthyroidism affect the ATP, ADP and AMP hydrolysis in rat hippocampal and cortical slices.

    Science.gov (United States)

    Bruno, Alessandra Nejar; Diniz, Gabriela Placoná; Ricachenevsky, Felipe Klein; Pochmann, Daniela; Bonan, Carla Denise; Barreto-Chaves, Maria Luiza M; Sarkis, João José Freitas

    2005-05-01

    The presence of severe neurological symptoms in thyroid diseases has highlighted the importance of thyroid hormones in the normal functioning of the mature brain. Since, ATP is an important excitatory neurotransmitter and adenosine acts as a neuromodulatory structure inhibiting neurotransmitters release in the central nervous system (CNS), the ectonucleotidase cascade that hydrolyzes ATP to adenosine, is also involved in the control of brain functions. Thus, we investigated the influence of hyper-and hypothyroidism on the ATP, ADP and AMP hydrolysis in hippocampal and cortical slices from adult rats. Hyperthyroidism was induced by daily injections of l-thyroxine (T4) 25 microg/100 g body weight, for 14 days. Hypothyroidism was induced by thyroidectomy and methimazole (0.05%) added to their drinking water for 14 days. Hypothyroid rats were hormonally replaced by daily injections of T4 (5 microg/100 g body weight, i.p.) for 5 days. Hyperthyroidism significantly inhibited the ATP, ADP and AMP hydrolysis in hippocampal slices. In brain cortical slices, hyperthyroidism inhibited the AMP hydrolysis. In contrast, hypothyroidism increased the ATP, ADP and AMP hydrolysis in both hippocampal and cortical slices and these effects were reverted by T4 replacement. Furthermore, hypothyroidism increased the expression of NTPDase1 and 5'-nucleotidase, whereas hyperthyroidism decreased the expression of 5'-nucleotidase in hippocampus of adult rats. These findings demonstrate that thyroid disorders may influence the enzymes involved in the complete degradation of ATP to adenosine and possibly affects the responses mediated by adenine nucleotides in the CNS of adult rats.

  20. Kainate toxicity in energy-compromised rat hippocampal slices: differences between oxygen and glucose deprivation.

    Science.gov (United States)

    Schurr, A; Rigor, B M

    1993-06-18

    The effects of kainate (KA) on the recovery of neuronal function in rat hippocampal slices after hypoxia or glucose deprivation (GD) were investigated and compared to those of (R,S)-alpha-amino-3-hydroxy-5-methyl-4- isoxazoleproprionate (AMPA). KA and AMPA were found to be more toxic than either N-methyl-D-aspartate (NMDA), quinolinate, or glutamate, both under normal conditions and under states of energy deprivation. Doses as low as 1 microM KA or AMPA were sufficient to significantly reduce the recovery rate of neuronal function in slices after a standardized period of hypoxia or GD. The enhancement of hypoxic neuronal damage by both agonists could be partially blocked by the antagonist kynurenate, by the NMDA competitive antagonist AP5, and by elevating [Mg2+] in or by omitting Ca2+ from the perfusion medium. The AMPA antagonist glutamic acid diethyl ester was ineffective in preventing the enhanced hypoxic neuronal damage by either KA or AMPA. The antagonist of the glycine modulatory site on the NMDA receptor, 7-chlorokynurenate, did not block the KA toxicity but was able to block the toxicity of AMPA. 2,3-Dihydroxyquinoxaline completely blocked the KA- and AMPA-enhanced hypoxic neuronal damage. The KA-enhanced, GD-induced neuronal damage was prevented by Ca2+ depletion and partially antagonized by kynurenate but not by AP5 or elevated [Mg2+]. The results of the present study indicate that the KA receptor is involved in the mechanism of neuronal damage induced by hypoxia and GD, probably allowing Ca2+ influx and subsequent intracellular Ca2+ overload.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices

    Directory of Open Access Journals (Sweden)

    Torres I.L.S.

    2001-01-01

    Full Text Available It has been suggested that glucocorticoids released during stress might impair neuronal function by decreasing glucose uptake by hippocampal neurons. Previous work has demonstrated that glucose uptake is reduced in hippocampal and cerebral cortex slices 24 h after exposure to acute stress, while no effect was observed after repeated stress. Here, we report the effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices and on plasma glucose and corticosterone levels. Male adult Wistar rats were exposed to restraint 1 h/day for 50 days in the chronic model. In the acute model there was a single exposure. Immediately or 24 h after stress, the animals were sacrificed and the hippocampus and cerebral cortex were dissected, sliced, and incubated with Krebs buffer, pH 7.4, containing 5 mM glucose and 0.2 µCi D-[U-14C] glucose. CO2 production from glucose was estimated. Trunk blood was also collected, and both corticosterone and glucose were measured. The results showed that corticosterone levels after exposure to acute restraint were increased, but the increase was smaller when the animals were submitted to repeated stress. Blood glucose levels increased after both acute and repeated stress. However, glucose utilization, measured as CO2 production in hippocampal and cerebral cortex slices, was the same in stressed and control groups under conditions of both acute and chronic stress. We conclude that, although stress may induce a decrease in glucose uptake, this effect is not sufficient to affect the energy metabolism of these cells.

  2. Effects of uniform extracellular DC electric fields on excitability in rat hippocampal slices in vitro.

    Science.gov (United States)

    Bikson, Marom; Inoue, Masashi; Akiyama, Hiroki; Deans, Jackie K; Fox, John E; Miyakawa, Hiroyoshi; Jefferys, John G R

    2004-05-15

    The effects of uniform steady state (DC) extracellular electric fields on neuronal excitability were characterized in rat hippocampal slices using field, intracellular and voltage-sensitive dye recordings. Small electric fields (tips of basal and apical dendrites. The polarization was biphasic in the mid-apical dendrites; there was a time-dependent shift in the polarity reversal site. DC fields altered the thresholds of action potentials evoked by orthodromic stimulation, and shifted their initiation site along the apical dendrites. Large electric fields could trigger neuronal firing and epileptiform activity, and induce long-term (>1 s) changes in neuronal excitability. Electric fields perpendicular to the apical-dendritic axis did not induce somatic polarization, but did modulate orthodromic responses, indicating an effect on afferents. These results demonstrate that DC fields can modulate neuronal excitability in a time-dependent manner, with no clear threshold, as a result of interactions between neuronal compartments, the non-linear properties of the cell membrane, and effects on afferents.

  3. The effect of propofol on CA1 pyramidal cell excitability and GABAA-mediated inhibition in the rat hippocampal slice.

    Science.gov (United States)

    Albertson, T E; Walby, W F; Stark, L G; Joy, R M

    1996-05-24

    An in vitro paired-pulse orthodromic stimulation technique was used to examine the effects of propofol on excitatory afferent terminals, CA1 pyramidal cells and recurrent collateral evoked inhibition in the rat hippocampal slice. Hippocampal slices 400 microns thick were perfused with oxygenated artificial cerebrospinal fluid, and electrodes were placed in the CA1 region to record extracellular field population spike (PS) or excitatory postsynaptic potential (EPSP) responses to stimulation of Schaffer collateral/commissural fibers. Gamma-aminobutyric acid (GABA)-mediated recurrent inhibition was measured using a paired-pulse technique. The major effect of propofol (7-28 microM) was a dose and time dependent increase in the intensity and duration of GABA-mediated inhibition. This propofol effect could be rapidly and completely reversed by exposure to known GABAA antagonists, including picrotoxin, bicuculline and pentylenetetrazol. It was also reversed by the chloride channel antagonist, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). It was not antagonized by central (flumazenil) or peripheral (PK11195) benzodiazepine antagonists. Reversal of endogenous inhibition was also noted with the antagonists picrotoxin and pentylenetetrazol. Input/output curves constructed using stimulus propofol caused only a small enhancement of EPSPs at higher stimulus intensities but had no effect on PS amplitudes. These studies are consistent with propofol having a GABAA-chloride channel mechanism causing its effect on recurrent collateral evoked inhibition in the rat hippocampal slice.

  4. Characterization of cortical neuronal and glial alterations during culture of organotypic whole brain slices from neonatal and mature mice.

    Science.gov (United States)

    Staal, Jerome A; Alexander, Samuel R; Liu, Yao; Dickson, Tracey D; Vickers, James C

    2011-01-01

    Organotypic brain slice culturing techniques are extensively used in a wide range of experimental procedures and are particularly useful in providing mechanistic insights into neurological disorders or injury. The cellular and morphological alterations associated with hippocampal brain slice cultures has been well established, however, the neuronal response of mouse cortical neurons to culture is not well documented. In the current study, we compared the cell viability, as well as phenotypic and protein expression changes in cortical neurons, in whole brain slice cultures from mouse neonates (P4-6), adolescent animals (P25-28) and mature adults (P50+). Cultures were prepared using the membrane interface method. Propidium iodide labeling of nuclei (due to compromised cell membrane) and AlamarBlue™ (cell respiration) analysis demonstrated that neonatal tissue was significantly less vulnerable to long-term culture in comparison to the more mature brain tissues. Cultures from P6 animals showed a significant increase in the expression of synaptic markers and a decrease in growth-associated proteins over the entire culture period. However, morphological analysis of organotypic brain slices cultured from neonatal tissue demonstrated that there were substantial changes to neuronal and glial organization within the neocortex, with a distinct loss of cytoarchitectural stratification and increased GFAP expression (pglial limitans and, after 14 DIV, displayed substantial cellular protrusions from slice edges, including cells that expressed both glial and neuronal markers. In summary, we present a substantial evaluation of the viability and morphological changes that occur in the neocortex of whole brain tissue cultures, from different ages, over an extended period of culture.

  5. Slices

    KAUST Repository

    McCrae, James

    2011-01-01

    Minimalist object representations or shape-proxies that spark and inspire human perception of shape remain an incompletely understood, yet powerful aspect of visual communication. We explore the use of planar sections, i.e., the contours of intersection of planes with a 3D object, for creating shape abstractions, motivated by their popularity in art and engineering. We first perform a user study to show that humans do define consistent and similar planar section proxies for common objects. Interestingly, we observe a strong correlation between user-defined planes and geometric features of objects. Further we show that the problem of finding the minimum set of planes that capture a set of 3D geometric shape features is both NP-hard and not always the proxy a user would pick. Guided by the principles inferred from our user study, we present an algorithm that progressively selects planes to maximize feature coverage, which in turn influence the selection of subsequent planes. The algorithmic framework easily incorporates various shape features, while their relative importance values are computed and validated from the user study data. We use our algorithm to compute planar slices for various objects, validate their utility towards object abstraction using a second user study, and conclude showing the potential applications of the extracted planar slice shape proxies. © 2011 ACM.

  6. Colchicine induces apoptosis in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Kristensen, Bjarne W; Noer, Helle; Gramsbergen, Jan Bert

    2003-01-01

    The microtubule-disrupting agent colchicine is known to be particular toxic for certain types of neurons, including the granule cells of the dentate gyrus. In this study we investigated whether colchicine could induce such neuron-specific degeneration in developing (1 week in vitro) and mature (3...

  7. Effects of met-enkephalin on GABAergic spontaneous miniature IPSPs in organotypic slice cultures of the rat hippocampus

    DEFF Research Database (Denmark)

    Rekling, J C

    1993-01-01

    The action of met-enkephalin on GABAergic spontaneous miniature IPSPs (smIPSPs) was investigated in CA1 neurons from hippocampal slice cultures. In the presence of excitatory amino acid blockers (2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline, DL-2-amino-5-phosphonovaleric acid) and TTX...... the amplitude distribution of the smIPSPs. The proportion of "large" smIPSPs was reduced, but a loss of "small" smIPSPs also contributed to the reduction in smIPSP frequency. The selective mu-receptor agonist DAGO mimicked the effect of met-enkephalin and naloxone blocked the effect of DAGO. Hyperpolarization......IPSP frequency, nor did it block the effect of DAGO. These results suggest that CA1 pyramidal cells of hippocampal organotypic cultures are tonically inhibited by spontaneous release of GABA, through a release mechanism that is independent of propagated sodium action potentials. Met-enkephalin and DAGO reduce...

  8. A testbed to explore the optimal electrical stimulation parameters for suppressing inter-ictal spikes in human hippocampal slices.

    Science.gov (United States)

    Min-Chi Hsiao; Pen-Ning Yu; Dong Song; Liu, Charles Y; Heck, Christi N; Millett, David; Berger, Theodore W

    2014-01-01

    New interventions using neuromodulatory devices such as vagus nerve stimulation, deep brain stimulation and responsive neurostimulation are available or under study for the treatment of refractory epilepsy. Since the actual mechanisms of the onset and termination of the seizure are still unclear, most researchers or clinicians determine the optimal stimulation parameters through trial-and-error procedures. It is necessary to further explore what types of electrical stimulation parameters (these may include stimulation frequency, amplitude, duration, interval pattern, and location) constitute a set of optimal stimulation paradigms to suppress seizures. In a previous study, we developed an in vitro epilepsy model using hippocampal slices from patients suffering from mesial temporal lobe epilepsy. Using a planar multi-electrode array system, inter-ictal activity from human hippocampal slices was consistently recorded. In this study, we have further transferred this in vitro seizure model to a testbed for exploring the possible neurostimulation paradigms to inhibit inter-ictal spikes. The methodology used to collect the electrophysiological data, the approach to apply different electrical stimulation parameters to the slices are provided in this paper. The results show that this experimental testbed will provide a platform for testing the optimal stimulation parameters of seizure cessation. We expect this testbed will expedite the process for identifying the most effective parameters, and may ultimately be used to guide programming of new stimulating paradigms for neuromodulatory devices.

  9. Low-frequency electrical stimulation enhances the effectiveness of phenobarbital on GABAergic currents in hippocampal slices of kindled rats.

    Science.gov (United States)

    Asgari, Azam; Semnanian, Saeed; Atapour, Nafiseh; Shojaei, Amir; Moradi-Chameh, Homeira; Ghafouri, Samireh; Sheibani, Vahid; Mirnajafi-Zadeh, Javad

    2016-08-25

    Low frequency stimulation (LFS) has been proposed as a new approach in the treatment of epilepsy. The anticonvulsant mechanism of LFS may be through its effect on GABAA receptors, which are the main target of phenobarbital anticonvulsant action. We supposed that co-application of LFS and phenobarbital may increase the efficacy of phenobarbital. Therefore, the interaction of LFS and phenobarbital on GABAergic inhibitory post-synaptic currents (IPSCs) in kindled and control rats was investigated. Animals were kindled by electrical stimulation of basolateral amygdala in a semi rapid manner (12 stimulations/day). The effect of phenobarbital, LFS and phenobarbital+LFS was investigated on GABAA-mediated evoked and miniature IPSCs in the hippocampal brain slices in control and fully kindled animals. Phenobarbital and LFS had positive interaction on GABAergic currents. In vitro co-application of an ineffective pattern of LFS (100 pulses at afterdischarge threshold intensity) and a sub-threshold dose of phenobarbital (100μM) which had no significant effect on GABAergic currents alone, increased the amplitude and area under curve of GABAergic currents in CA1 pyramidal neurons of hippocampal slices significantly. Interestingly, the sub-threshold dose of phenobarbital potentiated the GABAergic currents when applied on the hippocampal slices of kindled animals which received LFS in vivo. Post-synaptic mechanisms may be involved in observed interactions. Obtained results implied a positive interaction between LFS and phenobarbital through GABAA currents. It may be suggested that a combined therapy of phenobarbital and LFS may be a useful manner for reinforcing the anticonvulsant action of phenobarbital. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Human Dental Pulp Cells Differentiate toward Neuronal Cells and Promote Neuroregeneration in Adult Organotypic Hippocampal Slices In Vitro.

    Science.gov (United States)

    Xiao, Li; Ide, Ryoji; Saiki, Chikako; Kumazawa, Yasuo; Okamura, Hisashi

    2017-08-11

    The adult mammalian central nerve system has fundamental difficulties regarding effective neuroregeneration. The aim of this study is to investigate whether human dental pulp cells (DPCs) can promote neuroregeneration by (i) being differentiated toward neuronal cells and/or (ii) stimulating local neurogenesis in the adult hippocampus. Using immunostaining, we demonstrated that adult human dental pulp contains multipotent DPCs, including STRO-1, CD146 and P75-positive stem cells. DPC-formed spheroids were able to differentiate into neuronal, vascular, osteogenic and cartilaginous lineages under osteogenic induction. However, under neuronal inductive conditions, cells in the DPC-formed spheroids differentiated toward neuronal rather than other lineages. Electrophysiological study showed that these cells consistently exhibit the capacity to produce action potentials, suggesting that they have a functional feature in neuronal cells. We further co-cultivated DPCs with adult mouse hippocampal slices on matrigel in vitro. Immunostaining and presto blue assay showed that DPCs were able to stimulate the growth of neuronal cells (especially neurons) in both the CA1 zone and the edges of the hippocampal slices. Brain-derived neurotrophic factor (BDNF), was expressed in co-cultivated DPCs. In conclusion, our data demonstrated that DPCs are well-suited to differentiate into the neuronal lineage. They are able to stimulate neurogenesis in the adult mouse hippocampus through neurotrophic support in vitro.

  11. PROPYLTHIOURACIL (PTU)-INDUCED HYPOTHYROIDISM: EFFECTS ON SYNAPTIC TRANSMISSION AND LONG TERM POTENTIATION IN HIPPOCAMPAL SLICES.

    Science.gov (United States)

    Concern has been raised over endocrine effects of some classes of environmental chemicals. Severe hypothyroidism during critical periods of brain developmental leads to alterations in hippocampal structure, learning deficits, yet neurophysiological properties of the hippocampus...

  12. Metabolic Characterization of Acutely Isolated Hippocampal and Cerebral Cortical Slices Using [U-13C]Glucose and [1,2-13C]Acetate as Substrates.

    Science.gov (United States)

    McNair, Laura F; Kornfelt, Rasmus; Walls, Anne B; Andersen, Jens V; Aldana, Blanca I; Nissen, Jakob D; Schousboe, Arne; Waagepetersen, Helle S

    2017-03-01

    Brain slice preparations from rats, mice and guinea pigs have served as important tools for studies of neurotransmission and metabolism. While hippocampal slices routinely have been used for electrophysiology studies, metabolic processes have mostly been studied in cerebral cortical slices. Few comparative characterization studies exist for acute hippocampal and cerebral cortical slices, hence, the aim of the current study was to characterize and compare glucose and acetate metabolism in these slice preparations in a newly established incubation design. Cerebral cortical and hippocampal slices prepared from 16 to 18-week-old mice were incubated for 15-90 min with unlabeled glucose in combination with [U- 13 C]glucose or [1,2- 13 C]acetate. Our newly developed incubation apparatus allows accurate control of temperature and is designed to avoid evaporation of the incubation medium. Subsequent to incubation, slices were extracted and extracts analyzed for 13 C-labeling (%) and total amino acid contents (µmol/mg protein) using gas chromatography-mass spectrometry and high performance liquid chromatography, respectively. Release of lactate from the slices was quantified by analysis of the incubation media. Based on the measured 13 C-labeling (%), total amino acid contents and relative activity of metabolic enzymes/pathways, we conclude that the slice preparations in the current incubation apparatus exhibited a high degree of metabolic integrity. Comparison of 13 C-labeling observed with [U- 13 C]glucose in slices from cerebral cortex and hippocampus revealed no significant regional differences regarding glycolytic or total TCA cycle activities. On the contrary, results from the incubations with [1,2- 13 C]acetate suggest a higher capacity of the astrocytic TCA cycle in hippocampus compared to cerebral cortex. Finally, we propose a new approach for assessing compartmentation of metabolite pools between astrocytes and neurons using 13 C-labeling (%) data obtained from

  13. Effects of dimethylarsinic and dimethylarsinous acid on evoked synaptic potentials in hippocampal slices of young and adult rats

    International Nuclear Information System (INIS)

    Krueger, Katharina; Repges, Hendrik; Hippler, Joerg; Hartmann, Louise M.; Hirner, Alfred V.; Straub, Heidrun; Binding, Norbert; Musshoff, Ulrich

    2007-01-01

    In this study, the effects of pentavalent dimethylarsinic acid ((CH 3 ) 2 AsO(OH); DMA V ) and trivalent dimethylarsinous acid ((CH 3 ) 2 As(OH); DMA III ) on synaptic transmission generated by the excitatory Schaffer collateral-CA1 synapse were tested in hippocampal slices of young (14-21 day-old) and adult (2-4 month-old) rats. Both compounds were applied in concentrations of 1 to 100 μmol/l. DMA V had no effect on the amplitudes of evoked fEPSPs or the induction of LTP recorded from the CA1 dendritic region either in adult or in young rats. However, application of DMA III significantly reduced the amplitudes of evoked fEPSPs in a concentration-dependent manner with a total depression following application of 100 μmol/l DMA III in adult and 10 μmol/l DMA III in young rats. Moreover, DMA III significantly affected the LTP-induction. Application of 10 μmol/l DMA III resulted in a complete failure of the postsynaptic potentiation of the fEPSP amplitudes in slices taken both from adult and young rats. The depressant effect was not reversible after a 30-min washout of the DMA III . In slices of young rats, the depressant effects of DMA III were more pronounced than in those taken from adult ones. Compared to the (absent) effect of DMA V on synaptic transmission, the trivalent compound possesses a considerably higher neurotoxic potential

  14. Effects of monomethylarsonic and monomethylarsonous acid on evoked synaptic potentials in hippocampal slices of adult and young rats

    International Nuclear Information System (INIS)

    Krueger, Katharina; Straub, Heidrun; Hirner, Alfred V.; Hippler, Joerg; Binding, Norbert; Musshoff, Ulrich

    2009-01-01

    Arsenite and its metabolites, dimethylarsinic or dimethylarsinous acid, have previously been shown to disturb synaptic transmission in hippocampal slices of rats (Krueger, K., Gruner, J., Madeja, M., Hartmann, L.M., Hirner, A.V., Binding, N., Muβhoff, U., 2006a. Blockade and enhancement of glutamate receptor responses in Xenopus oocytes by methylated arsenicals. Arch. Toxicol. 80, 492-501, Krueger, K., Straub, H., Binding, N., Muβhoff, U., 2006b. Effects of arsenite on long-term potentiation in hippocampal slices from adult and young rats. Toxicol. Lett. 165, 167-173, Krueger, K., Repges, H., Hippler, J., Hartmann, L.M., Hirner, A.V., Straub, H., Binding, N., Muβhoff, U., 2007. Effects of dimethylarsinic and dimethylarsinous acid on evoked synaptic potentials in hippocampal slices of young and adult rats. Toxicol. Appl. Pharmacol. 225, 40-46). The present experiments investigate, whether the important arsenic metabolites monomethylarsonic acid (MMA V ) and monomethylarsonous acid (MMA III ) also influence the synaptic functions of the hippocampus. In hippocampal slices of young (14-21 days-old) and adult (2-4 months-old) rats, evoked synaptic field potentials from the Schaffer collateral-CA1 synapse were measured under control conditions and during and after 30 and 60 min of application of the arsenic compounds. MMA V had no effect on the synapse functions neither in slices of adult nor in those from young rats. However, MMA III strongly influenced the synaptic transmission: it totally depressed the amplitudes of fEPSPs at concentrations of 50 μmol/l (adult rats) and 25 μmol/l (young rats) and LTP amplitudes at concentrations of 25 μmol/l (adult rats) and 10 μmol/l (young rats), respectively. In contrast, application of 1 μmol/l MMA III led to an enhancement of the LTP amplitude in young rats, which is interpretable by an enhancing effect on NMDA receptors and a lack of the blocking effect on AMPA receptors at this concentration (Krueger, K., Gruner, J

  15. Rat brain sagittal organotypic slice cultures as an ex vivo dopamine cell loss system.

    Science.gov (United States)

    McCaughey-Chapman, Amy; Connor, Bronwen

    2017-02-01

    Organotypic brain slice cultures are a useful tool to study neurological function as they provide a more complex, 3-dimensional system than standard 2-dimensional in vitro cell cultures. Building on a previously developed mouse brain slice culture protocol, we have developed a rat sagittal brain slice culture system as an ex vivo model of dopamine cell loss. We show that rat brain organotypic slice cultures remain viable for up to 6 weeks in culture. Using Fluoro-Gold axonal tracing, we demonstrate that the slice 3-dimensional cytoarchitecture is maintained over a 4 week culturing period, with particular focus on the nigrostriatal pathway. Treatment of the cultures with 6-hydroxydopamine and desipramine induces a progressive loss of Fluoro-Gold-positive nigral cells with a sustained loss of tyrosine hydroxylase-positive nigral cells. This recapitulates the pattern of dopaminergic degeneration observed in the rat partial 6-hydroxydopamine lesion model and, most importantly, the progressive pathology of Parkinson's disease. Our slice culture platform provides an advance over other systems, as we demonstrate for the first time 3-dimensional cytoarchitecture maintenance of rat nigrostriatal sagittal slices for up to 6 weeks. Our ex vivo organotypic slice culture system provides a long term cellular platform to model Parkinson's disease, allowing for the elucidation of mechanisms involved in dopaminergic neuron degeneration and the capability to study cellular integration and plasticity ex vivo. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. PARP Inhibition Prevents Ethanol-Induced Neuroinflammatory Signaling and Neurodegeneration in Rat Adult-Age Brain Slice Cultures

    Science.gov (United States)

    Tajuddin, Nuzhath; Kim, Hee-Yong

    2018-01-01

    Using rat adult-age hippocampal-entorhinal cortical (HEC) slice cultures, we examined the role of poly [ADP-ribose] polymerase (PARP) in binge ethanol’s brain inflammatory and neurodegenerative mechanisms. Activated by DNA strand breaks, PARP (principally PARP1 in the brain) promotes DNA repair via poly [ADP-ribose] (PAR) products, but PARP overactivation triggers regulated neuronal necrosis (e.g., parthanatos). Previously, we found that brain PARP1 levels were upregulated by neurotoxic ethanol binges in adult rats and HEC slices, and PARP inhibitor PJ34 abrogated slice neurodegeneration. Binged HEC slices also exhibited increased Ca+2-dependent phospholipase A2 (PLA2) isoenzymes (cPLA2 IVA and sPLA2 IIA) that mobilize proinflammatory ω6 arachidonic acid (ARA). We now find in 4-day–binged HEC slice cultures (100 mM ethanol) that PARP1 elevations after two overnight binges precede PAR, cPLA2, and sPLA2 enhancements by 1 day and high-mobility group box-1 (HMGB1), an ethanol-responsive alarmin that augments proinflammatory cytokines via toll-like receptor-4 (TLR4), by 2 days. After verifying that PJ34 effectively blocks PARP activity (↑PAR), we demonstrated that, like PJ34, three other PARP inhibitors—olaparib, veliparib, and 4-aminobenzamide—provided neuroprotection from ethanol. Importantly, PJ34 and olaparib also prevented ethanol’s amplification of the PLA2 isoenzymes, and two PLA2 inhibitors were neuroprotective—thus coupling PARP to PLA2, with PLA2 activity promoting neurodegeneration. Also, PJ34 and olaparib blocked ethanol-induced HMGB1 elevations, linking brain PARP induction to TLR4 activation. The results provide evidence in adult brains that induction of PARP1 may mediate dual neuroinflammatory pathways (PLA2→phospholipid→ARA and HMGB1→TLR4→proinflammatory cytokines) that are complicit in binge ethanol-induced neurodegeneration. PMID:29339456

  17. The effects of lindane and long-term potentiation (LTP) on pyramidal cell excitability in the rat hippocampal slice.

    Science.gov (United States)

    Albertson, T E; Walby, W F; Stark, L G; Joy, R M

    1997-01-01

    An in vitro orthodromic stimulation technique was used to examine the effects of lindane and long-term potentiation (LTP) inducing stimuli, alone or in combination, on the excitatory afferent terminal of CA1 pyramidal cells and on recurrent collateral evoked inhibition using the rat hippocampal slice model. Hippocampal slices of 400 microns thickness were perfused with oxygenated artificial cerebrospinal fluid. Stimulation of Schaffer collateral/commissural fibers produced extracellular excitatory postsynaptic potential (EPSP) and/or populations spike (PS) responses recorded from electrodes in the CA1 region. A paired-pulse technique was used to measure gamma-aminobutyric acid (GABAA)-mediated recurrent inhibition before and after treatments. After both lindane and LTP, larger PS amplitudes for a given stimulus intensity were seen. The resulting leftward shift in the curve of the PS amplitude versus stimulus intensity was larger after LTP than after 25 microM lindane. Both lindane and LTP treatments reduced PS thresholds and reduced or eliminated recurrent inhibition as measured by paired-pulse stimulation at the 15 msec interval. The reduction of recurrent inhibition after both treatments was more pronounced at lower stimulus intensities. When LTP stimuli were applied after lindane exposure a further large shift to the left was seen in the PS amplitude versus stimulus intensity curve. A smaller shift to the left was seen in the PS amplitude versus stimulus intensity curve only at the higher stimuli when lindane exposure occurred after LTP. Only at low stimulus intensities were further argumentations seen in PS amplitudes when the LTP stimuli was followed by a second LTP stimuli. Previous exposure to 25 microM lindane stimuli does not block the development of a further robust LTP in this in vitro model.

  18. Attenuation of hypoxic current by intracellular applications of ATP regenerating agents in hippocampal CA1 neurons of rat brain slices.

    Science.gov (United States)

    Chung, I; Zhang, Y; Eubanks, J H; Zhang, L

    1998-10-01

    Hypoxia-induced outward currents (hyperpolarization) were examined in hippocampal CA1 neurons of rat brain slices, using the whole-cell recording technique. Hypoxic episodes were induced by perfusing slices with an artificial cerebrospinal fluid aerated with 5% CO2/95% N2 rather than 5% CO2/95% O2, for about 3 min. The hypoxic current was consistently and reproducibly induced in CA1 neurons dialysed with an ATP-free patch pipette solution. This current manifested as an outward shift in the holding current in association with increased conductance, and it reversed at -78 +/- 2.5 mV, with a linear I-V relation in the range of -100 to -40 mV. To provide extra energy resources to individual neurons recorded, agents were added to the patch pipette solution, including MgATP alone, MgATP + phosphocreatine + creatine kinase, or MgATP + creatine. In CA1 neurons dialysed with patch solutions including these agents, hypoxia produced small outward currents in comparison with those observed in CA1 neurons dialysed with the ATP-free solution. Among the above agents examined, whole-cell dialysis with MgATP + creatine was the most effective at decreasing the hypoxic outward currents. We suggest that the hypoxic hyperpolarization is closely related to energy metabolism in individual CA1 neurons, and that the energy supply provided by phosphocreatine metabolism may play a critical role during transient metabolic stress.

  19. Complex modulation by stress of the effect of seizures on long term potentiation in mouse hippocampal slices.

    Science.gov (United States)

    Maggio, Nicola; Shavit Stein, Efrat; Segal, Menahem

    2017-08-01

    Stress has a profound effect on ability to express neuronal plasticity, learning, and memory. Likewise, epileptic seizures lead to massive changes in brain connectivity, and in ability to undergo long term changes in reactivity to afferent stimulation. In this study, we analyzed possible long lasting interactions between a stressful experience and reactivity to pilocarpine, on the ability to produce long term potentiation (LTP) in a mouse hippocampus. Pilocarpine lowers paired pulse potentiation as well as LTP in CA1 region of the mouse hippocampal slice. When stress experience precedes exposure to pilocarpine, it protects the brain from the lasting effect of pilocarpine. When stress follows pilocarpine, it exacerbates the effect of the drug, to produce a long lasting reduction in LTP. These changes are accompanied by a parallel change in blood corticosterone level. A single exposure to selective mineralo- or gluco-corticosterone (MR and GR, respectively) agonists and antagonists can mimic the stress effects, indicating that GR's underlie the lasting detrimental effects of stress whereas MRs are instrumental in counteracting the effects of stress. These studies open a new avenue of understanding of the interactive effects of stress and epileptic seizures on brain plasticity. © 2017 Wiley Periodicals, Inc.

  20. Three-dimensional electrode array for brain slice culture

    DEFF Research Database (Denmark)

    Vazquez Rodriguez, Patricia

    Multielektroder arrays (MEA) er rækker af elektroder mest i mikrometer størrelse, som er blevet brugt i stor omfang til at stimulere og måle elektrisk aktivitet fra neuronale netværker. Brug af disse for at analysere hjerne slices (hjerneskiver) kan give indsigt i interaktioner mellem neuroner, e...

  1. Organotypic slice cultures containing the preBötzinger complex generate respiratory-like rhythms

    DEFF Research Database (Denmark)

    Phillips, Wiktor S; Herly, Mikkel; Del Negro, Christopher A

    2016-01-01

    containing the preBötzinger complex (preBötC), the core inspiratory rhythm generator of the ventrolateral brainstem. We measured bilateral synchronous network oscillations, using calcium-sensitive fluorescent dyes, in both ventrolateral (presumably the preBötC) and dorsomedial regions of 7-43 days in vitro......Acute brainstem slice preparations in vitro have advanced understanding of the cellular and synaptic mechanisms of respiratory rhythm generation, but their inherent limitations preclude long-term manipulation and recording experiments. Here, we developed an organotypic slice culture preparation...... of the brainstem displayed up to 193% faster burst frequency (22.4 ± 8.3 bursts/min) and higher signal amplitude (340%) compared to acute slices. We conclude that preBötC-containing slice cultures retain inspiratory-like rhythmic function and therefore may facilitate lines of experimentation that involve extended...

  2. Ketone bodies effectively compete with glucose for neuronal acetyl-CoA generation in rat hippocampal slices.

    Science.gov (United States)

    Valente-Silva, Paula; Lemos, Cristina; Köfalvi, Attila; Cunha, Rodrigo A; Jones, John G

    2015-09-01

    Ketone bodies can be used for cerebral energy generation in situ, when their availability is increased as during fasting or ingestion of a ketogenic diet. However, it is not known how effectively ketone bodies compete with glucose, lactate, and pyruvate for energy generation in the brain parenchyma. Hence, the contributions of exogenous 5.0 mM [1-(13)C]glucose and 1.0 mM [2-(13)C]lactate + 0.1 mM pyruvate (combined [2-(13)C]lactate + [2-(13)C]pyruvate) to acetyl-CoA production were measured both without and with 5.0 mM [U-(13)C]3-hydroxybutyrate in superfused rat hippocampal slices by (13)C NMR non-steady-state isotopomer analysis of tissue glutamate and GABA. Without [U-(13)C]3-hydroxybutyrate, glucose, combined lactate + pyruvate, and unlabeled endogenous sources contributed (mean ± SEM) 70 ± 7%, 10 ± 2%, and 20 ± 8% of acetyl-CoA, respectively. With [U-(13)C]3-hydroxybutyrate, glucose contributions significantly fell from 70 ± 7% to 21 ± 3% (p neurons. The appearance of superfusate lactate derived from glycolysis of [1-(13)C]glucose did not decrease significantly in the presence of 3-hydroxybutyrate, hence total glycolytic flux (Krebs cycle inflow + exogenous lactate formation) was attenuated by 3-hydroxybutyrate. This indicates that, under these conditions, 3-hydroxybutyrate inhibited glycolytic flux upstream of pyruvate kinase. Copyright © 2015 John Wiley & Sons, Ltd.

  3. No evidence for role of extracellular choline-acetyltransferase in generation of gamma oscillations in rat hippocampal slices in vitro.

    Science.gov (United States)

    Hollnagel, J O; ul Haq, R; Behrens, C J; Maslarova, A; Mody, I; Heinemann, U

    2015-01-22

    Acetylcholine (ACh) is well known to induce persistent γ-oscillations in the hippocampus when applied together with physostigmine, an inhibitor of the ACh degrading enzyme acetylcholinesterase (AChE). Here we report that physostigmine alone can also dose-dependently induce γ-oscillations in rat hippocampal slices. We hypothesized that this effect was due to the presence of choline in the extracellular space and that this choline is taken up into cholinergic fibers where it is converted to ACh by the enzyme choline-acetyltransferase (ChAT). Release of ACh from cholinergic fibers in turn may then induce γ-oscillations. We therefore tested the effects of the choline uptake inhibitor hemicholinium-3 (HC-3) on persistent γ-oscillations either induced by physostigmine alone or by co-application of ACh and physostigmine. We found that HC-3 itself did not induce γ-oscillations and also did not prevent physostigmine-induced γ-oscillation while washout of physostigmine and ACh-induced γ-oscillations was accelerated. It was recently reported that ChAT might also be present in the extracellular space (Vijayaraghavan et al., 2013). Here we show that the effect of physostigmine was prevented by the ChAT inhibitor (2-benzoylethyl)-trimethylammonium iodide (BETA) which could indicate extracellular synthesis of ACh. However, when we tested for effects of extracellularly applied acetyl-CoA, a substrate of ChAT for synthesis of ACh, physostigmine-induced γ-oscillations were attenuated. Together, these findings do not support the idea that ACh can be synthesized by an extracellularly located ChAT. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Excitotoxic effects of non-NMDA receptor agonists in organotypic corticostriatal slice cultures

    DEFF Research Database (Denmark)

    Kristensen, B W; Noraberg, J; Jakobsen, B

    1999-01-01

    of the cytosolic enzyme lactate dehydrogenase (LDH) into the culture medium and loss of glutamic acid decarboxylase (GAD) activity in the tissue. Histological sections were also stained by the fluorescent dye Fluoro-Jade (FJ), for degenerating neurons and by immunocytochemical staining for gamma-aminobutyric acid...... density of Fluoro-Jade staining, (3) loss of GAD-activity in tissue homogenates, and (4) loss of GABA-immunostained neurons. We conclude that both differences between compounds (AMPA vs. KA) and brain areas (striatum vs. cortex) can be demonstrated in corticostriatal slice cultures, which in conjunction...... in corticostriatal slice cultures. The purpose was to examine the feasibility of these cultures for excitotoxic studies, and to demonstrate possible differential excitotoxic effects of KA and AMPA on striatal and cortical neurons. Slices of dorsolateral striatum with overlying neocortex were obtained from neonatal...

  5. Higher transport and metabolism of glucose in astrocytes compared with neurons: a multiphoton study of hippocampal and cerebellar tissue slices.

    Science.gov (United States)

    Jakoby, Patrick; Schmidt, Elke; Ruminot, Iván; Gutiérrez, Robin; Barros, L Felipe; Deitmer, Joachim W

    2014-01-01

    Glucose is the most important energy substrate for the brain, and its cellular distribution is a subject of great current interest. We have employed fluorescent glucose probes, the 2-deoxy-D-glucose derivates 6- and 2-([N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose) (2-NBDG), to measure transport and metabolism of glucose in acute slices of mouse hippocampus and cerebellum. In the hippocampus, 6-NBDG, which is not metabolized and hence indicates glucose transport, was taken up faster in astrocyte-rich layers (Stratum radiatum [S.r.], Stratum oriens [S.o.]) than in pyramidal cells. Metabolizable 2-NBDG showed larger signals in S.r. and S.o. than in Stratum pyramidale, suggesting faster glucose utilization rate in the astrocyte versus the neuronal compartment. Similarly, we found higher uptake and temperature-sensitive metabolism of 2-NBDG in Bergmann glia when compared with adjacent Purkinje neurons of cerebellar slices. A comparison between 6-NBDG transport and glucose transport in cultured cells using a fluorescence resonance energy transfer nanosensor showed that relative to glucose, 6-NBDG is transported better by neurons than by astrocytes. These results indicate that the preferential transport and metabolism of glucose by glial cells versus neurons proposed for the hippocampus and cerebellum by ourselves (in vitro) and for the barrel cortex by Chuquet et al. (in vivo) is more pronounced than anticipated.

  6. Epileptogenesis in organotypic hippocampal cultures has limited dependence on culture medium composition

    OpenAIRE

    Liu, Jing; Saponjian, Yero; Mahoney, Mark M.; Staley, Kevin J.; Berdichevsky, Yevgeny

    2017-01-01

    Rodent organotypic hippocampal cultures spontaneously develop epileptiform activity after approximately 2 weeks in vitro and are increasingly used as a model of chronic post-traumatic epilepsy. However, organotypic cultures are maintained in an artificial environment (culture medium), which contains electrolytes, glucose, amino acids and other components that are not present at the same concentrations in cerebrospinal fluid (CSF). Therefore, it is possible that epileptogenesis in organotypic ...

  7. Coupling of organotypic brain slice cultures to silicon-based arrays of electrodes

    DEFF Research Database (Denmark)

    Jahnsen, Henrik; Kristensen, Bjarne Winther; Thiébaud, P

    1999-01-01

    Fetal or early postnatal brain tissue can be cultured in viable and healthy condition for several weeks with development and preservation of the basic cellular and connective organization as so-called organotypic brain slice cultures. Here we demonstrate and describe how it is possible to establish...

  8. β-Adrenoceptor activation depresses brain inflammation and is neuroprotective in lipopolysaccharide-induced sensitization to oxygen-glucose deprivation in organotypic hippocampal slices

    Directory of Open Access Journals (Sweden)

    Cilio Corrado

    2010-12-01

    Full Text Available Abstract Background Inflammation acting in synergy with brain ischemia aggravates perinatal ischemic brain damage. The sensitizing effect of pro-inflammatory exposure prior to hypoxia is dependent on signaling by TNF-α through TNF receptor (TNFR 1. Adrenoceptor (AR activation is known to modulate the immune response and synaptic transmission. The possible protective effect of α˜ and β˜AR activation against neuronal damage caused by tissue ischemia and inflammation, acting in concert, was evaluated in murine hippocampal organotypic slices treated with lipopolysaccharide (LPS and subsequently subjected to oxygen-glucose deprivation (OGD. Method Hippocampal slices from mice were obtained at P6, and were grown in vitro for 9 days on nitrocellulose membranes. Slices were treated with β1(dobutamine-, β2(terbutaline-, α1(phenylephrine- and α2(clonidine-AR agonists (5 and 50 μM, respectively during LPS (1 μg/mL, 24 h -exposure followed by exposure to OGD (15 min in a hypoxic chamber. Cell death in the slice CA1 region was assessed by propidium iodide staining of dead cells. Results Exposure to LPS + OGD caused extensive cell death from 4 up to 48 h after reoxygenation. Co-incubation with β1-agonist (50 μM during LPS exposure before OGD conferred complete protection from cell death (P -/- and TNFR2-/- slices exposed to LPS followed by OGD. Conclusions Our data demonstrate that activation of both β1- and β2-receptors is neuroprotective and may offer mechanistic insights valuable for development of neuro-protective strategies in neonates.

  9. Functional clustering in hippocampal cultures: relating network structure and dynamics

    International Nuclear Information System (INIS)

    Feldt, S; Dzakpasu, R; Olariu, E; Żochowski, M; Wang, J X; Shtrahman, E

    2010-01-01

    In this work we investigate the relationship between gross anatomic structural network properties, neuronal dynamics and the resultant functional structure in dissociated rat hippocampal cultures. Specifically, we studied cultures as they developed under two conditions: the first supporting glial cell growth (high glial group), and the second one inhibiting it (low glial group). We then compared structural network properties and the spatio-temporal activity patterns of the neurons. Differences in dynamics between the two groups could be linked to the impact of the glial network on the neuronal network as the cultures developed. We also implemented a recently developed algorithm called the functional clustering algorithm (FCA) to obtain the resulting functional network structure. We show that this new algorithm is useful for capturing changes in functional network structure as the networks evolve over time. The FCA detects changes in functional structure that are consistent with expected dynamical differences due to the impact of the glial network. Cultures in the high glial group show an increase in global synchronization as the cultures age, while those in the low glial group remain locally synchronized. We additionally use the FCA to quantify the amount of synchronization present in the cultures and show that the total level of synchronization in the high glial group is stronger than in the low glial group. These results indicate an interdependence between the glial and neuronal networks present in dissociated cultures

  10. Discerning cultural identification from a thinly sliced behavioral sample.

    Science.gov (United States)

    Hamamura, Takeshi; Li, Liman Man Wai

    2012-12-01

    This research examined whether individual differences in cultural identification can be discerned at zero acquaintance. This issue was examined in Hong Kong, where the idiosyncrasy of cultural identification is a salient social-psychological issue. The participants were able to perceive accurately the targets' identification with Western culture from a video clip and from a still image. Findings also indicated that a stereotype of Western cultural identity (i.e., extraversion and particular hairstyle) facilitated these perceptions. Specifically, (a) the participants with a stronger stereotype were more accurate in perceiving Western cultural identification, (b) the targets who were experimentally manipulated to appear extraverted were rated as more strongly identifying with Western culture, and (c) the participants relatively unfamiliar with these stereotypes did not correctly perceive Western cultural identification. Implications of these findings on research on multiculturalism are also discussed.

  11. Dopaminergic differentiation of human neural stem cells mediated by co-cultured rat striatal brain slices

    DEFF Research Database (Denmark)

    Anwar, Mohammad Raffaqat; Andreasen, Christian Maaløv; Lippert, Solvej Kølvraa

    2008-01-01

    differentiation, we co-cultured cells from a human neural forebrain-derived stem cell line (hNS1) with rat striatal brain slices. In brief, coronal slices of neonatal rat striatum were cultured on semiporous membrane inserts placed in six-well trays overlying monolayers of hNS1 cells. After 12 days of co......Properly committed neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. To establish a setting for identification of secreted neural compounds promoting dopaminergic...

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

    Science.gov (United States)

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

    2017-02-01

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

  13. Excitatory amino acid neurotoxicity and modulation of glutamate receptor expression in organotypic brain slice cultures

    DEFF Research Database (Denmark)

    Zimmer, J; Kristensen, Bjarne Winther; Jakobsen, B

    2000-01-01

    Using organotypic slice cultures of hippocampus and cortex-striatum from newborn to 7 day old rats, we are currently studying the excitotoxic effects of kainic acid (KA), AMPA and NMDA and the neuroprotective effects of glutamate receptor blockers, like NBQX. For detection and quantitation...

  14. Effects of chemotherapeutics on organotypic corticostriatal slice cultures identified by a panel of fluorescent and immunohistochemical markers

    DEFF Research Database (Denmark)

    Nørregaard, Annette; Jensen, Stine Skov; Kolenda, Jesper

    2012-01-01

    no toxicity was observed. Corresponding immunostaining showed loss of MAP2 and increased expression of GFAP and p25α for cultures exposed to 1,000 nM VCR. Cultures exposed to high concentrations of ACNU and IM disintegrated, leaving no tissue for histology. In conclusion, corticostriatal slice cultures...... specific neuronal and glial degeneration induced by chemotherapeutics in organotypic rat corticostriatal slice cultures. The slice cultures were exposed to the alkylating agents temozolomide (TMZ) and nimustine (ACNU), the tyrosine kinase inhibitor imatinib mesylate (IM) and the microtubule...

  15. Electrophysiology of Hypothalamic Magnocellular Neurons In vitro: A Rhythmic Drive in Organotypic Cultures and Acute Slices.

    Science.gov (United States)

    Israel, Jean-Marc; Oliet, Stéphane H; Ciofi, Philippe

    2016-01-01

    Hypothalamic neurohormones are released in a pulsatile manner. The mechanisms of this pulsatility remain poorly understood and several hypotheses are available, depending upon the neuroendocrine system considered. Among these systems, hypothalamo-neurohypophyseal magnocellular neurons have been early-considered models, as they typically display an electrical activity consisting of bursts of action potentials that is optimal for the release of boluses of the neurohormones oxytocin and vasopressin. The cellular mechanisms underlying this bursting behavior have been studied in vitro, using either acute slices of the adult hypothalamus, or organotypic cultures of neonatal hypothalamic tissue. We have recently proposed, from experiments in organotypic cultures, that specific central pattern generator networks, upstream of magnocellular neurons, determine their bursting activity. Here, we have tested whether a similar hypothesis can be derived from in vitro experiments in acute slices of the adult hypothalamus. To this aim we have screened our electrophysiological recordings of the magnocellular neurons, previously obtained from acute slices, with an analysis of autocorrelation of action potentials to detect a rhythmic drive as we recently did for organotypic cultures. This confirmed that the bursting behavior of magnocellular neurons is governed by central pattern generator networks whose rhythmic drive, and thus probably integrity, is however less satisfactorily preserved in the acute slices from adult brains.

  16. Electrophysiology of hypothalamic magnocellular neurons in vitro: a rhythmic drive in organotypic cultures and acute slices

    Directory of Open Access Journals (Sweden)

    Jean-Marc eIsrael

    2016-03-01

    Full Text Available Hypothalamic neurohormones are released in a pulsatile manner. The mechanisms of this pulsatility remain poorly understood and several hypotheses are available, depending upon the neuroendocrine system considered. Among these systems, hypothalamo-neurohypophyseal magnocellular neurons have been early-considered models, as they typically display an electrical activity consisting of bursts of action potentials that is optimal for the release of boluses of the neurohormones oxytocin and vasopressin. The cellular mechanisms underlying this bursting behavior have been studied in vitro, using either acute slices of the adult hypothalamus, or organotypic cultures of neonatal hypothalamic tissue. We have recently proposed, from experiments in organotypic cultures, that specific central pattern generator networks, upstream of magnocellular neurons, determine their bursting activity. Here, we have tested whether a similar hypothesis can be derived from in vitro experiments in acute slices of the adult hypothalamus. To this aim we have screened our electrophysiological recordings of the magnocellular neurons, previously obtained from acute slices, with an analysis of autocorrelation of action potentials to detect a rhythmic drive as we recently did for organotypic cultures. This confirmed that the bursting behavior of magnocellular neurons is governed by central pattern generator networks whose rhythmic drive, and thus probably integrity, is however less satisfactorily preserved in the acute slices from adult brains.

  17. The impact of aging, hearing loss, and body weight on mouse hippocampal redox state, measured in brain slices using fluorescence imaging.

    Science.gov (United States)

    Stebbings, Kevin A; Choi, Hyun W; Ravindra, Aditya; Llano, Daniel Adolfo

    2016-06-01

    The relationships between oxidative stress in the hippocampus and other aging-related changes such as hearing loss, cortical thinning, or changes in body weight are not yet known. We measured the redox ratio in a number of neural structures in brain slices taken from young and aged mice. Hearing thresholds, body weight, and cortical thickness were also measured. We found striking aging-related increases in the redox ratio that were isolated to the stratum pyramidale, while such changes were not observed in thalamus or cortex. These changes were driven primarily by changes in flavin adenine dinucleotide, not nicotinamide adenine dinucleotide hydride. Multiple regression analysis suggested that neither hearing threshold nor cortical thickness independently contributed to this change in hippocampal redox ratio. However, body weight did independently contribute to predicted changes in hippocampal redox ratio. These data suggest that aging-related changes in hippocampal redox ratio are not a general reflection of overall brain oxidative state but are highly localized, while still being related to at least one marker of late aging, weight loss at the end of life. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Epileptogenesis in organotypic hippocampal cultures has limited dependence on culture medium composition.

    Directory of Open Access Journals (Sweden)

    Jing Liu

    Full Text Available Rodent organotypic hippocampal cultures spontaneously develop epileptiform activity after approximately 2 weeks in vitro and are increasingly used as a model of chronic post-traumatic epilepsy. However, organotypic cultures are maintained in an artificial environment (culture medium, which contains electrolytes, glucose, amino acids and other components that are not present at the same concentrations in cerebrospinal fluid (CSF. Therefore, it is possible that epileptogenesis in organotypic cultures is driven by these components. We examined the influence of medium composition on epileptogenesis. Epileptogenesis was evaluated by measurements of lactate and lactate dehydrogenase (LDH levels (biomarkers of ictal activity and cell death, respectively in spent culture media, immunohistochemistry and automated 3-D cell counts, and extracellular recordings from CA3 regions. Changes in culture medium components moderately influenced lactate and LDH levels as well as electrographic seizure burden and cell death. However, epileptogenesis occurred in any culture medium that was capable of supporting neural survival. We conclude that medium composition is unlikely to be the cause of epileptogenesis in the organotypic hippocampal culture model of chronic post-traumatic epilepsy.

  19. Epileptogenesis in organotypic hippocampal cultures has limited dependence on culture medium composition.

    Science.gov (United States)

    Liu, Jing; Saponjian, Yero; Mahoney, Mark M; Staley, Kevin J; Berdichevsky, Yevgeny

    2017-01-01

    Rodent organotypic hippocampal cultures spontaneously develop epileptiform activity after approximately 2 weeks in vitro and are increasingly used as a model of chronic post-traumatic epilepsy. However, organotypic cultures are maintained in an artificial environment (culture medium), which contains electrolytes, glucose, amino acids and other components that are not present at the same concentrations in cerebrospinal fluid (CSF). Therefore, it is possible that epileptogenesis in organotypic cultures is driven by these components. We examined the influence of medium composition on epileptogenesis. Epileptogenesis was evaluated by measurements of lactate and lactate dehydrogenase (LDH) levels (biomarkers of ictal activity and cell death, respectively) in spent culture media, immunohistochemistry and automated 3-D cell counts, and extracellular recordings from CA3 regions. Changes in culture medium components moderately influenced lactate and LDH levels as well as electrographic seizure burden and cell death. However, epileptogenesis occurred in any culture medium that was capable of supporting neural survival. We conclude that medium composition is unlikely to be the cause of epileptogenesis in the organotypic hippocampal culture model of chronic post-traumatic epilepsy.

  20. Release of [3H]GABA formed from [3H]glutamate in rat hippocampal slices: comparison with endogenous and exogenous labeled GABA

    International Nuclear Information System (INIS)

    Szerb, J.C.

    1983-01-01

    To compare the storage and release of endogenous GABA, of [ 3 H]GABA formed endogenously from glutamate, and of exogenous [ 14 C]GABA, hippocampal slices were incubated with 5 microCi/ml [3,4- 3 H]1-glutamate and 0.5 microCi/ml [U- 14 C]GABA and then were superfused in the presence or absence of Ca + with either 50 mM K + or 50 microM veratridine. Exogenous [ 14 C]GABA content of the slices declined spontaneously while endogenous GABA and endogenously formed [ 3 H]GABA stayed constant over a 48 min period. In the presence of Ca + 50 mM K + and in the presence or absence of Ca2 + veratridine released exogenous [ 14 C]GABA more rapidly than endogenous or endogenously formed [ 3 H]GABA, the release of the latter two occurring always in parallel. The initial specific activity of released exogenous [ 14 C]GABA was three times, while that of endogenously formed [ 3 H]GABA was only 50% higher than that in the slices. The observation that endogenous GABA and [ 3 H]GABA formed endogenously from glutamate are stored and released in parallel but differently from exogenous labelled GABA, suggests that exogenous [ 3 H] glutamate can enter a glutamate pool that normally serves as precursor of GABA

  1. BDNF downregulates 5-HT(2A) receptor protein levels in hippocampal cultures

    DEFF Research Database (Denmark)

    Trajkovska, V; Santini, M A; Marcussen, Anders Bue

    2009-01-01

    Both brain-derived neurotrophic factor (BDNF) and the serotonin receptor 2A (5-HT(2A)) have been related to depression pathology. Specific 5-HT(2A) receptor changes seen in BDNF conditional mutant mice suggest that BDNF regulates the 5-HT(2A) receptor level. Here we show a direct effect of BDNF...... on 5-HT(2A) receptor protein levels in primary hippocampal neuronal and mature hippocampal organotypic cultures exposed to different BDNF concentrations for either 1, 3, 5 or 7 days. In vivo effects of BDNF on hippocampal 5-HT(2A) receptor levels were further corroborated in (BDNF +/-) mice...... with reduced BDNF levels. In primary neuronal cultures, 7 days exposure to 25 and 50ng/mL BDNF resulted in downregulation of 5-HT(2A), but not of 5-HT(1A), receptor protein levels. The BDNF-associated downregulation of 5-HT(2A) receptor levels was also observed in mature hippocampal organotypic cultures...

  2. Organotypic brain slice cultures of adult transgenic P301S mice--a model for tauopathy studies.

    Directory of Open Access Journals (Sweden)

    Agneta Mewes

    Full Text Available BACKGROUND: Organotypic brain slice cultures represent an excellent compromise between single cell cultures and complete animal studies, in this way replacing and reducing the number of animal experiments. Organotypic brain slices are widely applied to model neuronal development and regeneration as well as neuronal pathology concerning stroke, epilepsy and Alzheimer's disease (AD. AD is characterized by two protein alterations, namely tau hyperphosphorylation and excessive amyloid β deposition, both causing microglia and astrocyte activation. Deposits of hyperphosphorylated tau, called neurofibrillary tangles (NFTs, surrounded by activated glia are modeled in transgenic mice, e.g. the tauopathy model P301S. METHODOLOGY/PRINCIPAL FINDINGS: In this study we explore the benefits and limitations of organotypic brain slice cultures made of mature adult transgenic mice as a potential model system for the multifactorial phenotype of AD. First, neonatal (P1 and adult organotypic brain slice cultures from 7- to 10-month-old transgenic P301S mice have been compared with regard to vitality, which was monitored with the lactate dehydrogenase (LDH- and the MTT (3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assays over 15 days. Neonatal slices displayed a constant high vitality level, while the vitality of adult slice cultures decreased significantly upon cultivation. Various preparation and cultivation conditions were tested to augment the vitality of adult slices and improvements were achieved with a reduced slice thickness, a mild hypothermic cultivation temperature and a cultivation CO(2 concentration of 5%. Furthermore, we present a substantial immunohistochemical characterization analyzing the morphology of neurons, astrocytes and microglia in comparison to neonatal tissue. CONCLUSION/SIGNIFICANCE: Until now only adolescent animals with a maximum age of two months have been used to prepare organotypic brain slices. The current study

  3. Miniature excitatory synaptic currents in cultured hippocampal neurons.

    Science.gov (United States)

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

    1990-06-04

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

  4. Assessment of seizure liability of Org 306039, a 5-HT2c agonist, using hippocampal brain slice and rodent EEG telemetry.

    Science.gov (United States)

    Markgraf, Carrie G; DeBoer, Erik; Zhai, Jin; Cornelius, Lara; Zhou, Ying Ying; MacSweeney, Cliona

    2014-01-01

    Evaluation of the seizure potential for a CNS-targeted pharmaceutical compound before it is administered to humans is an important part of development. The current in vitro and in vivo studies were undertaken to characterize the seizure potential of the potent and selective 5-HT2c agonist Org 306039. Rat hippocampal slices (n=5) were prepared and Org 306039 was applied over a concentration range of 0-1000μM. Male Sprague-Dawley rats, implanted with telemetry EEG recording electrodes received either vehicle (n=4) or 100mg/kg Org 306039 (n=4) by oral gavage daily for 10days. EEG was recorded continuously for 22±1h post-dose each day. Post-dose behavior observations were conducted daily for 2h. Body temperature was measured at 1 and 2h post-dose. On Day 7, blood samples were drawn for pharmacokinetic analysis of Org 306039. In hippocampal slice, Org 306039 elicited a concentration-dependent increase in population spike area and number recorded from CA1 area, indicating seizure-genic potential. In telemetered rats, Org 306039 was associated with a decrease in body weight, a decrease in body temperature and the appearance of seizure-related behaviors and pre-seizure waveforms on EEG. One rat exhibited an overt seizure. Plasma concentrations of Org 306039 were similar among the 4 rats in the Org-treated group. Small group size made it difficult to determine a PK-PD relationship. These results indicate that the in vitro and in vivo models complement each other in the characterization of the seizure potential of CNS-targeted compounds such as the 5-HT2c agonist Org 306039. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Removal of area CA3 from hippocampal slices induces postsynaptic plasticity at Schaffer collateral synapses that normalizes CA1 pyramidal cell discharge.

    Science.gov (United States)

    Dumas, Theodore C; Uttaro, Michael R; Barriga, Carolina; Brinkley, Tiffany; Halavi, Maryam; Wright, Susan N; Ferrante, Michele; Evans, Rebekah C; Hawes, Sarah L; Sanders, Erin M

    2018-05-05

    Neural networks that undergo acute insults display remarkable reorganization. This injury related plasticity is thought to permit recovery of function in the face of damage that cannot be reversed. Previously, an increase in the transmission strength at Schaffer collateral to CA1 pyramidal cell synapses was observed after long-term activity reduction in organotypic hippocampal slices. Here we report that, following acute preparation of adult rat hippocampal slices and surgical removal of area CA3, input to area CA1 was reduced and Schaffer collateral synapses underwent functional strengthening. This increase in synaptic strength was limited to Schaffer collateral inputs (no alteration to temporoammonic synapses) and acted to normalize postsynaptic discharge, supporting a homeostatic or compensatory response. Short-term plasticity was not altered, but an increase in immunohistochemical labeling of GluA1 subunits was observed in the stratum radiatum (but not stratum moleculare), suggesting increased numbers of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and a postsynaptic locus of expression. Combined, these data support the idea that, in response to the reduction in presynaptic activity caused by removal of area CA3, Schaffer collateral synapses undergo a relatively rapid increase in functional efficacy likely supported by insertion of more AMPARs, which maintains postsynaptic excitability in CA1 pyramidal neurons. This novel fast compensatory plasticity exhibits properties that would allow it to maintain optimal network activity levels in the hippocampus, a brain structure lauded for its ongoing experience-dependent malleability. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Differences in kainate receptor involvement in hippocampal mossy fibre long-term potentiation depending on slice orientation.

    Science.gov (United States)

    Sherwood, John L; Amici, Mascia; Dargan, Sheila L; Culley, Georgia R; Fitzjohn, Stephen M; Jane, David E; Collingridge, Graham L; Lodge, David; Bortolotto, Zuner A

    2012-09-01

    Long-term potentiation (LTP) is a well-established experimental model used to investigate the synaptic basis of learning and memory. LTP at mossy fibre - CA3 synapses in the hippocampus is unusual because it is normally N-methyl-d-aspartate (NMDA) receptor-independent. Instead it seems that the trigger for mossy fibre LTP involves kainate receptors (KARs). Although it is generally accepted that pre-synaptic KARs play an essential role in frequency facilitation and LTP, their subunit composition remains a matter of significant controversy. We have reported previously that both frequency facilitation and LTP can be blocked by selective antagonism of GluK1 (formerly GluR5/Glu(K5))-containing KARs, but other groups have failed to reproduce this effect. Moreover, data from receptor knockout and mRNA expression studies argue against a major role of GluK1, supporting a more central role for GluK2 (formerly GluR6/Glu(K6)). A potential reason underlying the controversy in the pharmacological experiments may reside in differences in the preparations used. Here we show differences in pharmacological sensitivity of synaptic plasticity at mossy fibre - CA3 synapses depend critically on slice orientation. In transverse slices, LTP of fEPSPs was invariably resistant to GluK1-selective antagonists whereas in parasagittal slices LTP was consistently blocked by GluK1-selective antagonists. In addition, there were pronounced differences in the magnitude of frequency facilitation and the sensitivity to the mGlu2/3 receptor agonist DCG-IV. Using anterograde labelling of granule cells we show that slices of both orientations possess intact mossy fibres and both large and small presynaptic boutons. Transverse slices have denser fibre tracts but a smaller proportion of giant mossy fibre boutons. These results further demonstrate a considerable heterogeneity in the functional properties of the mossy fibre projection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. The Glycolytic Metabolite, Fructose-1,6-bisphosphate, Blocks Epileptiform Bursts by Attenuating Voltage-Activated Calcium Currents in Hippocampal Slices

    Directory of Open Access Journals (Sweden)

    Li-Rong Shao

    2018-06-01

    Full Text Available Manipulation of metabolic pathways (e.g., ketogenic diet (KD, glycolytic inhibition alters neural excitability and represents a novel strategy for treatment of drug-refractory seizures. We have previously shown that inhibition of glycolysis suppresses epileptiform activity in hippocampal slices. In the present study, we aimed to examine the role of a “branching” metabolic pathway stemming off glycolysis (i.e., the pentose-phosphate pathway, PPP in regulating seizure activity, by using a potent PPP stimulator and glycolytic intermediate, fructose-1,6-bisphosphate (F1,6BP. Employing electrophysiological approaches, we investigated the action of F1,6BP on epileptiform population bursts, intrinsic neuronal firing, glutamatergic and GABAergic synaptic transmission and voltage-activated calcium currents (ICa in the CA3 area of hippocampal slices. Bath application of F1,6BP (2.5–5 mM blocked epileptiform population bursts induced in Mg2+-free medium containing 4-aminopyridine, in ~2/3 of the slices. The blockade occurred relatively rapidly (~4 min, suggesting an extracellular mechanism. However, F1,6BP did not block spontaneous intrinsic firing of the CA3 neurons (when synaptic transmission was eliminated with DNQX, AP-5 and SR95531, nor did it significantly reduce AMPA or NMDA receptor-mediated excitatory postsynaptic currents (EPSCAMPA and EPSCNMDA. In contrast, F1,6BP caused moderate reduction (~50% in GABAA receptor-mediated current, suggesting it affects excitatory and inhibitory synapses differently. Finally and unexpectedly, F1,6BP consistently attenuated ICa by ~40% without altering channel activation or inactivation kinetics, which may explain its anticonvulsant action, at least in this in vitro seizure model. Consistent with these results, epileptiform population bursts in CA3 were readily blocked by the nonspecific Ca2+ channel blocker, CdCl2 (20 μM, suggesting that these bursts are calcium dependent. Altogether, these data

  8. Tetrahydrobiopterin precursor sepiapterin provides protection against neurotoxicity of 1-methyl-4-phenylpyridinium in nigral slice cultures

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Jansen, Pernille; Hesslinger, Christian

    2003-01-01

    Complex-I inhibition and oxidative processes have been implicated in the loss of nigral dopamine neurones in Parkinson's disease and the toxicity of MPTP and its metabolite MPP+. Tetrahydrobiopterin, an essential cofactor for tyrosine hydroxylase, may act as an antioxidant in dopaminergic neurones...... and protects against the toxic consequences of glutathione depletion. Here we studied the effects of manipulating tetrahydrobiopterin levels on MPP+ toxicity in organotypic, rat ventral mesencephalic slice cultures. In cultures exposed to 30 micro m MPP+ for 2 days, followed by 8 days 'recovery' in control...... medium, we measured dopamine and its metabolites in the tissue and culture medium by HPLC, lactate dehydrogenase release to the culture medium, cellular uptake of propidium iodide and counted the tyrosine hydroxylase-immunoreactive neurones. Inhibition of tetrahydrobiopterin synthesis by 2,4-diamino-6...

  9. Element distribution of the barley plant grown in an agar slice suspended culture

    International Nuclear Information System (INIS)

    Makino-Nakanishi, Tomoko; Matsumoto, Satoshi

    1991-01-01

    An agar slice suspended culture was devised for the further study of the barley root. The roots were placed into an agar covered with a nylon cloth and suspended in a water culture vessel. Barley roots grown in the agar developed hardly any root hair. The element contents of the root grown in the agar culture and that in the water culture were measured by neutron activation analysis. The concentrations of K, Mg and Cl in the root grown in the agar were about half of these grown in the water. Na and Mn concentrations were the same and Ca concentration was slightly higher when grown in the agar. The agar system is expected to provide more information to study the root hair. (author)

  10. Modelling glioblastoma tumour-host cell interactions using adult brain organotypic slice co-culture

    Directory of Open Access Journals (Sweden)

    Maria Angeles Marques-Torrejon

    2018-02-01

    Full Text Available Glioblastoma multiforme (GBM is an aggressive incurable brain cancer. The cells that fuel the growth of tumours resemble neural stem cells found in the developing and adult mammalian forebrain. These are referred to as glioma stem cells (GSCs. Similar to neural stem cells, GSCs exhibit a variety of phenotypic states: dormant, quiescent, proliferative and differentiating. How environmental cues within the brain influence these distinct states is not well understood. Laboratory models of GBM can be generated using either genetically engineered mouse models, or via intracranial transplantation of cultured tumour initiating cells (mouse or human. Unfortunately, these approaches are expensive, time-consuming, low-throughput and ill-suited for monitoring live cell behaviours. Here, we explored whole adult brain coronal organotypic slices as an alternative model. Mouse adult brain slices remain viable in a serum-free basal medium for several weeks. GSCs can be easily microinjected into specific anatomical sites ex vivo, and we demonstrate distinct responses of engrafted GSCs to diverse microenvironments in the brain tissue. Within the subependymal zone – one of the adult neural stem cell niches – injected tumour cells could effectively engraft and respond to endothelial niche signals. Tumour-transplanted slices were treated with the antimitotic drug temozolomide as proof of principle of the utility in modelling responses to existing treatments. Engraftment of mouse or human GSCs onto whole brain coronal organotypic brain slices therefore provides a simplified, yet flexible, experimental model. This will help to increase the precision and throughput of modelling GSC-host brain interactions and complements ongoing in vivo studies. This article has an associated First Person interview with the first author of the paper.

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

    DEFF Research Database (Denmark)

    STEENSEN, BH; NEDERGAARD, S; OSTERGAARD, K

    1995-01-01

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

  12. Microchromatographic study of hippocampal area CA3 proteins during prolonged post-tetanic potentiation in surviving slices

    International Nuclear Information System (INIS)

    Pankova, T.M.; Mikichur, N.I.; Ratushayak, A.S.; Shtark, M.B.

    1985-01-01

    This paper studies the synthesis of proteins and, in particular, of brain-specific proteins in a homogeneous population of postsynaptic cells during the development of prolonged post-tetanic potentiation (PPTP). By using a system of synaptic connections incorporation of tritium-leucine into water-soluble protein of this zone has been investigated during the development of PPTP (in surviving slices after stimulation of mossy fibers). During statistical analysis of the results mean values of deviation of relative radioactivity compared with the control in each fraction was expressed as a percentage. The results were analyzed by Student's test, at the 95% level of significance

  13. Preventive effect of piracetam and vinpocetine on hypoxia-reoxygenation induced injury in primary hippocampal culture.

    Science.gov (United States)

    Solanki, P; Prasad, D; Muthuraju, S; Sharma, A K; Singh, S B; Ilavzhagan, G

    2011-04-01

    The present study investigates the potential of Piracetam and Vinpocetine (nootropic drugs, known to possess neuroprotective properties) in preventing hypoxia-reoxygenation induced oxidative stress in primary hippocampal cell culture. The hippocampal culture was exposed to hypoxia (95% N(2), 5% CO(2)) for 3h and followed by 1h of reoxygenation (21% O(2) and 5% CO(2)) at 37 °C. The primary hippocampal cultures were supplemented with the optimum dose of Piracetam and Vinpocetine, independently, and the cultures were divided into six groups, viz. Control/Normoxia, Hypoxia, Hypoxia+Piracetam, Hypoxia+Vinpocetine, Normoxia + Piracetam and Normoxia+Vinpocetine. The cell-viability assays and biochemical oxidative stress parameters were evaluated for each of the six groups. Administration of 1mM Piracetam or 500 nM Vinpocetine significantly prevents the culture from hypoxia-reoxygenation injury when determined by Neutral Red assay, LDH release and Acetylcholine esterase activity. Results showed that Piracetam and Vinpocetine supplementation significantly prevented the fall of mitochondrial membrane potential, rise in ROS generation and reduction in antioxidant levels associated with the hypoxia-reoxygenation injury. In conclusion, the present study establishes that both Piracetam and Vinpocetine give neuroprotection against hypoxia-reoxygenation injury in primary hippocampal cell culture. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Mesenchymal stem cells support neuronal fiber growth in an organotypic brain slice co-culture model.

    Science.gov (United States)

    Sygnecka, Katja; Heider, Andreas; Scherf, Nico; Alt, Rüdiger; Franke, Heike; Heine, Claudia

    2015-04-01

    Mesenchymal stem cells (MSCs) have been identified as promising candidates for neuroregenerative cell therapies. However, the impact of different isolation procedures on the functional and regenerative characteristics of MSC populations has not been studied thoroughly. To quantify these differences, we directly compared classically isolated bulk bone marrow-derived MSCs (bulk BM-MSCs) to the subpopulation Sca-1(+)Lin(-)CD45(-)-derived MSCs(-) (SL45-MSCs), isolated by fluorescence-activated cell sorting from bulk BM-cell suspensions. Both populations were analyzed with respect to functional readouts, that are, frequency of fibroblast colony forming units (CFU-f), general morphology, and expression of stem cell markers. The SL45-MSC population is characterized by greater morphological homogeneity, higher CFU-f frequency, and significantly increased nestin expression compared with bulk BM-MSCs. We further quantified the potential of both cell populations to enhance neuronal fiber growth, using an ex vivo model of organotypic brain slice co-cultures of the mesocortical dopaminergic projection system. The MSC populations were cultivated underneath the slice co-cultures without direct contact using a transwell system. After cultivation, the fiber density in the border region between the two brain slices was quantified. While both populations significantly enhanced fiber outgrowth as compared with controls, purified SL45-MSCs stimulated fiber growth to a larger degree. Subsequently, we analyzed the expression of different growth factors in both cell populations. The results show a significantly higher expression of brain-derived neurotrophic factor (BDNF) and basic fibroblast growth factor in the SL45-MSCs population. Altogether, we conclude that MSC preparations enriched for primary MSCs promote neuronal regeneration and axonal regrowth, more effectively than bulk BM-MSCs, an effect that may be mediated by a higher BDNF secretion.

  15. Rubia cordifolia, Fagonia cretica linn and Tinospora cordifolia exert neuroprotection by modulating the antioxidant system in rat hippocampal slices subjected to oxygen glucose deprivation

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    Biswas Saibal K

    2004-08-01

    Full Text Available Abstract Background The major damaging factor during and after the ischemic/hypoxic insult is the generation of free radicals, which leads to apoptosis, necrosis and ultimately cell death. Rubia cordifolia (RC, Fagonia cretica linn (FC and Tinospora cordifolia (TC have been reported to contain a wide variety of antioxidants and have been in use in the eastern system of medicine for various disorders. However, their mechanism of action was largely unknown. We therefore selected these herbs for the present study to test their neuroprotective ability and the associated mechanism in rat hippocampal slices subjected to oxygen-glucose deprivation (OGD. Methods Hippocampal Slices were subjected to OGD (oxygen glucose deprivation and divided into 3 groups: control, OGD and OGD + drug treated. Cytosolic Cu-Zn superoxide dismutase (Cu-Zn SOD, reduced glutathione (GSH, glutathione peroxidase (GPx, nitric oxide (NO was measured as nitrite (NO2 in the supernatant and protein assays were performed in the respective groups at various time intervals. EPR was used to establish the antioxidant effect of RC, FC and TC with respect to superoxide anion (O2.-, hydroxyl radicals (. OH, nitric oxide (NO radical and peroxynitrite anion (ONOO generated from pyrogallol, menadione, DETA-NO and Sin-1 respectively. RT-PCR was performed for the three groups for GCLC, iNOS, Cu-Zn SOD and GAPDH gene expression. Results All the three herbs were effective in elevating the GSH levels, expression of the gamma-glutamylcysteine ligase and Cu-Zn SOD genes. The herbs also exhibited strong free radical scavenging properties against reactive oxygen and nitrogen species as studied by electron paramagnetic resonance spectroscopy. In addition all the three herbs significantly diminished the expression of iNOS gene after 48 hours which plays a major role in neuronal injury during hypoxia/ischemia. Conclusions RC, FC and TC therefore attenuate oxidative stress mediated cell injury during OGD

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

    DEFF Research Database (Denmark)

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

    The brain is the center of the nervous system, where serious neurodegenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s are products of functional loss in the neural cells (1). Typical techniques used to investigate these diseases lack precise control of the cellular surroundings......, in addition to isolating the neural tissue from nutrient delivery and to creating unwanted gradients (2). This means that typical techniques used to investigate neurodegenerative diseases cannot mimic in vivo conditions, as closely as desired. We have developed a novel microfluidic system for culturing PC12...... cells, neuronal cells, astrocytes cultures and brain slices. The microfluidic system provides efficient nutrient delivery, waste removal, access to oxygen, fine control over the neurochemical environment and access to modern microscopy. Additionally, the setup consists of an in vitro culturing...

  17. Mouse pancreas tissue slice culture facilitates long-term studies of exocrine and endocrine cell physiology in situ.

    Science.gov (United States)

    Marciniak, Anja; Selck, Claudia; Friedrich, Betty; Speier, Stephan

    2013-01-01

    Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To overcome these limitations, we aimed to establish a pancreas tissue slice culture platform to allow long-term studies on exocrine and endocrine cells in the intact pancreatic environment. Mouse pancreas tissue slice morphology was assessed to determine optimal long-term culture settings for intact pancreatic tissue. Utilizing optimized culture conditions, cell specificity and function of exocrine acinar cells and endocrine beta cells were characterized over a culture period of 7 days. We found pancreas tissue slices cultured under optimized conditions to have intact tissue specific morphology for the entire culture period. Amylase positive intact acini were present at all time points of culture and acinar cells displayed a typical strong cell polarity. Amylase release from pancreas tissue slices decreased during culture, but maintained the characteristic bell-shaped dose-response curve to increasing caerulein concentrations and a ca. 4-fold maximal over basal release. Additionally, endocrine beta cell viability and function was well preserved until the end of the observation period. Our results show that the tissue slice culture platform provides unprecedented maintenance of pancreatic tissue specific morphology and function over a culture period for at least 4 days and in part even up to 1 week. This analytical advancement now allows mid -to long-term studies on the cell biology of pancreatic disorder pathogenesis and therapy in an intact surrounding in situ.

  18. Mouse pancreas tissue slice culture facilitates long-term studies of exocrine and endocrine cell physiology in situ.

    Directory of Open Access Journals (Sweden)

    Anja Marciniak

    Full Text Available Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To overcome these limitations, we aimed to establish a pancreas tissue slice culture platform to allow long-term studies on exocrine and endocrine cells in the intact pancreatic environment. Mouse pancreas tissue slice morphology was assessed to determine optimal long-term culture settings for intact pancreatic tissue. Utilizing optimized culture conditions, cell specificity and function of exocrine acinar cells and endocrine beta cells were characterized over a culture period of 7 days. We found pancreas tissue slices cultured under optimized conditions to have intact tissue specific morphology for the entire culture period. Amylase positive intact acini were present at all time points of culture and acinar cells displayed a typical strong cell polarity. Amylase release from pancreas tissue slices decreased during culture, but maintained the characteristic bell-shaped dose-response curve to increasing caerulein concentrations and a ca. 4-fold maximal over basal release. Additionally, endocrine beta cell viability and function was well preserved until the end of the observation period. Our results show that the tissue slice culture platform provides unprecedented maintenance of pancreatic tissue specific morphology and function over a culture period for at least 4 days and in part even up to 1 week. This analytical advancement now allows mid -to long-term studies on the cell biology of pancreatic disorder pathogenesis and therapy in an intact surrounding in situ.

  19. Effect of Rubia cordifolia, Fagonia cretica linn, and Tinospora cordifolia on free radical generation and lipid peroxidation during oxygen-glucose deprivation in rat hippocampal slices

    International Nuclear Information System (INIS)

    Rawal, Avinash; Muddeshwar, Manohar; Biswas, Saibal

    2004-01-01

    The major damaging factor during and after the ischemic/hypoxic insult is the generation of free radicals, which leads to apoptosis, necrosis, and ultimately cell death. Rubia cordifolia (RC), Fagonia cretica linn (FC), and Tinospora cordifolia (TC) have been reported to contain a wide variety of antioxidants and have been in use in the eastern system of medicine for various disorders. Hippocampal slices were subjected to oxygen-glucose deprivation (OGD) and divided into three groups, control, OGD, and OGD+drug treated. Cytosolic reduced glutathione (GSH), nitric oxide [NO, measured as nitrite (NO 2 )]. EPR was used to establish the antioxidant effect of RC, FC, and TC with respect to superoxide anion (O2-), hydroxyl radicals (OH), nitric oxide (NO) radical, and peroxynitrite anion (ONOO - ) generated from pyrogallol, menadione, DETA-NO, and Sin-1, respectively. RT-PCR was performed for the three herbs to assess their effect on the expression of γ-glutamylcysteine ligase (GCLC), iNOS, and GAPDH gene expression. All the three herbs were effective in elevating the GSH levels and expression of the GCLC. The herbs also exhibited strong free radical scavenging properties against reactive oxygen and nitrogen species as revealed by electron paramagnetic resonance spectroscopy, diminishing the expression of iNOS gene. RC, FC, and TC therefore attenuate oxidative stress mediated cell injury during OGD and exert the above effects at both the cytosolic as well as at gene expression levels and may be effective therapeutic tool against ischemic brain damage

  20. [Effect of (+/-)-pindolol on the central 5-HT1A receptor by the use of in vivo microdialysis and hippocampal slice preparations].

    Science.gov (United States)

    Tsuji, Keiichiro

    2002-06-01

    Although it is suggested that (+/-)-pindolol, a beta-adrenergic/5-HT1A receptor antagonist, may enhance the efficacy of selective serotonin reuptake inhibitors (SSRI), the results of double-blind studies are contradictory and recent animal studies suggest that (+/-)-pindolol may act as a partial agonist to the 5-HT1A receptor. In this study we have investigated the effect of (+/-)-pindolol on both pre- and postsynaptic 5-HT1A receptors using in vivo microdialysis and hippocampal slice preparations. (+/-)-pindolol and flesinoxan, a 5-HT1A receptor full agonist, significantly decreased the extracellular levels of 5-HT in the raphe and prefrontal cortex. The 5-HT and other 5-HT1A receptor agonists, flesinoxan and 8-hydroxy-2- (di-n-propylamino)tetralon (8-OH-DPAT), significantly decreased the population excitatory postsynaptic potential (EPSP) in the CA3-CA1 excitatory synapse in a dose-dependent manner. The effect of 5-HT and other 5-HT1A receptor agonists accompanied the increase in paired-pulse facilitation (ppf) induced by short-interval two stimuli and were reversed by the coadministration of the 5-HT1A receptor agonist, NAN-190, but not by (+/-)-pindolol. (+/-)-pindolol also suppressed the EPSP, but this effect was not reversed by NAN-190. These results suggest that (+/-)-pindolol acts as a partial agonist to the somatodendritic 5-HT1A receptor in the raphe, whereas it may have no action on the postsynaptic 5-HT1A receptor in the hippocampus.

  1. Neuroprotective effects of anticonvulsants in rat hippocampal slice cultures exposed to oxygen/glucose deprivation

    DEFF Research Database (Denmark)

    Rekling, Jens C

    2003-01-01

    cell death induced by OGD. The newer anticonvulsants carbamazepine, felbamate, lamotrigine, tiagabine, and oxcarbazepine also had significant neuroprotective effects, but gabapentin, valproic acid (10 mM), levetiracetam and retigabine were not neuroprotective at a concentration up to 300 micro...

  2. Neuroprotective effects of ginsenoside Rg1 against oxygen–glucose deprivation in cultured hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Qing He

    2014-03-01

    Conclusion: Ginsenoside Rg1 has neuroprotective effect on ischemia–reperfusion injury in cultured hippocampal cells mediated by blocking calcium over-influx into neuronal cells and decreasing the nNOS activity after OGD exposure. We infer that ginsenoside Rg1 may serve as a potential therapeutic agent for cerebral ischemia injury.

  3. Implantation of glioblastoma spheroids into organotypic brain slice cultures as a model for investigating effects of irradiation

    DEFF Research Database (Denmark)

    Petterson, Stine Asferg; Jakobsen, Ida Pind; Jensen, Stine Skov

    2016-01-01

    , models for studying the effects of radiotherapy in combination with novel strategies are lacking but important since radiotherapy is the most successful non-surgical treatment of brain tumors. The aim of this study was to establish a glioblastoma spheroid-organotypic rat brain slice culture model...... comprising both tumors, tumor-brain interface and brain tissue to provide a proof of concept that this model is useful for studying effects of radiotherapy. Organotypic brain slice cultures cultured for 1-2 days or 11-16 days corresponding to immature brain and mature brain respectively were irradiated...... with doses between 10 and 50 Gy. There was a high uptake of the cell death marker propidium iodide in the immature cultures. In addition, MAP2 expression decreased whereas GFAP expression increased in these cultures suggesting neuronal death and astrogliosis. We therefore proceeded with the mature cultures...

  4. Functional Stem Cell Integration into Neural Networks Assessed by Organotypic Slice Cultures.

    Science.gov (United States)

    Forsberg, David; Thonabulsombat, Charoensri; Jäderstad, Johan; Jäderstad, Linda Maria; Olivius, Petri; Herlenius, Eric

    2017-08-14

    Re-formation or preservation of functional, electrically active neural networks has been proffered as one of the goals of stem cell-mediated neural therapeutics. A primary issue for a cell therapy approach is the formation of functional contacts between the implanted cells and the host tissue. Therefore, it is of fundamental interest to establish protocols that allow us to delineate a detailed time course of grafted stem cell survival, migration, differentiation, integration, and functional interaction with the host. One option for in vitro studies is to examine the integration of exogenous stem cells into an existing active neural network in ex vivo organotypic cultures. Organotypic cultures leave the structural integrity essentially intact while still allowing the microenvironment to be carefully controlled. This allows detailed studies over time of cellular responses and cell-cell interactions, which are not readily performed in vivo. This unit describes procedures for using organotypic slice cultures as ex vivo model systems for studying neural stem cell and embryonic stem cell engraftment and communication with CNS host tissue. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  5. Cytokines effects on radio-induced apoptosis in cortical and hippocampal rat cells in culture

    International Nuclear Information System (INIS)

    Coffigny, H.; Briot, D.; Le Nin, I.

    2000-01-01

    In the central nervous system in development the radio-induced cell death occurs mainly by apoptosis. The effects of modulating factors like cytokines were studied on this kind of death. To handle more easily parameters implicated in nerve cell apoptosis, we studied the effects of radiation with a in vitro system. Cells were isolated from rat foetal cortex and hippocampus, two of the major structures implicated in human mental retardation observed after exposition in utero at Hiroshima and Nagasaki. Cortical or hippocampal cells were isolated from 17 day-old rat foetuses by enzymatic and mechanical treatments and irradiated with 0.50 or 1 Gy. The cells from both structures were cultured 1 or 3 days in serum free medium. Cytokines like βNGF, NT3, EGF, βTGF, α and βFGF, IGF I and II, interleukines like Il 1β, Il 2 and IL 6 were added to the medium. In 3 days cortical cell culture, only βFGF increased cell survival with as little as 10 ng/ml. This effect was dose dependent. In hippocampal cell culture, no significant increase of cell survival occurred with 10 ng/ml of any cytokines. In the same system culture with 1 Gy irradiation, the positive or negative effect of the association of βFGF with another cytokine was tested on cell survival. Only the association with EGF induced higher cell survival in cortical cell culture. In hippocampal cell culture where βFGF alone had no effect, the cell survival was not modified by the association. In the same system, the triple association of βFGF-EGF with another cytokine was tested on hippocampal and cortical cell cultures. No significant effect was observed in both cultures but cell survival trented to decrease with βTGF. In order to avoid the mitotic effect of cytokines in the 3 day-old culture, experiments were carried out on 20 hours cell culture, before the end of the first round of the cell cycle, with the selected cytokines (βFGF or βFGF-EGF). Without irradiation, the percentage of cortical cell survival

  6. Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

    Science.gov (United States)

    Lehrberg, Jeffrey; Gardiner, David M

    2015-01-01

    We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

  7. Regulation of Axolotl (Ambystoma mexicanum Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

    Directory of Open Access Journals (Sweden)

    Jeffrey Lehrberg

    Full Text Available We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

  8. Resveratrol Ameliorates Tau Hyperphosphorylation at Ser396 Site and Oxidative Damage in Rat Hippocampal Slices Exposed to Vanadate: Implication of ERK1/2 and GSK-3β Signaling Cascades.

    Science.gov (United States)

    Jhang, Kyoung A; Park, Jin-Sun; Kim, Hee-Sun; Chong, Young Hae

    2017-11-08

    The objective of this study was to investigate the effect of resveratrol (a natural polyphenolic phytostilbene) on tau hyperphosphorylation and oxidative damage induced by sodium orthovanadate (Na 3 VO 4 ), the prevalent species of vanadium (vanadate), in rat hippocampal slices. Our results showed that resveratrol significantly inhibited Na 3 VO 4 -induced hyperphosphorylation of tau at the Ser396 (p-S396-tau) site, which is upregulated in the hippocampus of Alzheimer's disease (AD) brains and principally linked to AD-associated cognitive dysfunction. Subsequent mechanistic studies revealed that reduction of ERK1/2 activation was involved in the inhibitory effect of resveratrol by inhibiting the ERK1/2 pathway with SL327 mimicking the aforementioned effect of resveratrol. Moreover, resveratrol potently induced GSK-3β Ser9 phosphorylation and reduced Na 3 VO 4 -induced p-S396-tau levels, which were markedly replicated by pharmacologic inhibition of GSK-3β with LiCl. These results indicate that resveratrol could suppress Na 3 VO 4 -induced p-S396-tau levels via downregulating ERK1/2 and GSK-3β signaling cascades in rat hippocampal slices. In addition, resveratrol diminished the increased extracellular reactive oxygen species generation and hippocampal toxicity upon long-term exposure to Na 3 VO 4 or FeCl 2 . Our findings strongly support the notion that resveratrol may serve as a potential nutraceutical agent for AD.

  9. Neuroprotective effects of ginsenoside Rg1 against oxygen–glucose deprivation in cultured hippocampal neurons

    OpenAIRE

    He, Qing; Sun, Jianguo; Wang, Qin; Wang, Wei; He, Bin

    2014-01-01

    Background: Ginsenoside Rg1 (Rg1) is believed to be one of the main active principles in ginseng, a traditional Chinese medicine extensively used to enhance stamina and deal with fatigue as well as physical stress. It has been reported that Rg1 performs multiple biological activities, including neuroprotective activity. In this study, we investigated the efficacy of ginsenoside Rg1 on ischemia–reperfusion injury in cultured hippocampal cells and also probed its possible mechanisms. Methods...

  10. Tumor tissue slice cultures as a platform for analyzing tissue-penetration and biological activities of nanoparticles.

    Science.gov (United States)

    Merz, Lea; Höbel, Sabrina; Kallendrusch, Sonja; Ewe, Alexander; Bechmann, Ingo; Franke, Heike; Merz, Felicitas; Aigner, Achim

    2017-03-01

    The success of therapeutic nanoparticles depends, among others, on their ability to penetrate a tissue for actually reaching the target cells, and their efficient cellular uptake in the context of intact tissue and stroma. Various nanoparticle modifications have been implemented for altering physicochemical and biological properties. Their analysis, however, so far mainly relies on cell culture experiments which only poorly reflect the in vivo situation, or is based on in vivo experiments that are often complicated by whole-body pharmacokinetics and are rather tedious especially when analyzing larger nanoparticle sets. For the more precise analysis of nanoparticle properties at their desired site of action, efficient ex vivo systems closely mimicking in vivo tissue properties are needed. In this paper, we describe the setup of organotypic tumor tissue slice cultures for the analysis of tissue-penetrating properties and biological activities of nanoparticles. As a model system, we employ 350μm thick slice cultures from different tumor xenograft tissues, and analyze modified or non-modified polyethylenimine (PEI) complexes as well as their lipopolyplex derivatives for siRNA delivery. The described conditions for tissue slice preparation and culture ensure excellent tissue preservation for at least 14days, thus allowing for prolonged experimentation and analysis. When using fluorescently labeled siRNA for complex visualization, fluorescence microscopy of cryo-sectioned tissue slices reveals different degrees of nanoparticle tissue penetration, dependent on their surface charge. More importantly, the determination of siRNA-mediated knockdown efficacies of an endogenous target gene, the oncogenic survival factor Survivin, reveals the possibility to accurately assess biological nanoparticle activities in situ, i.e. in living cells in their original environment. Taken together, we establish tumor (xenograft) tissue slices for the accurate and facile ex vivo assessment of

  11. 3-Nitropropionic acid neurotoxicity in organotypic striatal and corticostriatal slice cultures is dependent on glucose and glutamate

    DEFF Research Database (Denmark)

    Storgaard, J; Kornblit, B T; Zimmer, J

    2000-01-01

    of lactate dehydrogenase in the medium and glutamic acid decarboxylase in tissue homogenates. 3-NPA toxicity (25-100 microM in 5 mM glucose, 24-48 h) appeared to be highly dependent on culture medium glucose levels. 3-NPA treatment caused also a dose-dependent lactate increase, reaching a maximum......Mitochondrial inhibition by 3-nitropropionic acid (3-NPA) causes striatal degeneration reminiscent of Huntington's disease. We studied 3-NPA neurotoxicity and possible indirect excitotoxicity in organotypic striatal and corticostriatal slice cultures. Neurotoxicity was quantified by assay...... of threefold increase above control at 100 microM. Both a high dose of glutamate (5 mM) and glutamate uptake blockade by dl-threo-beta-hydroxyaspartate potentiated 3-NPA neurotoxicity in corticostriatal slice cultures. Furthermore, striatum from corticostriatal cocultures was more sensitive to 3-NPA than...

  12. Evaluation of the relative biological effectiveness of carbon ion beams in the cerebellum using the rat organotypic slice culture system

    International Nuclear Information System (INIS)

    Yoshida, Yukari; Katoh, Hiroyuki; Nakano, Takashi; Suzuki, Yoshiyuki; Al-Jahdari, Wael S.; Shirai, Katsuyuki; Hamada, Nobuyuki; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

    2012-01-01

    The purpose of this study was to clarify the relative biological effectiveness (RBE) values of carbon ion (C) beams in normal brain tissues, a rat organotypic slice culture system was used. The cerebellum was dissected from 10-day-old Wistar rats, cut parasagittally into approximately 600-μm-thick slices and cultivated using a membrane-based culture system with a liquid-air interface. Slices were irradiated with 140 kV X-rays and 18.3 MeV/amu C-beams (linear energy transfer=108 keV/μm). After irradiation, the slices were evaluated histopathologically using hematoxylin and eosin staining, and apoptosis was quantified using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Disorganization of the external granule cell layer (EGL) and apoptosis of the external granule cells (EGCs) were induced within 24 h after exposure to doses of more than 5 Gy from C-beams and X-rays. In the early postnatal cerebellum, morphological changes following exposure to C-beams were similar to those following exposure to X-rays. The RBEs values of C-beams using the EGL disorganization and the EGC TUNEL index endpoints ranged from 1.4 to 1.5. This system represents a useful model for assaying the biological effects of radiation on the brain, especially physiological and time-dependent phenomena. (author)

  13. Streptozotocin Inhibits Electrophysiological Determinants of Excitatory and Inhibitory Synaptic Transmission in CA1 Pyramidal Neurons of Rat Hippocampal Slices: Reduction of These Effects by Edaravone

    Directory of Open Access Journals (Sweden)

    Ting Ju

    2016-12-01

    Full Text Available Background: Streptozotocin (STZ has served as an agent to generate an Alzheimer's disease (AD model in rats, while edaravone (EDA, a novel free radical scavenger, has recently emerged as an effective treatment for use in vivo and vitro AD models. However, to date, these beneficial effects of EDA have only been clearly demonstrated within STZ-induced animal models of AD and in cell models of AD. A better understanding of the mechanisms of EDA may provide the opportunity for their clinical application in the treatment of AD. Therefore, the purpose of this study was to investigate the underlying mechanisms of STZ and EDA as assessed upon electrophysiological alterations in CA1 pyramidal neurons of rat hippocampal slices. Methods: Through measures of evoked excitatory postsynaptic currents (eEPSCs, AMPAR-mediated eEPSCs (eEPSCsAMPA, evoked inhibitory postsynaptic currents (eIPSCs, evoked excitatory postsynaptic current paired pulse ratio (eEPSC PPR and evoked inhibitory postsynaptic current paired pulse ratio (eIPSC PPR, it was possible to investigate mechanisms as related to the neurotoxicity of STZ and reductions in these effects by EDA. Results: Our results showed that STZ (1000 µM significantly inhibited peak amplitudes of eEPSCs, eEPSCsAMPA and eIPSCs, while EDA (1000 µM attenuated these STZ-induced changes at holding potentials ranging from -60mV to +40 mV for EPSCs and -60mV to +20 mV for IPSCs. Our work also indicated that mean eEPSC PPR were substantially altered by STZ, effects which were partially restored by EDA. In contrast, no significant effects upon eIPSC PPR were obtained in response to STZ and EDA. Conclusion: Our data suggest that STZ inhibits glutamatergic transmission involving pre-synaptic mechanisms and AMPAR, and that STZ inhibits GABAergic transmission by post-synaptic mechanisms within CA1 pyramidal neurons. These effects are attenuated by EDA.

  14. Neuroprotective effects of ginsenoside Rg1 against oxygen-glucose deprivation in cultured hippocampal neurons.

    Science.gov (United States)

    He, Qing; Sun, Jianguo; Wang, Qin; Wang, Wei; He, Bin

    2014-03-01

    Ginsenoside Rg1 (Rg1) is believed to be one of the main active principles in ginseng, a traditional Chinese medicine extensively used to enhance stamina and deal with fatigue as well as physical stress. It has been reported that Rg1 performs multiple biological activities, including neuroprotective activity. In this study, we investigated the efficacy of ginsenoside Rg1 on ischemia-reperfusion injury in cultured hippocampal cells and also probed its possible mechanisms. To establish a model of oxygen-glucose deprivation (OGD) and reperfusion, cultured hippocampal neurons were exposed to OGD for 2.5 hours, followed by a 24-hour reoxygenation. Cultured hippocampal neurons were randomly divided into control group, model group (vehicle), and ginsenoside Rg1 treatment groups (5μM, 20μM, 60μM). At 24 hours post-OGD, the intracellular free calcium concentration was detected using Furo-3/AM-loaded hippocampal neurons deprived of oxygen and glucose. Neuronal nitric oxide synthase (nNOS) activity was measured by chemical colorimetry. Cell apoptosis was evaluated by Hoechst staining, and the neuron viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Excitotoxic neuronal injury of OGD was demonstrated by the increase of intracellular free calcium concentrations and elevated nNOS activity in the model group compared with the control group. The intracellular free calcium concentrations and the nNOS activity in the groups receiving intermediate and high dose of ginsenoside Rg1 were significantly lower than those of the control group (p cell viability loss (p cell apoptosis induced by OGD. Ginsenoside Rg1 has neuroprotective effect on ischemia-reperfusion injury in cultured hippocampal cells mediated by blocking calcium over-influx into neuronal cells and decreasing the nNOS activity after OGD exposure. We infer that ginsenoside Rg1 may serve as a potential therapeutic agent for cerebral ischemia injury. Copyright © 2014

  15. Erythropoietin promotes oligodendrogenesis and myelin repair following lysolecithin-induced injury in spinal cord slice culture

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yun Kyung; Kim, Gunha; Park, Serah; Sim, Ju Hee; Won, You Jin [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Hwang, Chang Ho [Department of Physical Medicine and Rehabilitation, Ulsan University Hospital, University of Ulsan College of Medicine, 290-3 Jeonha-dong, Dong-gu, Ulsan 682-714 (Korea, Republic of); Yoo, Jong Yoon, E-mail: jyyoo@amc.seoul.kr [Department of Rehabilitation Medicine, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Hong, Hea Nam, E-mail: hnhong@amc.seoul.kr [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of)

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Lysolecithin-induced demyelination elevated EpoR expression in OPCs. Black-Right-Pointing-Pointer In association with elevated EpoR, EPO increased OPCs proliferation. Black-Right-Pointing-Pointer EPO enhanced the oligodendrogenesis via activation of JAK2 pathway. Black-Right-Pointing-Pointer EPO promoted myelin repair following lysolecithin-induced demyelination. -- Abstract: Here, we sought to delineate the effect of EPO on the remyelination processes using an in vitro model of demyelination. We report that lysolecithin-induced demyelination elevated EPO receptor (EpoR) expression in oligodendrocyte progenitor cells (OPCs), facilitating the beneficial effect of EPO on the formation of oligodendrocytes (oligodendrogenesis). In the absence of EPO, the resultant remyelination was insufficient, possibly due to a limiting number of oligodendrocytes rather than their progenitors, which proliferate in response to lysolecithin-induced injury. By EPO treatment, lysolecithin-induced proliferation of OPCs was accelerated and the number of myelinating oligodendrocytes and myelin recovery was increased. EPO also enhanced the differentiation of neural progenitor cells expressing EpoR at high level toward the oligodendrocyte-lineage cells through activation of cyclin E and Janus kinase 2 pathways. Induction of myelin-forming oligodendrocytes by high dose of EPO implies that EPO might be the key factor influencing the final differentiation of OPCs. Taken together, our data suggest that EPO treatment could be an effective way to enhance remyelination by promoting oligodendrogenesis in association with elevated EpoR expression in spinal cord slice culture after lysolecithin-induced demyelination.

  16. 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

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

    Directory of Open Access Journals (Sweden)

    Zha YY

    2012-06-01

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

  18. Effects of exposure to high glucose on primary cultured hippocampal neurons: involvement of intracellular ROS accumulation.

    Science.gov (United States)

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

    2014-06-01

    Recent studies showed that hyperglycemia is the main trigger of diabetic cognitive impairment and can cause hippocampus abnormalities. The goal of this study is to explore the effects of different concentrations of high glucose for different exposure time on cell viability as well as intracellular reactive oxygen species (ROS) generation of primary cultured hippocampal neurons. Hippocampal neurons were exposed to different concentrations of high glucose (50, 75, 100, 125, and 150 mM) for 24, 48, 72 and 96 h. Cell viability and nuclear morphology were evaluated by MTT and Hoechst assays, respectively. Intracellular ROS were monitored using the fluorescent probe DCFH-DA. The results showed that, compared with control group, the cell viability of all high glucose-treated groups decreased significantly after 72 h and there also was a significant increase of apoptotic nuclei in high glucose-treated groups from 72 to 96 h. Furthermore, 50 mM glucose induced a peak rise in ROS generation at 24 h and the intracellular ROS levels of 50 mM glucose group were significantly higher than the corresponding control group from 6 to 72 h. These results suggest that hippocampal neurons could be injured by high glucose exposure and the neuronal injury induced by high glucose is potentially mediated through intracellular ROS accumulation.

  19. Large-scale, high-resolution multielectrode-array recording depicts functional network differences of cortical and hippocampal cultures.

    Directory of Open Access Journals (Sweden)

    Shinya Ito

    Full Text Available Understanding the detailed circuitry of functioning neuronal networks is one of the major goals of neuroscience. Recent improvements in neuronal recording techniques have made it possible to record the spiking activity from hundreds of neurons simultaneously with sub-millisecond temporal resolution. Here we used a 512-channel multielectrode array system to record the activity from hundreds of neurons in organotypic cultures of cortico-hippocampal brain slices from mice. To probe the network structure, we employed a wavelet transform of the cross-correlogram to categorize the functional connectivity in different frequency ranges. With this method we directly compare, for the first time, in any preparation, the neuronal network structures of cortex and hippocampus, on the scale of hundreds of neurons, with sub-millisecond time resolution. Among the three frequency ranges that we investigated, the lower two frequency ranges (gamma (30-80 Hz and beta (12-30 Hz range showed similar network structure between cortex and hippocampus, but there were many significant differences between these structures in the high frequency range (100-1000 Hz. The high frequency networks in cortex showed short tailed degree-distributions, shorter decay length of connectivity density, smaller clustering coefficients, and positive assortativity. Our results suggest that our method can characterize frequency dependent differences of network architecture from different brain regions. Crucially, because these differences between brain regions require millisecond temporal scales to be observed and characterized, these results underscore the importance of high temporal resolution recordings for the understanding of functional networks in neuronal systems.

  20. [Establishment of oxygen and glucose deprive model of in vitro cultured hippocampal neuron and effect of ligustrazine on intracellular Ca+ level in model neurons].

    Science.gov (United States)

    Wan, Hai-tong; Wang, Yu; Yang, Jie-hong

    2007-03-01

    To establish the oxygen and glucose deprive (OGD) model in cultured hippocampal neuron and study the effect of ligustrazine on intracellular Ca2+ level in the model neurons. The OGD model was established in cultured hippocampal neuron, and the intracellular Ca2+ level in it was detected by laser scanning confocal microscope (LSCM). The OGD model was successfully established in cultured hippocampal neurons; the intracellular Ca2+ level in the OGD model group was significantly higher than that in the blank control group (P neuron, which could be antagonized by ligustrazine, indicating that ligustrazine has a protective effect on hippocampal neuron from hypoxic-ischemic injury.

  1. Neuroprotective function for ramified microglia in hippocampal excitotoxicity

    Directory of Open Access Journals (Sweden)

    Vinet Jonathan

    2012-01-01

    Full Text Available Abstract Background Most of the known functions of microglia, including neurotoxic and neuroprotective properties, are attributed to morphologically-activated microglia. Resting, ramified microglia are suggested to primarily monitor their environment including synapses. Here, we show an active protective role of ramified microglia in excitotoxicity-induced neurodegeneration. Methods Mouse organotypic hippocampal slice cultures were treated with N-methyl-D-aspartic acid (NMDA to induce excitotoxic neuronal cell death. This procedure was performed in slices containing resting microglia or slices that were chemically or genetically depleted of their endogenous microglia. Results Treatment of mouse organotypic hippocampal slice cultures with 10-50 μM N-methyl-D-aspartic acid (NMDA induced region-specific excitotoxic neuronal cell death with CA1 neurons being most vulnerable, whereas CA3 and DG neurons were affected less. Ablation of ramified microglia severely enhanced NMDA-induced neuronal cell death in the CA3 and DG region rendering them almost as sensitive as CA1 neurons. Replenishment of microglia-free slices with microglia restored the original resistance of CA3 and DG neurons towards NMDA. Conclusions Our data strongly suggest that ramified microglia not only screen their microenvironment but additionally protect hippocampal neurons under pathological conditions. Morphological activation of ramified microglia is thus not required to influence neuronal survival.

  2. 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

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

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    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.

  4. Neurogenic and neurotrophic effects of BDNF peptides in mouse hippocampal primary neuronal cell cultures.

    Directory of Open Access Journals (Sweden)

    Maria del Carmen Cardenas-Aguayo

    Full Text Available The level of brain-derived neurotrophic factor (BDNF, a member of the neurotrophin family, is down regulated in Alzheimer's disease (AD, Parkinson's disease (PD, depression, stress, and anxiety; conversely the level of this neurotrophin is increased in autism spectrum disorders. Thus, modulating the level of BDNF can be a potential therapeutic approach for nervous system pathologies. In the present study, we designed five different tetra peptides (peptides B-1 to B-5 corresponding to different active regions of BDNF. These tetra peptides were found to be non-toxic, and they induced the expression of neuronal markers in mouse embryonic day 18 (E18 primary hippocampal neuronal cultures. Additionally, peptide B-5 induced the expression of BDNF and its receptor, TrkB, suggesting a positive feedback mechanism. The BDNF peptides induced only a moderate activation (phosphorylation at Tyr 706 of the TrkB receptor, which could be blocked by the Trk's inhibitor, K252a. Peptide B-3, when combined with BDNF, potentiated the survival effect of this neurotrophin on H(2O(2-treated E18 hippocampal cells. Peptides B-3 and B-5 were found to work as partial agonists and as partial antagonists competing with BDNF to activate the TrkB receptor in a dose-dependent manner. Taken together, these results suggest that the described BDNF tetra peptides are neurotrophic, can modulate BDNF signaling in a partial agonist/antagonist way, and offer a novel therapeutic approach to neural pathologies where BDNF levels are dysregulated.

  5. Apoptosis after irradiation of the rat cortical and hippocampal cells in culture

    International Nuclear Information System (INIS)

    Coffigny, H.; Lane, M.C.

    1997-01-01

    During the development of the central nervous system many neurons are generated but over 50% die by natural apoptosis; this phenomenon occurred in neurons without or with wrong connections with their target cells. Children exposed in utero to Hiroshima or Nagasaki bombing presented microcephaly due to cell deaths and mental retardation. In animals, the number of apoptotic cells in the developing central nervous system increased as a function of the dose received. In vitro, we have shown that 1 Gy irradiation induced 50 % decrease of cortical and hippocampal cell survival. Nervous cells when seeded in a plate were round without processes. Neuritis outgrowth increased with culture time and physical contacts were established between cells. Our purpose is to test the importance of these contacts in the radio-induced apoptosis. (authors)

  6. BDNF regulates the expression and distribution of vesicular glutamate transporters in cultured hippocampal neurons.

    Directory of Open Access Journals (Sweden)

    Carlos V Melo

    Full Text Available BDNF is a pro-survival protein involved in neuronal development and synaptic plasticity. BDNF strengthens excitatory synapses and contributes to LTP, presynaptically, through enhancement of glutamate release, and postsynaptically, via phosphorylation of neurotransmitter receptors, modulation of receptor traffic and activation of the translation machinery. We examined whether BDNF upregulated vesicular glutamate receptor (VGLUT 1 and 2 expression, which would partly account for the increased glutamate release in LTP. Cultured rat hippocampal neurons were incubated with 100 ng/ml BDNF, for different periods of time, and VGLUT gene and protein expression were assessed by real-time PCR and immunoblotting, respectively. At DIV7, exogenous application of BDNF rapidly increased VGLUT2 mRNA and protein levels, in a dose-dependent manner. VGLUT1 expression also increased but only transiently. However, at DIV14, BDNF stably increased VGLUT1 expression, whilst VGLUT2 levels remained low. Transcription inhibition with actinomycin-D or α-amanitine, and translation inhibition with emetine or anisomycin, fully blocked BDNF-induced VGLUT upregulation. Fluorescence microscopy imaging showed that BDNF stimulation upregulates the number, integrated density and intensity of VGLUT1 and VGLUT2 puncta in neurites of cultured hippocampal neurons (DIV7, indicating that the neurotrophin also affects the subcellular distribution of the transporter in developing neurons. Increased VGLUT1 somatic signals were also found 3 h after stimulation with BDNF, further suggesting an increased de novo transcription and translation. BDNF regulation of VGLUT expression was specifically mediated by BDNF, as no effect was found upon application of IGF-1 or bFGF, which activate other receptor tyrosine kinases. Moreover, inhibition of TrkB receptors with K252a and PLCγ signaling with U-73122 precluded BDNF-induced VGLUT upregulation. Hippocampal neurons express both isoforms during

  7. Combined Stimulation with the Tumor Necrosis Factor α and the Epidermal Growth Factor Promotes the Proliferation of Hepatocytes in Rat Liver Cultured Slices

    Directory of Open Access Journals (Sweden)

    Francis Finot

    2012-01-01

    Full Text Available The culture liver slices are mainly used to investigate drug metabolism and xenobiotic-mediated liver injuries while apoptosis and proliferation remain unexplored in this culture model. Here, we show a transient increase in LDH release and caspase activities indicating an ischemic injury during the slicing procedure. Then, caspase activities decrease and remain low in cultured slices demonstrating a low level of apoptosis. The slicing procedure is also associated with the G0/G1 transition of hepatocytes demonstrated by the activation of stress and proliferation signalling pathways including the ERK1/2 and JNK1/2/3 MAPKinases and the transient upregulation of c-fos. The cells further progress up to mid-G1 phase as indicated by the sequential induction of c-myc and p53 mRNA levels after the slicing procedure and at 24 h of culture, respectively. The stimulation by epidermal growth factor induces the ERK1/2 phosphorylation but fails to activate expression of late G1 and S phase markers such as cyclin D1 and Cdk1 indicating that hepatocytes are arrested in mid-G1 phase of the cell cycle. However, we found that combined stimulation by the proinflammatory cytokine tumor necrosis factor α and the epidermal growth factor promotes the commitment to DNA replication as observed in vivo during the liver regeneration.

  8. Slice cultures of the imprinting-relevant forebrain area MNH of the domestic chick: quantitative characterization of neuronal morphology.

    Science.gov (United States)

    Hofmann, H; Braun, K

    1995-05-26

    The persistence of morphological features of neurons in slice cultures of the imprinting-relevant forebrain area MNH (mediorostral neostriatum and hyperstriatum ventrale) of the domestic chick was analysed at 7, 14, 21 and 28 days in vitro. After having been explanted and kept in culture the neurons in vitro have larger soma areas, longer and more extensively branched dendritic trees and lower spine frequencies compared to the neurons in vivo. During the analyzed culturing period, the parameters soma area, total and mean dendritic length, number of dendrites, number of dendritic nodes per dendrite and per neuron as well as the spine densities in different dendritic segments showed no significant differences between early and late periods. Highly correlated in every age group were the total dendritic length and the number of dendritic nodes per neuron, indicating regular ramification during dendritic growth. Since these morphological parameters remain stable during the first 4 weeks in vitro, this culture system may provide a suitable model to investigate experimentally induced morphological changes.

  9. 5-HT4-receptors modulate induction of long-term depression but not potentiation at hippocampal output synapses in acute rat brain slices.

    Directory of Open Access Journals (Sweden)

    Matthias Wawra

    Full Text Available The subiculum is the principal target of CA1 pyramidal cells and mediates hippocampal output to various cortical and subcortical regions of the brain. The majority of subicular pyramidal cells are burst-spiking neurons. Previous studies indicated that high frequency stimulation in subicular burst-spiking cells causes presynaptic NMDA-receptor dependent long-term potentiation (LTP whereas low frequency stimulation induces postsynaptic NMDA-receptor-dependent long-term depression (LTD. In the present study, we investigate the effect of 5-hydroxytryptamine type 4 (5-HT4 receptor activation and blockade on both forms of synaptic plasticity in burst-spiking cells. We demonstrate that neither activation nor block of 5-HT4 receptors modulate the induction or expression of LTP. In contrast, activation of 5-HT4 receptors facilitates expression of LTD, and block of the 5-HT4 receptor prevents induction of short-term depression and LTD. As 5-HT4 receptors are positively coupled to adenylate cyclase 1 (AC1, 5-HT4 receptors might modulate PKA activity through AC1. Since LTD is blocked in the presence of 5-HT4 receptor antagonists, our data are consistent with 5-HT4 receptor activation by ambient serotonin or intrinsically active 5-HT4 receptors. Our findings provide new insight into aminergic modulation of hippocampal output.

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

    Science.gov (United States)

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

    2000-01-28

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

  11. Prostaglandin E(2) stimulates glutamate receptor-dependent astrocyte neuromodulation in cultured hippocampal cells.

    Science.gov (United States)

    Sanzgiri, R P; Araque, A; Haydon, P G

    1999-11-05

    Recent Ca(2+) imaging studies in cell culture and in situ have shown that Ca(2+) elevations in astrocytes stimulate glutamate release and increase neuronal Ca(2+) levels, and that this astrocyte-neuron signaling can be stimulated by prostaglandin E(2) (PGE(2)). We investigated the electrophysiological consequences of the PGE(2)-mediated astrocyte-neuron signaling using whole-cell recordings on cultured rat hippocampal cells. Focal application of PGE(2) to astrocytes evoked a Ca(2+) elevation in the stimulated cell by mobilizing internal Ca(2+) stores, which further propagated as a Ca(2+) wave to neighboring astrocytes. Whole-cell recordings from neurons revealed that PGE(2) evoked a slow inward current in neurons adjacent to astrocytes. This neuronal response required the presence of an astrocyte Ca(2+) wave and was mediated through both N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors. Taken together with previous studies, these data demonstrate that PGE(2)-evoked Ca(2+) elevations in astrocyte cause the release of glutamate which activates neuronal ionotropic receptors. Copyright 1999 John Wiley & Sons, Inc.

  12. Cells in human postmortem brain tissue slices remain alive for several weeks in culture

    NARCIS (Netherlands)

    Verwer, Ronald W. H.; Hermens, Wim T. J. M. C.; Dijkhuizen, PaulaA; ter Brake, Olivier; Baker, Robert E.; Salehi, Ahmad; Sluiter, Arja A.; Kok, Marloes J. M.; Muller, Linda J.; Verhaagen, Joost; Swaab, Dick F.

    2002-01-01

    Animal models for human neurological and psychiatric diseases only partially mimic the underlying pathogenic processes. Therefore, we investigated the potential use of cultured postmortem brain tissue from adult neurological patients and controls. The present study shows that human brain tissue

  13. Neuroprotective effects of Rhodiola rosea extracts against excitotoxicity and oxygen-glucose deprivation in hippocampal slice cultures

    DEFF Research Database (Denmark)

    Gramsbergen, Jan Bert; Sindberg, J.; Lundberg, L.

    .g. salidroside) and phenylpropanoid glycosides (e.g. rosavin). Many of these compounds are considered potent antioxidants, but the significance of the various substances for the beneficial effects of roseroot is still largely unknown. Here we tested the neuroprotective effects of crude methanolic extracts of R...... and quantified by propidium iodide uptake and immunohistochemical staining for MAP2 as a neuronal marker. Significant and dose-dependent protection against NMDA and OGD-induced CA1 pyramidal cell death was obtained by crude extracts using 250 µg/ml (33-50% protection) or 500 µg/ml (45-65% protection). A number...... of chemical fractions of methanolic Rhodiola extracts, as well as the purified constituents salidrosid and rosavin were tested, but - so far - none of the tested fractions or single constituents showed protection against NMDA or OGD. To study the mechanisms of action of R. rosea extracts, we are currently...

  14. Altered Loyalties of Neuronal Markers in Cultured Slices of Resected Human Brain Tissue

    NARCIS (Netherlands)

    Verwer, Ronald W. H.; Sluiter, Arja A.; Balesar, Rawien A.; Baayen, Johannes C.; Speijer, Dave; Idema, Sander; Swaab, Dick F.

    2016-01-01

    Organotypic cultures from normal neocortical tissue obtained at epilepsy surgery show a severe injury response. This response involves both neuronal degeneration and the proliferation of reactive cells. A salient feature of the reactive cells is the co-expression of microglial and astrocytic

  15. Dynamic inhibition of excitatory synaptic transmission by astrocyte-derived ATP in hippocampal cultures

    Science.gov (United States)

    Koizumi, Schuichi; Fujishita, Kayoko; Tsuda, Makoto; Shigemoto-Mogami, Yukari; Inoue, Kazuhide

    2003-09-01

    Originally ascribed passive roles in the CNS, astrocytes are now known to have an active role in the regulation of synaptic transmission. Neuronal activity can evoke Ca2+ transients in astrocytes, and Ca2+ transients in astrocytes can evoke changes in neuronal activity. The excitatory neurotransmitter glutamate has been shown to mediate such bidirectional communication between astrocytes and neurons. We demonstrate here that ATP, a primary mediator of intercellular Ca2+ signaling among astrocytes, also mediates intercellular signaling between astrocytes and neurons in hippocampal cultures. Mechanical stimulation of astrocytes evoked Ca2+ waves mediated by the release of ATP and the activation of P2 receptors. Mechanically evoked Ca2+ waves led to decreased excitatory glutamatergic synaptic transmission in an ATP-dependent manner. Exogenous application of ATP does not affect postsynaptic glutamatergic responses but decreased presynaptic exocytotic events. Finally, we show that astrocytes exhibit spontaneous Ca2+ waves mediated by extracellular ATP and that inhibition of these Ca2+ responses enhanced excitatory glutamatergic transmission. We therefore conclude that ATP released from astrocytes exerts tonic and activity-dependent down-regulation of synaptic transmission via presynaptic mechanisms.

  16. Real-time monitoring of extracellular l-glutamate levels released by high-frequency stimulation at region CA1 of hippocampal slices with a glass capillary-based l-glutamate sensor

    Directory of Open Access Journals (Sweden)

    Yuki Ikegami

    2014-12-01

    Full Text Available Real-time monitoring of l-glutamate released by high-frequency stimulation in region CA1 of mouse hippocampal slices was performed with a glass capillary-based sensor, in combination with the recoding of excitatory postsynaptic potentials (fEPSPs. A method for extracting l-glutamate currents from the recorded ones was described and applied for determining the level of extracellular l-glutamate released by 100 Hz stimulation. Recording of an l-glutamate current with a current sampling interval of 1 Hz was found to be useful for acquiring a Faradaic current that reflects l-glutamate level released by the high-frequency stimulation of 7 trains, each 20 stimuli at 100 Hz and inter-train interval of 3 s. The l-glutamate level was obtained as 15 ± 6 μM (n = 8 for the persistent enhancement of fEPSPs, i.e., the induction of long-term potentiation (LTP, and 3 ± 1 μM (n = 5 for the case of no LTP induction. Based on these observations, the level of the extracellular l-glutamate was shown to play a crucial role in the induction of LTP.

  17. Glutamate reduces glucose utilization while concomitantly enhancing AQP9 and MCT2 expression in cultured rat hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Fabio eTescarollo

    2014-08-01

    Full Text Available The excitatory neurotransmitter glutamate has been reported to have a major impact on brain energy metabolism. Using primary cultures of rat hippocampal neurons, we observed that glutamate reduces glucose utilization in this cell type, suggesting alteration in mitochondrial oxidative metabolism. The aquaglyceroporin AQP9 and the monocarboxylate transporter MCT2, two transporters for oxidative energy substrates, appear to be present in mitochondria of these neurons. Moreover, they not only co-localize but they interact with each other as they were found to co-immunoprecipitate from hippocampal neuron homogenates. Exposure of cultured hippocampal neurons to glutamate 100 µM for 1 hour led to enhanced expression of both AQP9 and MCT2 at the protein level without any significant change at the mRNA level. In parallel, a similar increase in the protein expression of LDHA was evidenced without an effect on the mRNA level. These data suggest that glutamate exerts an influence on neuronal energy metabolism likely through a regulation of the expression of some key mitochondrial proteins.

  18. Cytotoxicity of retinoic acid, menadione and aflatoxin B1 in rat liver slices using netwell inserts as a culture system

    NARCIS (Netherlands)

    Leeman, W.R.; Gevel, I.A. van de; Rutten, A.A.J.J.L.

    1995-01-01

    Precision-cut rat liver slices were used to develop a new dynamic incubation system in which histomorphology and measurement of the release of lactate dehydrogenase (LDH) and the conversion of MTT were applied to evaluate cytotoxicity. Liver slices, precision-cut using a Krumdieck tissue slicer,

  19. Architectural slicing

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2013-01-01

    Architectural prototyping is a widely used practice, con- cerned with taking architectural decisions through experiments with light- weight implementations. However, many architectural decisions are only taken when systems are already (partially) implemented. This is prob- lematic in the context...... of architectural prototyping since experiments with full systems are complex and expensive and thus architectural learn- ing is hindered. In this paper, we propose a novel technique for harvest- ing architectural prototypes from existing systems, \\architectural slic- ing", based on dynamic program slicing. Given...... a system and a slicing criterion, architectural slicing produces an architectural prototype that contain the elements in the architecture that are dependent on the ele- ments in the slicing criterion. Furthermore, we present an initial design and implementation of an architectural slicer for Java....

  20. Expression of hypoxia-inducible factor 1 alpha and oligodendrocyte lineage gene-1 in cultured brain slices after oxygen-glucose deprivation☆

    OpenAIRE

    Cui, Hong; Han, Weijuan; Yang, Lijun; Chang, Yanzhong

    2013-01-01

    Oligodendrocyte lineage gene-1 expressed in oligodendrocytes may trigger the repair of neuronal myelin impairment, and play a crucial role in myelin repair. Hypoxia-inducible factor 1α, a transcription factor, is of great significance in premature infants with hypoxic-ischemic brain damage. There is little evidence of direct regulatory effects of hypoxia-inducible factor 1α on oligodendrocyte lineage gene-1. In this study, brain slices of Sprague-Dawley rats were cultured and subjected to oxy...

  1. PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of posttraumatic epilepsy

    OpenAIRE

    Berdichevsky, Yevgeny; Dryer, Alexandra M.; Saponjian, Yero; Mahoney, Mark M.; Pimentel, Corrin A.; Lucini, Corrina A.; Usenovic, Marija; Staley, Kevin J.

    2013-01-01

    mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an antiepileptogenic, or merely anti-convulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordi...

  2. Stability of cytochromes P450 and phase II conjugation systems in precision-cut rat lung slices cultured up to 72 h.

    Science.gov (United States)

    Umachandran, Meera; Ioannides, Costas

    2006-07-05

    The objective of the present study was to evaluate the stability of cytochrome P450 enzymes and of the conjugation enzyme systems epoxide hydrolase, glucuronosyl transferase, sulphotransferase and glutathione S-transferase in precision-cut rat lung slices incubated in RPMI media for different time periods up to 72 h. Moreover, the effect of culturing of lung slices on total glutathione levels and glutathione reductase was also investigated. Monitoring of cytochrome P450 activity was achieved using established diagnostic probes, but when activity in the lung was low the maintenance of the various enzymes in culture was determined immunologically using Western blotting. The dealkylation of pentoxyresorufin declined markedly during the first 4h of incubation but in the case of ethoxyresorufin loss of activity was more gradual and less severe. Western blot analysis revealed that the rate of decrease in cytochrome P450 apoprotein levels was isoform-specific with CYP2E1 being the most stable and CYP3A the least stable. Generally, phase II activities, especially cytosolic sulphotransferase, were relatively more stable throughout the incubation period compared with cytochromes P450. Finally, glutathione reductase activity and total glutathione levels were maintained throughout the 72 h incubation. The present studies indicate that xenobiotic-metabolising enzymes in precision-cut rat lung slices decline in culture, but the rate of loss differs and depends on the nature of the enzyme.

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

    Directory of Open Access Journals (Sweden)

    Matthew E Pamenter

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

  4. Correlation between in vivo and in vitro pulmonary responses to jet propulsion fuel-8 using precision-cut lung slices and a dynamic organ culture system.

    Science.gov (United States)

    Hays, Allison M; Lantz, R Clark; Witten, Mark L

    2003-01-01

    In tissue slice models, interactions between the heterogeneous cell types comprising the lung parenchyma are maintained thus providing a controlled system for the study of pulmonary toxicology in vitro. However, validation of the model in vitro system must be affirmed. Previous reports, in in vivo systems, have demonstrated that Clara cells and alveolar type II cells are the targets following inhalation of JP-8 jet fuel. We have utilized the lung slice model to determine if cellular targets are similar following in vitro exposure to JP-8. Agar-filled adult rat lung explants were cored and precision cut, using the Brende/Vitron tissue slicer. Slices were cultured on titanium screens located as half-cylinders in cylindrical Teflon cradles that were loaded into standard scintillation vials and incubated at 37 degrees C. Slices were exposed to JP-8 jet fuel (0.5 mg/ml, 1.0 mg/ml, and 1.5 mg/ml in medium) for up to 24 hours. We determined ATP content using a luciferin-luciferase bioluminescent assay. No significant difference was found between the JP-8 jet fuel doses or time points, when compared to controls. Results were correlated with structural alterations following aerosol inhalation of JP-8. As a general observation, ultrastructural evaluation of alveolar type cells revealed an apparent increase in the number and size of surfactant secreting lamellar bodies that was JP-8 jet fuel-dose dependent. These results are similar to those observed following aerosol inhalation exposure. Thus, the lung tissue slice model appears to mimic in vivo effects of JP-8 and therefore is a useful model system for studying the mechanisms of lunginjury following JP-8 exposure.

  5. Reduced Hyperpolarization-Activated Current Contributes to Enhanced Intrinsic Excitability in Cultured Hippocampal Neurons from PrP(-/-) Mice.

    Science.gov (United States)

    Fan, Jing; Stemkowski, Patrick L; Gandini, Maria A; Black, Stefanie A; Zhang, Zizhen; Souza, Ivana A; Chen, Lina; Zamponi, Gerald W

    2016-01-01

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

  6. Gonadal Steroids: Effects on Excitability of Hippocampal Pyramidal Cells

    Science.gov (United States)

    Teyler, Timothy J.; Vardaris, Richard M.; Lewis, Deborah; Rawitch, Allen B.

    1980-08-01

    Electrophysiological field potentials from hippocampal slices of rat brain show sex-linked differences in response to 1 × 10-10M concentrations of estradiol and testosterone added to the incubation medium. Slices from male rats show increased excitability to estradiol and not to testosterone. Slices from female rats are not affected by estradiol, but slices from female rats in diestrus show increased excitability in response to testosterone whereas slices from females in proestrus show decreased excitability.

  7. Neuroprotective effects of oxysophocarpine on neonatal rat primary cultured hippocampal neurons injured by oxygen-glucose deprivation and reperfusion.

    Science.gov (United States)

    Zhu, Qing-Luan; Li, Yu-Xiang; Zhou, Ru; Ma, Ning-Tian; Chang, Ren-Yuan; Wang, Teng-Fei; Zhang, Yi; Chen, Xiao-Ping; Hao, Yin-Ju; Jin, Shao-Ju; Ma, Lin; Du, Juan; Sun, Tao; Yu, Jian-Qiang

    2014-08-01

    Oxysophocarpine (OSC), a quinolizidine alkaloid extracted from leguminous plants of the genus Robinia, is traditionally used for various diseases including neuronal disorders. This study investigated the protective effects of OSC on neonatal rat primary-cultured hippocampal neurons were injured by oxygen-glucose deprivation and reperfusion (OGD/RP). Cultured hippocampal neurons were exposed to OGD for 2 h followed by a 24 h RP. OSC (1, 2, and 5 μmol/L) and nimodipine (Nim) (12 μmol/L) were added to the culture after OGD but before RP. The cultures of the control group were not exposed to OGD/RP. MTT and LDH assay were used to evaluate the protective effects of OSC. The concentration of intracellular-free calcium [Ca(2+)]i and mitochondrial membrane potential (MMP) were determined to evaluate the degree of neuronal damage. Morphologic changes of neurons following OGD/RP were observed with a microscope. The expression of caspase-3 and caspase-12 mRNA was examined by real-time quantitative PCR. The IC50 of OSC was found to be 100 μmol/L. Treatment with OSC (1, 2, and 5 μmol/L) attenuated neuronal damage (p < 0.001), with evidence of increased cell viability (p < 0.001) and decreased cell morphologic impairment. Furthermore, OSC increased MMP (p < 0.001), but it inhibited [Ca(2+)]i (p < 0.001) elevation in a dose-dependent manner at OGD/RP. OSC (5 μmol/L) also decreased the expression of caspase-3 (p < 0.05) and caspase-12 (p < 0.05). The results suggested that OSC has significant neuroprotective effects that can be attributed to inhibiting endoplasmic reticulum (ER) stress-induced apoptosis.

  8. Single-cell axotomy of cultured hippocampal neurons integrated in neuronal circuits.

    Science.gov (United States)

    Gomis-Rüth, Susana; Stiess, Michael; Wierenga, Corette J; Meyn, Liane; Bradke, Frank

    2014-05-01

    An understanding of the molecular mechanisms of axon regeneration after injury is key for the development of potential therapies. Single-cell axotomy of dissociated neurons enables the study of the intrinsic regenerative capacities of injured axons. This protocol describes how to perform single-cell axotomy on dissociated hippocampal neurons containing synapses. Furthermore, to axotomize hippocampal neurons integrated in neuronal circuits, we describe how to set up coculture with a few fluorescently labeled neurons. This approach allows axotomy of single cells in a complex neuronal network and the observation of morphological and molecular changes during axon regeneration. Thus, single-cell axotomy of mature neurons is a valuable tool for gaining insights into cell intrinsic axon regeneration and the plasticity of neuronal polarity of mature neurons. Dissociation of the hippocampus and plating of hippocampal neurons takes ∼2 h. Neurons are then left to grow for 2 weeks, during which time they integrate into neuronal circuits. Subsequent axotomy takes 10 min per neuron and further imaging takes 10 min per neuron.

  9. Chronic zinc exposure decreases the surface expression of NR2A-containing NMDA receptors in cultured hippocampal neurons.

    Directory of Open Access Journals (Sweden)

    Jia Zhu

    Full Text Available Zinc distributes widely in the central nervous system, especially in the hippocampus, amygdala and cortex. The dynamic balance of zinc is critical for neuronal functions. Zinc modulates the activity of N-methyl-D-aspartate receptors (NMDARs through the direct inhibition and various intracellular signaling pathways. Abnormal NMDAR activities have been implicated in the aetiology of many brain diseases. Sustained zinc accumulation in the extracellular fluid is known to link to pathological conditions. However, the mechanism linking this chronic zinc exposure and NMDAR dysfunction is poorly understood.We reported that chronic zinc exposure reduced the numbers of NR1 and NR2A clusters in cultured hippocampal pyramidal neurons. Whole-cell and synaptic NR2A-mediated currents also decreased. By contrast, zinc did not affect NR2B, suggesting that chronic zinc exposure specifically influences NR2A-containg NMDARs. Surface biotinylation indicated that zinc exposure attenuated the membrane expression of NR1 and NR2A, which might arise from to the dissociation of the NR2A-PSD-95-Src complex.Chronic zinc exposure perturbs the interaction of NR2A to PSD-95 and causes the disorder of NMDARs in hippocampal neurons, suggesting a novel action of zinc distinct from its acute effects on NMDAR activity.

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

    Directory of Open Access Journals (Sweden)

    Xin Xu

    2017-07-01

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

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

    DEFF Research Database (Denmark)

    Novitskaya, V; Grigorian, M; Kriajevska, M

    2000-01-01

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

  12. [Protective effect of pretreatment of Salvia miltiorrhiza Bunge. f. alba plasma against oxygen-glucose deprivation-induced injury of cultured rat hippocampal neurons by inhibiting apoptosis].

    Science.gov (United States)

    Li, Mei-Yi; Zhang, Yan-Bo; Zuo, Huan; Liu, Li-Li; Niu, Jing-Zhong

    2012-02-25

    The present study was to investigate the effect of Salvia miltiorrhiza Bunge. f. alba (SMA) pharmacological pretreatment on apoptosis of cultured hippocampal neurons from neonate rats under oxygen-glucose deprivation (OGD). Cultured hippocampal neurons were randomly divided into five groups (n = 6): normal plasma group, low dose SMA plasma (2.5%) group, middle dose SMA plasma (5%) group, high dose SMA plasma (10%) group and control group. The hippocampal neurons were cultured and treated with plasma from adult Wistar rats intragastrically administered with saline or aqueous extract of SMA. The apoptosis of neurons was induced by glucose-free Earle's solution containing 1 mmol/L Na2S2O4 and labeled by MTT and Annexin V/PI double staining. Moreover, protein expressions of Bcl-2 and Bax were detected by immunofluorescence. The results showed that few apoptotic cells were observed in control group, whereas the number of apoptotic cells was greatly increased in normal plasma group and low dose SMA plasma group. Both middle and high dose SMA plasma could protect cultured hippocampal neurons from apoptosis induced by OGD (P control, normal plasma and low dose SMA plasma groups, middle and high dose SMA plasma groups both showed significantly higher levels of Bcl-2 (P neurons by up-regulating the expression of Bcl-2 and down-regulating the expression of Bax.

  13. A study of epileptogenic network structures in rat hippocampal cultures using first spike latencies during synchronization events

    International Nuclear Information System (INIS)

    Raghavan, Mohan; Amrutur, Bharadwaj; Srinivas, Kalyan V; Sikdar, Sujit K

    2012-01-01

    Study of hypersynchronous activity is of prime importance for combating epilepsy. Studies on network structure typically reconstruct the network by measuring various aspects of the interaction between neurons and subsequently measure the properties of the reconstructed network. In sub-sampled networks such methods lead to significant errors in reconstruction. Using rat hippocampal neurons cultured on a multi-electrode array dish and a glutamate injury model of epilepsy in vitro, we studied synchronous activity in neuronal networks. Using the first spike latencies in various neurons during a network burst, we extract various recurring spatio-temporal onset patterns in the networks. Comparing the patterns seen in control and injured networks, we observe that injured networks express a wide diversity in their foci (origin) and activation pattern, while control networks show limited diversity. Furthermore, we note that onset patterns in glutamate injured networks show a positive correlation between synchronization delay and physical distance between neurons, while control networks do not. (paper)

  14. PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of posttraumatic epilepsy

    Science.gov (United States)

    Berdichevsky, Yevgeny; Dryer, Alexandra M.; Saponjian, Yero; Mahoney, Mark M.; Pimentel, Corrin A.; Lucini, Corrina A.; Usenovic, Marija; Staley, Kevin J.

    2013-01-01

    mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an antiepileptogenic, or merely anti-convulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordings, and cell death was quantified with LDH release measurements and Nissl-stained neuron counts. Lactate and LDH measurements were well-correlated with electrographic activity and neuron counts, respectively. Inhibition of PI3K and Akt prevented activation of mTOR, and was as effective as inhibition of mTOR in reducing ictal activity and cell death. A dual inhibitor of PI3K and mTOR, NVP-BEZ235, was also effective. Inhibition of mTOR with rapamycin reduced axon sprouting. Late start of rapamycin treatment was effective in reducing epileptic activity and cell death, while early termination of rapamycin treatment did not result in increased epileptic activity or cell death. The conclusions of the study are: (1), the organotypic hippocampal culture model of posttraumatic epilepsy comprises a rapid assay of antiepileptogenic and neuroprotective activities and, in this model (2), mTOR activation depends on PI3K-Akt signaling, and (3) transient inhibition of mTOR has sustained effects on epilepsy. PMID:23699517

  15. Hippocampal Dendritic Spines Are Segregated Depending on Their Actin Polymerization.

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    Domínguez-Iturza, Nuria; Calvo, María; Benoist, Marion; Esteban, José Antonio; Morales, Miguel

    2016-01-01

    Dendritic spines are mushroom-shaped protrusions of the postsynaptic membrane. Spines receive the majority of glutamatergic synaptic inputs. Their morphology, dynamics, and density have been related to synaptic plasticity and learning. The main determinant of spine shape is filamentous actin. Using FRAP, we have reexamined the actin dynamics of individual spines from pyramidal hippocampal neurons, both in cultures and in hippocampal organotypic slices. Our results indicate that, in cultures, the actin mobile fraction is independently regulated at the individual spine level, and mobile fraction values do not correlate with either age or distance from the soma. The most significant factor regulating actin mobile fraction was the presence of astrocytes in the culture substrate. Spines from neurons growing in the virtual absence of astrocytes have a more stable actin cytoskeleton, while spines from neurons growing in close contact with astrocytes show a more dynamic cytoskeleton. According to their recovery time, spines were distributed into two populations with slower and faster recovery times, while spines from slice cultures were grouped into one population. Finally, employing fast lineal acquisition protocols, we confirmed the existence of loci with high polymerization rates within the spine.

  16. 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.

  17. Inhibition of RhoA GTPase and the subsequent activation of PTP1B protects cultured hippocampal neurons against amyloid β toxicity

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    Rodriguez-Tebar Alfredo

    2011-02-01

    Full Text Available Abstract Background Amyloid beta (Aβ is the main agent responsible for the advent and progression of Alzheimer's disease. This peptide can at least partially antagonize nerve growth factor (NGF signalling in neurons, which may be responsible for some of the effects produced by Aβ. Accordingly, better understanding the NGF signalling pathway may provide clues as to how to protect neurons from the toxic effects of Aβ. Results We show here that Aβ activates the RhoA GTPase by binding to p75NTR, thereby preventing the NGF-induced activation of protein tyrosine phosphatase 1B (PTP1B that is required for neuron survival. We also show that the inactivation of RhoA GTPase and the activation of PTP1B protect cultured hippocampal neurons against the noxious effects of Aβ. Indeed, either pharmacological inhibition of RhoA with C3 ADP ribosyl transferase or the transfection of cultured neurons with a dominant negative form of RhoA protects cultured hippocampal neurons from the effects of Aβ. In addition, over-expression of PTP1B also prevents the deleterious effects of Aβ on cultured hippocampal neurons. Conclusion Our findings indicate that potentiating the activity of NGF at the level of RhoA inactivation and PTP1B activation may represent a new means to combat the noxious effects of Aβ in Alzheimer's disease.

  18. Effects of Single and Repeated Exposure to a 50-Hz 2-mT Electromagnetic Field on Primary Cultured Hippocampal Neurons.

    Science.gov (United States)

    Zeng, Ying; Shen, Yunyun; Hong, Ling; Chen, Yanfeng; Shi, Xiaofang; Zeng, Qunli; Yu, Peilin

    2017-06-01

    The prevalence of domestic and industrial electrical appliances has raised concerns about the health risk of extremely low-frequency magnetic fields (ELF-MFs). At present, the effects of ELF-MFs on the central nervous system are still highly controversial, and few studies have investigated its effects on cultured neurons. Here, we evaluated the biological effects of different patterns of ELF-MF exposure on primary cultured hippocampal neurons in terms of viability, apoptosis, genomic instability, and oxidative stress. The results showed that repeated exposure to 50-Hz 2-mT ELF-MF for 8 h per day after different times in culture decreased the viability and increased the production of intracellular reactive oxidative species in hippocampal neurons. The mechanism was potentially related to the up-regulation of Nox2 expression. Moreover, none of the repeated exposure patterns had significant effects on DNA damage, apoptosis, or autophagy, which suggested that ELF-MF exposure has no severe biological consequences in cultured hippocampal neurons.

  19. Synaptic potentiation facilitates memory-like attractor dynamics in cultured in vitro hippocampal networks.

    Directory of Open Access Journals (Sweden)

    Mark Niedringhaus

    Full Text Available Collective rhythmic dynamics from neurons is vital for cognitive functions such as memory formation but how neurons self-organize to produce such activity is not well understood. Attractor-based computational models have been successfully implemented as a theoretical framework for memory storage in networks of neurons. Additionally, activity-dependent modification of synaptic transmission is thought to be the physiological basis of learning and memory. The goal of this study is to demonstrate that using a pharmacological treatment that has been shown to increase synaptic strength within in vitro networks of hippocampal neurons follows the dynamical postulates theorized by attractor models. We use a grid of extracellular electrodes to study changes in network activity after this perturbation and show that there is a persistent increase in overall spiking and bursting activity after treatment. This increase in activity appears to recruit more "errant" spikes into bursts. Phase plots indicate a conserved activity pattern suggesting that a synaptic potentiation perturbation to the attractor leaves it unchanged. Lastly, we construct a computational model to demonstrate that these synaptic perturbations can account for the dynamical changes seen within the network.

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

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    Farida Veliev

    2017-08-01

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

  3. Localization of the kinesin adaptor proteins trafficking kinesin proteins 1 and 2 in primary cultures of hippocampal pyramidal and cortical neurons.

    Science.gov (United States)

    Loss, Omar; Stephenson, F Anne

    2015-07-01

    Neuronal function requires regulated anterograde and retrograde trafficking of mitochondria along microtubules by using the molecular motors kinesin and dynein. Previous work has established that trafficking kinesin proteins (TRAKs),TRAK1 and TRAK2, are kinesin adaptor proteins that link mitochondria to kinesin motor proteins via an acceptor protein in the mitochondrial outer membrane, etc. the Rho GTPase Miro. Recent studies have shown that TRAK1 preferentially controls mitochondrial transport in axons of hippocampal neurons by virtue of its binding to both kinesin and dynein motor proteins, whereas TRAK2 controls mitochondrial transport in dendrites resulting from its binding to dynein. This study further investigates the subcellular localization of TRAK1 and TRAK2 in primary cultures of hippocampal and cortical neurons by using both commercial antibodies and anti-TRAK1 and anti-TRAK2 antibodies raised in our own laboratory (in-house). Whereas TRAK1 was prevalently localized in axons of hippocampal and cortical neurons, TRAK2 was more prevalent in dendrites of hippocampal neurons. In cortical neurons, TRAK2 was equally distributed between axons and dendrites. Some qualitative differences were observed between commercial and in-house-generated antibody immunostaining. © 2015 Wiley Periodicals, Inc.

  4. Blood cell oxidative stress precedes hemolysis in whole blood-liver slice co-cultures of rat, dog, and human tissues

    International Nuclear Information System (INIS)

    Vickers, Alison E.M.; Sinclair, John R.; Fisher, Robyn L.; Morris, Stephen R.; Way, William

    2010-01-01

    A novel in vitro model to investigate time-dependent and concentration-dependent responses in blood cells and hemolytic events is studied for rat, dog, and human tissues. Whole blood is co-cultured with a precision-cut liver slice. Methimazole (MMI) was selected as a reference compound, since metabolism of its imidazole thione moiety is linked with hematologic disorders and hepatotoxicity. An oxidative stress response occurred in all three species, marked by a decline in blood GSH levels by 24 h that progressed, and preceded hemolysis, which occurred at high MMI concentrations in the presence of a liver slice with rat (≥ 1000 μM at 48 h) and human tissues (≥ 1000 μM at 48 h, ≥ 750 μM at 72 h) but not dog. Human blood-only cultures exhibited a decline of GSH levels but minimal to no hemolysis. The up-regulation of liver genes for heme degradation (Hmox1 and Prdx1), iron cellular transport (Slc40a1), and GSH synthesis and utilization (mGST1 and Gclc) were early markers of the oxidative stress response. The up-regulation of the Kupffer cell lectin Lgals3 gene expression indicated a response to damaged red blood cells, and Hp (haptoglobin) up-regulation is indicative of increased hemoglobin uptake. Up-regulation of liver IL-6 and IL-8 gene expression suggested an activation of an inflammatory response by liver endothelial cells. In summary, MMI exposure led to an oxidative stress response in blood cells, and an up-regulation of liver genes involved with oxidative stress and heme homeostasis, which was clearly separate and preceded frank hemolysis.

  5. [Lessening effect of hypoxia-preconditioned rat cerebrospinal fluid on oxygen-glucose deprivation-induced injury of cultured hippocampal neurons in neonate rats and possible mechanism].

    Science.gov (United States)

    Niu, Jing-Zhong; Zhang, Yan-Bo; Li, Mei-Yi; Liu, Li-Li

    2011-12-25

    The present study was to investigate the effect of cerebrospinal fluid (CSF) from the rats with hypoxic preconditioning (HPC) on apoptosis of cultured hippocampal neurons in neonate rats under oxygen glucose deprivation (OGD). Adult Wistar rats were exposed to 3 h of hypoxia for HPC, and then their CSF was taken out. Cultured hippocampal neurons from the neonate rats were randomly divided into four groups (n = 6): normal control group, OGD group, normal CSF group and HPC CSF group. OGD group received 1.5 h of incubation in glucose-free Earle's solution containing 1 mmol/L Na2S2O4, and normal and HPC CSF groups were subjected to 1 d of corresponding CSF treatments followed by 1.5 h OGD. The apoptosis of neurons was analyzed by confocal laser scanning microscope and flow cytometry using Annexin V/PI double staining. Moreover, protein expressions of Bcl-2 and Bax were detected by immunofluorescence. The results showed that few apoptotic cells were observed in normal control group, whereas the number of apoptotic cells was greatly increased in OGD group. Both normal and HPC CSF could decrease the apoptosis of cultured hippocampal neurons injured by OGD (P neurons by up-regulating expression of Bcl-2 and down-regulating expression of Bax.

  6. Brain stem slice conditioned medium contains endogenous BDNF and GDNF that affect neural crest boundary cap cells in co-culture.

    Science.gov (United States)

    Kaiser, Andreas; Kale, Ajay; Novozhilova, Ekaterina; Siratirakun, Piyaporn; Aquino, Jorge B; Thonabulsombat, Charoensri; Ernfors, Patrik; Olivius, Petri

    2014-05-30

    Conditioned medium (CM), made by collecting medium after a few days in cell culture and then re-using it to further stimulate other cells, is a known experimental concept since the 1950s. Our group has explored this technique to stimulate the performance of cells in culture in general, and to evaluate stem- and progenitor cell aptitude for auditory nerve repair enhancement in particular. As compared to other mediums, all primary endpoints in our published experimental settings have weighed in favor of conditioned culture medium, where we have shown that conditioned culture medium has a stimulatory effect on cell survival. In order to explore the reasons for this improved survival we set out to analyze the conditioned culture medium. We utilized ELISA kits to investigate whether brain stem (BS) slice CM contains any significant amounts of brain-derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF). We further looked for a donor cell with progenitor characteristics that would be receptive to BDNF and GDNF. We chose the well-documented boundary cap (BC) progenitor cells to be tested in our in vitro co-culture setting together with cochlear nucleus (CN) of the BS. The results show that BS CM contains BDNF and GDNF and that survival of BC cells, as well as BC cell differentiation into neurons, were enhanced when BS CM were used. Altogether, we conclude that BC cells transplanted into a BDNF and GDNF rich environment could be suitable for treatment of a traumatized or degenerated auditory nerve. Copyright © 2014 Elsevier B.V. All rights reserved.

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

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    Chi-Fai Lau

    2014-01-01

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

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

    Science.gov (United States)

    Waddell, Jaylyn; Kim, Jimok; Alger, Bradley E; McCarthy, Margaret M

    2011-01-01

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

  9. Cooperation of HIF- and NCAM-mediated mechanisms in cell viability of hippocampal cultures after oxygen-glucose deprivation.

    Science.gov (United States)

    Lushnikova, Iryna; Nikandrova, Yelyzaveta; Skibo, Galyna

    2017-10-01

    Neurodegenerative diseases of different genesis are the result of cellular damages including those caused by oxygen and glucose deficit. Neuronal survival or death in brain pathologies depends on a variety of interrelated molecular mechanisms. A key role in modulation of neuron viability belongs to HIF (hypoxia-inducible factor) and NCAM (neural cell adhesion molecules) signaling pathways. In this work, we used organotypic and dissociated hippocampal cultures to analyze cell viability and HIF-1α immunopositive (HIF-1α + ) signal after 30 min oxygen-glucose deprivation (OGD) followed by 24 h of reoxygenation in the presence of FGL (synthetic NCAM-derived mimetic peptide). According to LDH- and MTS-assay of cell viability, FGL showed a neuroprotective effect, which was attributed to the association with FGFR. We showed that these effects correlated with changes of the HIF-1α + level suggesting the communications of HIF and NCAM signaling pathways. These data extend our knowledge of neurodegeneration mechanisms and open additional potential for the development of neuroprotection strategies. © 2017 International Federation for Cell Biology.

  10. Caloric restriction mimetic 2-deoxyglucose maintains cytoarchitecture and reduces tau phosphorylation in primary culture of mouse hippocampal pyramidal neurons.

    Science.gov (United States)

    Bele, M S; Gajare, K A; Deshmukh, A A

    2015-06-01

    Typical form of neurons is crucially important for their functions. This is maintained by microtubules and associated proteins like tau. Hyperphosphorylation of tau is a major concern in neurodegenerative diseases. Glycogen synthase kinase3β (GSK3β) and cyclin-dependent protein kinase 5 (Cdk5) are the enzymes that govern tau phosphorylation. Currently, efforts are being made to target GSK3β and Cdk5 as possible therapeutic avenues to control tau phosphorylation and treat neurodegenerative diseases related to taupathies. In a number of studies, caloric restriction mimetic 2-deoxyglucose (C6H12O5) was found to be beneficial in improving the brain functions. However, no reports are available on the effect of 2-deoxyglucose 2-DG on tau phosphorylation. In the present study, hippocampal pyramidal neurons from E17 mouse embryos were isolated and cultured on poly-L-lysine-coated coverslips. Neurons from the experimental group were treated with 10 mM 2-deoxyglucose. The treatment of 2-DG resulted in healthier neuronal morphology in terms of significantly lower number of cytoplasmic vacuoles, little or no membrane blebbings, maintained axon hillock and intact neurites. There were decreased immunofluorescence signals for GSK3β, pTau at Ser262, Cdk5 and pTau at Ser235 suggesting decreased tau phosphorylation, which was further confirmed by Western blotting. The results indicate the beneficial effects of 2-DG in controlling the tau phosphorylation and maintaining the healthy neuronal cytoarchitecture.

  11. Long-term exposure to high glucose induces changes in the content and distribution of some exocytotic proteins in cultured hippocampal neurons.

    Science.gov (United States)

    Gaspar, J M; Castilho, Á; Baptista, F I; Liberal, J; Ambrósio, A F

    2010-12-29

    A few studies have reported the existence of depletion of synaptic vesicles, and changes in neurotransmitter release and in the content of exocytotic proteins in the hippocampus of diabetic rats. Recently, we found that diabetes alters the levels of synaptic proteins in hippocampal nerve terminals. Hyperglycemia is considered the main trigger of diabetic complications, although other factors, such as low insulin levels, also contribute to diabetes-induced changes. Thus, the aim of this work was to evaluate whether long-term elevated glucose per se, which mimics prolonged hyperglycemia, induces significant changes in the content and localization of synaptic proteins involved in exocytosis in hippocampal neurons. Hippocampal cell cultures were cultured for 14 days and were exposed to high glucose (50 mM) or mannitol (osmotic control; 25 mM plus 25 mM glucose), for 7 days. Cell viability and nuclear morphology were evaluated by MTT and Hoechst assays, respectively. The protein levels of vesicle-associated membrane protein-2 (VAMP-2), synaptosomal-associated protein-25 (SNAP-25), syntaxin-1, synapsin-1, synaptophysin, synaptotagmin-1, rabphilin 3a, and also of vesicular glutamate and GABA transporters (VGluT-1 and VGAT), were evaluated by immunoblotting, and its localization was analyzed by immunocytochemistry. The majority of the proteins were not affected. However, elevated glucose decreased the content of SNAP-25 and increased the content of synaptotagmin-1 and VGluT-1. Moreover, there was an accumulation of syntaxin-1, synaptotagmin-1 and VGluT-1 in the cell body of some hippocampal neurons exposed to high glucose. No changes were detected in mannitol-treated cells. In conclusion, elevated glucose per se did not induce significant changes in the content of the majority of the synaptic proteins studied in hippocampal cultures, with the exception of SNAP-25, synaptotagmin-1 and VGluT-1. However, there was an accumulation of some proteins in cell bodies of hippocampal

  12. Hippocampal MR volumetry

    Science.gov (United States)

    Haller, John W.; Botteron, K.; Brunsden, Barry S.; Sheline, Yvette I.; Walkup, Ronald K.; Black, Kevin J.; Gado, Mokhtar; Vannier, Michael W.

    1994-09-01

    Goal: To estimate hippocampal volumes from in vivo 3D magnetic resonance (MR) brain images and determine inter-rater and intra- rater repeatability. Objective: The precision and repeatability of hippocampal volume estimates using stereologic measurement methods is sought. Design: Five normal control and five schizophrenic subjects were MR scanned using a MPRAGE protocol. Fixed grid stereologic methods were used to estimate hippocampal volumes on a graphics workstation. The images were preprocessed using histogram analysis to standardize 3D MR image scaling from 16 to 8 bits and image volumes were interpolated to 0.5 mm3 isotropic voxels. The following variables were constant for the repeated stereologic measures: grid size, inter-slice distance (1.5 mm), voxel dimensions (0.5 mm3), number of hippocampi measured (10), total number of measurements per rater (40), and number of raters (5). Two grid sizes were tested to determine the coefficient of error associated with the number of sampled 'hits' (approximately 140 and 280) on the hippocampus. Starting slice and grid position were randomly varied to assure unbiased volume estimates. Raters were blind to subject identity, diagnosis, and side of the brain from which the image volumes were extracted and the order of subject presentation was randomized for each of the raters. Inter- and intra-rater intraclass correlation coefficients (ICC) were determined. Results: The data indicate excellent repeatability of fixed grid stereologic hippocampal volume measures when using an inter-slice distance of 1.5 mm and a 6.25 mm2 grid (inter-rater ICCs equals 0.86 - 0.97, intra- rater ICCs equals 0.85 - 0.97). One major advantage of the current study was the use of 3D MR data which significantly improved visualization of hippocampal boundaries by providing the ability to access simultaneous orthogonal views while counting stereological marks within the hippocampus. Conclusion: Stereological estimates of 3D volumes from 2D MR

  13. Anticonvulsant Effects of Memantine and MK-801 in Guinea Pig Hippocampal Neurons.

    Science.gov (United States)

    investigation we compared the anticonvulsant properties of Mem to those of MK-801 in guinea pig hippocampal slices. Extracellular recordings were...obtained from area CA1 of guinea pig hippocampal slices in a total submersion chamber at 32 deg C in normal oxygenated artificial cerebrospinal fluid (ACSF

  14. Adaptive enhancement of learning protocol in hippocampal cultured networks grown on multielectrode arrays

    Science.gov (United States)

    Pimashkin, Alexey; Gladkov, Arseniy; Mukhina, Irina; Kazantsev, Victor

    2013-01-01

    Learning in neuronal networks can be investigated using dissociated cultures on multielectrode arrays supplied with appropriate closed-loop stimulation. It was shown in previous studies that weakly respondent neurons on the electrodes can be trained to increase their evoked spiking rate within a predefined time window after the stimulus. Such neurons can be associated with weak synaptic connections in nearby culture network. The stimulation leads to the increase in the connectivity and in the response. However, it was not possible to perform the learning protocol for the neurons on electrodes with relatively strong synaptic inputs and responding at higher rates. We proposed an adaptive closed-loop stimulation protocol capable to achieve learning even for the highly respondent electrodes. It means that the culture network can reorganize appropriately its synaptic connectivity to generate a desired response. We introduced an adaptive reinforcement condition accounting for the response variability in control stimulation. It significantly enhanced the learning protocol to a large number of responding electrodes independently on its base response level. We also found that learning effect preserved after 4–6 h after training. PMID:23745105

  15. Precision-cut intestinal slices as a culture system to analyze the infection of differentiated intestinal epithelial cells by avian influenza viruses.

    Science.gov (United States)

    Punyadarsaniya, Darsaniya; Winter, Christine; Mork, Ann-Kathrin; Amiri, Mahdi; Naim, Hassan Y; Rautenschlein, Silke; Herrler, Georg

    2015-02-01

    Many viruses infect and replicate in their host via the intestinal tract, e.g. many picornaviruses, several coronaviruses and avian influenza viruses of waterfowl. To analyze infection of enterocytes is a challenging task as culture systems for differentiated intestinal epithelial cells are not readily available and often have a life span that is too short for infection studies. Precision-cut intestinal slices (PCIS) from chicken embryos were prepared and shown that the epithelial cells lining the lumen of the intestine are viable for up to 4 days. Using lectin staining, it was demonstrated that α2,3-linked sialic acids, the preferred receptor determinants of avian influenza viruses, are present on the apical side of the epithelial cells. Furthermore, the epithelial cells (at the tips) of the villi were shown to be susceptible to infection by an avian influenza virus of the H9N2 subtype. This culture system will be useful to analyze virus infection of intestinal epithelial cells and it should be applicable also to the intestine of other species. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Mouse Pancreas Tissue Slice Culture Facilitates Long-Term Studies of Exocrine and Endocrine Cell Physiology in situ

    OpenAIRE

    Marciniak, Anja; Selck, Claudia; Friedrich, Betty; Speier, Stephan

    2013-01-01

    Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To ove...

  17. The energy demand of fast neuronal network oscillations: insights from brain slice preparations

    Directory of Open Access Journals (Sweden)

    Oliver eKann

    2012-01-01

    Full Text Available Fast neuronal network oscillations in the gamma range (30-100 Hz in the cerebral cortex have been implicated in higher cognitive functions such as sensual perception, working memory, and, perhaps, consciousness. However, little is known about the energy demand of gamma oscillations. This is mainly caused by technical limitations that are associated with simultaneous recordings of neuronal activity and energy metabolism in small neuronal networks and at the level of mitochondria in vivo. Thus recent studies have focused on brain slice preparations to address the energy demand of gamma oscillations in vitro. Here, reports will be summarized and discussed that combined electrophysiological recordings, oxygen sensor microelectrodes and live-cell fluorescence imaging in acutely prepared slices and organotypic slice cultures of the hippocampus from both, mouse and rat. These reports consistently show that gamma oscillations can be reliably induced in hippocampal slice preparations by different pharmacological tools. They suggest that gamma oscillations are associated with high energy demand, requiring both rapid adaptation of oxidative energy metabolism and sufficient supply with oxygen and nutrients. These findings might help to explain the exceptional vulnerability of higher cognitive functions during pathological processes of the brain, such as circulatory disturbances, genetic mitochondrial diseases, and neurodegeneration.

  18. Minocycline Has Anti-inflammatory Effects and Reduces Cytotoxicity in an Ex Vivo Spinal Cord Slice Culture Model of West Nile Virus Infection.

    Science.gov (United States)

    Quick, Eamon D; Seitz, Scott; Clarke, Penny; Tyler, Kenneth L

    2017-11-15

    West Nile virus (WNV) is a neurotropic flavivirus that can cause significant neurological disease. Mouse models of WNV infection demonstrate that a proinflammatory environment is induced within the central nervous system (CNS) after WNV infection, leading to entry of activated peripheral immune cells. We utilized ex vivo spinal cord slice cultures (SCSC) to demonstrate that anti-inflammatory mechanisms may also play a role in WNV-induced pathology and/or recovery. Microglia are a type of macrophage that function as resident CNS immune cells. Similar to mouse models, infection of SCSC with WNV induces the upregulation of proinflammatory genes and proteins that are associated with microglial activation, including the microglial activation marker Iba1 and CC motif chemokines CCL2, CCL3, and CCL5. This suggests that microglia assume a proinflammatory phenotype in response to WNV infection similar to the proinflammatory (M1) activation that can be displayed by other macrophages. We now show that the WNV-induced expression of these and other proinflammatory genes was significantly decreased in the presence of minocycline, which has antineuroinflammatory properties, including the ability to inhibit proinflammatory microglial responses. Minocycline also caused a significant increase in the expression of anti-inflammatory genes associated with alternative anti-inflammatory (M2) macrophage activation, including interleukin 4 (IL-4), IL-13, and FIZZ1. Minocycline-dependent alterations to M1/M2 gene expression were associated with a significant increase in survival of neurons, microglia, and astrocytes in WNV-infected slices and markedly decreased levels of inducible nitric oxide synthase (iNOS). These results demonstrate that an anti-inflammatory environment induced by minocycline reduces viral cytotoxicity during WNV infection in ex vivo CNS tissue. IMPORTANCE West Nile virus (WNV) causes substantial morbidity and mortality, with no specific therapeutic treatments available

  19. Thick Slice and Thin Slice Teaching Evaluations

    Science.gov (United States)

    Tom, Gail; Tong, Stephanie Tom; Hesse, Charles

    2010-01-01

    Student-based teaching evaluations are an integral component to institutions of higher education. Previous work on student-based teaching evaluations suggest that evaluations of instructors based upon "thin slice" 30-s video clips of them in the classroom correlate strongly with their end of the term "thick slice" student evaluations. This study's…

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

    Directory of Open Access Journals (Sweden)

    Marianna E. Jung

    2009-04-01

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

  1. BDNF-induced nitric oxide signals in cultured rat hippocampal neurons: time course, mechanism of generation, and effect on neurotrophin secretion.

    Science.gov (United States)

    Kolarow, Richard; Kuhlmann, Christoph R W; Munsch, Thomas; Zehendner, Christoph; Brigadski, Tanja; Luhmann, Heiko J; Lessmann, Volkmar

    2014-01-01

    BDNF and nitric oxide signaling both contribute to plasticity at glutamatergic synapses. However, the role of combined signaling of both pathways at the same synapse is largely unknown. Using NO imaging with diaminofluoresceine in cultured hippocampal neurons we analyzed the time course of neurotrophin-induced NO signals. Application of exogenous BDNF, NT-4, and NT-3 (but not NGF) induced NO signals in the soma and in proximal dendrites of hippocampal neurons that were sensitive to NO synthase activity, TrkB signaling, and intracellular calcium elevation. The effect of NO signaling on neurotrophin secretion was analyzed in BDNF-GFP, and NT-3-GFP transfected hippocampal neurons. Exogenous application of the NO donor sodium-nitroprusside markedly inhibited neurotrophin secretion. However, endogenously generated NO in response to depolarization and neurotrophin stimulation, both did not result in a negative feedback on neurotrophin secretion. These results suggest that a negative feedback of NO signaling on synaptic secretion of neurotrophins operates only at high intracellular levels of nitric oxide that are under physiological conditions not reached by depolarization or BDNF signaling.

  2. Live imaging of dense-core vesicles in primary cultured hippocampal neurons.

    Science.gov (United States)

    Kwinter, David M; Silverman, Michael A; Kwinter, David; Michael, Silverman

    2009-05-29

    Observing and characterizing dynamic cellular processes can yield important information about cellular activity that cannot be gained from static images. Vital fluorescent probes, particularly green fluorescent protein (GFP) have revolutionized cell biology stemming from the ability to label specific intracellular compartments and cellular structures. For example, the live imaging of GFP (and its spectral variants) chimeras have allowed for a dynamic analysis of the cytoskeleton, organelle transport, and membrane dynamics in a multitude of organisms and cell types [1-3]. Although live imaging has become prevalent, this approach still poses many technical challenges, particularly in primary cultured neurons. One challenge is the expression of GFP-tagged proteins in post-mitotic neurons; the other is the ability to capture fluorescent images while minimizing phototoxicity, photobleaching, and maintaining general cell health. Here we provide a protocol that describes a lipid-based transfection method that yields a relatively low transfection rate (~0.5%), however is ideal for the imaging of fully polarized neurons. A low transfection rate is essential so that single axons and dendrites can be characterized as to their orientation to the cell body to confirm directionality of transport, i.e., anterograde v. retrograde. Our approach to imaging GFP expressing neurons relies on a standard wide-field fluorescent microscope outfitted with a CCD camera, image capture software, and a heated imaging chamber. We have imaged a wide variety of organelles or structures, for example, dense-core vesicles, mitochondria, growth cones, and actin without any special optics or excitation requirements other than a fluorescent light source. Additionally, spectrally-distinct, fluorescently labeled proteins, e.g., GFP and dsRed-tagged proteins, can be visualized near simultaneously to characterize co-transport or other coordinated cellular events. The imaging approach described here is

  3. Lipopolysaccharide-induced dopaminergic cell death in rat midbrain slice cultures: role of inducible nitric oxide synthase and protection by indomethacin.

    Science.gov (United States)

    Shibata, Haruki; Katsuki, Hiroshi; Nishiwaki, Mayumi; Kume, Toshiaki; Kaneko, Shuji; Akaike, Akinori

    2003-09-01

    Glial cell activation associated with inflammatory reaction may contribute to pathogenic processes of neurodegenerative disorders, through production of several cytotoxic molecules. We investigated the consequences of glial activation by interferon-gamma (IFN-gamma)/lipopolysaccharide (LPS) in rat midbrain slice cultures. Application of IFN-gamma followed by LPS caused dopaminergic cell death and accompanying increases in nitrite production and lactate dehydrogenase release. Aminoguanidine, an inhibitor of inducible nitric oxide synthase (iNOS), or SB203580, an inhibitor of p38 mitogen-activated protein kinase, prevented dopaminergic cell loss as well as nitrite production. SB203580 also suppressed expression of iNOS and cyclooxygenase-2 (COX-2) induced by IFN-gamma/LPS. A COX inhibitor indomethacin protected dopaminergic neurons from IFN-gamma/LPS-induced injury, whereas selective COX-2 inhibitors such as NS-398 and nimesulide did not. Notably, indomethacin was able to attenuate neurotoxicity of a nitric oxide (NO) donor. Neutralizing antibodies against tumour necrosis factor-alpha and interleukin-1beta did not inhibit dopaminergic cell death caused by IFN-gamma/LPS, although combined application of these antibodies blocked lactate dehydrogenase release and decrease in the number of non-dopaminergic neurons. These results indicate that iNOS-derived NO plays a crucial role in IFN-gamma/LPS-induced dopaminergic cell death, and that indomethacin exerts protective effect by mechanisms probably related to NO neurotoxicity rather than through COX inhibition.

  4. Industrial application of an antilisterial strain of Lactobacillus sakei as a protective culture and its effect on the sensory acceptability of cooked, sliced, vacuum-packaged meats.

    Science.gov (United States)

    Bredholt, S; Nesbakken, T; Holck, A

    2001-06-15

    The application of a protective lactic acid bacterium (LAB) during the commercial production of cooked meat products is described. The LAB, a strain of Lactobacillus sakei, was previously isolated from cooked ham and inhibited growth of Listeria monocytogenes and Escherichia coli O157:H7 in this product. L. sakei was applied to the cooked products at a concentration of 10(5)-10(6) cfu/g immediately before slicing and vacuum-packaging using a hand-operated spraying bottle. The LAB strain inhibited growth of 10(3) cfu/g of a cocktail of three rifampicin resistant mutant L. monocytogenes strains both at 8 degrees C and 4 degrees C. Consumer acceptance tests of cooked ham and of servelat sausage, a Norwegian non-fermented cooked meat sausage, showed that control and inoculated products were equally acceptable. The products were still acceptable after storage for 28 days at 4 degrees C and, after opening the packages, for a further 5 days at 4 degrees C. The findings presented here confirm that the L. sakei strain is suitable for use as a protective culture and may technically easily be implemented in the commercial production of cooked meat products.

  5. Differential Alterations in Excitatory and Inhibitory Networks Involving Dentate Granule Cells Following Chronic Treatment with Distinct Classes of NMDAR Antagonists in Hippocampal Slice Cultures

    Science.gov (United States)

    2010-03-08

    Rev. 8-98) Prescribed by ANSI Std Z39-18 Copyright Statement The author herby certitles thaI the use of any copyrighted material in the thesis...synaptic Ras-GTPase activating protein TBI: traumatic brain injury TeNT: tetanus toxin TLE: temporal lobe epilepsy TEA : tetraethylammonium TTX...antagonist QX-314 non membrane permeable sodium channel blocker TEA Kv channel blocker XVI XVII List of compounds and their pharmacological actions

  6. The use of organotypic hippocampal slice cultures to evaluate protection by non-competitive NMDA receptor antagonists against excitotoxicity

    DEFF Research Database (Denmark)

    Ring, Avi; Tanso, Rita; Noraberg, Jens

    2010-01-01

    There is a wide interest in testing neuroprotectants which inhibit the neurodegeneration that results from excessive activation of brain NMDA receptors.  As an alternative to in vivo testing in animal models we demonstrate here the use of a complex in vitro model to compare the efficacy and toxic...

  7. PKC/CREB pathway mediates the expressions of GABAA receptor subunits in cultured hippocampal neurons after low-Mg2+ solution treatment.

    Science.gov (United States)

    Wu, Guofeng; Yu, Jinpeng; Wang, Likun; Ren, Siying; Zhang, Yixia

    2018-02-01

    To investigate the potential effects of the PKC/CREB pathway on the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons using a model of epilepsy that employed conditions of low magnesium (Mg 2+ ). A total of 108 embryonic rats at the age of 18 embryonic days (E18)prepared from adult female SD rats were used as experimental subjects. Primary rat hippocampal cultures were prepared from the embryonic 18 days rats. The cultured hippocampal neurons were then treated with artificial cerebrospinal fluid containing low Mg 2+ solutions to generate a low Mg 2+ model of epilepsy. The low Mg 2+ stimulation lasted for 3 h and then returned to in maintenance medium for 20 h. The changes of the GABA A receptor subunit α1, γ2, δ were observed by blocking or activating the function of the CREB. The quantification of the GABA A receptor subunit α1, γ2, δ and the CREB were determined by a qRT-PCR and a Western blot method. After the neurons were exposed to a low-Mg 2+ solution for 3 h, GABA A receptor mRNA expression markedly increased compared to the control, and then gradually decreased. In contrast, CREB mRNA levels exhibited a dramatic down-regulation 3 h after terminating low-Mg 2+ treatment, and then peaked at 9 h. Western blot analyses verified that staurosporine suppressed CREB phosphorylation (p-CREB). The mRNA expression of GABA A receptor subunit α1 increased only in the presence of staurosporine, whereas the expressions of subunits γ2 and δ significantly increased in the presence of either KG-501 or staurosporine. Furthermore, phorbol 12-myristate 13-acetate (PMA) decreased the expressions of GABA A subunits α1, γ2, and δ when administered alone. However, the administration of either KG-501 or staurosporine reversed the inhibitory effects of PMA. The PKC/CREB pathway may negatively regulate the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons in low Mg 2+ model of

  8. Calcium-sensitive regulation of monoamine oxidase-A contributes to the production of peroxyradicals in hippocampal cultures: implications for Alzheimer disease-related pathology

    Directory of Open Access Journals (Sweden)

    Li XinMin

    2007-09-01

    Full Text Available Abstract Background Calcium (Ca2+ has recently been shown to selectively increase the activity of monoamine oxidase-A (MAO-A, a mitochondria-bound enzyme that generates peroxyradicals as a natural by-product of the deamination of neurotransmitters such as serotonin. It has also been suggested that increased intracellular free Ca2+ levels as well as MAO-A may be contributing to the oxidative stress associated with Alzheimer disease (AD. Results Incubation with Ca2+ selectively increases MAO-A enzymatic activity in protein extracts from mouse hippocampal HT-22 cell cultures. Treatment of HT-22 cultures with the Ca2+ ionophore A23187 also increases MAO-A activity, whereas overexpression of calbindin-D28K (CB-28K, a Ca2+-binding protein in brain that is greatly reduced in AD, decreases MAO-A activity. The effects of A23187 and CB-28K are both independent of any change in MAO-A protein or gene expression. The toxicity (via production of peroxyradicals and/or chromatin condensation associated with either A23187 or the AD-related β-amyloid peptide, which also increases free intracellular Ca2+, is attenuated by MAO-A inhibition in HT-22 cells as well as in primary hippocampal cultures. Conclusion These data suggest that increases in intracellular Ca2+ availability could contribute to a MAO-A-mediated mechanism with a role in AD-related oxidative stress.

  9. ATP induces NO production in hippocampal neurons by P2X(7 receptor activation independent of glutamate signaling.

    Directory of Open Access Journals (Sweden)

    Juan Francisco Codocedo

    Full Text Available To assess the putative role of adenosine triphosphate (ATP upon nitric oxide (NO production in the hippocampus, we used as a model both rat hippocampal slices and isolated hippocampal neurons in culture, lacking glial cells. In hippocampal slices, additions of exogenous ATP or 2'(3'-O-(4-Benzoylbenzoyl ATP (Bz-ATP elicited concentration-dependent NO production, which increased linearly within the first 15 min and plateaued thereafter; agonist EC50 values were 50 and 15 µM, respectively. The NO increase evoked by ATP was antagonized in a concentration-dependent manner by Coomassie brilliant blue G (BBG or by N(ω-propyl-L-arginine, suggesting the involvement of P2X7Rs and neuronal NOS, respectively. The ATP induced NO production was independent of N-methyl-D-aspartic acid (NMDA receptor activity as effects were not alleviated by DL-2-Amino-5-phosphonopentanoic acid (APV, but antagonized by BBG. In sum, exogenous ATP elicited NO production in hippocampal neurons independently of NMDA receptor activity.

  10. Caffeine Increases Hippocampal Sharp Waves in Vitro.

    Science.gov (United States)

    Watanabe, Yusuke; Ikegaya, Yuji

    2017-01-01

    Caffeine promotes memory consolidation. Memory consolidation is thought to depend at least in part on hippocampal sharp waves (SWs). In the present study, we investigated the effect of bath-application of caffeine in spontaneously occurring SWs in mouse acute hippocampal slices. Caffeine induced an about 100% increase in the event frequency of SWs at concentrations of 60 and 200 µM. The effect of caffeine was reversible after washout of caffeine and was mimicked by an adenosine A 1 receptor antagonist, but not by an A 2A receptor antagonist. Caffeine increased SWs even in dentate-CA3 mini-slices without the CA2 regions, in which adenosine A 1 receptors are abundantly expressed in the hippocampus. Thus, caffeine facilitates SWs by inhibiting adenosine A 1 receptors in the hippocampal CA3 region or the dentate gyrus.

  11. Indole and synthetic derivative activate chaperone expression to reduce polyQ aggregation in SCA17 neuronal cell and slice culture models

    Directory of Open Access Journals (Sweden)

    Kung PJ

    2014-10-01

    Full Text Available Pin-Jui Kung,1,* Yu-Chen Tao,1,* Ho-Chiang Hsu,1 Wan-Ling Chen,1 Te-Hsien Lin,1 Donala Janreddy,2 Ching-Fa Yao,2 Kuo-Hsuan Chang,3 Jung-Yaw Lin,1 Ming-Tsan Su,1 Chung-Hsin Wu,1 Guey-Jen Lee-Chen,1 Hsiu-Mei Hsieh-Li1 1Department of Life Science, 2Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan; 3Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan *These authors contributed equally to this work Abstract: In spinocerebellar ataxia type 17 (SCA17, the expansion of a translated CAG repeat in the TATA box binding protein (TBP gene results in a long polyglutamine (polyQ tract in the TBP protein, leading to intracellular accumulation of aggregated TBP and cell death. The molecular chaperones act in preventing protein aggregation to ameliorate downstream harmful events. In this study, we used Tet-On SH-SY5Y cells with inducible SCA17 TBP/Q79-green fluorescent protein (GFP expression to test indole and synthetic derivative NC001-8 for neuroprotection. We found that indole and NC001-8 up-regulated chaperone expression to reduce polyQ aggregation in neuronal differentiated TBP/Q79 cells. The effects on promoting neurite outgrowth and on reduction of aggregation on Purkinje cells were also confirmed with cerebellar primary and slice cultures of SCA17 transgenic mice. Our results demonstrate how indole and derivative NC001-8 reduce polyQ aggregation to support their therapeutic potentials in SCA17 treatment. Keywords: spinocerebellar ataxia type 17, TATA box binding protein, polyQ aggregation, indole and derivative, therapeutics

  12. U-shape suppressive effect of phenol red on the epileptiform burst activity via activation of estrogen receptors in primary hippocampal culture.

    Directory of Open Access Journals (Sweden)

    Xu Liu

    Full Text Available Phenol red is widely used in cell culture as a pH indicator. Recently, it also has been reported to have estrogen-like bioactivity and be capable of promoting cell proliferation in different cell lines. However, the effect of phenol red on primary neuronal culture has never been investigated. By using patch clamp technique, we demonstrated that hippocampal pyramidal neurons cultured in neurobasal medium containing no phenol red had large depolarization-associated epileptiform bursting activities, which were rarely seen in neurons cultured in phenol red-containing medium. Further experiment data indicate that the suppressive effect of the phenol red on the abnormal epileptiform burst neuronal activities was U-shape dose related, with the most effective concentration at 28 µM. In addition, this concentration related inhibitory effect of phenol red on the epileptiform neuronal discharges was mimicked by 17-β-estradiol, an estrogen receptor agonist, and inhibited by ICI-182,780, an estrogen receptor antagonist. Our results suggest that estrogen receptor activation by phenol red in the culture medium prevents formation of abnormal, epileptiform burst activity. These studies highlight the importance of phenol red as estrogen receptor stimulator and cautions of careful use of phenol red in cell culture media.

  13. Iron mediates N-methyl-D-aspartate receptor-dependent stimulation of calcium-induced pathways and hippocampal synaptic plasticity.

    Science.gov (United States)

    Muñoz, Pablo; Humeres, Alexis; Elgueta, Claudio; Kirkwood, Alfredo; Hidalgo, Cecilia; Núñez, Marco T

    2011-04-15

    Iron deficiency hinders hippocampus-dependent learning processes and impairs cognitive performance, but current knowledge on the molecular mechanisms underlying the unique role of iron in neuronal function is sparse. Here, we investigated the participation of iron on calcium signal generation and ERK1/2 stimulation induced by the glutamate agonist N-methyl-D-aspartate (NMDA), and the effects of iron addition/chelation on hippocampal basal synaptic transmission and long-term potentiation (LTP). Addition of NMDA to primary hippocampal cultures elicited persistent calcium signals that required functional NMDA receptors and were independent of calcium influx through L-type calcium channels or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors; NMDA also promoted ERK1/2 phosphorylation and nuclear translocation. Iron chelation with desferrioxamine or inhibition of ryanodine receptor (RyR)-mediated calcium release with ryanodine-reduced calcium signal duration and prevented NMDA-induced ERK1/2 activation. Iron addition to hippocampal neurons readily increased the intracellular labile iron pool and stimulated reactive oxygen species production; the antioxidant N-acetylcysteine or the hydroxyl radical trapper MCI-186 prevented these responses. Iron addition to primary hippocampal cultures kept in calcium-free medium elicited calcium signals and stimulated ERK1/2 phosphorylation; RyR inhibition abolished these effects. Iron chelation decreased basal synaptic transmission in hippocampal slices, inhibited iron-induced synaptic stimulation, and impaired sustained LTP in hippocampal CA1 neurons induced by strong stimulation. In contrast, iron addition facilitated sustained LTP induction after suboptimal tetanic stimulation. Together, these results suggest that hippocampal neurons require iron to generate RyR-mediated calcium signals after NMDA receptor stimulation, which in turn promotes ERK1/2 activation, an essential step of sustained LTP.

  14. Effects of acetylpuerarin on hippocampal neurons and intracellular free calcium subjected to oxygen-glucose deprivation/reperfusion in primary culture.

    Science.gov (United States)

    Liu, Rui; Wei, Xin-bing; Zhang, Xiu-Mei

    2007-05-25

    This study was undertaken to find out the effects of acetylpuerarin on hippocampal neurons and intracellular free calcium in primary culture subjected to oxygen-glucose deprivation/reperfusion. According to different reperfusion time (1 h, 6 h, 12 h, 24 h), three concentrations (1.6 micromol l(-1), 0.4 micromol l(-1), 0.1 micromol l(-1)) of acetylpuerarin, and MK-801 (10 micromol l(-1)), a positive control drug, neurons were randomly divided into 21 groups. Each group was observed by inverted phase contrast microscope; neuron viability was measured by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT); intracellular Ca(2+) was observed by Fura-2/AM ester through fluorospectrophotometer. The injured neurons were protected and degeneration and necrosis were alleviated in treatment groups of acetylpuerarin and MK-801. Acetylpuerarin increased the neuron viability at high, middle and low concentrations. Fluorescence detection results showed that the calcium concentration in the group treated with acetylpuerarin and MK-801 was lowered in each reperfusion time. Our results demonstrated that acetylpuerarin could protect the hippocampal neurons from ischemia-reperfusion injury in rats by alleviating the morphological damage, increasing neuron viability and decreasing calcium concentration in neuron.

  15. Mitogen-Activated Protein Kinase Phosphatase-2 Deletion Impairs Synaptic Plasticity and Hippocampal-Dependent Memory.

    Science.gov (United States)

    Abdul Rahman, Nor Zaihana; Greenwood, Sam M; Brett, Ros R; Tossell, Kyoko; Ungless, Mark A; Plevin, Robin; Bushell, Trevor J

    2016-02-24

    Mitogen-activated protein kinases (MAPKs) regulate brain function and their dysfunction is implicated in a number of brain disorders, including Alzheimer's disease. Thus, there is great interest in understanding the signaling systems that control MAPK function. One family of proteins that contribute to this process, the mitogen-activated protein kinase phosphatases (MKPs), directly inactivate MAPKs through dephosphorylation. Recent studies have identified novel functions of MKPs in development, the immune system, and cancer. However, a significant gap in our knowledge remains in relation to their role in brain functioning. Here, using transgenic mice where the Dusp4 gene encoding MKP-2 has been knocked out (MKP-2(-/-) mice), we show that long-term potentiation is impaired in MKP-2(-/-) mice compared with MKP-2(+/+) controls whereas neuronal excitability, evoked synaptic transmission, and paired-pulse facilitation remain unaltered. Furthermore, spontaneous EPSC (sEPSC) frequency was increased in acute slices and primary hippocampal cultures prepared from MKP-2(-/-) mice with no effect on EPSC amplitude observed. An increase in synapse number was evident in primary hippocampal cultures, which may account for the increase in sEPSC frequency. In addition, no change in ERK activity was detected in both brain tissue and primary hippocampal cultures, suggesting that the effects of MKP-2 deletion were MAPK independent. Consistent with these alterations in hippocampal function, MKP-2(-/-) mice show deficits in spatial reference and working memory when investigated using the Morris water maze. These data show that MKP-2 plays a role in regulating hippocampal function and that this effect may be independent of MAPK signaling. Copyright © 2016 Abdul Rahman et al.

  16. Cdk5 Is Essential for Amphetamine to Increase Dendritic Spine Density in Hippocampal Pyramidal Neurons

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    Soledad Ferreras

    2017-11-01

    Full Text Available Psychostimulant drugs of abuse increase dendritic spine density in reward centers of the brain. However, little is known about their effects in the hippocampus, where activity-dependent changes in the density of dendritic spine are associated with learning and memory. Recent reports suggest that Cdk5 plays an important role in drug addiction, but its role in psychostimulant’s effects on dendritic spines in hippocampus remain unknown. We used in vivo and in vitro approaches to demonstrate that amphetamine increases dendritic spine density in pyramidal neurons of the hippocampus. Primary cultures and organotypic slice cultures were used for cellular, molecular, pharmacological and biochemical analyses of the role of Cdk5/p25 in amphetamine-induced dendritic spine formation. Amphetamine (two-injection protocol increased dendritic spine density in hippocampal neurons of thy1-green fluorescent protein (GFP mice, as well as in hippocampal cultured neurons and organotypic slice cultures. Either genetic or pharmacological inhibition of Cdk5 activity prevented the amphetamine–induced increase in dendritic spine density. Amphetamine also increased spine density in neurons overexpressing the strong Cdk5 activator p25. Finally, inhibition of calpain, the protease necessary for the conversion of p35 to p25, prevented amphetamine’s effect on dendritic spine density. We demonstrate, for the first time, that amphetamine increases the density of dendritic spine in hippocampal pyramidal neurons in vivo and in vitro. Moreover, we show that the Cdk5/p25 signaling and calpain activity are both necessary for the effect of amphetamine on dendritic spine density. The identification of molecular mechanisms underlying psychostimulant effects provides novel and promising therapeutic approaches for the treatment of drug addiction.

  17. Hippocampal Astrocyte Cultures from Adult and Aged Rats Reproduce Changes in Glial Functionality Observed in the Aging Brain.

    Science.gov (United States)

    Bellaver, Bruna; Souza, Débora Guerini; Souza, Diogo Onofre; Quincozes-Santos, André

    2017-05-01

    Astrocytes are dynamic cells that maintain brain homeostasis, regulate neurotransmitter systems, and process synaptic information, energy metabolism, antioxidant defenses, and inflammatory response. Aging is a biological process that is closely associated with hippocampal astrocyte dysfunction. In this sense, we demonstrated that hippocampal astrocytes from adult and aged Wistar rats reproduce the glial functionality alterations observed in aging by evaluating several senescence, glutamatergic, oxidative and inflammatory parameters commonly associated with the aging process. Here, we show that the p21 senescence-associated gene and classical astrocyte markers, such as glial fibrillary acidic protein (GFAP), vimentin, and actin, changed their expressions in adult and aged astrocytes. Age-dependent changes were also observed in glutamate transporters (glutamate aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1)) and glutamine synthetase immunolabeling and activity. Additionally, according to in vivo aging, astrocytes from adult and aged rats showed an increase in oxidative/nitrosative stress with mitochondrial dysfunction, an increase in RNA oxidation, NADPH oxidase (NOX) activity, superoxide levels, and inducible nitric oxide synthase (iNOS) expression levels. Changes in antioxidant defenses were also observed. Hippocampal astrocytes also displayed age-dependent inflammatory response with augmentation of proinflammatory cytokine levels, such as TNF-α, IL-1β, IL-6, IL-18, and messenger RNA (mRNA) levels of cyclo-oxygenase 2 (COX-2). Furthermore, these cells secrete neurotrophic factors, including glia-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), S100 calcium-binding protein B (S100B) protein, and transforming growth factor-β (TGF-β), which changed in an age-dependent manner. Classical signaling pathways associated with aging, such as nuclear factor erythroid-derived 2-like 2 (Nrf2), nuclear factor kappa B (NFκ

  18. PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of post-traumatic epilepsy.

    Science.gov (United States)

    Berdichevsky, Yevgeny; Dryer, Alexandra M; Saponjian, Yero; Mahoney, Mark M; Pimentel, Corrin A; Lucini, Corrina A; Usenovic, Marija; Staley, Kevin J

    2013-05-22

    mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an anti-epileptogenic, or merely anticonvulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long-term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordings, and cell death was quantified with lactate dehydrogenase (LDH) release measurements and Nissl-stained neuron counts. Lactate and LDH measurements were well correlated with electrographic activity and neuron counts, respectively. Inhibition of PI3K and Akt prevented activation of mTOR, and was as effective as inhibition of mTOR in reducing ictal activity and cell death. A dual inhibitor of PI3K and mTOR, NVP-BEZ235, was also effective. Inhibition of mTOR with rapamycin reduced axon sprouting. Late start of rapamycin treatment was effective in reducing epileptic activity and cell death, while early termination of rapamycin treatment did not result in increased epileptic activity or cell death. The conclusions of the study are as follows: (1) the organotypic hippocampal culture model of post-traumatic epilepsy comprises a rapid assay of anti-epileptogenic and neuroprotective activities and, in this model (2) mTOR activation depends on PI3K-Akt signaling, and (3) transient inhibition of mTOR has sustained effects on epilepsy.

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

    Science.gov (United States)

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

    2010-01-01

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

  20. Specific accumulation of 18F-deoxyglucose in three-dimensional long-term cultures of human and rodent brain tissue

    International Nuclear Information System (INIS)

    Hocke, C.; Prante, O.; Kuwert, T.; Bluemcke, I.; Jeske, I.; Romstoeck, J.; Stefan, H.

    2007-01-01

    Aim: Organotypic slice cultures (OSC) of human brain specimens represent an intriguing experimental model for translational studies addressing, e.g., stem cell transplantation in neurodegenerative diseases or targeting invasion by malignant glioma ex vivo. However, long-term viability and phenomena of structural reorganization of human OSC remain to be further characterized. Here, we report the use of 18 F-deoxyglucose (FDG) for evaluating the viability of brain slice preparations obtained either from postnatal rats or human hippocampal specimens. Methods: Anatomically well preserved human hippocampi obtained from epilepsy surgery and rat hippocampus slice cultures obtained from six day old Wistar rats were dissected into horizontal slices. The slices were incubated with FDG in phosphate buffered saline up to 1 h, either with or without supplementation of glucose at a concentration of 2.5 mg/ml. Radioactivity within the medium or slice cultures was measured using a gamma-counter. In addition, distribution of radioactivity was autoradiographically visualized and quantified as counts per mm 2 . Results: In rat hippocampal slices, FDG accumulated with 1 300 000 ± 68 000 counts/mm 2 , whereas the incorporation of the radioactive label in human slices was in the order of 1 500 000 ± 370 000 counts/mm 2 . The elevation of glucose concentration within the medium led to a significant three-fold decrease of FDG accumulation in rat slices and to a 2.4-fold decrease in human specimens. Conclusions: FDG accumulated in organotypic brain cultures of human or rodent origin. FDG is thus suited to investigate the viability of OSC. Furthermore, these preparations open new ways to study the factors governing cerebral FDG uptake in brain tissue ex vivo. (orig.)

  1. Induksi Ginogenesis melalui Kultur Multi Ovule Slice dan Kultur Ovary Slice Dianthus chinensis

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    Suskandari Kartikaningrum

    2013-10-01

    Full Text Available Callus induction was studied in five genotypes of Dianthus chinensis using 2.4 D and NAA. Calluses can be obtainedfrom unfertilized ovule culture and ovary culture. The aim of the research was to study gynogenic potential and responseof Dianthus chinensis through ovule slice and ovary slice culture for obtaining haploid plants. Five genotypes of Dianthuschinensis and five media were used in ovule slice culture and two genotypes and three medium were used in ovary culture.Flower buds in the 7th stage were incubated for the purpose of dark pre-treatment at 4 oC for one day. Ovules and ovaries wereisolated and cultured in induction medium. Cultures were incubated for the purpose of dark pre-treatment at 4 oC for seven days, followed by 25 oC light incubation. The result showed that 2.4D was better than NAA in inducing callus. Percentage of regenerated calluses were produced in V11, V13 and V15 genotypes in M7 medium (MS + 2 mg L-1 2.4D + 1 mg L-1 BAP + 30 g L-1 sucrose and M10 medium (MS + 1 mg L-1 2.4D + 1 mg L-1 BAP + 20 g L-1 sucrose. All calluses originated from ovule and ovary cultures flowered prematurely. Double haploid (V11-34 were obtained from ovule slice culture based on PER (peroksidase and EST (esterase isoenzym marker.Keywords: ovule slice culture, ovary slice culture, callus, Dianthus sp., haploid

  2. Asymmetry of limbic structure (hippocampal formation and amygdaloidal complex at PTSD

    Directory of Open Access Journals (Sweden)

    Aida Sarač-Hadžihalilović

    2003-05-01

    Full Text Available Defining exact position of weak anatomic function which is find in a base of neurological and psychiatric disorder is just became the subject of intensive research interest. For this purposes it is important to implement structural and functional MRI techniques, also for further lightening and seeing subject of this work, more concretely connected to PTSD. Therefore, exactly MRI gives most sensitive volumetric measuring of hippocampal formation and amygdaloidal complex.The goal of this work was to research asymmetry of hippocampal formation and amygdaloidal complex to the PTSD patients.Results showed that at the axial slice length of hippocampal formation on the left and right side of all patients are significantly asymmetric. At the sagittal slice from the left side of hippocampal formation is in many cases longer than right about 50 %. At the coronal slice, there are no significant differences toward patient proportion according to symm. / asymm. of the hippocampal formation width at the right and left side. Difference in volume average of hippocampal formation between right and left side for axial and coronal slice is not statistically significant, but it is significant for sagittal slice. In about amygdaloidal complex patients with PTSD toward symm. / asymm. Amygdaloidal complex at the right and left side of axial and sagittal slice in all three measurement shows asymmetry, what is especially shown at sagittal slice. Difference in average length of amygdaloidal complex at the right and left side is not statistically significant for no one slice.Therefore, results of a new research that are used MRI, showed smaller hippocampal level at PTSD (researched by Van der Kolka 1996, Pitman 1996, Bremner et al., 1995.. Application of MRI technique in research of asymmetry of hippocampal formation and amygdaloidal complex, which we used in our research, we recommend as a template for future researches in a sense of lightening anatomic function that is

  3. Slice hyperholomorphic Schur analysis

    CERN Document Server

    Alpay, Daniel; Sabadini, Irene

    2016-01-01

    This book defines and examines the counterpart of Schur functions and Schur analysis in the slice hyperholomorphic setting. It is organized into three parts: the first introduces readers to classical Schur analysis, while the second offers background material on quaternions, slice hyperholomorphic functions, and quaternionic functional analysis. The third part represents the core of the book and explores quaternionic Schur analysis and its various applications. The book includes previously unpublished results and provides the basis for new directions of research.

  4. Brain-derived neurotrophic factor/neurotrophin 3 regulate axon initial segment location and affect neuronal excitability in cultured hippocampal neurons.

    Science.gov (United States)

    Guo, Yu; Su, Zi-Jun; Chen, Yi-Kun; Chai, Zhen

    2017-07-01

    Plasticity of the axon initial segment (AIS) has aroused great interest in recent years because it regulates action potential initiation and neuronal excitability. AIS plasticity manifests as modulation of ion channels or variation in AIS structure. However, the mechanisms underlying structural plasticity of the AIS are not well understood. Here, we combined immunofluorescence, patch-clamp recordings, and pharmacological methods in cultured hippocampal neurons to investigate the factors participating in AIS structural plasticity during development. With lowered neuronal density, the distance between the AIS and the soma increased, while neuronal excitability decreased, as shown by the increased action potential threshold and current threshold for firing an action potential. This variation in the location of the AIS was associated with cellular secretory substances, including brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3). Indeed, blocking BDNF and NT3 with TrkB-Fc eliminated the effect of conditioned medium collected from high-density cultures on AIS relocation. Elevating the extracellular concentration of BDNF or NT3 promoted movement of the AIS proximally to the soma and increased neuronal excitability. Furthermore, knockdown of neurotrophin receptors TrkB and TrkC caused distal movement of the AIS. Our results demonstrate that BDNF and NT3 regulate AIS location and neuronal excitability. These regulatory functions of neurotrophic factors provide insight into the molecular mechanisms underlying AIS biology. © 2017 International Society for Neurochemistry.

  5. Characterization of Eag1 channel lateral mobility in rat hippocampal cultures by single-particle-tracking with quantum dots.

    Directory of Open Access Journals (Sweden)

    David Gómez-Varela

    2010-01-01

    Full Text Available Voltage-gated ion channels are main players involved in fast synaptic events. However, only slow intracellular mechanisms have so far been described for controlling their localization as real-time visualization of endogenous voltage-gated channels at high temporal and spatial resolution has not been achieved yet. Using a specific extracellular antibody and quantum dots we reveal and characterize lateral mobility as a faster mechanism to dynamically control the number of endogenous ether-a-go-go (Eag1 ion channels inside synapses. We visualize Eag1 entering and leaving synapses by lateral diffusion in the plasma membrane of rat hippocampal neurons. Mathematical analysis of their trajectories revealed how the motion of Eag1 gets restricted when the channels diffuse into the synapse, suggesting molecular interactions between Eag1 and synaptic components. In contrast, Eag1 channels switch to Brownian movement when they exit synapses and diffuse into extrasynaptic membranes. Furthermore, we demonstrate that the mobility of Eag1 channels is specifically regulated inside synapses by actin filaments, microtubules and electrical activity. In summary, using single-particle-tracking techniques with quantum dots nanocrystals, our study shows for the first time the lateral diffusion of an endogenous voltage-gated ion channel in neurons. The location-dependent constraints imposed by cytoskeletal elements together with the regulatory role of electrical activity strongly suggest a pivotal role for the mobility of voltage-gated ion channels in synaptic activity.

  6. The virtual slice setup.

    Science.gov (United States)

    Lytton, William W; Neymotin, Samuel A; Hines, Michael L

    2008-06-30

    In an effort to design a simulation environment that is more similar to that of neurophysiology, we introduce a virtual slice setup in the NEURON simulator. The virtual slice setup runs continuously and permits parameter changes, including changes to synaptic weights and time course and to intrinsic cell properties. The virtual slice setup permits shocks to be applied at chosen locations and activity to be sampled intra- or extracellularly from chosen locations. By default, a summed population display is shown during a run to indicate the level of activity and no states are saved. Simulations can run for hours of model time, therefore it is not practical to save all of the state variables. These, in any case, are primarily of interest at discrete times when experiments are being run: the simulation can be stopped momentarily at such times to save activity patterns. The virtual slice setup maintains an automated notebook showing shocks and parameter changes as well as user comments. We demonstrate how interaction with a continuously running simulation encourages experimental prototyping and can suggest additional dynamical features such as ligand wash-in and wash-out-alternatives to typical instantaneous parameter change. The virtual slice setup currently uses event-driven cells and runs at approximately 2 min/h on a laptop.

  7. 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.

  8. 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.

  9. Experimental investigation on spontaneously active hippocampal cultures recorded by means of high-density MEAs: analysis of the spatial resolution effects

    Directory of Open Access Journals (Sweden)

    Alessandro Maccione

    2010-05-01

    Full Text Available Based on experiments performed with high-resolution Active Pixel Sensor microelectrode arrays (APS-MEAs coupled with spontaneously active hippocampal cultures, this work investigates the spatial resolution effects of the neuroelectronic interface on the analysis of the recorded electrophysiological signals. The adopted methodology consists, first, in recording the spontaneous activity at the highest spatial resolution (inter-electrode separation of 21 µm from the whole array of 4096 microelectrodes. Then, the full resolution dataset is spatially down sampled in order to evaluate the effects on raster plot representation, array-wide spike rate (AWSR, mean firing rate (MFR and mean bursting rate (MBR. Furthermore, the effects of the array-to-network relative position are evaluated by shifting a subset of equally spaced electrodes on the entire recorded area. Results highlight that MFR and MBR are particularly influenced by the spatial resolution provided by the neuroelectronic interface. On high-resolution large MEAs, such analysis better represent the time-based parameterization of the network dynamics. Finally, this work suggest interesting capabilities of high-resolution MEAs for spatial-based analysis in dense and low-dense neuronal preparation for investigating signalling at both local and global neuronal circuitries.

  10. The selective alpha7 nicotinic acetylcholine receptor agonist PNU-282987 [N-[(3R)-1-Azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide hydrochloride] enhances GABAergic synaptic activity in brain slices and restores auditory gating deficits in anesthetized rats.

    Science.gov (United States)

    Hajós, M; Hurst, R S; Hoffmann, W E; Krause, M; Wall, T M; Higdon, N R; Groppi, V E

    2005-03-01

    Schizophrenic patients are thought to have an impaired ability to process sensory information. This deficit leads to disrupted auditory gating measured electrophysiologically as a reduced suppression of the second of paired auditoryevoked responses (P50) and is proposed to be associated with decreased function and/or expression of the homomeric alpha7 nicotinic acetylcholine receptor (nAChR). Here, we provide evidence that N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide hydrochloride (PNU-282987), a novel selective agonist of the alpha7 nAChR, evoked whole-cell currents from cultured rat hippocampal neurons that were sensitive to the selective alpha7 nAChR antagonist methyllycaconitine (MLA) and enhanced GABAergic synaptic activity when applied to hippocampal slices. Amphetamine-induced sensory gating deficit, determined by auditory-evoked potentials in hippocampal CA3 region, was restored by systemic administration of PNU-282987 in chloral hydrate-anesthetized rats. Auditory gating of rat reticular thalamic neurons was also disrupted by amphetamine; however, PNU-282987 normalized gating deficit only in a subset of tested neurons (6 of 11). Furthermore, PNU-282987 improved the inherent hippocampal gating deficit occurring in a subpopulation of anesthetized rats, and enhanced amphetamine-induced hippocampal oscillation. We propose that the alpha7 nAChR agonist PNU-282987, via modulating/enhancing hippocampal GABAergic neurotransmission, improves auditory gating and enhances hippocampal oscillatory activity. These results provide further support for the concept that drugs that selectively activate alpha7 nAChRs may offer a novel, potential pharmacotherapy in treatment of schizophrenia.

  11. Fluoxetine impairs GABAergic signaling in hippocampal slices from neonatal rats

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    Enrico eCherubini

    2013-05-01

    Full Text Available Fluoxetine (Prozac, an antidepressant known to selectively inhibit serotonin reuptake, is widely used to treat mood disorders in women suffering from depression during pregnancy and postpartum period. Several lines of evidence suggest that this drug, which crosses the human placenta and is secreted into milk during lactation, exerts its action not only by interfering with serotoninergic but also with GABAergic transmission. GABA is known to play a crucial role in the construction of neuronal circuits early in postnatal development. The immature hippocampus is characterized by an early type of network activity, the so-called Giant Depolarizing Potentials (GDPs, generated by the synergistic action of glutamate and GABA, both depolarizing and excitatory. Here we tested the hypothesis that fluoxetine may interfere with GABAergic signaling during the first postnatal week, thus producing harmful effects on brain development. At micromolar concentrations fluoxetine severely depressed GDPs frequency (IC50 22 M in a reversible manner and independently of its action on serotonin reuptake. This effect was dependent on a reduced GABAergic (but not glutamatergic drive to principal cells most probably from parvalbumin-positive fast spiking neurons. Cholecystokinin-positive GABAergic interneurons were not involved since the effects of the drug persisted when cannabinoid receptors were occluded with WIN55,212-2, a CB1/CB2 receptor agonist. Fluoxetine effects on GABAergic transmission were associated with a reduced firing rate of both principal cells and interneurons further suggesting that changes in network excitability account for GDPs disruption. This may have critical consequences on the functional organization and stabilization of neuronal circuits early in postnatal development.

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

    Science.gov (United States)

    Kaneko, Ai; Sankai, Yoshiyuki

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ai Kaneko

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

  14. Portable Device Slices Thermoplastic Prepregs

    Science.gov (United States)

    Taylor, Beverly A.; Boston, Morton W.; Wilson, Maywood L.

    1993-01-01

    Prepreg slitter designed to slit various widths rapidly by use of slicing bar holding several blades, each capable of slicing strip of preset width in single pass. Produces material evenly sliced and does not contain jagged edges. Used for various applications in such batch processes involving composite materials as press molding and autoclaving, and in such continuous processes as pultrusion. Useful to all manufacturers of thermoplastic composites, and in slicing B-staged thermoset composites.

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

    Science.gov (United States)

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

    2009-01-01

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

  16. The influence of cold temperature on cellular excitability of hippocampal networks.

    Science.gov (United States)

    de la Peña, Elvira; Mälkiä, Annika; Vara, Hugo; Caires, Rebeca; Ballesta, Juan J; Belmonte, Carlos; Viana, Felix

    2012-01-01

    The hippocampus plays an important role in short term memory, learning and spatial navigation. A characteristic feature of the hippocampal region is its expression of different electrical population rhythms and activities during different brain states. Physiological fluctuations in brain temperature affect the activity patterns in hippocampus, but the underlying cellular mechanisms are poorly understood. In this work, we investigated the thermal modulation of hippocampal activity at the cellular network level. Primary cell cultures of mouse E17 hippocampus displayed robust network activation upon light cooling of the extracellular solution from baseline physiological temperatures. The activity generated was dependent on action potential firing and excitatory glutamatergic synaptic transmission. Involvement of thermosensitive channels from the transient receptor potential (TRP) family in network activation by temperature changes was ruled out, whereas pharmacological and immunochemical experiments strongly pointed towards the involvement of temperature-sensitive two-pore-domain potassium channels (K(2P)), TREK/TRAAK family. In hippocampal slices we could show an increase in evoked and spontaneous synaptic activity produced by mild cooling in the physiological range that was prevented by chloroform, a K(2P) channel opener. We propose that cold-induced closure of background TREK/TRAAK family channels increases the excitability of some hippocampal neurons, acting as a temperature-sensitive gate of network activation. Our findings in the hippocampus open the possibility that small temperature variations in the brain in vivo, associated with metabolism or blood flow oscillations, act as a switch mechanism of neuronal activity and determination of firing patterns through regulation of thermosensitive background potassium channel activity.

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

    Science.gov (United States)

    Salameh, Ahlam I.; Hübner, Christian A.

    2016-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  20. Comparison with hippocampal atrophy and hypoperfusion in Alzheimer's disease

    International Nuclear Information System (INIS)

    Chung, YA; Kim, SH; Chung, SK; Juh, RH; Sohn, HS; Suh, TS; Choe, BY

    2004-01-01

    Objective: Hypoperfusion and hippocampal atropy of the medial temporal lobe are peculiarity of Alzheimer's disease (AD). The manual ROI (region of interest) technique for hippocampal volume estimation is specific and sensitive for the detection of hippocampal atrophy. In patients with AD reported a significant correlation between hippocampal volume and hypoperfusion. This study investigated correlations between atrophy distinct medial temporal lobe structure and hypoperfusion in hippocampal volumetry. Methods: The hippocampi were individually outlined on Tl-weighted volumetry MRI and calculated with MATLAB in 12 patients with AD. All volume measurements were performed by a segmentation technique with a combination of tracing and thresholding. The volume of a given structure in each slice was obtained by automatically counting the number of pixels within the segmented regions and multiplying the number by a voxel size. In order to permit direct regional comparisons, both of each patient's Tc- 99m ECD SPECT was then registered to the patient's MRI. Delineation continued anteriorly in each contiguous slice reaching the head of the hippocampus, which was distinguished from the overlying amygdala by the presence of the alveus or uncal recess. The right hippocampus (RH) was measured first, followed by the left hippocampus (LH). The accuracy of registration was investigated in a validation study with developed brain phantom. Results:The mean total intracranial volume of the AD was significantly smaller volume (1492.9 cm 3 ) and hypo perfused than those in normal subjects. The mean hippocampal volumes were 2.01 cm 3 and l.99 cm 3 for the RH and LH. The correlations between volume and hypoperfusion in the affected hippocampi were found to be significant; especially the medial temporal lobe is markedly hypo perfused. Conclusion: Volumetry is the most sensitive tool for the detection of hippocampal abnormality in AD, and significant correlation between asymmetry in

  1. 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.

  2. Slice sensitivity profiles and pixel noise of multi-slice CT in comparison with single-slice CT

    International Nuclear Information System (INIS)

    Schorn, C.; Obenauer, S.; Funke, M.; Hermann, K.P.; Kopka, L.; Grabbe, E.

    1999-01-01

    Purpose: Presentation and evaluation of slice sensitivity profile and pixel noise of multi-slice CT in comparison to single-slice CT. Methods: Slice sensitivity profiles and pixel noise of a multi-slice CT equiped with a 2D matrix detector array and of a single-slice CT were evaluated in phantom studies. Results: For the single-slice CT the width of the slice sensitivity profiles increased with increasing pitch. In spite of a much higher table speed the slice sensitivity profiles of multi-slice CT were narrower and did not increase with higher pitch. Noise in single-slice CT was independent of pitch. For multi-slice CT noise increased with higher pitch and for the higher pitch decreased slightly with higher detector row collimation. Conclusions: Multi-slice CT provides superior z-resolution and higher volume coverage speed. These qualities fulfill one of the prerequisites for improvement of 3D postprocessing. (orig.) [de

  3. Hippocampal deletion of BDNF gene attenuates gamma oscillations in area CA1 by up-regulating 5-HT3 receptor.

    Directory of Open Access Journals (Sweden)

    Ying Huang

    2011-01-01

    Full Text Available Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown.Here we examined carbachol-induced gamma oscillations in hippocampal slices lacking BDNF gene in the area CA3. The power of oscillations was reduced in the hippocampal area CA1, which coincided with increases in the expression and activity of 5-HT3 receptor. Pharmacological block of this receptor partially restored power of gamma oscillations in slices from KO mice, but had no effect in slices from WT mice.These data suggest that BDNF facilitates gamma oscillations in the hippocampus by attenuating signaling through 5-HT3 receptor. Thus, BDNF modulates hippocampal oscillations through serotonergic system.

  4. Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

    International Nuclear Information System (INIS)

    Eells, J.T.; Dubocovich, M.L.

    1988-01-01

    The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [ 3 H]dopamine and [ 3 H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [ 3 H]dopamine and [ 3 H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [ 3 H]norepinephrine or [ 3 H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

  5. The time slice system

    International Nuclear Information System (INIS)

    DeWitt, J.

    1990-01-01

    We have designed a fast readout system for silicon microstrip detectors which could be used at HERA, LHC, and SSC. The system consists of an analog amplifier-comparator chip (AACC) and a digital time slice chip (DTSC). The analog ship is designed in dielectric isolated bipolar technology for low noise and potential radiation hardness. The DTSC is built in CMOS for low power use and high circuit density. The main implementation aims are low power consumption and compactness. The architectural goal is automatic data reduction, and ease of external interface. The pipelining of event information is done digitally in the DTSC. It has a 64 word deep level 1 buffer acting as a FIFO, and a 16 word deep level 2 buffer acting as a dequeue. The DTSC also includes an asynchronous bus interface. We are first building a scaled up (100 μm instead of 25 μm pitch) and slower (10 MHz instead of 60 MHz) version in 2 μm CMOS and plan to test the principle of operation of this system in the Leading Proton Spectrometer (LPS) of the ZEUS detector at HERA. Another very important development will be tested there: the radiation hardening of the chips. We have started a collaboration with a rad-hard foundry and with Los Alamos National Laboratories to test and evaluate rad-hard processes and the final rad-hard product. Initial data are very promising, because radiation resistance of up to many Mrad have been achieved. (orig.)

  6. Updating the lamellar hypothesis of hippocampal organization

    Directory of Open Access Journals (Sweden)

    Robert S Sloviter

    2012-12-01

    Full Text Available In 1971, Andersen and colleagues proposed that excitatory activity in the entorhinal cortex propagates topographically to the dentate gyrus, and on through a trisynaptic circuit lying within transverse hippocampal slices or lamellae [Andersen, Bliss, and Skrede. 1971. Lamellar organization of hippocampal pathways. Exp Brain Res 13, 222-238]. In this way, a relatively simple structure might mediate complex functions in a manner analogous to the way independent piano keys can produce a nearly infinite variety of unique outputs. The lamellar hypothesis derives primary support from the lamellar distribution of dentate granule cell axons (the mossy fibers, which innervate dentate hilar neurons and area CA3 pyramidal cells and interneurons within the confines of a thin transverse hippocampal segment. Following the initial formulation of the lamellar hypothesis, anatomical studies revealed that unlike granule cells, hilar mossy cells, CA3 pyramidal cells, and Layer II entorhinal cells all form axonal projections that are more divergent along the longitudinal axis than the clearly lamellar mossy fiber pathway. The existence of pathways with translamellar distribution patterns has been interpreted, incorrectly in our view, as justifying outright rejection of the lamellar hypothesis [Amaral and Witter. 1989. The three-dimensional organization of the hippocampal formation: a review of anatomical data. Neuroscience 31, 571-591]. We suggest that the functional implications of longitudinally-projecting axons depend not on whether they exist, but on what they do. The observation that focal granule cell layer discharges normally inhibit, rather than excite, distant granule cells suggests that longitudinal axons in the dentate gyrus may mediate "lateral" inhibition and define lamellar function, rather than undermine it. In this review, we attempt a reconsideration of the evidence that most directly impacts the physiological concept of hippocampal lamellar

  7. Radioisotopic investigations of zinc uptake into brain slices

    International Nuclear Information System (INIS)

    Howell, G.A.

    1983-01-01

    The presence of zinc in the vicinity of the hippocampal mossy fibers has been repeatedly demonstrated, and several lines of evidence suggest that the mossy-fiber zinc is concentrated within the terminals of mossy fibers. In search of insight into the metabolism and function of mossy-fiber zinc, the present study investigated the transport of zinc into tissue slices and the response of the zinc transport to depolarization. Kinetic analysis of zinc accumulation by mouse brain slices in vitro revealed the presence of a high affinity uptake component with an apparent Km of 17.7 μM for hippocampus, 16.6 μM< for cortex and 25 μM for striatum and a V/sub max/ of 9.2 ng/mg/hr for the hippocampus, 10.1 ng/mg/hr for cortex and 9.6 ng/mg/hr for striatum. Cytoarchitectonic differences in zinc transport between the different hippocampal subregions were found with those regions containing granule cells or mossy fiber axons accumulating greater amounts of zinc than the CA 1 region. The present finding that mossy-fiber neuropil selectivity accumulates zinc suggests the presence of a zinc-binding substance unique to mossy-fiber tissue

  8. Lycium barbarum polysaccharide protects against oxygen glucose deprivation/reoxygenation-induced apoptosis and autophagic cell death via the PI3K/Akt/mTOR signaling pathway in primary cultured hippocampal neurons.

    Science.gov (United States)

    Yu, Yang; Wu, Xiuquan; Pu, Jingnan; Luo, Peng; Ma, Wenke; Wang, Jiu; Wei, Jialiang; Wang, Yuanxin; Fei, Zhou

    2018-01-01

    Lycium barbarum polysaccharide (LBP) is the main active ingredient of Lycium barbarum, which exhibits several beneficial effects, including neuroprotection, anti-aging and anti-oxidation. However, the mechanism by which LBP protects against cerebral ischemia/reperfusion-induced injury remains obscure. In this study, we found that LBP pretreatment greatly attenuated oxygen glucose deprivation/reperfusion (OGD/R) injury in primary cultured hippocampal neurons. LBP also suppressed OGD/R-induced lactate dehydrogenase (LDH) leakage, and ameliorated oxidative stress. In addition, LBP significantly reduced OGD/R-induced apoptosis and autophagic cell death. LBP caused the down-regulation of cleaved Caspase-3/Caspase-3, LC3II/LC3I and Beclin 1, as well as up-regulation of Bcl-2/Bax and p62. Furthermore, mechanistic studies indicated that LBP pretreatment increased p-Akt and p-mTOR levels after OGD/R. In summary, our results indicated that LBP protects against OGD/R-induced neuronal injury in primary hippocampal neurons by activating the PI3K/Akt/mTOR signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Flat slices in Minkowski space

    Science.gov (United States)

    Murchadha, Niall Ó.; Xie, Naqing

    2015-03-01

    Minkowski space, flat spacetime, with a distance measure in natural units of d{{s}2}=-d{{t}2}+d{{x}2}+d{{y}2}+d{{z}2}, or equivalently, with spacetime metric diag(-1, +1, +1, +1), is recognized as a fundamental arena for physics. The Poincaré group, the set of all rigid spacetime rotations and translations, is the symmetry group of Minkowski space. The action of this group preserves the form of the spacetime metric. Each t = constant slice of each preferred coordinate system is flat. We show that there are also nontrivial non-singular representations of Minkowski space with complete flat slices. If the embedding of the flat slices decays appropriately at infinity, the only flat slices are the standard ones. However, if we remove the decay condition, we find non-trivial flat slices with non-vanishing extrinsic curvature. We write out explicitly the coordinate transformation to a frame with such slices.

  10. Active sulforhodamine 101 uptake into hippocampal astrocytes.

    Directory of Open Access Journals (Sweden)

    Christian Schnell

    Full Text Available Sulforhodamine 101 (SR101 is widely used as a marker of astrocytes. In this study we investigated labeling of astrocytes by SR101 in acute slices from the ventrolateral medulla and the hippocampus of transgenic mice expressing EGFP under the control of the astrocyte-specific human GFAP promoter. While SR101 efficiently and specifically labeled EGFP-expressing astrocytes in hippocampus, we found that the same staining procedure failed to label astrocytes efficiently in the ventrolateral medulla. Although carbenoxolone is able to decrease the SR101-labeling of astrocytes in the hippocampus, it is unlikely that SR101 is taken up via gap-junction hemichannels because mefloquine, a blocker for pannexin and connexin hemichannels, was unable to prevent SR101-labeling of hippocampal astrocytes. However, SR101-labeling of the hippocampal astrocytes was significantly reduced by substrates of organic anion transport polypeptides, including estron-3-sulfate and dehydroepiandrosterone sulfate, suggesting that SR101 is actively transported into hippocampal astrocytes.

  11. Analysis of lipid raft molecules in the living brain slices.

    Science.gov (United States)

    Kotani, Norihiro; Nakano, Takanari; Ida, Yui; Ito, Rina; Hashizume, Miki; Yamaguchi, Arisa; Seo, Makoto; Araki, Tomoyuki; Hojo, Yasushi; Honke, Koichi; Murakoshi, Takayuki

    2017-08-24

    Neuronal plasma membrane has been thought to retain a lot of lipid raft components which play important roles in the neural function. Although the biochemical analyses of lipid raft using brain tissues have been extensively carried out in the past 20 years, many of their experimental conditions do not coincide with those of standard neuroscience researches such as neurophysiology and neuropharmacology. Hence, the physiological methods for lipid raft analysis that can be compatible with general neuroscience have been required. Herein, we developed a system to physiologically analyze ganglioside GM1-enriched lipid rafts in brain tissues using the "Enzyme-Mediated Activation of Radical Sources (EMARS)" method that we reported (Kotani N. et al. Proc. Natl. Acad. Sci. U S A 105, 7405-7409 (2008)). The EMARS method was applied to acute brain slices prepared from mouse brains in aCSF solution using the EMARS probe, HRP-conjugated cholera toxin subunit B, which recognizes ganglioside GM1. The membrane molecules present in the GM1-enriched lipid rafts were then labeled with fluorescein under the physiological condition. The fluorescein-tagged lipid raft molecules called "EMARS products" distributed differentially among various parts of the brain. On the other hand, appreciable differences were not detected among segments along the longitudinal axis of the hippocampus. We further developed a device to label the lipid raft molecules in acute hippocampal slices under two different physiological conditions to detect dynamics of the lipid raft molecules during neural excitation. Using this device, several cell membrane molecules including Thy1, known as a lipid raft resident molecule in neurons, were confirmed by the EMARS method in living hippocampal slices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. BID Mediates Oxygen-Glucose Deprivation-Induced Neuronal Injury in Organotypic Hippocampal Slice Cultures and Modulates Tissue Inflammation in a Transient Focal Cerebral Ischemia Model without Changing Lesion Volume

    DEFF Research Database (Denmark)

    Martin, Nellie Anne; Bonner, Helena; Elkjær, Maria Louise

    2016-01-01

    The BH3 interacting-domain death agonist (BID) is a pro-apoptotic protein involved in death receptor-induced and mitochondria-mediated apoptosis. Recently, it has also been suggested that BID is involved in the regulation of inflammatory responses in the central nervous system. We found that BID...

  13. Abnormalities of hippocampal signal intensity in patients with familial mesial temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Coan A.C.

    2004-01-01

    Full Text Available Mesial temporal lobe epilepsy (MTLE is associated with hippocampal atrophy and hippocampal signal abnormalities. In our series of familial MTLE (FMTLE, we found a high proportion of hippocampal abnormalities. To quantify signal abnormalities in patients with FMTLE we studied 152 individuals (46 of them asymptomatic with FMTLE. We used NIH-Image® for volumetry and signal quantification in coronal T1 inversion recovery and T2 for all cross-sections of the hippocampus. Values diverging by 2 or more SD from the control mean were considered abnormal. T2 hippocampal signal abnormalities were found in 52% of all individuals: 54% of affected subjects and 48% of asymptomatic subjects. T1 hippocampal signal changes were found in 34% of all individuals: 42.5% of affected subjects and 15% of asymptomatic subjects. Analysis of the hippocampal head (first three slices revealed T2 abnormalities in 73% of all individuals (74% of affected subjects and 72% of asymptomatic subjects and T1 abnormalities in 59% (67% of affected subjects and 41% of asymptomatic subjects. Affected individuals had smaller volumes than controls (P < 0.0001. There was no difference in hippocampal volumes between asymptomatic subjects and controls, although 39% of asymptomatic patients had hippocampal atrophy. Patients with an abnormal hippocampal signal (133 individuals had smaller ipsilateral volume, but no linear correlation could be determined. Hippocampal signal abnormalities in FMTLE were more frequently found in the hippocampal head in both affected and asymptomatic family members, including those with normal volumes. These results indicate that subtle abnormalities leading to an abnormal hippocampal signal in FMTLE are not necessarily related to seizures and may be determined by genetic factors.

  14. Associations between hippocampal morphometry and neuropathologic markers of Alzheimer's disease using 7 T MRI

    Directory of Open Access Journals (Sweden)

    Anna E. Blanken

    2017-01-01

    Full Text Available Hippocampal atrophy, amyloid plaques, and neurofibrillary tangles are established pathologic markers of Alzheimer's disease. We analyzed the temporal lobes of 9 Alzheimer's dementia (AD and 7 cognitively normal (NC subjects. Brains were scanned post-mortem at 7 Tesla. We extracted hippocampal volumes and radial distances using automated segmentation techniques. Hippocampal slices were stained for amyloid beta (Aβ, tau, and cresyl violet to evaluate neuronal counts. The hippocampal subfields, CA1, CA2, CA3, CA4, and subiculum were manually traced so that the neuronal counts, Aβ, and tau burden could be obtained for each region. We used linear regression to detect associations between hippocampal atrophy in 3D, clinical diagnosis and total as well as subfield pathology burden measures. As expected, we found significant correlations between hippocampal radial distance and mean neuronal count, as well as diagnosis. There were subfield specific associations between hippocampal radial distance and tau in CA2, and cresyl violet neuronal counts in CA1 and subiculum. These results provide further validation for the European Alzheimer's Disease Consortium Alzheimer's Disease Neuroimaging Initiative Center Harmonized Hippocampal Segmentation Protocol (HarP.

  15. Thin slices and Sherlock Holmes

    African Journals Online (AJOL)

    based on very little information, and often in a matter of seconds. This is partly based on very narrow slices of our experience, and involves pattern recognition, as well as the memory banks of our senses. It is also partly a heuristic process whereby one rapidly discards ideas or notions, or promotes other hypotheses, as one.

  16. Sugar uptake and starch biosynthesis by slices of developing maize endosperm

    International Nuclear Information System (INIS)

    Felker, F.C.; Liu, Kangchien; Shannon, J.C.

    1990-01-01

    14 C-Sugar uptake and incorporation into starch by slices of developing maize (Zea mays L.) endosperm were examined and compared with sugar uptake by maize endosperm-derived suspension cultures. Rates of sucrose, fructose, and D- and L-glucose uptake by slices were similar, whereas uptake rates for these sugars differed greatly in suspension cultures. Concentration dependence of sucrose, fructose, and D-glucose uptake was biphasic (consisting of linear plus saturable components) with suspension cultures but linear with slices. These and other differences suggest that endosperm slices are freely permeable to sugars. After diffusion into the slices, sugars were metabolized and incorporated into starch. Starch synthesis, but not sugar accumulation, was greatly reduced by 2.5 millimolar p-chloromercuribenzenesulfonic acid and 0.1 millimolar carbonyl cyanide m-chlorophenylhydrazone. Starch synthesis was dependent on kernel age and incubation temperature, but not on external pH (5 through 8). Competing sugars generally did not affect the distribution of 14 C among the soluble sugars extracted from endosperm slices incubated in 14 C-sugars. Competing hexoses reduced the incorporation of 14 C into starch, but competing sucrose did not, suggesting that sucrose is not a necessary intermediate in starch biosynthesis. The bidirectional permeability of endosperm slices to sugars makes the characterization of sugar transport into endosperm slices impossible, however the model system is useful for experiments dealing with starch biosynthesis which occurs in the metabolically active tissue

  17. Differential regulation of axon outgrowth and reinnervation by neurotrophin-3 and neurotrophin-4 in the hippocampal formation.

    Science.gov (United States)

    Hechler, Daniel; Boato, Francesco; Nitsch, Robert; Hendrix, Sven

    2010-08-01

    In this study, we investigated the hypothesis whether neurotrophins have a differential influence on neurite growth from the entorhinal cortex depending on the presence or absence of hippocampal target tissue. We investigated organotypic brain slices derived from the entorhinal-hippocampal system to analyze the effects of endogenous and recombinant neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) on neurite outgrowth and reinnervation. In the reinnervation assay, entorhinal cortex explants of transgenic mice expressing enhanced green fluorescent protein (EGFP) were co-cultured with wild-type hippocampi under the influence of recombinant NT-3 and NT-4 (500 ng/ml). Both recombinant NT-3 and NT-4 significantly increased the growth of EGFP+ nerve fibers into the target tissue. Consistently, reinnervation of the hippocampi of NT-4(-/-) and NT-3(+/-)NT-4(-/-) mice was substantially reduced. In contrast, the outgrowth assay did not exhibit reduction in axon outgrowth of NT-4(-/-) or NT-3(+/-)NT-4(-/-) cortex explants, while the application of recombinant NT-3 (500 ng/ml) induced a significant increase in the neurite extension of cortex explants. Recombinant NT-4 had no effect. In summary, only recombinant NT-3 stimulates axon outgrowth from cortex explants, while both endogenous and recombinant NT-3 and NT-4 synergistically promote reinnervation of the denervated hippocampus. These results suggest that endogenous and exogenous NT-3 and NT-4 differentially influence neurite growth depending on the presence or absence of target tissue.

  18. Thin-Slice Measurement of Wisdom

    Directory of Open Access Journals (Sweden)

    Chao S. Hu

    2017-08-01

    Full Text Available Objective Measurement of Wisdom within a short period of time is vital for both the public interest (e.g., understanding a presidential election and research (e.g., testing factors that facilitate wisdom development. A measurement of emotion associated with wisdom would be especially informative; therefore, a novel Thin-Slice measurement of wisdom was developed based on the Berlin Paradigm. For about 2 min, participants imagined the lens of a camera as the eyes of their friend/teacher whom they advised about a life dilemma. Verbal response and facial expression were both recorded by a camera: verbal responses were then rated on both the Berlin Wisdom criteria and newly developed Chinese wisdom criteria; facial expressions were analyzed by the software iMotion FACET module. Results showed acceptable inter-rater and inter-item reliability for this novel paradigm. Moreover, both wisdom ratings were not significantly correlated with Social desirability, and the Berlin wisdom rating was significantly negatively correlated with Neuroticism; feeling of surprise was significantly positively correlated with both wisdom criteria ratings. Our results provide the first evidence of this Thin-slice Wisdom Paradigm’s reliability, its immunity to social desirability, and its validity for assessing candidates’ wisdom within a short timeframe. Although still awaiting further development, this novel Paradigm contributes to an emerging Universal Wisdom Paradigm applicable across cultures.

  19. Stress, depression and hippocampal damage

    Indian Academy of Sciences (India)

    Amongst the prime targets of stress in the brain is the hippocampus, which has high receptor ... effects on different hippocampal subfields (McEwen 1999). ... disorders, and decreases in hippocampal volume have been observed in patients of ...

  20. Inflammation subverts hippocampal synaptic plasticity in experimental multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Robert Nisticò

    Full Text Available Abnormal use-dependent synaptic plasticity is universally accepted as the main physiological correlate of memory deficits in neurodegenerative disorders. It is unclear whether synaptic plasticity deficits take place during neuroinflammatory diseases, such as multiple sclerosis (MS and its mouse model, experimental autoimmune encephalomyelitis (EAE. In EAE mice, we found significant alterations of synaptic plasticity rules in the hippocampus. When compared to control mice, in fact, hippocampal long-term potentiation (LTP induction was favored over long-term depression (LTD in EAE, as shown by a significant rightward shift in the frequency-synaptic response function. Notably, LTP induction was also enhanced in hippocampal slices from control mice following interleukin-1β (IL-1β perfusion, and both EAE and IL-1β inhibited GABAergic spontaneous inhibitory postsynaptic currents (sIPSC without affecting glutamatergic transmission and AMPA/NMDA ratio. EAE was also associated with selective loss of GABAergic interneurons and with reduced gamma-frequency oscillations in the CA1 region of the hippocampus. Finally, we provided evidence that microglial activation in the EAE hippocampus was associated with IL-1β expression, and hippocampal slices from control mice incubated with activated microglia displayed alterations of GABAergic transmission similar to those seen in EAE brains, through a mechanism dependent on enhanced IL-1β signaling. These data may yield novel insights into the basis of cognitive deficits in EAE and possibly of MS.

  1. Inflammation Subverts Hippocampal Synaptic Plasticity in Experimental Multiple Sclerosis

    Science.gov (United States)

    Mandolesi, Georgia; Piccinin, Sonia; Berretta, Nicola; Pignatelli, Marco; Feligioni, Marco; Musella, Alessandra; Gentile, Antonietta; Mori, Francesco; Bernardi, Giorgio; Nicoletti, Ferdinando; Mercuri, Nicola B.; Centonze, Diego

    2013-01-01

    Abnormal use-dependent synaptic plasticity is universally accepted as the main physiological correlate of memory deficits in neurodegenerative disorders. It is unclear whether synaptic plasticity deficits take place during neuroinflammatory diseases, such as multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). In EAE mice, we found significant alterations of synaptic plasticity rules in the hippocampus. When compared to control mice, in fact, hippocampal long-term potentiation (LTP) induction was favored over long-term depression (LTD) in EAE, as shown by a significant rightward shift in the frequency–synaptic response function. Notably, LTP induction was also enhanced in hippocampal slices from control mice following interleukin-1β (IL-1β) perfusion, and both EAE and IL-1β inhibited GABAergic spontaneous inhibitory postsynaptic currents (sIPSC) without affecting glutamatergic transmission and AMPA/NMDA ratio. EAE was also associated with selective loss of GABAergic interneurons and with reduced gamma-frequency oscillations in the CA1 region of the hippocampus. Finally, we provided evidence that microglial activation in the EAE hippocampus was associated with IL-1β expression, and hippocampal slices from control mice incubated with activated microglia displayed alterations of GABAergic transmission similar to those seen in EAE brains, through a mechanism dependent on enhanced IL-1β signaling. These data may yield novel insights into the basis of cognitive deficits in EAE and possibly of MS. PMID:23355887

  2. Oral administration of fisetin promotes the induction of hippocampal long-term potentiation in vivo

    Directory of Open Access Journals (Sweden)

    Wen-bin He

    2018-01-01

    Full Text Available To explore memory enhancing effect of the flavonoid fisetin, we investigated the effect of oral administration of flavonoids on the induction of long-term potentiation (LTP at hippocampal CA1 synapses of anesthetized rats. Among four flavonoids (fisetin, quercetin, luteolin and myricetin tested, only fisetin significantly facilitated the induction of hippocampal LTP. The effect of oral fisetin was abolished by intracerebroventricular injection of U0126, an agent that was previously found to inhibit its effect in hippocampal slices in vitro. These results suggest that orally administered fisetin crosses the blood–brain barrier and promotes synaptic functions in the hippocampus.

  3. Loss of mTOR repressors Tsc1 or Pten has divergent effects on excitatory and inhibitory synaptic transmission in single hippocampal neuron cultures.

    Science.gov (United States)

    Weston, Matthew C; Chen, Hongmei; Swann, John W

    2014-01-01

    The Pten and Tsc1 genes both encode proteins that repress mechanistic target of rapamycin (mTOR) signaling. Disruption of either gene in the brain results in epilepsy and autism-like symptoms in humans and mouse models, therefore it is important to understand the molecular and physiological events that lead from gene disruption to disease phenotypes. Given the similar roles these two molecules play in the regulation of cellular growth and the overlap in the phenotypes that result from their loss, we predicted that the deletion of either the Pten or Tsc1 gene from autaptic hippocampal neurons would have similar effects on neuronal morphology and synaptic transmission. Accordingly, we found that loss of either Pten or Tsc1 caused comparable increases in soma size, dendrite length and action potential properties. However, the effects of Pten and Tsc1 loss on synaptic transmission were different. Loss of Pten lead to an increase in both excitatory and inhibitory neurotransmission, while loss of Tsc1 did not affect excitatory neurotransmission and reduced inhibitory transmission by decreasing mIPSC amplitude. Although the loss of Pten or Tsc1 both increased downstream mTORC1 signaling, phosphorylation of Akt was increased in Pten-ko and decreased in Tsc1-ko neurons, potentially accounting for the different effects on synaptic transmission. Despite the different effects at the synaptic level, our data suggest that loss of Pten or Tsc1 may both lead to an increase in the ratio of excitation to inhibition at the network level, an effect that has been proposed to underlie both epilepsy and autism.

  4. The Nanoscale Observation of the Three-Dimensional Structures of Neurosynapses, Membranous Conjunctions Between Cultured Hippocampal Neurons and Their Significance in the Development of Epilepsy.

    Science.gov (United States)

    Sun, Lan; Jiang, Shuang; Tang, Xianhua; Zhang, Yingge; Qin, Luye; Jiang, Xia; Yu, Albert Cheung Hoi

    2016-12-01

    The nanoscale three-dimensional structures of neurosynapses are unknown, and the neuroanatomical basis of epilepsy remains to be elucidated. Here, we studied the nanoscale three-dimensional synapses between hippocampal neurons, and membranous conjunctions between neurons were found with atomic force microscopy (AFM) and confirmed by transmission electron microscope (TEM), and their pathophysiological significance was primarily investigated. The neurons and dendrites were marked by MAP-2, axons by neurofilament 200, and synapses by synapsin I immunological staining. In the synapsin I-positive neurite ends of the neurons positively stained with MAP-2 and neurofilament 200, neurosynapses with various nanoscale morphology and structure could be found by AFM. The neurosynapses had typical three-dimensional structures of synaptic triplet including the presynaptic neurite end, synaptic cleft of 30 ∼ 40 in chemical synapses and 2 ∼ 6 nm in electrical ones, the postsynaptic neurite or dendrite spine, the typical neurite end button, the distinct pre- and postsynaptic membranes, and the obvious thickening of the postsynaptic membranes or neurites. Some membranous connections including membrane-like junctions (MLJ) and fiber-tube links (FTL) without triplet structures and cleft were found between neurons. The development frequencies of the two membranous conjunctions increased while those of the synaptic conjunctions decreased between the neurons from Otx1 knock-out mice in comparison with those between the neurons from normal mice. These results suggested that the neuroanatomical basis of Otx1 knock-out epilepsy is the combination of the decreased synaptic conjunctions and the increased membranous conjunctions.

  5. 17β Estradiol increases resilience and improves hippocampal synaptic function in helpless ovariectomized rats

    Science.gov (United States)

    Bredemann, Teruko M.; McMahon, Lori L.

    2014-01-01

    Summary Memory impairment is the most commonly reported cognitive symptom associated with major depressive disorder. Decreased hippocampal volume and neurogenesis in depression link hippocampal dysfunction with deficits in memory. Stress decreases hippocampal dendritic spine density and long-term potentiation (LTP) at glutamate synapses, a cellular correlate of learning and memory. However, elevated plasma levels of 17β estradiol (E2) during proestrus increase hippocampal structure and function, directly opposing the negative consequences of stress. In women, significant fluctuations in ovarian hormones likely increase vulnerability of hippocampal circuits to stress, potentially contributing to the greater incidence of depression compared to men. Using the learned helplessness model of depression and ovariectomized female rats, we investigated whether acquisition of helplessness and hippocampal synaptic dysfunction is differentially impacted by the presence or absence of plasma E2. We find that inescapable shock induces a greater incidence of helplessness in vehicle- versus E2-treated OVX rats. In the vehicle-treated group, LTP was absent at CA3-CA1 synapses in slices only from helpless rats, and CA1 spine density was decreased compared to resilient rats. In contrast, significant LTP was observed in slices from E2-treated helpless rats; importantly, spine density was not different between E2-treated helpless and resilient rats, dissociating spine density from the LTP magnitude. We also find that E2 replacement can reverse previously established helpless behavior. Thus, our results show that E2 replacement in OVX rats increases resilience and improves hippocampal plasticity, suggesting that E2 therapy may increase resilience to stress and preserve hippocampal function in women experiencing large fluctuations in plasma estrogen levels. PMID:24636504

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  7. Slices

    KAUST Repository

    McCrae, James; Singh, Karan; Mitra, Niloy J.

    2011-01-01

    Minimalist object representations or shape-proxies that spark and inspire human perception of shape remain an incompletely understood, yet powerful aspect of visual communication. We explore the use of planar sections, i.e., the contours

  8. Inhibition of local estrogen synthesis in the hippocampus impairs hippocampal memory consolidation in ovariectomized female mice.

    Science.gov (United States)

    Tuscher, Jennifer J; Szinte, Julia S; Starrett, Joseph R; Krentzel, Amanda A; Fortress, Ashley M; Remage-Healey, Luke; Frick, Karyn M

    2016-07-01

    The potent estrogen 17β-Estradiol (E2) plays a critical role in mediating hippocampal function, yet the precise mechanisms through which E2 enhances hippocampal memory remain unclear. In young adult female rodents, the beneficial effects of E2 on memory are generally attributed to ovarian-synthesized E2. However, E2 is also synthesized in the adult brain in numerous species, where it regulates synaptic plasticity and is synthesized in response to experiences such as exposure to females or conspecific song. Although de novo E2 synthesis has been demonstrated in rodent hippocampal cultures, little is known about the functional role of local E2 synthesis in mediating hippocampal memory function. Therefore, the present study examined the role of hippocampal E2 synthesis in hippocampal memory consolidation. Using bilateral dorsal hippocampal infusions of the aromatase inhibitor letrozole, we first found that blockade of dorsal hippocampal E2 synthesis impaired hippocampal memory consolidation. We next found that elevated levels of E2 in the dorsal hippocampus observed 30min after object training were blocked by dorsal hippocampal infusion of letrozole, suggesting that behavioral experience increases acute and local E2 synthesis. Finally, aromatase inhibition did not prevent exogenous E2 from enhancing hippocampal memory consolidation, indicating that hippocampal E2 synthesis is not necessary for exogenous E2 to enhance hippocampal memory. Combined, these data are consistent with the hypothesis that hippocampally-synthesized E2 is necessary for hippocampus-dependent memory consolidation in rodents. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Hippocampal development at gestation weeks 23 to 36. An ultrasound study on preterm neonates

    Energy Technology Data Exchange (ETDEWEB)

    Bajic, Dragan; Raininko, Raili [Uppsala University, Department of Radiology, University Hospital, Uppsala (Sweden); Ewald, Uwe [Uppsala University, Department of Women' s and Children' s Health, Uppsala (Sweden)

    2010-06-15

    During fetal development, the hippocampal structures fold around the hippocampal sulcus into the temporal lobe. According to the literature, this inversion should be completed at gestation week (GW) 21. Thereafter, the hippocampal shape should resemble the adult shape. However, incomplete hippocampal inversion (IHI) is found in 19% of the common population. The aim of this study was to study fetal hippocampal development by examining neonates born preterm. We analyzed cranial ultrasound examinations, performed as a part of the routine assessment of all preterm infants, over a 3-year period and excluded the infants with brain pathology. The final material consisted of 158 children born <35 GW. A rounded form (the ratio between the horizontal and vertical diameters of the hippocampal body {<=}1) in coronal slices was considered the sign of IHI. The age at examination was 23-24 GW in 24 neonates, 25-28 GW in 70 neonates, and 29-36 GW in 64 neonates. IHI was found in 50%, 24%, and 14%, respectively. The difference between the neonates <25 GW and {>=}25 GW was statistically highly significant (p < 0.001). The frequency of bilateral IHI was highest in the youngest age group. In the other groups, the left-sided IHI was the most common. In about 50% of the neonates, hippocampal inversion is not completed up to GW 24; but from 25 GW onwards, the frequency and laterality of IHI is similar to that in the adult population. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-18

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

  11. Choline-mediated modulation of hippocampal sharp wave-ripple complexes in vitro.

    Science.gov (United States)

    Fischer, Viktoria; Both, Martin; Draguhn, Andreas; Egorov, Alexei V

    2014-06-01

    The cholinergic system is critically involved in the modulation of cognitive functions, including learning and memory. Acetylcholine acts through muscarinic (mAChRs) and nicotinic receptors (nAChRs), which are both abundantly expressed in the hippocampus. Previous evidence indicates that choline, the precursor and degradation product of Acetylcholine, can itself activate nAChRs and thereby affects intrinsic and synaptic neuronal functions. Here, we asked whether the cellular actions of choline directly affect hippocampal network activity. Using mouse hippocampal slices we found that choline efficiently suppresses spontaneously occurring sharp wave-ripple complexes (SPW-R) and can induce gamma oscillations. In addition, choline reduces synaptic transmission between hippocampal subfields CA3 and CA1. Surprisingly, these effects are mediated by activation of both mAChRs and α7-containing nAChRs. Most nicotinic effects became only apparent after local, fast application of choline, indicating rapid desensitization kinetics of nAChRs. Effects were still present following block of choline uptake and are, therefore, likely because of direct actions of choline at the respective receptors. Together, choline turns out to be a potent regulator of patterned network activity within the hippocampus. These actions may be of importance for understanding state transitions in normal and pathologically altered neuronal networks. In this study we asked whether choline, the precursor and degradation product of acetylcholine, directly affects hippocampal network activity. Using mouse hippocampal slices we found that choline efficiently suppresses spontaneously occurring sharp wave-ripple complexes (SPW-R). In addition, choline reduces synaptic transmission between hippocampal subfields. These effects are mediated by direct activation of muscarinic as well as nicotinic cholinergic pathways. Together, choline turns out to be a potent regulator of patterned activity within hippocampal

  12. Lysosome stabilization in slices of rat liver when incubated with vitamin A excess

    International Nuclear Information System (INIS)

    Morre, D.M.; Morre, D.J.; Bowen, S.; Reutter, W.

    1986-01-01

    An organ culture of slices of livers from adult rats was used to study effect of vitamin A (all-trans retinol) on lysosome stability. Lysosomes were purified by centrifugation in Percoll gradients. Preparations were monitored by electron microscopy and evaluated by morphometry and assays of marker enzymes. Enrichments relative to homogenates and crude pellets were estimated from latent (triton X-100) acid p-nitrophenylphosphatase specific activities. Lysosomes prepared from unincubated slices were enriched 50-fold in latent acid phosphatase relative to homogenates. In contrast, lysosomes prepared from slices incubated for 30 min in PBS alone were enriched only 20-fold. When 25 μg/ml retinol was included in the incubation medium, enrichments of 40-fold were obtained. The integrity of the slices was monitored by electron microscopy and their viability was confirmed by a sustained uptake and incorporation of [ 3 H]leucine into protein (up to 2 h in culture). The loss of lysosomes from homogenates of slices incubated in the absence of retinol was accompanied by a loss of acid phosphatase from the lysosomal pellet to the supernatant during purification. Addition of retinol to slices just prior to homogenization was without effect. The results demonstrate a stabilizing influence of vitamin A on lysosomes during incubation of licer slices. The findings contrast earlier reports of retinol-induced lysosome fragility in other in vitro systems

  13. Radiation sterilization and identification of gizzard slices

    International Nuclear Information System (INIS)

    Zhu, S.; Fu, C.; Jiang, W.; Yao, D.; Zhao, K.; Zhang, Y.

    1998-01-01

    An orthogonal test of 4 factors of radiation dose, storage temperature, storage time, and sanitation of cutting places was carried out to optimize the conditions for disinfection of gizzard slices. In the optimized condition, both the sanitary quality and the shelf-life of gizzard slices were improved. To identify irradiated gizzard slices, the sensory change, and the levels of water-soluble nitrogen, amino acid, total volatile basic nitrogen, peroxide value, vitamin C consumption and KMnO 4 consumption were determinated. No significant change was observed except for the color which was light brown on the surface of irradiated slices

  14. Two cell circuits of oriented adult hippocampal neurons on self-assembled monolayers for use in the study of neuronal communication in a defined system.

    Science.gov (United States)

    Edwards, Darin; Stancescu, Maria; Molnar, Peter; Hickman, James J

    2013-08-21

    In this study, we demonstrate the directed formation of small circuits of electrically active, synaptically connected neurons derived from the hippocampus of adult rats through the use of engineered chemically modified culture surfaces that orient the polarity of the neuronal processes. Although synaptogenesis, synaptic communication, synaptic plasticity, and brain disease pathophysiology can be studied using brain slice or dissociated embryonic neuronal culture systems, the complex elements found in neuronal synapses makes specific studies difficult in these random cultures. The study of synaptic transmission in mature adult neurons and factors affecting synaptic transmission are generally studied in organotypic cultures, in brain slices, or in vivo. However, engineered neuronal networks would allow these studies to be performed instead on simple functional neuronal circuits derived from adult brain tissue. Photolithographic patterned self-assembled monolayers (SAMs) were used to create the two-cell "bidirectional polarity" circuit patterns. This pattern consisted of a cell permissive SAM, N-1[3-(trimethoxysilyl)propyl] diethylenetriamine (DETA), and was composed of two 25 μm somal adhesion sites connected with 5 μm lines acting as surface cues for guided axonal and dendritic regeneration. Surrounding the DETA pattern was a background of a non-cell-permissive poly(ethylene glycol) (PEG) SAM. Adult hippocampal neurons were first cultured on coverslips coated with DETA monolayers and were later passaged onto the PEG-DETA bidirectional polarity patterns in serum-free medium. These neurons followed surface cues, attaching and regenerating only along the DETA substrate to form small engineered neuronal circuits. These circuits were stable for more than 21 days in vitro (DIV), during which synaptic connectivity was evaluated using basic electrophysiological methods.

  15. Slice of LHC dipole wiring

    CERN Multimedia

    Dipole model slice made in 1994 by Ansaldo. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. 50’000 tonnes of steel sheets are used to make the magnet yokes that keep the wiring firmly in place. The yokes constitute approximately 80% of the accelerator's weight and, placed side by side, stretch over 20 km!

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

    Science.gov (United States)

    van Deijk, Anne-Lieke F; Broersen, Laus M; Verkuyl, J Martin; Smit, August B; Verheijen, Mark H G

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Anne-Lieke F. van Deijk

    2017-08-01

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

  18. Integrating interface slicing into software engineering processes

    Science.gov (United States)

    Beck, Jon

    1993-01-01

    Interface slicing is a tool which was developed to facilitate software engineering. As previously presented, it was described in terms of its techniques and mechanisms. The integration of interface slicing into specific software engineering activities is considered by discussing a number of potential applications of interface slicing. The applications discussed specifically address the problems, issues, or concerns raised in a previous project. Because a complete interface slicer is still under development, these applications must be phrased in future tenses. Nonetheless, the interface slicing techniques which were presented can be implemented using current compiler and static analysis technology. Whether implemented as a standalone tool or as a module in an integrated development or reverse engineering environment, they require analysis no more complex than that required for current system development environments. By contrast, conventional slicing is a methodology which, while showing much promise and intuitive appeal, has yet to be fully implemented in a production language environment despite 12 years of development.

  19. Glucocorticoid effects on hippocampal protein synthesis

    International Nuclear Information System (INIS)

    Schlatter, L.K.

    1988-01-01

    Following subcutaneous injection of rats with 5 mg corticosterone, hippocampal slices in vitro show increased [ 35 S]-methionine labeling of a cytosolic protein with an apparent molecular weight (M r ) of 35,000 and an isoelectric point (IEP) of 6.6. This labeling is temporally consistent with a transcriptional event, and is steroid- and tissue-specific. The pear serum concentration of steroid occurs one hour or less following the injection. Maximal labeling of this protein is reached whenever serum corticosterone values are approximately 100 ng/ml. When endogenous corticosterone levels are elevated to 100 ng/ml through stressors or exogenous ACTH injections the same maximal increase in synthesis of the 35,000 M r protein is observed. Adrenalectomy prevents the observed response from occurring following stressor application or ACTH injections. Comparison of the increases observed after administration of the type 2 receptor agonist RU 28362 and aldosterone, which has a higher affinity for the type 1 receptor, shows a 50-fold greater sensitivity of the response to the type 2 receptor agonist. Synthesis of this protein following serum increases of steroid possibly correlates to the theorized function of the type 2 receptor feedback regulation. The similar protein in the liver has an IEP of 6.8 and a slightly higher M r . A second hippocampal protein with an M r of 46,000 and an IEP of 6.2 is also increased in labeling. Two additional liver proteins, one of Mr 53,000 (IEP of 6.2) and the other with an M r of 45,000 (IEP of 8.7-7.8) are increased in the liver following glucocorticoid administration

  20. Measurement of slice sensitivity profile for a 64-slice spiral CT system

    International Nuclear Information System (INIS)

    Liu Chuanya; Qin Weichang; Wang Wei; Lu Chuanyou

    2006-01-01

    Objective: To measure and evaluate slice sensitivity profile (SSP) and the full width at half-maximum(FWHM) for a 64-slice spiral CT system. Methods: Using the same CT technique and body mode as those used for clinical CT, delta phantom was scanned with Somatom Sensation 64-slice spiral CT. SSPs and FWHM were measured both with reconstruction slice width of 0.6 mm at pitch=0.50, 0.75, 1.00, 1.25, 1.50 and with reconstruction slice width of 0.6, 1.0, 1.5 mm at pitch=1 respectively. Results: For normal slice width of 0. 6 mm, the measured FWHM, i.e. effective slice width, is 0.67, 0.67, 0.66, 0.69, 0.69 mm at different pitch. All the measured FWHM deviate less than 0.1 mm from the nominal slice width. The measured SSPs are symmetrical, bell-shaped curves without far-reaching tails, and show only slight variations as a function of the spiral pitch. When reconstruction slice width increase, relative SSP become wider. Conclusions: The variation of pitch hardly has effect all on SSP, effective slice width, and z-direction spatial resolution for Sensation 64-slice spiral CT system, which is helpful to optimize CT scanning protocol. (authors)

  1. Intracerebroventricular administration of okadaic acid induces hippocampal glucose uptake dysfunction and tau phosphorylation.

    Science.gov (United States)

    Broetto, Núbia; Hansen, Fernanda; Brolese, Giovana; Batassini, Cristiane; Lirio, Franciane; Galland, Fabiana; Dos Santos, João Paulo Almeida; Dutra, Márcio Ferreira; Gonçalves, Carlos-Alberto

    2016-06-01

    Intraneuronal aggregates of neurofibrillary tangles (NFTs), together with beta-amyloid plaques and astrogliosis, are histological markers of Alzheimer's disease (AD). The underlying mechanism of sporadic AD remains poorly understood, but abnormal hyperphosphorylation of tau protein is suggested to have a role in NFTs genesis, which leads to neuronal dysfunction and death. Okadaic acid (OKA), a strong inhibitor of protein phosphatase 2A, has been used to induce dementia similar to AD in rats. We herein investigated the effect of intracerebroventricular (ICV) infusion of OKA (100 and 200ng) on hippocampal tau phosphorylation at Ser396, which is considered an important fibrillogenic tau protein site, and on glucose uptake, which is reduced early in AD. ICV infusion of OKA (at 200ng) induced a spatial cognitive deficit, hippocampal astrogliosis (based on GFAP increment) and increase in tau phosphorylation at site 396 in this model. Moreover, we observed a decreased glucose uptake in the hippocampal slices of OKA-treated rats. In vitro exposure of hippocampal slices to OKA altered tau phosphorylation at site 396, without any associated change in glucose uptake activity. Taken together, these findings further our understanding of OKA neurotoxicity, in vivo and vitro, particularly with regard to the role of tau phosphorylation, and reinforce the importance of the OKA dementia model for studying the neurochemical alterations that may occur in AD, such as NFTs and glucose hypometabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Active hippocampal networks undergo spontaneous synaptic modification.

    Directory of Open Access Journals (Sweden)

    Masako Tsukamoto-Yasui

    Full Text Available The brain is self-writable; as the brain voluntarily adapts itself to a changing environment, the neural circuitry rearranges its functional connectivity by referring to its own activity. How the internal activity modifies synaptic weights is largely unknown, however. Here we report that spontaneous activity causes complex reorganization of synaptic connectivity without any external (or artificial stimuli. Under physiologically relevant ionic conditions, CA3 pyramidal cells in hippocampal slices displayed spontaneous spikes with bistable slow oscillations of membrane potential, alternating between the so-called UP and DOWN states. The generation of slow oscillations did not require fast synaptic transmission, but their patterns were coordinated by local circuit activity. In the course of generating spontaneous activity, individual neurons acquired bidirectional long-lasting synaptic modification. The spontaneous synaptic plasticity depended on a rise in intracellular calcium concentrations of postsynaptic cells, but not on NMDA receptor activity. The direction and amount of the plasticity varied depending on slow oscillation patterns and synapse locations, and thus, they were diverse in a network. Once this global synaptic refinement occurred, the same neurons now displayed different patterns of spontaneous activity, which in turn exhibited different levels of synaptic plasticity. Thus, active networks continuously update their internal states through ongoing synaptic plasticity. With computational simulations, we suggest that with this slow oscillation-induced plasticity, a recurrent network converges on a more specific state, compared to that with spike timing-dependent plasticity alone.

  3. Identification of a small-molecule inhibitor of the PICK1 PDZ domain that inhibits hippocampal LTP and LTD

    DEFF Research Database (Denmark)

    Thorsen, Thor S; Madsen, Kenneth L; Rebola, Nelson

    2010-01-01

    interacting protein 1 (GRIP1). Pretreatment of cultured hippocampal neurons with FSC231 inhibited coimmunopreciptation of the AMPA receptor GluR2 subunit with PICK1. In agreement with inhibiting the role of PICK1 in GluR2 trafficking, FSC231 accelerated recycling of pHluorin-tagged GluR2 in hippocampal...

  4. State-dependent variation in the inhibitory effect of (D-Ala sup 2 , D-Leu sup 5 )-enkephalin on hippocampal serotonin release in ground squirrels

    Energy Technology Data Exchange (ETDEWEB)

    Kramarova, L.I.; Lee, T.F.; Cui, Y.; Wang, L.C.H. (Univ. of Alberta, Edmonton (Canada))

    1990-01-01

    Accumulated evidence has suggested that increased endogenous opioid activities may facilitate the onset of hibernation either directly or possibly through modulation of other neurotransmitter systems. The seasonal change of (D-Ala{sup 2}, D-Leu{sup 5})-enkephalin (DADLE), a {delta} receptor agonist, in modulating K{sup +}-induced ({sup 3}H)-5-hydroxytryptamine (5-HT) release from the hippocampal and hypothalamic slices of euthermic and hibernating Richardsons' ground squirrels was therefore investigated. DADLE had no effect on 5-HT release in the hypothalamic slices but elicited a dose-related inhibition on ({sup 3}H)-5-HT release from the hippocampal slices of the euthermic ground squirrel. The inhibitory effect of DADLE was completely reversed by naloxone, but not by tetrodotoxin. In contrast, DADLE failed to alter the K{sup +}-induced 5-HT release from the hippocampal slices of the hibernating ground squirrel. This state-dependent reduction in responsiveness to an opioid is consistent with the hypothesis that enhanced endogenous opioid activity in the hibernating phase could lead to down regulation of the opioid receptors and minimize its inhibition on hippocampal serotonergic activity. A high 5-HT activity would inhibit midbrain reticular activating system indirectly through non-serotonergic fibers, which in turn facilitate the onset or maintenance of hibernation.

  5. Prior Activation of Inositol 1,4,5-Trisphosphate Receptors Suppresses the Subsequent Induction of Long-Term Potentiation in Hippocampal CA1 Neurons

    Science.gov (United States)

    Fujii, Satoshi; Yamazaki, Yoshihiko; Goto, Jun-Ichi; Fujiwara, Hiroki; Mikoshiba, Katsuhiko

    2016-01-01

    We investigated the role of inositol 1,4,5-trisphosphate receptors (IP3Rs) activated by preconditioning low-frequency afferent stimulation (LFS) in the subsequent induction of long-term potentiation (LTP) in CA1 neurons in hippocampal slices from mature guinea pigs. Induction of LTP in the field excitatory postsynaptic potential or the population…

  6. Outline and handling manual of experimental data time slice monitoring software 'SLICE'

    International Nuclear Information System (INIS)

    Shirai, Hiroshi; Hirayama, Toshio; Shimizu, Katsuhiro; Tani, Keiji; Azumi, Masafumi; Hirai, Ken-ichiro; Konno, Satoshi; Takase, Keizou.

    1993-02-01

    We have developed a software 'SLICE' which maps various kinds of plasma experimental data measured at the different geometrical position of JT-60U and JFT-2M onto the equilibrium magnetic configuration and treats them as a function of volume averaged minor radius ρ. Experimental data can be handled uniformly by using 'SLICE'. Plenty of commands of 'SLICE' make it easy to process the mapped data. The experimental data measured as line integrated values are also transformed by Abel inversion. The mapped data are fitted to a functional form and saved to the database 'MAPDB'. 'SLICE' can read the data from 'MAPDB' and re-display and transform them. Still more 'SLICE' creates run data of orbit following Monte-Carlo code 'OFMC' and tokamak predictive and interpretation code system 'TOPICS'. This report summarizes an outline and the usage of 'SLICE'. (author)

  7. Inhibition of NKCC1 attenuated hippocampal LTP formation and inhibitory avoidance in rat.

    Directory of Open Access Journals (Sweden)

    Meng Chang Ko

    Full Text Available The loop diuretic bumetanide (Bumex is thought to have antiepileptic properties via modulate GABAA mediated signaling through their antagonism of cation-chloride cotransporters. Given that loop diuretics may act as antiepileptic drugs that modulate GABAergic signaling, we sought to investigate whether they also affect hippocampal function. The current study was performed to evaluate the possible role of NKCC1 on the hippocampal function. Brain slice extracellular recording, inhibitory avoidance, and western blot were applied in this study. Results showed that hippocampal Long-term potentiation was attenuated by suprafusion of NKCC1 inhibitor bumetanide, in a dose dependent manner. Sequent experiment result showed that Intravenous injection of bumetanide (15.2 mg/kg 30 min prior to the training session blocked inhibitory avoidance learning significantly. Subsequent control experiment's results excluded the possible non-specific effect of bumetanide on avoidance learning. We also found the phosphorylation of hippocampal MAPK was attenuated after bumetanide administration. These results suggested that hippocampal NKCC1 may via MAPK signaling cascade to possess its function.

  8. Maturation- and sex-sensitive depression of hippocampal excitatory transmission in a rat schizophrenia model.

    Science.gov (United States)

    Patrich, Eti; Piontkewitz, Yael; Peretz, Asher; Weiner, Ina; Attali, Bernard

    2016-01-01

    Schizophrenia is associated with behavioral and brain structural abnormalities, of which the hippocampus appears to be one of the most consistent region affected. Previous studies performed on the poly I:C model of schizophrenia suggest that alterations in hippocampal synaptic transmission and plasticity take place in the offspring. However, these investigations yielded conflicting results and the neurophysiological alterations responsible for these deficits are still unclear. Here we performed for the first time a longitudinal study examining the impact of prenatal poly I:C treatment and of gender on hippocampal excitatory neurotransmission. In addition, we examined the potential preventive/curative effects of risperidone (RIS) treatment during the peri-adolescence period. Excitatory synaptic transmission was determined by stimulating Schaffer collaterals and monitoring fiber volley amplitude and slope of field-EPSP (fEPSP) in CA1 pyramidal neurons in male and female offspring hippocampal slices from postnatal days (PNDs) 18-20, 34, 70 and 90. Depression of hippocampal excitatory transmission appeared at juvenile age in male offspring of the poly I:C group, while it expressed with a delay in female, manifesting at adulthood. In addition, a reduced hippocampal size was found in both adult male and female offspring of poly I:C treated dams. Treatment with RIS at the peri-adolescence period fully restored in males but partly repaired in females these deficiencies. A maturation- and sex-dependent decrease in hippocampal excitatory transmission occurs in the offspring of poly I:C treated pregnant mothers. Pharmacological intervention with RIS during peri-adolescence can cure in a gender-sensitive fashion early occurring hippocampal synaptic deficits. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Culture.

    Science.gov (United States)

    Smith, Timothy B; Rodríguez, Melanie Domenech; Bernal, Guillermo

    2011-02-01

    This article summarizes the definitions, means, and research of adapting psychotherapy to clients' cultural backgrounds. We begin by reviewing the prevailing definitions of cultural adaptation and providing a clinical example. We present an original meta-analysis of 65 experimental and quasi-experimental studies involving 8,620 participants. The omnibus effect size of d = .46 indicates that treatments specifically adapted for clients of color were moderately more effective with that clientele than traditional treatments. The most effective treatments tended to be those with greater numbers of cultural adaptations. Mental health services targeted to a specific cultural group were several times more effective than those provided to clients from a variety of cultural backgrounds. We recommend a series of research-supported therapeutic practices that account for clients' culture, with culture-specific treatments being more effective than generally culture-sensitive treatments. © 2010 Wiley Periodicals, Inc.

  10. Tight coupling of astrocyte energy metabolism to synaptic activity revealed by genetically encoded FRET nanosensors in hippocampal tissue.

    Science.gov (United States)

    Ruminot, Iván; Schmälzle, Jana; Leyton, Belén; Barros, L Felipe; Deitmer, Joachim W

    2017-01-01

    The potassium ion, K + , a neuronal signal that is released during excitatory synaptic activity, produces acute activation of glucose consumption in cultured astrocytes, a phenomenon mediated by the sodium bicarbonate cotransporter NBCe1 ( SLC4A4). We have explored here the relevance of this mechanism in brain tissue by imaging the effect of neuronal activity on pH, glucose, pyruvate and lactate dynamics in hippocampal astrocytes using BCECF and FRET nanosensors. Electrical stimulation of Schaffer collaterals produced fast activation of glucose consumption in astrocytes with a parallel increase in intracellular pyruvate and biphasic changes in lactate . These responses were blocked by TTX and were absent in tissue slices prepared from NBCe1-KO mice. Direct depolarization of astrocytes with elevated extracellular K + or Ba 2+ mimicked the metabolic effects of electrical stimulation. We conclude that the glycolytic pathway of astrocytes in situ is acutely sensitive to neuronal activity, and that extracellular K + and the NBCe1 cotransporter are involved in metabolic crosstalk between neurons and astrocytes. Glycolytic activation of astrocytes in response to neuronal K + helps to provide an adequate supply of lactate, a metabolite that is released by astrocytes and which acts as neuronal fuel and an intercellular signal.

  11. Effect of endothelin-1 on the excitability of rat cortical and hippocampal slices in vitro

    Czech Academy of Sciences Publication Activity Database

    Konopková, Renata; Világi, I.; Borbély, S.; Kubová, Hana; Otáhal, Jakub

    2012-01-01

    Roč. 61, č. 2 (2012), s. 215-219 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA AV ČR(CZ) 1QS501210509; GA ČR(CZ) GD305/08/H037 Institutional research plan: CEZ:AV0Z50110509 Keywords : Endothelin-1 * excitability * hippocampus * somatosensory cortex * rat * epileptogenesis Subject RIV: FH - Neurology Impact factor: 1.531, year: 2012

  12. Effects of Acetylcholinesterase Inhibition on Cholinergic Transmission in the Hippocampal Slice.

    Science.gov (United States)

    1985-02-08

    intracellular recording techniques. IGL stimulation produced a sizeable hyperpolarization the amplitude of which was dependent upon the menbrane ...link the elements of the cytoskeleton with each other and with the plasma membrane (Lynch and Baudry, 1984 for a review). Studies from • other groups

  13. Induction of the Wnt antagonist Dickkopf-1 is involved in stress-induced hippocampal damage.

    Directory of Open Access Journals (Sweden)

    Francesco Matrisciano

    Full Text Available The identification of mechanisms that mediate stress-induced hippocampal damage may shed new light into the pathophysiology of depressive disorders and provide new targets for therapeutic intervention. We focused on the secreted glycoprotein Dickkopf-1 (Dkk-1, an inhibitor of the canonical Wnt pathway, involved in neurodegeneration. Mice exposed to mild restraint stress showed increased hippocampal levels of Dkk-1 and reduced expression of β-catenin, an intracellular protein positively regulated by the canonical Wnt signalling pathway. In adrenalectomized mice, Dkk-1 was induced by corticosterone injection, but not by exposure to stress. Corticosterone also induced Dkk-1 in mouse organotypic hippocampal cultures and primary cultures of hippocampal neurons and, at least in the latter model, the action of corticosterone was reversed by the type-2 glucocorticoid receptor antagonist mifepristone. To examine whether induction of Dkk-1 was causally related to stress-induced hippocampal damage, we used doubleridge mice, which are characterized by a defective induction of Dkk-1. As compared to control mice, doubleridge mice showed a paradoxical increase in basal hippocampal Dkk-1 levels, but no Dkk-1 induction in response to stress. In contrast, stress reduced Dkk-1 levels in doubleridge mice. In control mice, chronic stress induced a reduction in hippocampal volume associated with neuronal loss and dendritic atrophy in the CA1 region, and a reduced neurogenesis in the dentate gyrus. Doubleridge mice were resistant to the detrimental effect of chronic stress and, instead, responded to stress with increases in dendritic arborisation and neurogenesis. Thus, the outcome of chronic stress was tightly related to changes in Dkk-1 expression in the hippocampus. These data indicate that induction of Dkk-1 is causally related to stress-induced hippocampal damage and provide the first evidence that Dkk-1 expression is regulated by corticosteroids in the central

  14. Novel genetic loci associated with hippocampal volume

    NARCIS (Netherlands)

    D.P. Hibar (Derrek); H.H.H. Adams (Hieab); N. Jahanshad (Neda); G. Chauhan (Ganesh); J.L. Stein; E. Hofer (Edith); M.E. Rentería (Miguel); J.C. Bis (Joshua); A. Arias-Vásquez (Alejandro); Ikram, M.K. (M. Kamran); S. Desrivières (Sylvane); M.W. Vernooij (Meike); L. Abramovic (Lucija); S. Alhusaini (Saud); N. Amin (Najaf); M. Andersson (Micael); K. Arfanakis (Konstantinos); B. Aribisala (Benjamin); N.J. Armstrong (Nicola J.); L. Athanasiu (Lavinia); T. Axelsson (Tomas); A.H. Beecham (Ashley); A. Beiser (Alexa); M. Bernard (Manon); S.H. Blanton (Susan H.); M.M. Bohlken (Marc M.); M.P.M. Boks (Marco); L.B.C. Bralten (Linda); A.M. Brickman (Adam M.); Carmichael, O. (Owen); M.M. Chakravarty (M. Mallar); Q. Chen (Qiang); C.R.K. Ching (Christopher); V. Chouraki (Vincent); G. Cuellar-Partida (Gabriel); F. Crivello (Fabrice); A. den Braber (Anouk); Doan, N.T. (Nhat Trung); S.M. Ehrlich (Stefan); S. Giddaluru (Sudheer); A.L. Goldman (Aaron L.); R.F. Gottesman (Rebecca); O. Grimm (Oliver); M.D. Griswold (Michael); T. Guadalupe (Tulio); Gutman, B.A. (Boris A.); J. Hass (Johanna); U.K. Haukvik (Unn); D. Hoehn (David); A.J. Holmes (Avram); M. Hoogman (Martine); D. Janowitz (Deborah); T. Jia (Tianye); Jørgensen, K.N. (Kjetil N.); N. Karbalai (Nazanin); D. Kasperaviciute (Dalia); S. Kim (Shinseog); M. Klein (Marieke); B. Kraemer (Bernd); P.H. Lee (Phil); D.C. Liewald (David C.); L.M. Lopez (Lorna); M. Luciano (Michelle); C. MacAre (Christine); Marquand, A.F. (Andre F.); M. Matarin (Mar); R. Mather; M. Mattheisen (Manuel); McKay, D.R. (David R.); Milaneschi, Y. (Yuri); S. Muñoz Maniega (Susana); K. Nho (Kwangsik); A.C. Nugent (Allison); P. Nyquist (Paul); Loohuis, L.M.O. (Loes M. Olde); J. Oosterlaan (Jaap); M. Papmeyer (Martina); Pirpamer, L. (Lukas); B. Pütz (Benno); A. Ramasamy (Adaikalavan); Richards, J.S. (Jennifer S.); S.L. Risacher (Shannon); R. Roiz-Santiañez (Roberto); N. Rommelse (Nanda); S. Ropele (Stefan); E.J. Rose (Emma); N.A. Royle (Natalie); T. Rundek (Tatjana); P.G. Sämann (Philipp); Saremi, A. (Arvin); C.L. Satizabal (Claudia L.); L. Schmaal (Lianne); N.J. Schork (Nicholas); Shen, L. (Li); J. Shin (Jean); Shumskaya, E. (Elena); A.V. Smith (Albert Vernon); R. Sprooten (Roy); L.T. Strike (Lachlan); A. Teumer (Alexander); D. Tordesillas-Gutierrez (Diana); R. Toro (Roberto); D. Trabzuni (Danyah); S. Trompet (Stella); D. Vaidya (Dhananjay); J. van der Grond (Jeroen); S.J. van der Lee (Sven); Van Der Meer, D. (Dennis); M.M.J. Van Donkelaar (Marjolein M. J.); K.R. van Eijk (Kristel); T.G.M. van Erp (Theo G.); Van Rooij, D. (Daan); E. Walton (Esther); L.T. Westlye (Lars); C.D. Whelan (Christopher); B.G. Windham (B Gwen); A.M. Winkler (Anderson); K. Wittfeld (Katharina); G. Woldehawariat (Girma); A. Björnsson (Asgeir); Wolfers, T. (Thomas); L.R. Yanek (Lisa); Yang, J. (Jingyun); A.P. Zijdenbos; M.P. Zwiers (Marcel); I. Agartz (Ingrid); L. Almasy (Laura); D.J. Ames (David); Amouyel, P. (Philippe); O.A. Andreassen (Ole); S. Arepalli (Sampath); A.A. Assareh; S. Barral (Sandra); M.E. Bastin (Mark); Becker, D.M. (Diane M.); J.T. Becker (James); D.A. Bennett (David A.); J. Blangero (John); H. van Bokhoven (Hans); D.I. Boomsma (Dorret); H. Brodaty (Henry); R.M. Brouwer (Rachel); H.G. Brunner; M. Buckner; J.K. Buitelaar (Jan); K. Bulayeva (Kazima); W. Cahn (Wiepke); V.D. Calhoun Vince D. (V.); D.M. Cannon (Dara); G. Cavalleri (Gianpiero); Cheng, C.-Y. (Ching-Yu); S. Cichon (Sven); M.R. Cookson (Mark); A. Corvin (Aiden); B. Crespo-Facorro (Benedicto); J.E. Curran (Joanne); M. Czisch (Michael); A.M. Dale (Anders); G.E. Davies (Gareth); A.J. de Craen (Anton); E.J.C. de Geus (Eco); P.L. de Jager (Philip); G.I. de Zubicaray (Greig); I.J. Deary (Ian J.); S. Debette (Stéphanie); C. DeCarli (Charles); N. Delanty; C. Depondt (Chantal); A.L. DeStefano (Anita); A. Dillman (Allissa); S. Djurovic (Srdjan); D.J. Donohoe (Dennis); D.A. Drevets (Douglas); Duggirala, R. (Ravi); M.D. Dyer (Matthew); C. Enzinger (Christian); S. Erk; T. Espeseth (Thomas); Fedko, I.O. (Iryna O.); Fernández, G. (Guillén); L. Ferrucci (Luigi); S.E. Fisher (Simon); D. Fleischman (Debra); I. Ford (Ian); M. Fornage (Myriam); T. Foroud (Tatiana); P.T. Fox (Peter); C. Francks (Clyde); Fukunaga, M. (Masaki); Gibbs, J.R. (J. Raphael); D.C. Glahn (David); R.L. Gollub (Randy); H.H.H. Göring (Harald H.); R.C. Green (Robert C.); O. Gruber (Oliver); V. Gudnason (Vilmundur); S. Guelfi (Sebastian); Håberg, A.K. (Asta K.); N.K. Hansell (Narelle); J. Hardy (John); C.A. Hartman (C.); Hashimoto, R. (Ryota); K. Hegenscheid (Katrin); J. Heinz (Judith); S. Le Hellard (Stephanie); D.G. Hernandez (Dena); D.J. Heslenfeld (Dirk); Ho, B.-C. (Beng-Choon); P.J. Hoekstra (Pieter); W. Hoffmann (Wolfgang); A. Hofman (Albert); F. Holsboer (Florian); G. Homuth (Georg); N. Hosten (Norbert); J.J. Hottenga (Jouke Jan); M.J. Huentelman (Matthew); H.H. Pol; Ikeda, M. (Masashi); Jack, C.R. (Clifford R.); S. Jenkinson (Sarah); R. Johnson (Robert); Jönsson, E.G. (Erik G.); J.W. Jukema; R. Kahn (René); Kanai, R. (Ryota); I. Kloszewska (Iwona); Knopman, D.S. (David S.); P. Kochunov (Peter); Kwok, J.B. (John B.); S. Lawrie (Stephen); H. Lemaître (Herve); X. Liu (Xinmin); D.L. Longo (Dan L.); O.L. Lopez (Oscar L.); S. Lovestone (Simon); Martinez, O. (Oliver); J.-L. Martinot (Jean-Luc); V.S. Mattay (Venkata S.); McDonald, C. (Colm); A.M. McIntosh (Andrew); McMahon, F.J. (Francis J.); McMahon, K.L. (Katie L.); P. Mecocci (Patrizia); I. Melle (Ingrid); Meyer-Lindenberg, A. (Andreas); S. Mohnke (Sebastian); Montgomery, G.W. (Grant W.); D.W. Morris (Derek W); T.H. Mosley (Thomas H.); T.W. Mühleisen (Thomas); B. Müller-Myhsok (B.); M.A. Nalls (Michael); M. Nauck (Matthias); T.E. Nichols (Thomas); W.J. Niessen (Wiro); M.M. Nöthen (Markus); L. Nyberg (Lars); Ohi, K. (Kazutaka); R.L. Olvera (Rene); R.A. Ophoff (Roel); M. Pandolfo (Massimo); T. Paus (Tomas); Z. Pausova (Zdenka); B.W.J.H. Penninx (Brenda); Pike, G.B. (G. Bruce); S.G. Potkin (Steven); B.M. Psaty (Bruce); S. Reppermund; M. Rietschel (Marcella); J.L. Roffman (Joshua); N. Seiferth (Nina); J.I. Rotter (Jerome I.); M. Ryten (Mina); Sacco, R.L. (Ralph L.); P.S. Sachdev (Perminder); A.J. Saykin (Andrew); R. Schmidt (Reinhold); Schmidt, H. (Helena); C.J. Schofield (Christopher); Sigursson, S. (Sigurdur); Simmons, A. (Andrew); A. Singleton (Andrew); S.M. Sisodiya (Sanjay); Smith, C. (Colin); J.W. Smoller; H. Soininen (H.); V.M. Steen (Vidar); D.J. Stott (David J.); J. Sussmann (Jessika); A. Thalamuthu (Anbupalam); A.W. Toga (Arthur W.); B. Traynor (Bryan); J.C. Troncoso (Juan); M. Tsolaki (Magda); C. Tzourio (Christophe); A.G. Uitterlinden (André); Hernández, M.C.V. (Maria C. Valdés); M.P. van der Brug (Marcel); A. van der Lugt (Aad); N.J. van der Wee (Nic); N.E.M. van Haren (Neeltje E.); D. van 't Ent (Dennis); M.J.D. van Tol (Marie-José); B.N. Vardarajan (Badri); B. Vellas (Bruno); D.J. Veltman (Dick); H. Völzke (Henry); H.J. Walter (Henrik); J. Wardlaw (Joanna); A.M.J. Wassink (Annemarie); M.E. Weale (Michael); Weinberger, D.R. (Daniel R.); Weiner, M.W. (Michael W.); Wen, W. (Wei); E. Westman (Eric); T.J.H. White (Tonya); Wong, T.Y. (Tien Y.); Wright, C.B. (Clinton B.); R.H. Zielke (Ronald H.); A.B. Zonderman; N.G. Martin (Nicholas); C.M. van Duijn (Cornelia); M.J. Wright (Margaret); W.T. Longstreth Jr; G. Schumann (Gunter); H.J. Grabe (Hans Jörgen); B. Franke (Barbara); L.J. Launer (Lenore); S.E. Medland (Sarah Elizabeth); S. Seshadri (Sudha); P.M. Thompson (Paul); M.K. Ikram (Kamran)

    2017-01-01

    textabstractThe hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic

  15. Novel genetic loci associated with hippocampal volume

    NARCIS (Netherlands)

    Hibar, Derrek P.; Adams, Hieab H. H.; Jahanshad, Neda; Chauhan, Ganesh; Stein, Jason L.; Hofer, Edith; Renteria, Miguel E.; Bis, Joshua C.; Arias-Vasquez, Alejandro; Ikram, M. Kamran; Desrivières, Sylvane; Vernooij, Meike W.; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf; Andersson, Micael; Arfanakis, Konstantinos; Aribisala, Benjamin S.; Armstrong, Nicola J.; Athanasiu, Lavinia; Axelsson, Tomas; Beecham, Ashley H.; Beiser, Alexa; Bernard, Manon; Blanton, Susan H.; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brickman, Adam M.; Carmichael, Owen; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Chouraki, Vincent; Cuellar-Partida, Gabriel; Crivello, Fabrice; den Braber, Anouk; Doan, Nhat Trung; Ehrlich, Stefan; Giddaluru, Sudheer; Goldman, Aaron L.; Gottesman, Rebecca F.; Grimm, Oliver; Griswold, Michael E.; Guadalupe, Tulio; Gutman, Boris A.; Hass, Johanna; Haukvik, Unn K.; Hoehn, David; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Jørgensen, Kjetil N.; Karbalai, Nazanin; Kasperaviciute, Dalia; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Liewald, David C. M.; Lopez, Lorna M.; Luciano, Michelle; Macare, Christine; Marquand, Andre F.; Matarin, Mar; Mather, Karen A.; Mattheisen, Manuel; McKay, David R.; Milaneschi, Yuri; Muñoz Maniega, Susana; Nho, Kwangsik; Nugent, Allison C.; Nyquist, Paul; Loohuis, Loes M. Olde; Oosterlaan, Jaap; Papmeyer, Martina; Pirpamer, Lukas; Pütz, Benno; Ramasamy, Adaikalavan; Richards, Jennifer S.; Risacher, Shannon L.; Roiz-Santiañez, Roberto; Rommelse, Nanda; Ropele, Stefan; Rose, Emma J.; Royle, Natalie A.; Rundek, Tatjana; Sämann, Philipp G.; Saremi, Arvin; Satizabal, Claudia L.; Schmaal, Lianne; Schork, Andrew J.; Shen, Li; Shin, Jean; Shumskaya, Elena; Smith, Albert V.; Sprooten, Emma; Strike, Lachlan T.; Teumer, Alexander; Tordesillas-Gutierrez, Diana; Toro, Roberto; Trabzuni, Daniah; Trompet, Stella; Vaidya, Dhananjay; van der Grond, Jeroen; van der Lee, Sven J.; van der Meer, Dennis; van Donkelaar, Marjolein M. J.; van Eijk, Kristel R.; van Erp, Theo G. M.; van Rooij, Daan; Walton, Esther; Westlye, Lars T.; Whelan, Christopher D.; Windham, Beverly G.; Winkler, Anderson M.; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Wolfers, Thomas; Yanek, Lisa R.; Yang, Jingyun; Zijdenbos, Alex; Zwiers, Marcel P.; Agartz, Ingrid; Almasy, Laura; Ames, David; Amouyel, Philippe; Andreassen, Ole A.; Arepalli, Sampath; Assareh, Amelia A.; Barral, Sandra; Bastin, Mark E.; Becker, Diane M.; Becker, James T.; Bennett, David A.; Blangero, John; van Bokhoven, Hans; Boomsma, Dorret I.; Brodaty, Henry; Brouwer, Rachel M.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Bulayeva, Kazima B.; Cahn, Wiepke; Calhoun, Vince D.; Cannon, Dara M.; Cavalleri, Gianpiero L.; Cheng, Ching-Yu; Cichon, Sven; Cookson, Mark R.; Corvin, Aiden; Crespo-Facorro, Benedicto; Curran, Joanne E.; Czisch, Michael; Dale, Anders M.; Davies, Gareth E.; de Craen, Anton J. M.; de Geus, Eco J. C.; de Jager, Philip L.; de Zubicaray, Greig I.; Deary, Ian J.; Debette, Stéphanie; Decarli, Charles; Delanty, Norman; Depondt, Chantal; DeStefano, Anita; Dillman, Allissa; Djurovic, Srdjan; Donohoe, Gary; Drevets, Wayne C.; Duggirala, Ravi; Dyer, Thomas D.; Enzinger, Christian; Erk, Susanne; Espeseth, Thomas; Fedko, Iryna O.; Fernández, Guillén; Ferrucci, Luigi; Fisher, Simon E.; Fleischman, Debra A.; Ford, Ian; Fornage, Myriam; Foroud, Tatiana M.; Fox, Peter T.; Francks, Clyde; Fukunaga, Masaki; Gibbs, J. Raphael; Glahn, David C.; Gollub, Randy L.; Göring, Harald H. H.; Green, Robert C.; Gruber, Oliver; Gudnason, Vilmundur; Guelfi, Sebastian; Håberg, Asta K.; Hansell, Narelle K.; Hardy, John; Hartman, Catharina A.; Hashimoto, Ryota; Hegenscheid, Katrin; Heinz, Andreas; Le Hellard, Stephanie; Hernandez, Dena G.; Heslenfeld, Dirk J.; Ho, Beng-Choon; Hoekstra, Pieter J.; Hoffmann, Wolfgang; Hofman, Albert; Holsboer, Florian; Homuth, Georg; Hosten, Norbert; Hottenga, Jouke-Jan; Huentelman, Matthew; Pol, Hilleke E. Hulshoff; Ikeda, Masashi; Jack, Clifford R.; Jenkinson, Mark; Johnson, Robert; Jönsson, Erik G.; Jukema, J. Wouter; Kahn, René S.; Kanai, Ryota; Kloszewska, Iwona; Knopman, David S.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Lemaître, Hervé; Liu, Xinmin; Longo, Dan L.; Lopez, Oscar L.; Lovestone, Simon; Martinez, Oliver; Martinot, Jean-Luc; Mattay, Venkata S.; McDonald, Colm; McIntosh, Andrew M.; McMahon, Francis J.; McMahon, Katie L.; Mecocci, Patrizia; Melle, Ingrid; Meyer-Lindenberg, Andreas; Mohnke, Sebastian; Montgomery, Grant W.; Morris, Derek W.; Mosley, Thomas H.; Mühleisen, Thomas W.; Müller-Myhsok, Bertram; Nalls, Michael A.; Nauck, Matthias; Nichols, Thomas E.; Niessen, Wiro J.; Nöthen, Markus M.; Nyberg, Lars; Ohi, Kazutaka; Olvera, Rene L.; Ophoff, Roel A.; Pandolfo, Massimo; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W. J. H.; Pike, G. Bruce; Potkin, Steven G.; Psaty, Bruce M.; Reppermund, Simone; Rietschel, Marcella; Roffman, Joshua L.; Romanczuk-Seiferth, Nina; Rotter, Jerome I.; Ryten, Mina; Sacco, Ralph L.; Sachdev, Perminder S.; Saykin, Andrew J.; Schmidt, Reinhold; Schmidt, Helena; Schofield, Peter R.; Sigursson, Sigurdur; Simmons, Andrew; Singleton, Andrew; Sisodiya, Sanjay M.; Smith, Colin; Smoller, Jordan W.; Soininen, Hilkka; Steen, Vidar M.; Stott, David J.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Tsolaki, Magda; Tzourio, Christophe; Uitterlinden, Andre G.; Hernández, Maria C. Valdés; van der Brug, Marcel; van der Lugt, Aad; van der Wee, Nic J. A.; van Haren, Neeltje E. M.; van 't Ent, Dennis; van Tol, Marie-Jose; Vardarajan, Badri N.; Vellas, Bruno; Veltman, Dick J.; Völzke, Henry; Walter, Henrik; Wardlaw, Joanna M.; Wassink, Thomas H.; Weale, Michael E.; Weinberger, Daniel R.; Weiner, Michael W.; Wen, Wei; Westman, Eric; White, Tonya; Wong, Tien Y.; Wright, Clinton B.; Zielke, Ronald H.; Zonderman, Alan B.; Martin, Nicholas G.; van Duijn, Cornelia M.; Wright, Margaret J.; Longstreth, W. T.; Schumann, Gunter; Grabe, Hans J.; Franke, Barbara; Launer, Lenore J.; Medland, Sarah E.; Seshadri, Sudha; Thompson, Paul M.; Ikram, M. Arfan

    2017-01-01

    The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of

  16. Interactive Slice of the CMS detector

    CERN Multimedia

    Davis, Siona Ruth

    2016-01-01

    This slice shows a colorful cross-section of the CMS detector with all parts of the detector labelled. Viewers are invited to click on buttons associated with five types of particles to see what happens when each type interacts with the sections of the detector. The five types of particles users can select to send through the slice are muons, electrons, neutral hadrons, charged hadrons and photons. Supplementary information on each type of particles is given. Useful for inclusion into general talks on CMS etc. *Animated CMS "slice" for Powerpoint (Mac & PC) Original version - 2004 Updated version - July 2010 *Six slides required - first is a set of buttons; others are for each particle type (muon, electron, charged/neutral hadron, photon) Recommend putting slide 1 anywhere in your presentation and the rest at the end

  17. Midazolam inhibits hippocampal long-term potentiation and learning through dual central and peripheral benzodiazepine receptor activation and neurosteroidogenesis

    OpenAIRE

    Tokuda, Kazuhiro; O’Dell, Kazuko A.; Izumi, Yukitoshi; Zorumski, Charles F.

    2010-01-01

    Benzodiazepines (BDZs) enhance γ-aminobutyric acid-A (GABAA) receptor inhibition by direct actions on central BDZ receptors (CBRs). Although some BDZs also bind mitochondrial receptors (translocator protein 18kDa, TSPO) and promote the synthesis of GABA-enhancing neurosteroids, the role of neurosteroids in the clinical effects of BDZs is unknown. In rat hippocampal slices, we compared midazolam, an anesthetic BDZ with clonazepam, an anticonvulsant/anxiolytic BDZ that activates CBRs selectivel...

  18. Extracellular calcium controls the expression of two different forms of ripple-like hippocampal oscillations.

    Science.gov (United States)

    Aivar, Paloma; Valero, Manuel; Bellistri, Elisa; Menendez de la Prida, Liset

    2014-02-19

    Hippocampal high-frequency oscillations (HFOs) are prominent in physiological and pathological conditions. During physiological ripples (100-200 Hz), few pyramidal cells fire together coordinated by rhythmic inhibitory potentials. In the epileptic hippocampus, fast ripples (>200 Hz) reflect population spikes (PSs) from clusters of bursting cells, but HFOs in the ripple and the fast ripple range are vastly intermixed. What is the meaning of this frequency range? What determines the expression of different HFOs? Here, we used different concentrations of Ca(2+) in a physiological range (1-3 mM) to record local field potentials and single cells in hippocampal slices from normal rats. Surprisingly, we found that this sole manipulation results in the emergence of two forms of HFOs reminiscent of ripples and fast ripples recorded in vivo from normal and epileptic rats, respectively. We scrutinized the cellular correlates and mechanisms underlying the emergence of these two forms of HFOs by combining multisite, single-cell and paired-cell recordings in slices prepared from a rat reporter line that facilitates identification of GABAergic cells. We found a major effect of extracellular Ca(2+) in modulating intrinsic excitability and disynaptic inhibition, two critical factors shaping network dynamics. Moreover, locally modulating the extracellular Ca(2+) concentration in an in vivo environment had a similar effect on disynaptic inhibition, pyramidal cell excitability, and ripple dynamics. Therefore, the HFO frequency band reflects a range of firing dynamics of hippocampal networks.

  19. Novel genetic loci associated with hippocampal volume

    OpenAIRE

    Hibar, Derrek P.; Adams, Hieab H. H.; Jahanshad, Neda; Chauhan, Ganesh; Stein, Jason L.; Hofer, Edith; Renteria, Miguel E.; Bis, Joshua C.; Arias-Vasquez, Alejandro; Ikram, M. Kamran; Desrivieres, Sylvane; Vernooij, Meike W.; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf

    2017-01-01

    International audience; The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal ...

  20. High-resolution multi-slice PET

    International Nuclear Information System (INIS)

    Yasillo, N.J.; Chintu Chen; Ordonez, C.E.; Kapp, O.H.; Sosnowski, J.; Beck, R.N.

    1992-01-01

    This report evaluates the progress to test the feasibility and to initiate the design of a high resolution multi-slice PET system. The following specific areas were evaluated: detector development and testing; electronics configuration and design; mechanical design; and system simulation. The design and construction of a multiple-slice, high-resolution positron tomograph will provide substantial improvements in the accuracy and reproducibility of measurements of the distribution of activity concentrations in the brain. The range of functional brain research and our understanding of local brain function will be greatly extended when the development of this instrumentation is completed

  1. Introduction to bit slices and microprogramming

    International Nuclear Information System (INIS)

    Van Dam, A.

    1981-01-01

    Bit-slice logic blocks are fourth-generation LSI components which are natural extensions of traditional mulitplexers, registers, decoders, counters, ALUs, etc. Their functionality is controlled by microprogramming, typically to implement CPUs and peripheral controllers where both speed and easy programmability are required for flexibility, ease of implementation and debugging, etc. Processors built from bit-slice logic give the designer an alternative for approaching the programmibility of traditional fixed-instruction-set microprocessors with a speed closer to that of hardwired random logic. (orig.)

  2. Slice through an LHC bending magnet

    CERN Multimedia

    Slice through an LHC superconducting dipole (bending) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. There are 1232 15m long dipole magnets in the LHC.

  3. The effects of slice thickness and reconstructive parameters on VR image quality in multi-slice CT

    International Nuclear Information System (INIS)

    Gao Zhenlong; Wang Qiang; Liu Caixia

    2005-01-01

    Objective: To explore the effects of slice thickness, reconstructive thickness and reconstructive interval on VR image quality in multi-slice CT, in order to select the best slice thickness and reconstructive parameters for the imaging. Methods: Multi-slice CT scan was applied on a rubber dinosaur model with different slice thickness. VR images were reconstructed with different reconstructive thickness and reconstructive interval. Five radiologists were invited to evaluate the quality of the images without knowing anything about the parameters. Results: The slice thickness, reconstructive thickness and reconstructive interval did have effects on VR image quality and the effective degree was different. The effective coefficients were V 1 =1413.033, V 2 =563.733, V 3 =390.533, respectively. The parameters interacted with the others (P<0.05). The smaller of those parameters, the better of the image quality. With a small slice thickness and a reconstructive slice equal to slice thickness, the image quality had no obvious difference when the reconstructive interval was 1/2, 1/3, 1/4 of the slice thickness. Conclusion: A relative small scan slice thickness, a reconstructive slice equal to slice thickness and a reconstructive interval 1/2 of the slice thickness should be selected for the best VR image quality. The image quality depends mostly on the slice thickness. (authors)

  4. Ripple artifact reduction using slice overlap in slice encoding for metal artifact correction.

    Science.gov (United States)

    den Harder, J Chiel; van Yperen, Gert H; Blume, Ulrike A; Bos, Clemens

    2015-01-01

    Multispectral imaging (MSI) significantly reduces metal artifacts. Yet, especially in techniques that use gradient selection, such as slice encoding for metal artifact correction (SEMAC), a residual ripple artifact may be prominent. Here, an analysis is presented of the ripple artifact and of slice overlap as an approach to reduce the artifact. The ripple artifact was analyzed theoretically to clarify its cause. Slice overlap, conceptually similar to spectral bin overlap in multi-acquisition with variable resonances image combination (MAVRIC), was achieved by reducing the selection gradient and, thus, increasing the slice profile width. Time domain simulations and phantom experiments were performed to validate the analyses and proposed solution. Discontinuities between slices are aggravated by signal displacement in the frequency encoding direction in areas with deviating B0. Specifically, it was demonstrated that ripple artifacts appear only where B0 varies both in-plane and through-plane. Simulations and phantom studies of metal implants confirmed the efficacy of slice overlap to reduce the artifact. The ripple artifact is an important limitation of gradient selection based MSI techniques, and can be understood using the presented simulations. At a scan-time penalty, slice overlap effectively addressed the artifact, thereby improving image quality near metal implants. © 2014 Wiley Periodicals, Inc.

  5. Oral administration of fisetin promotes the induction of hippocampal long-term potentiation in vivo.

    Science.gov (United States)

    He, Wen-Bin; Abe, Kazuho; Akaishi, Tatsuhiro

    2018-01-01

    To explore memory enhancing effect of the flavonoid fisetin, we investigated the effect of oral administration of flavonoids on the induction of long-term potentiation (LTP) at hippocampal CA1 synapses of anesthetized rats. Among four flavonoids (fisetin, quercetin, luteolin and myricetin) tested, only fisetin significantly facilitated the induction of hippocampal LTP. The effect of oral fisetin was abolished by intracerebroventricular injection of U0126, an agent that was previously found to inhibit its effect in hippocampal slices in vitro. These results suggest that orally administered fisetin crosses the blood-brain barrier and promotes synaptic functions in the hippocampus. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  6. Hippocampal Sclerosis in Older Patients

    Science.gov (United States)

    Cykowski, Matthew D.; Powell, Suzanne Z.; Schulz, Paul E.; Takei, Hidehiro; Rivera, Andreana L.; Jackson, Robert E.; Roman, Gustavo; Jicha, Gregory A.; Nelson, Peter T.

    2018-01-01

    Context Autopsy studies of the older population (≥65 years of age), and particularly of the “oldest-old” (≥85 years of age), have identified a significant proportion (~20%) of cognitively impaired patients in which hippocampal sclerosis is the major substrate of an amnestic syndrome. Hippocampal sclerosis may also be comorbid with frontotemporal lobar degeneration, Alzheimer disease, and Lewy body disease. Until recently, the terms hippocampal sclerosis of aging or hippocampal sclerosis dementia were applied in this context. Recent discoveries have prompted a conceptual expansion of hippocampal sclerosis of aging because (1) cellular inclusions of TAR DNA-binding protein 43 kDa (TDP-43) are frequent; (2) TDP-43 pathology may be found outside hippocampus; and (3) brain arteriolosclerosis is a common, possibly pathogenic, component. Objective To aid pathologists with recent recommendations for diagnoses of common neuropathologies in older persons, particularly hippocampal sclerosis, and highlight the recent shift in diagnostic terminology from HS-aging to cerebral age-related TDP-43 with sclerosis (CARTS). Data Sources Peer-reviewed literature and 5 autopsy examples that illustrate common age-related neuropathologies, including CARTS, and emphasize the importance of distinguishing CARTS from late-onset frontotemporal lobar degeneration with TDP-43 pathology and from advanced Alzheimer disease with TDP-43 pathology. Conclusions In advanced old age, the substrates of cognitive impairment are often multifactorial. This article demonstrates common and frequently comorbid neuropathologic substrates of cognitive impairment in the older population, including CARTS, to aid those practicing in this area of pathology. PMID:28467211

  7. Effects of Temperature and Slice Thickness on Drying Kinetics of Pumpkin Slices

    OpenAIRE

    Kongdej LIMPAIBOON

    2011-01-01

    Dried pumpkin slice is an alternative crisp food product. In this study, the effects of temperature and slice thickness on the drying characteristics of pumpkin were studied in a lab-scale tray dryer, using hot air temperatures of 55, 60 and 65 °C and 2, 3 and 4 mm slice thickness at a constant air velocity of 1.5 m/s. The initial moisture content of the pumpkin samples was 900.5 % (wb). The drying process was carried out until the final moisture content of product was 100.5 % (wb). The resul...

  8. Serum vitamin D and hippocampal gray matter volume in schizophrenia.

    Science.gov (United States)

    Shivakumar, Venkataram; Kalmady, Sunil V; Amaresha, Anekal C; Jose, Dania; Narayanaswamy, Janardhanan C; Agarwal, Sri Mahavir; Joseph, Boban; Venkatasubramanian, Ganesan; Ravi, Vasanthapuram; Keshavan, Matcheri S; Gangadhar, Bangalore N

    2015-08-30

    Disparate lines of evidence including epidemiological and case-control studies have increasingly implicated vitamin D in the pathogenesis of schizophrenia. Vitamin D deficiency can lead to dysfunction of the hippocampus--a brain region hypothesized to be critically involved in schizophrenia. In this study, we examined for potential association between serum vitamin D level and hippocampal gray matter volume in antipsychotic-naïve or antipsychotic-free schizophrenia patients (n = 35). Serum vitamin D level was estimated using 25-OH vitamin D immunoassay. Optimized voxel-based morphometry was used to analyze 3-Tesla magnetic resonance imaging (MRI) (1-mm slice thickness). Ninety-seven percent of the schizophrenia patients (n = 34) had sub-optimal levels of serum vitamin D (83%, deficiency; 14%, insufficiency). A significant positive correlation was seen between vitamin D and regional gray matter volume in the right hippocampus after controlling for age, years of education and total intracranial volume (Montreal Neurological Institute (MNI) coordinates: x = 35, y = -18, z = -8; t = 4.34 pFWE(Corrected) = 0.018). These observations support a potential role of vitamin D deficiency in mediating hippocampal volume deficits, possibly through neurotrophic, neuroimmunomodulatory and glutamatergic effects. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Transient extracellular application of gold nanostars increases hippocampal neuronal activity.

    Science.gov (United States)

    Salinas, Kirstie; Kereselidze, Zurab; DeLuna, Frank; Peralta, Xomalin G; Santamaria, Fidel

    2014-08-20

    With the increased use of nanoparticles in biomedical applications there is a growing need to understand the effects that nanoparticles may have on cell function. Identifying these effects and understanding the mechanism through which nanoparticles interfere with the normal functioning of a cell is necessary for any therapeutic or diagnostic application. The aim of this study is to evaluate if gold nanoparticles can affect the normal function of neurons, namely their activity and coding properties. We synthesized star shaped gold nanoparticles of 180 nm average size. We applied the nanoparticles to acute mouse hippocampal slices while recording the action potentials from single neurons in the CA3 region. Our results show that CA3 hippocampal neurons increase their firing rate by 17% after the application of gold nanostars. The increase in excitability lasted for as much as 50 minutes after a transient 5 min application of the nanoparticles. Further analyses of the action potential shape and computational modeling suggest that nanoparticles block potassium channels responsible for the repolarization of the action potentials, thus allowing the cell to increase its firing rate. Our results show that gold nanoparticles can affect the coding properties of neurons by modifying their excitability.

  10. Thin-Slice Perception Develops Slowly

    Science.gov (United States)

    Balas, Benjamin; Kanwisher, Nancy; Saxe, Rebecca

    2012-01-01

    Body language and facial gesture provide sufficient visual information to support high-level social inferences from "thin slices" of behavior. Given short movies of nonverbal behavior, adults make reliable judgments in a large number of tasks. Here we find that the high precision of adults' nonverbal social perception depends on the slow…

  11. Adaptive slices for acquisition of anisotropic BRDF

    Czech Academy of Sciences Publication Activity Database

    Vávra, Radomír; Filip, Jiří

    (2018) ISSN 2096-0433 R&D Projects: GA ČR GA17-18407S Institutional support: RVO:67985556 Keywords : anisotropic BRDF * slice * sampling Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2018/RO/vavra-0486116.pdf

  12. Detecting Psychopathy from Thin Slices of Behavior

    Science.gov (United States)

    Fowler, Katherine A.; Lilienfeld, Scott O.; Patrick, Christopher J.

    2009-01-01

    This study is the first to demonstrate that features of psychopathy can be reliably and validly detected by lay raters from "thin slices" (i.e., small samples) of behavior. Brief excerpts (5 s, 10 s, and 20 s) from interviews with 96 maximum-security inmates were presented in video or audio form or in both modalities combined. Forty raters used…

  13. Induction of Endothelial Phenotype From Wharton's Jelly-Derived MSCs and Comparison of Their Vasoprotective and Neuroprotective Potential With Primary WJ-MSCs in CA1 Hippocampal Region Ex Vivo.

    Science.gov (United States)

    Obtulowicz, Patrycja; Lech, Wioletta; Strojek, Lukasz; Sarnowska, Anna; Domanska-Janik, Krystyna

    2016-01-01

    Ischemic stroke results in violent impairment of tissue homeostasis leading to severe perturbation within the neurovascular unit (NVU) during the recovery period. The aim of this study was to assess the potential of mesenchymal stem cells (MSCs) originating from Wharton's jelly (WJ) to differentiate into functionally competent cells of endothelial lineage (WJ-EPCs). The protective effect(s) of either primary WJ-MSCs or induced WJ-EPCs was investigated and compared after oxygen-glucose deprivation (OGD) of hippocampal organotypic slices (OHC) in the indirect coculture model. WJ-MSCs, primed in EGM-2 (Lonza commercial medium) under 5% O2, acquired cobblestone endothelial-like morphology, formed capillary-like structures and actively took up DiI-Ac-LDL. Both cell types (WJ-MSCs and WJ-EPCs) were positive for CD73, CD90, CD105, VEGFR-2, and VEGF, but only endothelial-like culture expressed vWF and PECAM-1 markers at significant levels. In the presence of either WJ-MSCs or WJ-EPCs in the compartment below OGD-injured slices, cell death and vascular atrophy in the hypoxia-sensitive CA1 region were substantially decreased. This suggests that a paracrine mechanism may mediate WJ-MSC- and WJ-EPC-dependent protection. Thus, finally, we estimated secretion of the neuro/angio/immunomodulatory molecules IL-6, TGF-β1, and VEGF by these cell cultures. We have found that release of TGF-β1 and IL-6 was TLR ligand [LPS and Poly(I:C)] concentration dependent and stronger in WJ-EPC than WJ-MSC cultures. Simultaneously, the uneven pattern of TLR receptors and modulatory cytokine gene expression was confirmed also on qRT-PCR level, but no significant differences were noticed between WJ-EPC and primary WJ-MSC cultures.

  14. Anoxia increases potassium conductance in hippocampal nerve cells.

    Science.gov (United States)

    Hansen, A J; Hounsgaard, J; Jahnsen, H

    1982-07-01

    The effect of anoxia on nerve cell function was studied by intra- and extracellular microelectrode recordings from the CA1 and CA3 region in guinea pig hippocampal slices. Hyperpolarization and concomitant reduction of the nerve cell input resistance was observed early during anoxia. During this period the spontaneous activity first disappeared, then the evoked activity gradually disappeared. The hyperpolarization was followed by depolarization and an absence of a measurable input resistance. All the induced changes were reversed when the slice was reoxygenated. Reversal of the electro-chemical gradient for Cl- across the nerve cell membrane did not affect the course of events during anoxia. Aminopyridines blocked the anoxic hyperpolarization and attenuated the decrease of membrane resistance, but had no effect on the later depolarization. Blockers of synaptic transmission. Mn++, Mg++ and of Na+-channels (TTX) were without effect on the nerve cell changes during anoxia. It is suggested that the reduction of nerve cell excitability in anoxia is primarily due to increased K+-conductance. Thus, the nerve cells are hyperpolarized and the input resistance reduced, causing higher threshold and reduction of synaptic potentials. The mechanism of the K+-conductance activation is unknown at present.

  15. Comparison of Hippocampal Volume in Dementia Subtypes

    International Nuclear Information System (INIS)

    Vijayakumar, Avinash; Vijayakumar, Abhishek

    2012-01-01

    Aims. To examine the relationship between different types of dementia and hippocampal volume. Methods. Hippocampal volume was measured using FL3D sequence magnetic resonance imaging in 26 Alzheimer's, vascular dementia, mixed dementia, and normal pressure hydrocephalus patients and 15 healthy controls and also hippocampal ratio, analyzed. Minimental scale was used to stratify patients on cognitive function impairments. Results. Hippocampal volume and ratio was reduced by 25% in Alzheimer's disease, 21% in mixed dementia, 11% in vascular dementia and 5% in normal pressure hydrocephalus in comparison to control. Also an asymmetrical decrease in volume of left hippocampus was noted. The severity of dementia increased in accordance to decreasing hippocampal volume. Conclusion. Measurement in hippocampal volume may facilitate in differentiating different types of dementia and in disease progression. There was a correlation between hippocampal volume and severity of cognitive impairment

  16. Tetramethylpyrazine suppresses transient oxygen-glucose deprivation-induced connexin32 expression and cell apoptosis via the ERK1/2 and p38 MAPK pathway in cultured hippocampal neurons.

    Science.gov (United States)

    Gong, Gu; Yuan, Libang; Cai, Lin; Ran, Maorong; Zhang, Yulan; Gong, Huaqu; Dai, Xuemei; Wu, Wei; Dong, Hailong

    2014-01-01

    Tetramethylpyrazine (TMP) has been widely used in China as a drug for the treatment of various diseases. Recent studies have suggested that TMP has a protective effect on ischemic neuronal damage. However, the exact mechanism is still unclear. This study aims to investigate the mechanism of TMP mediated ischemic hippocampal neurons injury induced by oxygen-glucose deprivation (OGD). The effect of TMP on hippocampal neurons viability was detected by MTT assay, LDH release assay and apoptosis rate was measured by flow cytometry. TMP significantly suppressed neuron apoptosis in a concentration-dependent manner. TMP could significantly reduce the elevated levels of connexin32 (Cx32) induced by OGD. Knockdown of Cx32 by siRNA attenuated OGD injury. Moreover, our study showed that viability was increased in siRNA-Cx32-treated-neurons, and neuron apoptosis was suppressed by activating Bcl-2 expression and inhibiting Bax expression. Over expression of Cx32 could decrease neurons viability and increase LDH release. Furthermore, OGD increased phosphorylation of ERK1/2 and p38, whose inhibitors relieved the neuron injury and Cx32 up-regulation. Taken together, TMP can reverse the OGD-induced Cx32 expression and cell apoptosis via the ERK1/2 and p38 MAPK pathways.

  17. Tetramethylpyrazine suppresses transient oxygen-glucose deprivation-induced connexin32 expression and cell apoptosis via the ERK1/2 and p38 MAPK pathway in cultured hippocampal neurons.

    Directory of Open Access Journals (Sweden)

    Gu Gong

    Full Text Available Tetramethylpyrazine (TMP has been widely used in China as a drug for the treatment of various diseases. Recent studies have suggested that TMP has a protective effect on ischemic neuronal damage. However, the exact mechanism is still unclear. This study aims to investigate the mechanism of TMP mediated ischemic hippocampal neurons injury induced by oxygen-glucose deprivation (OGD. The effect of TMP on hippocampal neurons viability was detected by MTT assay, LDH release assay and apoptosis rate was measured by flow cytometry. TMP significantly suppressed neuron apoptosis in a concentration-dependent manner. TMP could significantly reduce the elevated levels of connexin32 (Cx32 induced by OGD. Knockdown of Cx32 by siRNA attenuated OGD injury. Moreover, our study showed that viability was increased in siRNA-Cx32-treated-neurons, and neuron apoptosis was suppressed by activating Bcl-2 expression and inhibiting Bax expression. Over expression of Cx32 could decrease neurons viability and increase LDH release. Furthermore, OGD increased phosphorylation of ERK1/2 and p38, whose inhibitors relieved the neuron injury and Cx32 up-regulation. Taken together, TMP can reverse the OGD-induced Cx32 expression and cell apoptosis via the ERK1/2 and p38 MAPK pathways.

  18. Hippocampal Abnormalities and Seizure Recurrence

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-08-01

    Full Text Available Hippocampal volumetry and T2 relaxometry were performed on 84 consecutive patients (adolescents and adults with partial epilepsy submitted to antiepileptic drug (AED withdrawal after at least 2 years of seizure control, in a study at State University of Campinas-UNICAMP, Brazil.

  19. Inhibitory neuron and hippocampal circuit dysfunction in an aged mouse model of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Anupam Hazra

    Full Text Available In Alzheimer's disease (AD, a decline in explicit memory is one of the earliest signs of disease and is associated with hippocampal dysfunction. Amyloid protein exerts a disruptive impact on neuronal function, but the specific effects on hippocampal network activity are not well known. In this study, fast voltage-sensitive dye imaging and extracellular and whole-cell electrophysiology were used on entorhinal cortical-hippocampal slice preparations to characterize hippocampal network activity in 12-16 month old female APPswe/PSEN1DeltaE9 (APdE9 mice mice. Aged APdE9 mice exhibited profound disruptions in dentate gyrus circuit activation. High frequency stimulation of the perforant pathway in the dentate gyrus (DG area of APdE9 mouse tissue evoked abnormally large field potential responses corresponding to the wider neural activation maps. Whole-cell patch clamp recordings of the identified inhibitory interneurons in the molecular layer of DG revealed that they fail to reliably fire action potentials. Taken together, abnormal DG excitability and an inhibitory neuron failure to generate action potentials are suggested to be important contributors to the underlying cellular mechanisms of early-stage Alzheimer's disease pathophysiology.

  20. A brain slice bath for physiology and compound microscopy, with dual-sided perifusion.

    Science.gov (United States)

    Heyward, P M

    2010-12-01

    Contemporary in vitro brain slice studies can employ compound microscopes to identify individual neurons or their processes for physiological recording or imaging. This requires that the bath used to maintain the tissue fits within the working distances of a water-dipping objective and microscope condenser. A common means of achieving this is to maintain thin tissue slices on the glass floor of a recording bath, exposing only one surface of the tissue to oxygenated bathing medium. Emerging evidence suggests that physiology can be compromised by this approach. Flowing medium past both sides of submerged brain slices is optimal, but recording baths utilizing this principle are not readily available for use on compound microscopes. This paper describes a tissue bath designed specifically for microscopy and physiological recording, in which temperature-controlled medium flows past both sides of the slices. A particular feature of this design is the use of concentric mesh rings to support and transport the live tissue without mechanical disturbance. The design is also easily adapted for use with thin acute slices, cultured slices, and acutely dispersed or cultured cells maintained either on cover slips or placed directly on the floor of the bath. The low profile of the bath provides a low angle of approach for electrodes, and allows use of standard condensers, nosepieces and water-dipping objective lenses. If visualization of individual neurons is not required, the bath can be mounted on a simple stand and used with a dissecting microscope. Heating is integral to the bath, and any temperature controller capable of driving a resistive load can be used. The bath is robust, readily constructed and requires minimal maintenance. Full construction and operation details are given. © 2010 The Author Journal of Microscopy © 2010 The Royal Microscopical Society.

  1. High-Frequency Stimulation-Induced Synaptic Potentiation in Dorsal and Ventral CA1 Hippocampal Synapses: The Involvement of NMDA Receptors, mGluR5, and (L-Type) Voltage-Gated Calcium Channels

    Science.gov (United States)

    Papatheodoropoulos, Costas; Kouvaros, Stylianos

    2016-01-01

    The ability of the ventral hippocampus (VH) for long-lasting long-term potentiation (LTP) and the mechanisms underlying its lower ability for shortlasting LTP compared with the dorsal hippocampus (DH) are unknown. Using recordings of field excitatory postsynaptic potentials (EPSPs) from the CA1 field of adult rat hippocampal slices, we found that…

  2. Development of a bread slicing machine from locally sourced ...

    African Journals Online (AJOL)

    This paper presents the development of a bread slicing machine which is a mechanical device that is used for slicing bread instead of the crude cumbersome and unhygienic method of manual slicing of bread. In an attempt to facilitate the final processing of bread which is a common daily food requirement of most Nigerians ...

  3. Slice through an LHC focusing magnet

    CERN Multimedia

    Slice through an LHC superconducting quadrupole (focusing) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. Bringing beams into collision requires a precision comparable to making two knitting needles collide, launched from either side of the Atlantic Ocean.

  4. Velocity slice imaging for dissociative electron attachment

    Science.gov (United States)

    Nandi, Dhananjay; Prabhudesai, Vaibhav S.; Krishnakumar, E.; Chatterjee, A.

    2005-05-01

    A velocity slice imaging method is developed for measuring the angular distribution of fragment negative ions arising from dissociative electron attachment (DEA) to molecules. A low energy pulsed electron gun, a pulsed field ion extraction, and a two-dimensional position sensitive detector consisting of microchannel plates and a wedge-and-strip anode are used for this purpose. Detection and storage of each ion separately for its position and flight time allows analysis of the data offline for any given time slice, without resorting to pulsing the detector bias. The performance of the system is evaluated by measuring the angular distribution of O- from O2 and comparing it with existing data obtained using conventional technique. The capability of this technique in obtaining forward and backward angular distribution data is shown to have helped in resolving one of the existing problems in the electron scattering on O2.

  5. Preliminary Study of Realistic Blast Impact on Cultured Brain Slices

    Science.gov (United States)

    2015-04-01

    Duhaime A, Bullock R, Maas A, Valadka A, Manley G. Classification of traumatic brain injury for targeted therapies. J Neurotrauma. 2008;25:719–738...RDRL CIO LL IMAL HRA MAIL & RECORDS MGMT 1 GOVT PRINTG OFC (PDF) A MALHOTRA 6 DIR USARL (PDF) RDRL WML C S AUBERT R BENJAMIN

  6. Tumor Slice Culture: A New Avatar in Personalized Oncology

    Science.gov (United States)

    2017-08-01

    Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden...Achilles heel of personalized oncology. The objective of this proposal is to establish a robust, efficient, reproducible platform to interrogate drug...establish a robust, efficient, reproducible platform to interrogate the response of a given tumor to drugs (cytotoxics, kinase inhibitors, immune

  7. Spontaneous calcium waves in granule cells in cerebellar slice cultures

    DEFF Research Database (Denmark)

    Apuschkin, Mia; Ougaard, Maria; Rekling, Jens C

    2013-01-01

    Multiple regions in the CNS display propagating correlated activity during embryonic and postnatal development. This activity can be recorded as waves of increased calcium concentrations in spiking neurons or glia cells, and have been suggested to be involved in patterning, axonal guidance and es......, that the propagating wave activity is carried through the tissue by axonal collaterals formed by neighboring granule cells, and further suggest that the correlated activity may be related to processes that ensure correct postnatal wiring of the cerebellar circuits....

  8. A Novel Slicing Method for Thin Supercapacitors.

    Science.gov (United States)

    Sun, Hao; Fu, Xuemei; Xie, Songlin; Jiang, Yishu; Guan, Guozhen; Wang, Bingjie; Li, Houpu; Peng, Huisheng

    2016-08-01

    Thin and flexible supercapacitors with low cost and individual variation are fabricated by a new and efficient slicing method. Tunable output voltage and energy can be realized with a high specific capacitance of 248.8 F g(-1) or 150.8 F cm(-3) , which is well maintained before and after bending. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Slice of a LEP bending magnet

    CERN Multimedia

    This is a slice of a LEP dipole bending magnet, made as a concrete and iron sandwich. The bending field needed in LEP is small (about 1000 Gauss), equivalent to two of the magnets people stick on fridge doors. Because it is very difficult to keep a low field steady, a high field was used in iron plates embedded in concrete. A CERN breakthrough in magnet design, LEP dipoles can be tuned easily and are cheaper than conventional magnets.

  10. Precision cut lung slices as an efficient tool for in vitro lung physio-pharmacotoxicology studies.

    Science.gov (United States)

    Morin, Jean-Paul; Baste, Jean-Marc; Gay, Arnaud; Crochemore, Clément; Corbière, Cécile; Monteil, Christelle

    2013-01-01

    1.We review the specific approaches for lung tissue slices preparation and incubation systems and the research application fields in which lung slices proved to be a very efficient alternative to animal experimentation for biomechanical, physiological, pharmacological and toxicological approaches. 2.Focus is made on air-liquid interface dynamic organ culture systems that allow direct tissue exposure to complex aerosol and that best mimic in vivo lung tissue physiology. 3.A compilation of research applications in the fields of vascular and airway reactivity, mucociliary transport, polyamine transport, xenobiotic biotransformation, chemicals toxicology and complex aerosols supports the concept that precision cut lung slices are a very efficient tool maintaining highly differentiated functions similar to in vivo lung organ when kept under dynamic organ culture. They also have been successfully used for lung gene transfer efficiency assessment, for lung viral infection efficiency assessment, for studies of tissue preservation media and tissue post-conditioning to optimize lung tissue viability before grafting. 4.Taken all together, the reviewed studies point to a great interest for precision cut lung slices as an efficient and valuable alternative to in vivo lung organ experimentation.

  11. Inhibition of hippocampal synaptic transmission by impairment of Ral function

    DEFF Research Database (Denmark)

    Owe-Larsson, Björn; Chaves-Olarte, Esteban; Chauhan, Ashok

    2005-01-01

    Large clostridial cytotoxins and protein overexpression were used to probe for involvement of Ras-related GTPases (guanosine triphosphate) in synaptic transmission in cultured rat hippocampal neurons. The toxins TcdA-10463 (inactivates Rho, Rac, Cdc42, Rap) and TcsL-1522 (inactivates Ral, Rac, Ras......, R-Ras, Rap) both inhibited autaptic responses. In a proportion of the neurons (25%, TcdA-10463; 54%, TcsL-1522), the inhibition was associated with a shift from activity-dependent depression to facilitation, indicating that the synaptic release probability was reduced. Overexpression of a dominant...... negative Ral mutant, Ral A28N, caused a strong inhibition of autaptic responses, which was associated with a shift to facilitation in a majority (80%) of the neurons. These results indicate that Ral, along with at least one other non-Rab GTPase, participates in presynaptic regulation in hippocampal neurons....

  12. D-Serine rescues the deficits of hippocampal long-term potentiation and learning and memory induced by sodium fluoroacetate.

    Science.gov (United States)

    Han, Huili; Peng, Yan; Dong, Zhifang

    2015-06-01

    It is well known that bidirectional glia-neuron interactions play important roles in the neurophysiological and neuropathological processes. It is reported that impairing glial functions with sodium fluoroacetate (FAC) impaired hippocampal long-term depression (LTD) and spatial memory retrieval. However, it remains unknown whether FAC impairs hippocampal long-term potentiation (LTP) and learning and/or memory, and if so, whether pharmacological treatment with exogenous d-serine can recuse the impairment. Here, we reported that systemic administration of FAC (3mg/kg, i.p.) before training resulted in dramatic impairments of spatial learning and memory in water maze and fear memory in contextual fear conditioning. Furthermore, the behavioral deficits were accompanied by impaired LTP induction in the hippocampal CA1 area of brain slices. More importantly, exogenous d-serine treatment succeeded in recusing the deficits of hippocampal LTP and learning and memory induced by FAC. Together, these results suggest that astrocytic d-serine may be essential for hippocampal synaptic plasticity and memory, and that alteration of its levels may be relevant to the induction and potentially treatment of psychiatric and neurological disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Restoration of hippocampal growth hormone reverses stress-induced hippocampal impairment

    Directory of Open Access Journals (Sweden)

    Caitlin M. Vander Weele

    2013-06-01

    Full Text Available Though growth hormone (GH is synthesized by hippocampal neurons, where its expression is influenced by stress exposure, its function is poorly characterized. Here, we show that a regimen of chronic stress that impairs hippocampal function in rats also leads to a profound decrease in hippocampal GH levels. Restoration of hippocampal GH in the dorsal hippocampus via viral-mediated gene transfer completely reversed stress-related impairment of two hippocampus-dependent behavioral tasks, auditory trace fear conditioning and contextual fear conditioning, without affecting hippocampal function in unstressed control rats. GH overexpression reversed stress-induced decrements in both fear acquisition and long-term fear memory. These results suggest that loss of hippocampal GH contributes to hippocampal dysfunction following prolonged stress and demonstrate that restoring hippocampal GH levels following stress can promote stress resilience.

  14. Image-guided recording system for spatial and temporal mapping of neuronal activities in brain slice.

    Science.gov (United States)

    Choi, Geonho; Lee, Jeonghyeon; Kim, Hyeongeun; Jang, Jaemyung; Im, Changkyun; Jeon, Nooli; Jung, Woonggyu

    2018-03-01

    In this study, we introduce the novel image-guided recording system (IGRS) for efficient interpretation of neuronal activities in the brain slice. IGRS is designed to combine microelectrode array (MEA) and optical coherence tomography at the customized upright microscope. It allows to record multi-site neuronal signals and image of the volumetric brain anatomy in a single body configuration. For convenient interconnection between a brain image and neuronal signals, we developed the automatic mapping protocol that enables us to project acquired neuronal signals on a brain image. To evaluate the performance of IGRS, hippocampal signals of the brain slice were monitored, and corresponding with two-dimensional neuronal maps were successfully reconstructed. Our results indicated that IGRS and mapping protocol can provide the intuitive information regarding long-term and multi-sites neuronal signals. In particular, the temporal and spatial mapping capability of neuronal signals would be a very promising tool to observe and analyze the massive neuronal activity and connectivity in MEA-based electrophysiological studies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. RETROSPECTIVE DETECTION OF INTERLEAVED SLICE ACQUISITION PARAMETERS FROM FMRI DATA

    Science.gov (United States)

    Parker, David; Rotival, Georges; Laine, Andrew; Razlighi, Qolamreza R.

    2015-01-01

    To minimize slice excitation leakage to adjacent slices, interleaved slice acquisition is nowadays performed regularly in fMRI scanners. In interleaved slice acquisition, the number of slices skipped between two consecutive slice acquisitions is often referred to as the ‘interleave parameter’; the loss of this parameter can be catastrophic for the analysis of fMRI data. In this article we present a method to retrospectively detect the interleave parameter and the axis in which it is applied. Our method relies on the smoothness of the temporal-distance correlation function, which becomes disrupted along the axis on which interleaved slice acquisition is applied. We examined this method on simulated and real data in the presence of fMRI artifacts such as physiological noise, motion, etc. We also examined the reliability of this method in detecting different types of interleave parameters and demonstrated an accuracy of about 94% in more than 1000 real fMRI scans. PMID:26161244

  16. A grading system for hippocampal sclerosis based on the degree of hippocampal mossy fiber sprouting

    NARCIS (Netherlands)

    Gispen, W.H.; Proper, E.A.; Jansen, G.H.; Veelen, C.W. van; Rijen, P.C. van; Graan, P.N.E. de

    2001-01-01

    Abstract. In patients suffering from temporal lobe epilepsy (TLE) a highly variable degree of hippocampal sclerosis (HS) can be observed. For standard neuropathological evaluation after hippocampal resection, neuronal cell loss in the hippocampal subareas is assessed (Wyler score 0-4) [Wyler et al.

  17. cultural

    Directory of Open Access Journals (Sweden)

    Irene Kreutz

    2006-01-01

    Full Text Available Es un estudio cualitativo que adoptó como referencial teorico-motodológico la antropología y la etnografía. Presenta las experiencias vivenciadas por mujeres de una comunidad en el proceso salud-enfermedad, con el objetivo de comprender los determinantes sócio-culturales e históricos de las prácticas de prevención y tratamiento adoptados por el grupo cultural por medio de la entrevista semi-estructurada. Los temas que emergieron fueron: la relación entre la alimentación y lo proceso salud-enfermedad, las relaciones con el sistema de salud oficial y el proceso salud-enfermedad y lo sobrenatural. Los dados revelaron que los moradores de la comunidad investigada tienen un modo particular de explicar sus procedimientos terapéuticos. Consideramos que es papel de los profesionales de la salud en sus prácticas, la adopción de abordajes o enfoques que consideren al individuo en su dimensión sócio-cultural e histórica, considerando la enorme diversidad cultural en nuestro país.

  18. A novel method for oxygen glucose deprivation model in organotypic spinal cord slices.

    Science.gov (United States)

    Liu, Jing-Jie; Ding, Xiao-Yan; Xiang, Li; Zhao, Feng; Huang, Sheng-Li

    2017-10-01

    This study aimed to establish a model to closely mimic spinal cord hypoxic-ischemic injury with high production and high reproducibility. Fourteen-day cultured organotypic spinal cord slices were divided into 4 groups: control (Ctrl), oxygen glucose deprived for 30min (OGD 30min), OGD 60min, and OGD 120min. The Ctrl slices were incubated with 1ml propidium iodide (PI) solution (5μg/ml) for 30min. The OGD groups were incubated with 1ml glucose-free DMEM/F12 medium and 5μl PI solution (1mg/ml) for 30min, 60min and 120min, respectively. Positive control slice was fixed by 4% paraformaldehyde for 20min. The culture medium in each group was then collected and the Lactate Dehydrogenase (LDH) level in the medium was tested using Multi-Analyte ELISArray kits. Structure and refraction of the spinal cord slices were observed by light microscope. Fluorescence intensity of PI was examined by fluorescence microscopy and was tested by IPP Software. Morphology of astrocytes was observed by immunofluorescence histochemistry. Caspase 3 and caspase 3 active in different groups were tested by Western blot. In the OGD groups, the refraction of spinal cord slices decreased and the structure was unclear. The changes of refraction and structure in the OGD 120min group were similar to that in the positive control slice. Astrocyte morphology changed significantly. With the increase of OGD time, processes became thick and twisted, and nuclear condensations became more apparent. Obvious changes in morphology were observed in the OGD 60min group, and normal morphology disappeared in the OGD 120min group. Fluorescence intensity of PI increased along with the extension of OGD time. The difference was significant between 30min and 60min, but not significant between 60min and 120min. The intensity at OGD 120min was close to that in the positive control. Compare with the Ctrl group, the OGD groups had significantly higher LDH levels and caspase 3 active/caspase 3 ratios. The values increased

  19. Fresh Slice Self-Seeding and Fresh Slice Harmonic Lasing at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Amann, J.W. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2018-04-01

    We present results from the successful demonstration of fresh slice self-seeding at the Linac Coherent Light Source (LCLS).* The performance is compared with SASE and regular self-seeding at photon energy of 5.5 keV, resulting in a relative average brightness increase of a factor of 12 and a factor of 2 respectively. Following this proof-of-principle we discuss the forthcoming plans to use the same technique** for fresh slice harmonic lasing in an upcoming experiment. The demonstration of fresh slice harmonic lasing provides an attractive solution for future XFELs aiming to achieve high efficiency, high brightness X-ray pulses at high photon energies (>12 keV).***

  20. Experimental demonstration of spectrum-sliced elastic optical path network (SLICE).

    Science.gov (United States)

    Kozicki, Bartłomiej; Takara, Hidehiko; Tsukishima, Yukio; Yoshimatsu, Toshihide; Yonenaga, Kazushige; Jinno, Masahiko

    2010-10-11

    We describe experimental demonstration of spectrum-sliced elastic optical path network (SLICE) architecture. We employ optical orthogonal frequency-division multiplexing (OFDM) modulation format and bandwidth-variable optical cross-connects (OXC) to generate, transmit and receive optical paths with bandwidths of up to 1 Tb/s. We experimentally demonstrate elastic optical path setup and spectrally-efficient transmission of multiple channels with bit rates ranging from 40 to 140 Gb/s between six nodes of a mesh network. We show dynamic bandwidth scalability for optical paths with bit rates of 40 to 440 Gb/s. Moreover, we demonstrate multihop transmission of a 1 Tb/s optical path over 400 km of standard single-mode fiber (SMF). Finally, we investigate the filtering properties and the required guard band width for spectrally-efficient allocation of optical paths in SLICE.

  1. Possible Role of the Glycogen Synthase Kinase-3 Signaling Pathway in Trimethyltin-Induced Hippocampal Neurodegeneration in Mice

    Science.gov (United States)

    Kim, Sung-Ho; Kim, Jong-Choon; Wang, Hongbing; Shin, Taekyun; Moon, Changjong

    2013-01-01

    Trimethyltin (TMT) is an organotin compound with potent neurotoxic effects characterized by neuronal destruction in selective regions, including the hippocampus. Glycogen synthase kinase-3 (GSK-3) regulates many cellular processes, and is implicated in several neurodegenerative disorders. In this study, we evaluated the therapeutic effect of lithium, a selective GSK-3 inhibitor, on the hippocampus of adult C57BL/6 mice with TMT treatment (2.6 mg/kg, intraperitoneal [i.p.]) and on cultured hippocampal neurons (12 days in vitro) with TMT treatment (5 µM). Lithium (50 mg/kg, i.p., 0 and 24 h after TMT injection) significantly attenuated TMT-induced hippocampal cell degeneration, seizure, and memory deficits in mice. In cultured hippocampal neurons, lithium treatment (0–10 mM; 1 h before TMT application) significantly reduced TMT-induced cytotoxicity in a dose-dependent manner. Additionally, the dynamic changes in GSK-3/β-catenin signaling were observed in the mouse hippocampus and cultured hippocampal neurons after TMT treatment with or without lithium. Therefore, lithium inhibited the detrimental effects of TMT on the hippocampal neurons in vivo and in vitro, suggesting involvement of the GSK-3/β-catenin signaling pathway in TMT-induced hippocampal cell degeneration and dysfunction. PMID:23940567

  2. 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.

  3. Pretreatment with apoaequorin protects hippocampal CA1 neurons from oxygen-glucose deprivation.

    Science.gov (United States)

    Detert, Julia A; Adams, Erin L; Lescher, Jacob D; Lyons, Jeri-Anne; Moyer, James R

    2013-01-01

    Ischemic stroke affects ∼795,000 people each year in the U.S., which results in an estimated annual cost of $73.7 billion. Calcium is pivotal in a variety of neuronal signaling cascades, however, during ischemia, excess calcium influx can trigger excitotoxic cell death. Calcium binding proteins help neurons regulate/buffer intracellular calcium levels during ischemia. Aequorin is a calcium binding protein isolated from the jellyfish Aequorea victoria, and has been used for years as a calcium indicator, but little is known about its neuroprotective properties. The present study used an in vitro rat brain slice preparation to test the hypothesis that an intra-hippocampal infusion of apoaequorin (the calcium binding component of aequorin) protects neurons from ischemic cell death. Bilaterally cannulated rats received an apoaequorin infusion in one hemisphere and vehicle control in the other. Hippocampal slices were then prepared and subjected to 5 minutes of oxygen-glucose deprivation (OGD), and cell death was assayed by trypan blue exclusion. Apoaequorin dose-dependently protected neurons from OGD--doses of 1% and 4% (but not 0.4%) significantly decreased the number of trypan blue-labeled neurons. This effect was also time dependent, lasting up to 48 hours. This time dependent effect was paralleled by changes in cytokine and chemokine expression, indicating that apoaequorin may protect neurons via a neuroimmunomodulatory mechanism. These data support the hypothesis that pretreatment with apoaequorin protects neurons against ischemic cell death, and may be an effective neurotherapeutic.

  4. [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.

  5. Mixed time slicing in path integral simulations

    International Nuclear Information System (INIS)

    Steele, Ryan P.; Zwickl, Jill; Shushkov, Philip; Tully, John C.

    2011-01-01

    A simple and efficient scheme is presented for using different time slices for different degrees of freedom in path integral calculations. This method bridges the gap between full quantization and the standard mixed quantum-classical (MQC) scheme and, therefore, still provides quantum mechanical effects in the less-quantized variables. Underlying the algorithm is the notion that time slices (beads) may be 'collapsed' in a manner that preserves quantization in the less quantum mechanical degrees of freedom. The method is shown to be analogous to multiple-time step integration techniques in classical molecular dynamics. The algorithm and its associated error are demonstrated on model systems containing coupled high- and low-frequency modes; results indicate that convergence of quantum mechanical observables can be achieved with disparate bead numbers in the different modes. Cost estimates indicate that this procedure, much like the MQC method, is most efficient for only a relatively few quantum mechanical degrees of freedom, such as proton transfer. In this regime, however, the cost of a fully quantum mechanical simulation is determined by the quantization of the least quantum mechanical degrees of freedom.

  6. Brain Slice Staining and Preparation for Three-Dimensional Super-Resolution Microscopy

    Science.gov (United States)

    German, Christopher L.; Gudheti, Manasa V.; Fleckenstein, Annette E.; Jorgensen, Erik M.

    2018-01-01

    Localization microscopy techniques – such as photoactivation localization microscopy (PALM), fluorescent PALM (FPALM), ground state depletion (GSD), and stochastic optical reconstruction microscopy (STORM) – provide the highest precision for single molecule localization currently available. However, localization microscopy has been largely limited to cell cultures due to the difficulties that arise in imaging thicker tissue sections. Sample fixation and antibody staining, background fluorescence, fluorophore photoinstability, light scattering in thick sections, and sample movement create significant challenges for imaging intact tissue. We have developed a sample preparation and image acquisition protocol to address these challenges in rat brain slices. The sample preparation combined multiple fixation steps, saponin permeabilization, and tissue clarification. Together, these preserve intracellular structures, promote antibody penetration, reduce background fluorescence and light scattering, and allow acquisition of images deep in a 30 μm thick slice. Image acquisition challenges were resolved by overlaying samples with a permeable agarose pad and custom-built stainless steel imaging adapter, and sealing the imaging chamber. This approach kept slices flat, immobile, bathed in imaging buffer, and prevented buffer oxidation during imaging. Using this protocol, we consistently obtained single molecule localizations of synaptic vesicle and active zone proteins in three-dimensions within individual synaptic terminals of the striatum in rat brain slices. These techniques may be easily adapted to the preparation and imaging of other tissues, substantially broadening the application of super-resolution imaging. PMID:28924666

  7. Comparison of 640-Slice Multidetector Computed Tomography Versus 32-Slice MDCT for Imaging of the Osteo-odonto-keratoprosthesis Lamina.

    Science.gov (United States)

    Norris, Joseph M; Kishikova, Lyudmila; Avadhanam, Venkata S; Koumellis, Panos; Francis, Ian S; Liu, Christopher S C

    2015-08-01

    To investigate the efficacy of 640-slice multidetector computed tomography (MDCT) for detecting osteo-odonto laminar resorption in the osteo-odonto-keratoprosthesis (OOKP) compared with the current standard 32-slice MDCT. Explanted OOKP laminae and bone-dentine fragments were scanned using 640-slice MDCT (Aquilion ONE; Toshiba) and 32-slice MDCT (LightSpeed Pro32; GE Healthcare). Pertinent comparisons including image quality, radiation dose, and scanning parameters were made. Benefits of 640-slice MDCT over 32-slice MDCT were shown. Key comparisons of 640-slice MDCT versus 32-slice MDCT included the following: percentage difference and correlation coefficient between radiological and anatomical measurements, 1.35% versus 3.67% and 0.9961 versus 0.9882, respectively; dose-length product, 63.50 versus 70.26; rotation time, 0.175 seconds versus 1.000 seconds; and detector coverage width, 16 cm versus 2 cm. Resorption of the osteo-odonto lamina after OOKP surgery can result in potentially sight-threatening complications, hence it warrants regular monitoring and timely intervention. MDCT remains the gold standard for radiological assessment of laminar resorption, which facilitates detection of subtle laminar changes earlier than the onset of clinical signs, thus indicating when preemptive measures can be taken. The 640-slice MDCT exhibits several advantages over traditional 32-slice MDCT. However, such benefits may not offset cost implications, except in rare cases, such as in young patients who might undergo years of radiation exposure.

  8. Gravitational collapse of charged dust shell and maximal slicing condition

    International Nuclear Information System (INIS)

    Maeda, Keiichi

    1980-01-01

    The maximal slicing condition is a good time coordinate condition qualitatively when pursuing the gravitational collapse by the numerical calculation. The analytic solution of the gravitational collapse under the maximal slicing condition is given in the case of a spherical charged dust shell and the behavior of time slices with this coordinate condition is investigated. It is concluded that under the maximal slicing condition we can pursue the gravitational collapse until the radius of the shell decreases to about 0.7 x (the radius of the event horizon). (author)

  9. Thin slices of child personality: Perceptual, situational, and behavioral contributions.

    Science.gov (United States)

    Tackett, Jennifer L; Herzhoff, Kathrin; Kushner, Shauna C; Rule, Nicholas

    2016-01-01

    The present study examined whether thin-slice ratings of child personality serve as a resource-efficient and theoretically valid measurement of child personality traits. We extended theoretical work on the observability, perceptual accuracy, and situational consistency of childhood personality traits by examining intersource and interjudge agreement, cross-situational consistency, and convergent, divergent, and predictive validity of thin-slice ratings. Forty-five unacquainted independent coders rated 326 children's (ages 8-12) personality in 1 of 15 thin-slice behavioral scenarios (i.e., 3 raters per slice, for over 14,000 independent thin-slice ratings). Mothers, fathers, and children rated children's personality, psychopathology, and competence. We found robust evidence for correlations between thin-slice and mother/father ratings of child personality, within- and across-task consistency of thin-slice ratings, and convergent and divergent validity with psychopathology and competence. Surprisingly, thin-slice ratings were more consistent across situations in this child sample than previously found for adults. Taken together, these results suggest that thin slices are a valid and reliable measure to assess child personality, offering a useful method of measurement beyond questionnaires, helping to address novel questions of personality perception and consistency in childhood. (c) 2016 APA, all rights reserved).

  10. Influence of γ-irradiation on drying of slice potato

    International Nuclear Information System (INIS)

    Wang Jun; Chao Yan; Fu Junjie; Wang Jianping

    2001-01-01

    A new technology is introduced to dry food products by hot-air after pretreated by irradiation. The influence of different dosage of irradiation, temperature of hot air, thickness of the slice potato on the rate of dehydration temperature of irradiated potato were studied. A conclusion is reached that the 3 factors, irradiation dosage, hot-air temperature and thickness of slice potato, affect the rate of dehydration and temperature of slice potato. The higher the dosage is, the greater the rate of dehydration of potato becomes, and the higher the temperature of the slice potato gets. (authors)

  11. Precision-cut liver slices as a model for the early onset of liver fibrosis to test antifibrotic drugs

    NARCIS (Netherlands)

    Westra, Inge M.; Oosterhuis, Dorenda; Groothuis, Geny M. M.; Olinga, Peter

    2014-01-01

    Induction of fibrosis during prolonged culture of precision-cut liver slices (PCLS) was reported. In this study, the use of rat PCLS was investigated to further characterize the mechanism of early onset of fibrosis in this model and the effects of antifibrotic compounds. Rat PCLS were incubated for

  12. Modulation of NMDA Receptor Properties and Synaptic Transmission by the NR3A Subunit in Mouse Hippocampal and Cerebrocortical Neurons

    Science.gov (United States)

    Tong, Gary; Takahashi, Hiroto; Tu, Shichun; Shin, Yeonsook; Talantova, Maria; Zago, Wagner; Xia, Peng; Nie, Zhiguo; Goetz, Thomas; Zhang, Dongxian; Lipton, Stuart A.; Nakanishi, Nobuki

    2015-01-01

    Expression of the NR3A subunit with NR1/NR2 in Xenopus oocytes or mammalian cell lines leads to a reduction in N-methyl-D-aspartate (NMDA)-induced currents and decreased Mg2+ sensitivity and Ca2+ permeability compared with NR1/NR2 receptors. Consistent with these findings, neurons from NR3A knockout (KO) mice exhibit enhanced NMDA-induced currents. Recombinant NR3A can also form excitatory glycine receptors with NR1 in the absence of NR2. However, the effects of NR3A on channel properties in neurons and synaptic transmission have not been fully elucidated. To study physiological roles of NR3A subunits, we generated NR3A transgenic (Tg) mice. Cultured NR3A Tg neurons exhibited two populations of NMDA receptor (NMDAR) channels, reduced Mg2+ sensitivity, and decreased Ca2+ permeability in response to NMDA/glycine, but glycine alone did not elicit excitatory currents. In addition, NMDAR-mediated excitatory postsynaptic currents (EPSCs) in NR3A Tg hippocampal slices showed reduced Mg2+ sensitivity, consistent with the notion that NR3A subunits incorporated into synaptic NMDARs. To study the function of endogenous NR3A subunits, we compared NMDAR-mediated EPSCs in NR3A KO and WT control mice. In NR3A KO mice, the ratio of the amplitudes of the NMDAR-mediated component to α-amino-3-hydroxy-5-methyl-4-isox-azolepropionic acid receptor-mediated component of the EPSC was significantly larger than that seen in WT littermates. This result suggests that NR3A subunits contributed to the NMDAR-mediated component of the EPSC in WT mice. Taken together, these results show that NR3A subunits contribute to NMDAR responses from both synaptic and extra-synaptic receptors, likely composed of NR1, NR2, and NR3 subunits. PMID:18003876

  13. Serotonin dependent masking of hippocampal sharp wave ripples.

    Science.gov (United States)

    ul Haq, Rizwan; Anderson, Marlene L; Hollnagel, Jan-Oliver; Worschech, Franziska; Sherkheli, Muhammad Azahr; Behrens, Christoph J; Heinemann, Uwe

    2016-02-01

    Sharp wave ripples (SPW-Rs) are thought to play an important role in memory consolidation. By rapid replay of previously stored information during slow wave sleep and consummatory behavior, they result from the formation of neural ensembles during a learning period. Serotonin (5-HT), suggested to be able to modify SPW-Rs, can affect many neurons simultaneously by volume transmission and alter network functions in an orchestrated fashion. In acute slices from dorsal hippocampus, SPW-Rs can be induced by repeated high frequency stimulation that induces long-lasting LTP. We used this model to study SPW-R appearance and modulation by 5-HT. Although stimulation in presence of 5-HT permitted LTP induction, SPW-Rs were "masked"--but appeared after 5-HT wash-out. This SPW-R masking was dose dependent with 100 nM 5-HT being sufficient--if the 5-HT re-uptake inhibitor citalopram was present. Fenfluramine, a serotonin releaser, could also mask SPW-Rs. Masking was due to 5-HT1A and 5-HT2A/C receptor activation. Neither membrane potential nor membrane conductance changes in pyramidal cells caused SPW-R blockade since both remained unaffected by combining 5-HT and citalopram. Moreover, 10 and 30 μM 5-HT mediated SPW-R masking preceded neuronal hyperpolarization and involved reduced presynaptic transmitter release. 5-HT, as well as a 5-HT1A agonist, augmented paired pulse facilitation and affected the coefficient of variance. Spontaneous SPW-Rs in mice hippocampal slices were also masked by 5-HT and fenfluramine. While neuronal ensembles can acquire long lasting LTP during higher 5-HT levels, lower 5-HT levels enable neural ensembles to replay previously stored information and thereby permit memory consolidation memory. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Src Kinase Dependent Rapid Non-genomic Modulation of Hippocampal Spinogenesis Induced by Androgen and Estrogen

    Directory of Open Access Journals (Sweden)

    Mika Soma

    2018-05-01

    Full Text Available Dendritic spine is a small membranous protrusion from a neuron's dendrite that typically receives input from an axon terminal at the synapse. Memories are stored in synapses which consist of spines and presynapses. Rapid modulations of dendritic spines induced by hippocampal sex steroids, including dihydrotestosterone (DHT, testosterone (T, and estradiol (E2, are essential for synaptic plasticity. Molecular mechanisms underlying the rapid non-genomic modulation through synaptic receptors of androgen (AR and estrogen (ER as well as its downstream kinase signaling, however, have not been well understood. We investigated the possible involvement of Src tyrosine kinase in rapid changes of dendritic spines in response to androgen and estrogen, including DHT, T, and E2, using hippocampal slices from adult male rats. We found that the treatments with DHT (10 nM, T (10 nM, and E2 (1 nM increased the total density of spines by ~1.22 to 1.26-fold within 2 h using super resolution confocal imaging of Lucifer Yellow-injected CA1 pyramidal neurons. We examined also morphological changes of spines in order to clarify differences between three sex steroids. From spine head diameter analysis, DHT increased middle- and large-head spines, whereas T increased small- and middle-head spines, and E2 increased small-head spines. Upon application of Src tyrosine kinase inhibitor, the spine increases induced through DHT, T, and E2 treatments were completely blocked. These results imply that Src kinase is essentially involved in sex steroid-induced non-genomic modulation of the spine density and morphology. These results also suggest that rapid effects of exogenously applied androgen and estrogen can occur in steroid-depleted conditions, including “acute” hippocampal slices and the hippocampus of gonadectomized animals.

  15. Control theory-based regulation of hippocampal CA1 nonlinear dynamics.

    Science.gov (United States)

    Hsiao, Min-Chi; Song, Dong; Berger, Theodore W

    2008-01-01

    We are developing a biomimetic electronic neural prosthesis to replace regions of the hippocampal brain area that have been damaged by disease or insult. Our previous study has shown that the VLSI implementation of a CA3 nonlinear dynamic model can functionally replace the CA3 subregion of the hippocampal slice. As a result, the propagation of temporal patterns of activity from DG-->VLSI-->CA1 reproduces the activity observed experimentally in the biological DG-->CA3-->CA1 circuit. In this project, we incorporate an open-loop controller to optimize the output (CA1) response. Specifically, we seek to optimize the stimulation signal to CA1 using a predictive dentate gyrus (DG)-CA1 nonlinear model (i.e., DG-CA1 trajectory model) and a CA1 input-output model (i.e., CA1 plant model), such that the ultimate CA1 response (i.e., desired output) can be first predicted by the DG-CA1 trajectory model and then transformed to the desired stimulation through the inversed CA1 plant model. Lastly, the desired CA1 output is evoked by the estimated optimal stimulation. This study will be the first stage of formulating an integrated modeling-control strategy for the hippocampal neural prosthetic system.

  16. Subfield-specific loss of hippocampal N-acetyl aspartate in temporal lobe epilepsy.

    Science.gov (United States)

    Vielhaber, Stefan; Niessen, Heiko G; Debska-Vielhaber, Grazyna; Kudin, Alexei P; Wellmer, Jörg; Kaufmann, Jörn; Schönfeld, Mircea Ariel; Fendrich, Robert; Willker, Wieland; Leibfritz, Dieter; Schramm, Johannes; Elger, Christian E; Heinze, Hans-Jochen; Kunz, Wolfram S

    2008-01-01

    In patients with mesial temporal lobe epilepsy (MTLE) it remains an unresolved issue whether the interictal decrease in N-acetyl aspartate (NAA) detected by proton magnetic resonance spectroscopy ((1)H-MRS) reflects the epilepsy-associated loss of hippocampal pyramidal neurons or metabolic dysfunction. To address this problem, we applied high-resolution (1)H-MRS at 14.1 Tesla to measure metabolite concentrations in ex vivo tissue slices from three hippocampal subfields (CA1, CA3, dentate gyrus) as well as from the parahippocampal region of 12 patients with MTLE. In contrast to four patients with lesion-caused MTLE, we found a large variance of NAA concentrations in the individual hippocampal regions of patients with Ammon's horn sclerosis (AHS). Specifically, in subfield CA3 of AHS patients despite of a moderate preservation of neuronal cell densities the concentration of NAA was significantly lowered, while the concentrations of lactate, glucose, and succinate were elevated. We suggest that these subfield-specific alterations of metabolite concentrations in AHS are very likely caused by impairment of mitochondrial function and not related to neuronal cell loss. A subfield-specific impairment of energy metabolism is the probable cause for lowered NAA concentrations in sclerotic hippocampi of MTLE patients.

  17. Validation of hippocampal volumes measured using a manual method and two automated methods (FreeSurfer and IBASPM) in chronic major depressive disorder

    Energy Technology Data Exchange (ETDEWEB)

    Tae, Woo Suk; Lee, Kang Uk; Nam, Eui-Cheol; Kim, Keun Woo [Kangwon National University College of Medicine, Neuroscience Research Institute, Kangwon (Korea); Kim, Sam Soo [Kangwon National University College of Medicine, Neuroscience Research Institute, Kangwon (Korea); Kangwon National University Hospital, Department of Radiology, Kangwon-do (Korea)

    2008-07-15

    To validate the usefulness of the packages available for automated hippocampal volumetry, we measured hippocampal volumes using one manual and two recently developed automated volumetric methods. The study included T1-weighted magnetic resonance imaging (MRI) of 21 patients with chronic major depressive disorder (MDD) and 20 normal controls. Using coronal turbo field echo (TFE) MRI with a slice thickness of 1.3 mm, the hippocampal volumes were measured using three methods: manual volumetry, surface-based parcellation using FreeSurfer, and individual atlas-based volumetry using IBASPM. In addition, the intracranial cavity volume (ICV) was measured manually. The absolute left hippocampal volume of the patients with MDD measured using all three methods was significantly smaller than the left hippocampal volume of the normal controls (manual P=0.029, FreeSurfer P=0.035, IBASPM P=0.018). After controlling for the ICV, except for the right hippocampal volume measured using FreeSurfer, both measured hippocampal volumes of the patients with MDD were significantly smaller than the measured hippocampal volumes of the normal controls (right manual P=0.019, IBASPM P=0.012; left manual P=0.003, FreeSurfer P=0.010, IBASPM P=0.002). In the intrarater reliability test, the intraclass correlation coefficients (ICCs) were all excellent (manual right 0.947, left 0.934; FreeSurfer right 1.000, left 1.000; IBASPM right 1.000, left 1.000). In the test of agreement between the volumetric methods, the ICCs were right 0.846 and left 0.848 (manual and FreeSurfer), and right 0.654 and left 0.717 (manual and IBASPM). The automated hippocampal volumetric methods showed good agreement with manual hippocampal volumetry, but the volume measured using FreeSurfer was 35% larger and the agreement was questionable with IBASPM. Although the automated methods could detect hippocampal atrophy in the patients with MDD, the results indicate that manual hippocampal volumetry is still the gold standard

  18. Validation of hippocampal volumes measured using a manual method and two automated methods (FreeSurfer and IBASPM) in chronic major depressive disorder

    International Nuclear Information System (INIS)

    Tae, Woo Suk; Lee, Kang Uk; Nam, Eui-Cheol; Kim, Keun Woo; Kim, Sam Soo

    2008-01-01

    To validate the usefulness of the packages available for automated hippocampal volumetry, we measured hippocampal volumes using one manual and two recently developed automated volumetric methods. The study included T1-weighted magnetic resonance imaging (MRI) of 21 patients with chronic major depressive disorder (MDD) and 20 normal controls. Using coronal turbo field echo (TFE) MRI with a slice thickness of 1.3 mm, the hippocampal volumes were measured using three methods: manual volumetry, surface-based parcellation using FreeSurfer, and individual atlas-based volumetry using IBASPM. In addition, the intracranial cavity volume (ICV) was measured manually. The absolute left hippocampal volume of the patients with MDD measured using all three methods was significantly smaller than the left hippocampal volume of the normal controls (manual P=0.029, FreeSurfer P=0.035, IBASPM P=0.018). After controlling for the ICV, except for the right hippocampal volume measured using FreeSurfer, both measured hippocampal volumes of the patients with MDD were significantly smaller than the measured hippocampal volumes of the normal controls (right manual P=0.019, IBASPM P=0.012; left manual P=0.003, FreeSurfer P=0.010, IBASPM P=0.002). In the intrarater reliability test, the intraclass correlation coefficients (ICCs) were all excellent (manual right 0.947, left 0.934; FreeSurfer right 1.000, left 1.000; IBASPM right 1.000, left 1.000). In the test of agreement between the volumetric methods, the ICCs were right 0.846 and left 0.848 (manual and FreeSurfer), and right 0.654 and left 0.717 (manual and IBASPM). The automated hippocampal volumetric methods showed good agreement with manual hippocampal volumetry, but the volume measured using FreeSurfer was 35% larger and the agreement was questionable with IBASPM. Although the automated methods could detect hippocampal atrophy in the patients with MDD, the results indicate that manual hippocampal volumetry is still the gold standard

  19. Dipeptide Piracetam Analogue Noopept Improves Viability of Hippocampal HT-22 Neurons in the Glutamate Toxicity Model.

    Science.gov (United States)

    Antipova, T A; Nikolaev, S V; Ostrovskaya, P U; Gudasheva, T A; Seredenin, S B

    2016-05-01

    Effect of noopept (N-phenylacetyl-prolylglycine ethyl ester) on viability of neurons exposed to neurotoxic action of glutamic acid (5 mM) was studied in vitro in immortalized mouse hippocampal HT-22 neurons. Noopept added to the medium before or after glutamic acid improved neuronal survival in a concentration range of 10-11-10-5 M. Comparison of the effective noopept concentrations determined in previous studies on cultured cortical and cerebellar neurons showed that hippocampal neurons are more sensitive to the protective effect of noopept.

  20. Phosphoinositide-3-kinase activation controls synaptogenesis and spinogenesis in hippocampal neurons.

    Science.gov (United States)

    Cuesto, Germán; Enriquez-Barreto, Lilian; Caramés, Cristina; Cantarero, Marta; Gasull, Xavier; Sandi, Carmen; Ferrús, Alberto; Acebes, Ángel; Morales, Miguel

    2011-02-23

    The possibility of changing the number of synapses may be an important asset in the treatment of neurological diseases. In this context, the synaptogenic role of the phosphoinositide-3-kinase (PI3K) signaling cascade has been previously demonstrated in Drosophila. This study shows that treatment with a PI3K-activating transduction peptide is able to promote synaptogenesis and spinogenesis in primary cultures of rat hippocampal neurons, as well as in CA1 hippocampal neurons in vivo. In culture, the peptide increases synapse density independently of cell density, culture age, dendritic complexity, or synapse type. The induced synapses also increase neurotransmitter release from cultured neurons. The synaptogenic signaling pathway includes PI3K-Akt. Furthermore, the treatment is effective on adult neurons, where it induces spinogenesis and enhances the cognitive behavior of treated animals in a fear-conditioning assay. These findings demonstrate that functional synaptogenesis can be induced in mature mammalian brains through PI3K activation.

  1. Lipopolysaccharide does not alter small airway reactivity in mouse lung slices.

    Science.gov (United States)

    Donovan, Chantal; Royce, Simon G; Vlahos, Ross; Bourke, Jane E

    2015-01-01

    The bacterial endotoxin, lipopolysaccharide (LPS) has been associated with occupational airway diseases with asthma-like symptoms and in acute exacerbations of COPD. The direct and indirect effects of LPS on small airway reactivity have not been fully elucidated. We tested the hypothesis that both in vitro and in vivo LPS treatment would increase contraction and impair relaxation of mouse small airways. Lung slices were prepared from naïve Balb/C mice and cultured in the absence or presence of LPS (10 μg/ml) for up to 48 h for measurement of TNFα levels in conditioned media. Alternatively, mice were challenged with PBS or LPS in vivo once a day for 4 days for preparation of lung slices or for harvest of lungs for Q-PCR analysis of gene expression of pro-inflammatory cytokines and receptors involved in airway contraction. Reactivity of small airways to contractile agonists, methacholine and serotonin, and bronchodilator agents, salbutamol, isoprenaline and rosiglitazone, were assessed using phase-contrast microscopy. In vitro LPS treatment of slices increased TNFα release 6-fold but did not alter contraction or relaxation to any agonists tested. In vivo LPS treatment increased lung gene expression of TNFα, IL-1β and ryanodine receptor isoform 2 more than 5-fold. However there were no changes in reactivity in lung slices from these mice, even when also incubated with LPS ex vivo. Despite evidence of LPS-induced inflammation, neither airway hyperresponsiveness or impaired dilator reactivity were evident. The increase in ryanodine receptor isoform 2, known to regulate calcium signaling in vascular smooth muscle, warrants investigation. Since LPS failed to elicit changes in small airway reactivity in mouse lung slices following in vitro or in vivo treatment, alternative approaches are required to define the potential contribution of this endotoxin to altered small airway reactivity in human lung diseases.

  2. Lipopolysaccharide does not alter small airway reactivity in mouse lung slices.

    Directory of Open Access Journals (Sweden)

    Chantal Donovan

    Full Text Available The bacterial endotoxin, lipopolysaccharide (LPS has been associated with occupational airway diseases with asthma-like symptoms and in acute exacerbations of COPD. The direct and indirect effects of LPS on small airway reactivity have not been fully elucidated. We tested the hypothesis that both in vitro and in vivo LPS treatment would increase contraction and impair relaxation of mouse small airways. Lung slices were prepared from naïve Balb/C mice and cultured in the absence or presence of LPS (10 μg/ml for up to 48 h for measurement of TNFα levels in conditioned media. Alternatively, mice were challenged with PBS or LPS in vivo once a day for 4 days for preparation of lung slices or for harvest of lungs for Q-PCR analysis of gene expression of pro-inflammatory cytokines and receptors involved in airway contraction. Reactivity of small airways to contractile agonists, methacholine and serotonin, and bronchodilator agents, salbutamol, isoprenaline and rosiglitazone, were assessed using phase-contrast microscopy. In vitro LPS treatment of slices increased TNFα release 6-fold but did not alter contraction or relaxation to any agonists tested. In vivo LPS treatment increased lung gene expression of TNFα, IL-1β and ryanodine receptor isoform 2 more than 5-fold. However there were no changes in reactivity in lung slices from these mice, even when also incubated with LPS ex vivo. Despite evidence of LPS-induced inflammation, neither airway hyperresponsiveness or impaired dilator reactivity were evident. The increase in ryanodine receptor isoform 2, known to regulate calcium signaling in vascular smooth muscle, warrants investigation. Since LPS failed to elicit changes in small airway reactivity in mouse lung slices following in vitro or in vivo treatment, alternative approaches are required to define the potential contribution of this endotoxin to altered small airway reactivity in human lung diseases.

  3. Metabolism of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) Atropisomers in Tissue Slices from Phenobarbital or Dexamethasone-Induced Rats is Sex-Dependent

    Science.gov (United States)

    Wu, Xianai; Kania-Korwel, Izabela; Chen, Hao; Stamou, Marianna; Dammanahalli, Karigowda J.; Duffel, Michael; Lein, Pamela J.; Lehmler, Hans-Joachim

    2013-01-01

    Chiral polychlorinated biphenyls (PCBs) such as PCB 136 enantioselectively sensitize the ryanodine receptor (RyR). In light of recent evidence that PCBs cause developmental neurotoxicity via RyR-dependent mechanisms, this suggests that enantioselective PCB metabolism may influence the developmental neurotoxicity of chiral PCBs. However, enantioselective disposition of PCBs has not been fully characterized.The effect of sex and cytochrome P450 (P450) enzyme induction on the enantioselective metabolism of PCB 136 was studied using liver tissue slices prepared from naïve control (CTL), phenobarbital (PB; CYP2B inducer) or dexamethasone (DEX; CYP3A inducer) pretreated adult Sprague-Dawley rats. PCB 136 metabolism was also examined in hippocampal slices derived from untreated rat pups.In liver tissue slices, hydroxylated PCB (OH-PCB) profiles depended on sex and inducer pretreatment, and OH-PCB levels followed the rank orders male > female and PB > DEX > CTL. In contrast, the enantiomeric enrichment of PCB 136 and its metabolites was independent of sex and inducer pretreatment. Only small amounts of PCB 136 partitioned into hippocampal tissue slices and no OH-PCB metabolites were detected.Our results suggest that enantioselective metabolism, sex and induction status of P450 enzymes in the liver may modulate the neurotoxic outcomes of developmental exposure to chiral PCBs. PMID:23581876

  4. Novel genetic loci associated with hippocampal volume.

    Science.gov (United States)

    Hibar, Derrek P; Adams, Hieab H H; Jahanshad, Neda; Chauhan, Ganesh; Stein, Jason L; Hofer, Edith; Renteria, Miguel E; Bis, Joshua C; Arias-Vasquez, Alejandro; Ikram, M Kamran; Desrivières, Sylvane; Vernooij, Meike W; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf; Andersson, Micael; Arfanakis, Konstantinos; Aribisala, Benjamin S; Armstrong, Nicola J; Athanasiu, Lavinia; Axelsson, Tomas; Beecham, Ashley H; Beiser, Alexa; Bernard, Manon; Blanton, Susan H; Bohlken, Marc M; Boks, Marco P; Bralten, Janita; Brickman, Adam M; Carmichael, Owen; Chakravarty, M Mallar; Chen, Qiang; Ching, Christopher R K; Chouraki, Vincent; Cuellar-Partida, Gabriel; Crivello, Fabrice; Den Braber, Anouk; Doan, Nhat Trung; Ehrlich, Stefan; Giddaluru, Sudheer; Goldman, Aaron L; Gottesman, Rebecca F; Grimm, Oliver; Griswold, Michael E; Guadalupe, Tulio; Gutman, Boris A; Hass, Johanna; Haukvik, Unn K; Hoehn, David; Holmes, Avram J; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Jørgensen, Kjetil N; Karbalai, Nazanin; Kasperaviciute, Dalia; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H; Liewald, David C M; Lopez, Lorna M; Luciano, Michelle; Macare, Christine; Marquand, Andre F; Matarin, Mar; Mather, Karen A; Mattheisen, Manuel; McKay, David R; Milaneschi, Yuri; Muñoz Maniega, Susana; Nho, Kwangsik; Nugent, Allison C; Nyquist, Paul; Loohuis, Loes M Olde; Oosterlaan, Jaap; Papmeyer, Martina; Pirpamer, Lukas; Pütz, Benno; Ramasamy, Adaikalavan; Richards, Jennifer S; Risacher, Shannon L; Roiz-Santiañez, Roberto; Rommelse, Nanda; Ropele, Stefan; Rose, Emma J; Royle, Natalie A; Rundek, Tatjana; Sämann, Philipp G; Saremi, Arvin; Satizabal, Claudia L; Schmaal, Lianne; Schork, Andrew J; Shen, Li; Shin, Jean; Shumskaya, Elena; Smith, Albert V; Sprooten, Emma; Strike, Lachlan T; Teumer, Alexander; Tordesillas-Gutierrez, Diana; Toro, Roberto; Trabzuni, Daniah; Trompet, Stella; Vaidya, Dhananjay; Van der Grond, Jeroen; Van der Lee, Sven J; Van der Meer, Dennis; Van Donkelaar, Marjolein M J; Van Eijk, Kristel R; Van Erp, Theo G M; Van Rooij, Daan; Walton, Esther; Westlye, Lars T; Whelan, Christopher D; Windham, Beverly G; Winkler, Anderson M; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Wolfers, Thomas; Yanek, Lisa R; Yang, Jingyun; Zijdenbos, Alex; Zwiers, Marcel P; Agartz, Ingrid; Almasy, Laura; Ames, David; Amouyel, Philippe; Andreassen, Ole A; Arepalli, Sampath; Assareh, Amelia A; Barral, Sandra; Bastin, Mark E; Becker, Diane M; Becker, James T; Bennett, David A; Blangero, John; van Bokhoven, Hans; Boomsma, Dorret I; Brodaty, Henry; Brouwer, Rachel M; Brunner, Han G; Buckner, Randy L; Buitelaar, Jan K; Bulayeva, Kazima B; Cahn, Wiepke; Calhoun, Vince D; Cannon, Dara M; Cavalleri, Gianpiero L; Cheng, Ching-Yu; Cichon, Sven; Cookson, Mark R; Corvin, Aiden; Crespo-Facorro, Benedicto; Curran, Joanne E; Czisch, Michael; Dale, Anders M; Davies, Gareth E; De Craen, Anton J M; De Geus, Eco J C; De Jager, Philip L; De Zubicaray, Greig I; Deary, Ian J; Debette, Stéphanie; DeCarli, Charles; Delanty, Norman; Depondt, Chantal; DeStefano, Anita; Dillman, Allissa; Djurovic, Srdjan; Donohoe, Gary; Drevets, Wayne C; Duggirala, Ravi; Dyer, Thomas D; Enzinger, Christian; Erk, Susanne; Espeseth, Thomas; Fedko, Iryna O; Fernández, Guillén; Ferrucci, Luigi; Fisher, Simon E; Fleischman, Debra A; Ford, Ian; Fornage, Myriam; Foroud, Tatiana M; Fox, Peter T; Francks, Clyde; Fukunaga, Masaki; Gibbs, J Raphael; Glahn, David C; Gollub, Randy L; Göring, Harald H H; Green, Robert C; Gruber, Oliver; Gudnason, Vilmundur; Guelfi, Sebastian; Håberg, Asta K; Hansell, Narelle K; Hardy, John; Hartman, Catharina A; Hashimoto, Ryota; Hegenscheid, Katrin; Heinz, Andreas; Le Hellard, Stephanie; Hernandez, Dena G; Heslenfeld, Dirk J; Ho, Beng-Choon; Hoekstra, Pieter J; Hoffmann, Wolfgang; Hofman, Albert; Holsboer, Florian; Homuth, Georg; Hosten, Norbert; Hottenga, Jouke-Jan; Huentelman, Matthew; Hulshoff Pol, Hilleke E; Ikeda, Masashi; Jack, Clifford R; Jenkinson, Mark; Johnson, Robert; Jönsson, Erik G; Jukema, J Wouter; Kahn, René S; Kanai, Ryota; Kloszewska, Iwona; Knopman, David S; Kochunov, Peter; Kwok, John B; Lawrie, Stephen M; Lemaître, Hervé; Liu, Xinmin; Longo, Dan L; Lopez, Oscar L; Lovestone, Simon; Martinez, Oliver; Martinot, Jean-Luc; Mattay, Venkata S; McDonald, Colm; McIntosh, Andrew M; McMahon, Francis J; McMahon, Katie L; Mecocci, Patrizia; Melle, Ingrid; Meyer-Lindenberg, Andreas; Mohnke, Sebastian; Montgomery, Grant W; Morris, Derek W; Mosley, Thomas H; Mühleisen, Thomas W; Müller-Myhsok, Bertram; Nalls, Michael A; Nauck, Matthias; Nichols, Thomas E; Niessen, Wiro J; Nöthen, Markus M; Nyberg, Lars; Ohi, Kazutaka; Olvera, Rene L; Ophoff, Roel A; Pandolfo, Massimo; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W J H; Pike, G Bruce; Potkin, Steven G; Psaty, Bruce M; Reppermund, Simone; Rietschel, Marcella; Roffman, Joshua L; Romanczuk-Seiferth, Nina; Rotter, Jerome I; Ryten, Mina; Sacco, Ralph L; Sachdev, Perminder S; Saykin, Andrew J; Schmidt, Reinhold; Schmidt, Helena; Schofield, Peter R; Sigursson, Sigurdur; Simmons, Andrew; Singleton, Andrew; Sisodiya, Sanjay M; Smith, Colin; Smoller, Jordan W; Soininen, Hilkka; Steen, Vidar M; Stott, David J; Sussmann, Jessika E; Thalamuthu, Anbupalam; Toga, Arthur W; Traynor, Bryan J; Troncoso, Juan; Tsolaki, Magda; Tzourio, Christophe; Uitterlinden, Andre G; Hernández, Maria C Valdés; Van der Brug, Marcel; van der Lugt, Aad; van der Wee, Nic J A; Van Haren, Neeltje E M; van 't Ent, Dennis; Van Tol, Marie-Jose; Vardarajan, Badri N; Vellas, Bruno; Veltman, Dick J; Völzke, Henry; Walter, Henrik; Wardlaw, Joanna M; Wassink, Thomas H; Weale, Michael E; Weinberger, Daniel R; Weiner, Michael W; Wen, Wei; Westman, Eric; White, Tonya; Wong, Tien Y; Wright, Clinton B; Zielke, Ronald H; Zonderman, Alan B; Martin, Nicholas G; Van Duijn, Cornelia M; Wright, Margaret J; Longstreth, W T; Schumann, Gunter; Grabe, Hans J; Franke, Barbara; Launer, Lenore J; Medland, Sarah E; Seshadri, Sudha; Thompson, Paul M; Ikram, M Arfan

    2017-01-18

    The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r g =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.

  5. Neurotoxic effect of 2,5-hexanedione on neural progenitor cells and hippocampal neurogenesis

    International Nuclear Information System (INIS)

    Kim, Min-Sun; Park, Hee Ra; Park, Mikyung; Kim, So Jung; Kwon, Mugil; Yu, Byung Pal; Chung, Hae Young; Kim, Hyung Sik; Kwack, Seung Jun; Kang, Tae Seok; Kim, Seung Hee; Lee, Jaewon

    2009-01-01

    2,5-Hexanedione (HD), a metabolite of n-hexane, causes central and peripheral neuropathy leading to motor neuron deficits. Although chronic exposure to n-hexane is known to cause gradual sensorimotor neuropathy, there are no reports on the effects of low doses of HD on neurogenesis in the central nervous system. In the current study, we explored HD toxicity in murine neural progenitor cells (NPC), primary neuronal culture and young adult mice. HD (500 nM∼50 μM) dose-dependently suppressed NPC proliferation and cell viability, and also increased the production of reactive oxygen species (ROS). HD (10 or 50 mg/kg for 2 weeks) inhibited hippocampal neuronal and NPC proliferation in 6-week-old male ICR mice, as measured by BrdU incorporation in the dentate gyrus, indicating HD impaired hippocampal neurogenesis. In addition, elevated microglial activation was observed in the hippocampal CA3 region and lateral ventricles of HD-treated mice. Lastly, HD dose-dependently decreased the viability of primary cultured neurons. Based on biochemical and histochemical evidence from both cell culture and HD-treated animals, the neurotoxic mechanisms by which HD inhibits NPC proliferation and hippocampal neurogenesis may relate to its ability to elicit an increased generation of deleterious ROS.

  6. Reactive Transformation and Increased BDNF Signaling by Hippocampal Astrocytes in Response to MK-801.

    Directory of Open Access Journals (Sweden)

    Wenjuan Yu

    Full Text Available MK-801, also known as dizocilpine, is a noncompetitive N-methyl-D-aspartic acid (NMDA receptor antagonist that induces schizophrenia-like symptoms. While astrocytes have been implicated in the pathophysiology of psychiatric disorders, including schizophrenia, astrocytic responses to MK-801 and their significance to schizotypic symptoms are unclear. Changes in the expression levels of glial fibrillary acid protein (GFAP, a marker of astrocyte activation in response to a variety of pathogenic stimuli, were examined in the hippocampus of rats treated with the repeated MK-801 injection (0.5 mg/10 ml/kg body weight for 6 days and in primary cultured hippocampal astrocytes incubated with MK-801 (5 or 20 μM for 24 h. Moreover, the expression levels of BDNF and its receptors TrkB and p75 were examined in MK-801-treated astrocyte cultures. MK-801 treatment enhanced GFAP expression in the rat hippocampus and also increased the levels of GFAP protein and mRNA in hippocampal astrocytes in vitro. Treatment of cultured hippocampal astrocytes with MK-801 enhanced protein and mRNA levels of BDNF, TrkB, and p75. Collectively, our results suggest that hippocampal astrocytes may contribute to the pathophysiology of schizophrenia symptoms associated with NMDA receptor hypofunction by reactive transformation and altered BDNF signaling.

  7. Reactive Transformation and Increased BDNF Signaling by Hippocampal Astrocytes in Response to MK-801

    Science.gov (United States)

    Wang, Yueming; Li, Guanjun; Wang, Lihua; Li, Huafang

    2015-01-01

    MK-801, also known as dizocilpine, is a noncompetitive N-methyl-D-aspartic acid (NMDA) receptor antagonist that induces schizophrenia-like symptoms. While astrocytes have been implicated in the pathophysiology of psychiatric disorders, including schizophrenia, astrocytic responses to MK-801 and their significance to schizotypic symptoms are unclear. Changes in the expression levels of glial fibrillary acid protein (GFAP), a marker of astrocyte activation in response to a variety of pathogenic stimuli, were examined in the hippocampus of rats treated with the repeated MK-801 injection (0.5 mg/10ml/kg body weight for 6 days) and in primary cultured hippocampal astrocytes incubated with MK-801 (5 or 20 μM for 24 h). Moreover, the expression levels of BDNF and its receptors TrkB and p75 were examined in MK-801-treated astrocyte cultures. MK-801 treatment enhanced GFAP expression in the rat hippocampus and also increased the levels of GFAP protein and mRNA in hippocampal astrocytes in vitro. Treatment of cultured hippocampal astrocytes with MK-801 enhanced protein and mRNA levels of BDNF, TrkB, and p75. Collectively, our results suggest that hippocampal astrocytes may contribute to the pathophysiology of schizophrenia symptoms associated with NMDA receptor hypofunction by reactive transformation and altered BDNF signaling. PMID:26700309

  8. Chronic treatment with ginsenoside Rg1 promotes memory and hippocampal long-term potentiation in middle-aged mice.

    Science.gov (United States)

    Zhu, G; Wang, Y; Li, J; Wang, J

    2015-04-30

    Ginseng serves as a potential candidate for the treatment of aging-related memory decline or memory loss. However, the related mechanism is not fully understood. In this study, we applied an intraperitoneal injection of ginsenoside Rg1, an active compound from ginseng in middle-aged mice and detected memory improvement and the underlying mechanisms. Our results showed that a period of 30-day administration of ginsenoside Rg1 enhanced long-term memory in the middle-aged animals. Consistent with the memory improvement, ginsenoside Rg1 administration facilitated weak theta-burst stimulation (TBS)-induced long-term potentiation (LTP) in acute hippocampal slices from middle-aged animals. Ginsenoside Rg1 administration increased the dendritic apical spine numbers and area in the CA1 region. In addition, ginsenoside Rg1 administration up-regulated the expression of hippocampal p-AKT, brain-derived neurotrophic factor (BDNF), proBDNF and glutamate receptor 1 (GluR1), but not p-ERK. Interestingly, the phosphatase and tensin homolog deleted on chromosome ten (PTEN) inhibitor (bpV) mimicked the ginsenoside Rg1 effects, including increasing p-AKT expression, promoting hippocampal basal synaptic transmission, LTP and memory. Taken together, our data suggest that ginsenoside Rg1 treatment improves memory in middle-aged mice possibly through regulating the PI3K/AKT pathway, altering apical spines and facilitating hippocampal LTP. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Visualizing form and function in organotypic slices of the adult mouse parotid gland.

    Science.gov (United States)

    Warner, Jennifer D; Peters, Christian G; Saunders, Rudel; Won, Jong Hak; Betzenhauser, Matthew J; Gunning, William T; Yule, David I; Giovannucci, David R

    2008-09-01

    An organotypic slice preparation of the adult mouse parotid salivary gland amenable to a variety of optical assessments of fluid and protein secretion dynamics is described. The semi-intact preparation rendered without the use of enzymatic treatment permitted live-cell imaging and multiphoton analysis of cellular and supracellular signals. Toward this end we demonstrated that the parotid slice is a significant addition to the repertoire of tools available to investigators to probe exocrine structure and function since there is currently no cell culture system that fully recapitulates parotid acinar cell biology. Importantly, we show that a subpopulation of the acinar cells of parotid slices can be maintained in short-term culture and retain their morphology and function for up to 2 days. This in vitro model system is a significant step forward compared with enzymatically dispersed acini that rapidly lose their morphological and functional characteristics over several hours, and it was shown to be long enough for the expression and trafficking of exogenous protein following adenoviral infection. This system is compatible with a variety of genetic and physiological approaches used to study secretory function.

  10. Negative regulation of TLX by IL-1β correlates with an inhibition of adult hippocampal neural precursor cell proliferation.

    Science.gov (United States)

    Ryan, Sinead M; O'Keeffe, Gerard W; O'Connor, Caitriona; Keeshan, Karen; Nolan, Yvonne M

    2013-10-01

    Adult hippocampal neurogenesis is modulated by a number of intrinsic and extrinsic factors including local signalling molecules, exercise, aging and inflammation. Inflammation is also a major contributor to several hippocampal-associated disorders. Interleukin-1beta (IL-1β) is the most predominant pro-inflammatory cytokine in the brain, and an increase in its concentration is known to decrease the proliferation of both embryonic and adult hippocampal neural precursor cells (NPCs). Recent research has focused on the role of nuclear receptors as intrinsic regulators of neurogenesis, and it is now established that the orphan nuclear receptor TLX is crucial in maintaining the NPC pool in neurogenic brain regions. To better understand the involvement of TLX in IL-1β-mediated effects on hippocampal NPC proliferation, we examined hippocampal NPC proliferation and TLX expression in response to IL-1β treatment in an adult rat hippocampal neurosphere culture system. We demonstrate that IL-1β reduced the proliferation of hippocampal NPCs and TLX expression in a dose and time-dependent manner and that co-treatment with IL-1β receptor antagonist or IL-1 receptor siRNA prevented these effects. We also report a dose-dependent effect of IL-1β on the composition of cell phenotypes in the culture and on expression of TLX in these cells. This study thus provides evidence of an involvement of TLX in IL-1β-induced changes in adult hippocampal neurogenesis, and offers mechanistic insight into disorders in which neuroinflammation and alterations in neurogenesis are characteristic features. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Intervention effects of ganoderma lucidum spores on epileptiform discharge hippocampal neurons and expression of neurotrophin-4 and N-cadherin.

    Directory of Open Access Journals (Sweden)

    Shu-Qiu Wang

    Full Text Available Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS, a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg(2+ free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE. Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i control, ii model (incubated with Mg(2+ free medium for 3 hours, iii GLS group I (incubated with Mg(2+ free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours and iv GLS group II (neurons incubated with Mg(2+ free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours. Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression.

  12. Mathematical Modeling of Thin Layer Microwave Drying of Taro Slices

    Science.gov (United States)

    Kumar, Vivek; Sharma, H. K.; Singh, K.

    2016-03-01

    The present study investigated the drying kinetics of taro slices precooked in different medium viz water (WC), steam (SC) and Lemon Solution (LC) and dried at different microwave power 360, 540 and 720 W. Drying curves of all precooked slices at all microwave powers showed falling rate period along with a very short accelerating period at the beginning of the drying. At all microwave powers, higher drying rate was observed for LC slices as compared to WC and SC slices. To select a suitable drying curve, seven thin-layer drying models were fitted to the experimental data. The data revealed that the Page model was most adequate in describing the microwave drying behavior of taro slices precooked in different medium. The highest effective moisture diffusivity value of 2.11 × 10-8 m2/s was obtained for LC samples while the lowest 0.83 × 10-8 m2/s was obtained for WC taro slices. The activation energy (E a ) of LC taro slices was lower than the E a of WC and SC taro slices.

  13. Design and Development of a tomato Slicing Machine

    OpenAIRE

    Kamaldeen Oladimeji Salaudeen; Awagu E. F.

    2012-01-01

    Principle of slicing was reviewed and tomato slicing machine was developed based on appropriate technology. Locally available materials like wood, stainless steel and mild steel were used in the fabrication. The machine was made to cut tomatoes in 2cm thickness. The capacity of the machine is 540.09g per minute and its performance efficiency is 70%.

  14. Visual performance of pigeons following hippocampal lesions.

    Science.gov (United States)

    Bingman, V P; Hodos, W

    1992-11-15

    The effect of hippocampal lesions on performance in two psychophysical measures of spatial vision (acuity and size-difference threshold) was examined in 7 pigeons. No difference between the preoperative and postoperative thresholds of the experimental birds was found. The visual performance of pigeons in the psychophysical tasks failed to reveal a role of the hippocampal formation in vision. The results argue strongly that the behavioral deficits found in pigeons with hippocampal lesions when tested in a variety of memory-related spatial tasks is not based on a defect in spatial vision but impaired spatial cognition.

  15. Both oophorectomy and obesity impaired solely hippocampal-dependent memory via increased hippocampal dysfunction.

    Science.gov (United States)

    Mantor, Duangkamol; Pratchayasakul, Wasana; Minta, Wanitchaya; Sutham, Wissuta; Palee, Siripong; Sripetchwandee, Jirapas; Kerdphoo, Sasiwan; Jaiwongkum, Thidarat; Sriwichaiin, Sirawit; Krintratun, Warunsorn; Chattipakorn, Nipon; Chattipakorn, Siriporn C

    2018-04-17

    Our previous study demonstrated that obesity aggravated peripheral insulin resistance and brain dysfunction in the ovariectomized condition. Conversely, the effect of obesity followed by oophorectomy on brain oxidative stress, brain apoptosis, synaptic function and cognitive function, particularly in hippocampal-dependent and hippocampal-independent memory, has not been investigated. Our hypothesis was that oophorectomy aggravated metabolic impairment, brain dysfunction and cognitive impairment in obese rats. Thirty-two female rats were fed with either a normal diet (ND, n = 16) or a high-fat diet (HFD, n = 16) for a total of 20 weeks. At week 13, rats in each group were subdivided into sham and ovariectomized subgroups (n = 8/subgroup). At week 20, all rats were tested for hippocampal-dependent and hippocampal-independent memory by using Morris water maze test (MWM) and Novel objective recognition (NOR) tests, respectively. We found that the obese-insulin resistant condition occurred in sham-HFD-fed rats (HFS), ovariectomized-ND-fed rats (NDO), and ovariectomized-HFD-fed rats (HFO). Increased hippocampal oxidative stress level, increased hippocampal apoptosis, increased hippocampal synaptic dysfunction, decreased hippocampal estrogen level and impaired hippocampal-dependent memory were observed in HFS, NDO, and HFO rats. However, the hippocampal-independent memory, cortical estrogen levels, cortical ROS production, and cortical apoptosis showed no significant difference between groups. These findings suggested that oophorectomy and obesity exclusively impaired hippocampal-dependent memory, possibly via increased hippocampal dysfunction. Nonetheless, oophorectomy did not aggravate these deleterious effects under conditions of obesity. Copyright © 2017. Published by Elsevier Inc.

  16. Targeting neurotransmitter receptors with nanoparticles in vivo allows single-molecule tracking in acute brain slices

    Science.gov (United States)

    Varela, Juan A.; Dupuis, Julien P.; Etchepare, Laetitia; Espana, Agnès; Cognet, Laurent; Groc, Laurent

    2016-03-01

    Single-molecule imaging has changed the way we understand many biological mechanisms, particularly in neurobiology, by shedding light on intricate molecular events down to the nanoscale. However, current single-molecule studies in neuroscience have been limited to cultured neurons or organotypic slices, leaving as an open question the existence of fast receptor diffusion in intact brain tissue. Here, for the first time, we targeted dopamine receptors in vivo with functionalized quantum dots and were able to perform single-molecule tracking in acute rat brain slices. We propose a novel delocalized and non-inflammatory way of delivering nanoparticles (NPs) in vivo to the brain, which allowed us to label and track genetically engineered surface dopamine receptors in neocortical neurons, revealing inherent behaviour and receptor activity regulations. We thus propose a NP-based platform for single-molecule studies in the living brain, opening new avenues of research in physiological and pathological animal models.

  17. Thermoluminescence results on slices from a Hiroshima tile UHFSFT03

    International Nuclear Information System (INIS)

    Stoneham, Doreen

    1987-01-01

    As was reported at the May 1984 Utah thermoluminescence (TL) workshop, high fired tiles and porcelain fragments can be sliced into 200 μm sections with constant surface area. When conventional pre-dose measurements were carried out on these slices the doses evaluated were in good agreement with results obtained by other workers using conventional quartz separation techniques. There are several advantages in using slices. First, less sample is needed as about 50 consecutive slices can be cut from a block measuring typically 1 cm 2 cross section and 2 cm in length. There are no problems with securing grains to the plate or loss of grains during measurement. Hypothetically there is less damage to the grains when they are cut slowly under cold water than when they are crushed. The disadvantage is that other minerals besides quartz are present in the slice and the signal is weaker than that obtained using quartz inclusions

  18. Correlation of NTD-silicon rod and slice resistivity

    International Nuclear Information System (INIS)

    Wolverton, W.M.

    1984-01-01

    Neutron transmutation doped silicon is an electronic material which presents an opportunity to explore a high level of resistivity characterization. This is due to its excellent uniformity of dopant concentration. Appropriate resistivity measurements on the ingot raw material can be used as a predictor of slice resistivity. Correlation of finished NTD rod (i.e. ingot) resistivity to as-cut slice resistivity (after the sawing process) is addressed in the scope of this paper. Empirical data show that the shift of slice-center resistivity compared to rod-end center resistivity is a function of a new kind of rod radial-resistivity gradient. This function has two domains, and most rods are in domain ''A''. Correlating equations show how to significantly improve the prediction of slice resistivity of rods in domain ''A''. The new rod resistivity specifications have resulted in manufacturing economies in the production of NTD silicon slices

  19. A survey of program slicing for software engineering

    Science.gov (United States)

    Beck, Jon

    1993-01-01

    This research concerns program slicing which is used as a tool for program maintainence of software systems. Program slicing decreases the level of effort required to understand and maintain complex software systems. It was first designed as a debugging aid, but it has since been generalized into various tools and extended to include program comprehension, module cohesion estimation, requirements verification, dead code elimination, and maintainence of several software systems, including reverse engineering, parallelization, portability, and reuse component generation. This paper seeks to address and define terminology, theoretical concepts, program representation, different program graphs, developments in static slicing, dynamic slicing, and semantics and mathematical models. Applications for conventional slicing are presented, along with a prognosis of future work in this field.

  20. RF slice profile effects in magnetic resonance fingerprinting.

    Science.gov (United States)

    Hong, Taehwa; Han, Dongyeob; Kim, Min-Oh; Kim, Dong-Hyun

    2017-09-01

    The radio frequency (RF) slice profile effects on T1 and T2 estimation in magnetic resonance fingerprinting (MRF) are investigated with respect to time-bandwidth product (TBW), flip angle (FA) level and field inhomogeneities. Signal evolutions are generated incorporating the non-ideal slice selective excitation process using Bloch simulation and matched to the original dictionary with and without the non-ideal slice profile taken into account. For validation, phantom and in vivo experiments are performed at 3T. Both simulations and experiments results show that T1 and T2 error from non-ideal slice profile increases with increasing FA level, off-resonance, and low TBW values. Therefore, RF slice profile effects should be compensated for accurate determination of the MR parameters. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Abnormalities of hippocampal-cortical connectivity in temporal lobe epilepsy patients with hippocampal sclerosis

    Science.gov (United States)

    Li, Wenjing; He, Huiguang; Lu, Jingjing; Wang, Chunheng; Li, Meng; Lv, Bin; Jin, Zhengyu

    2011-03-01

    Hippocampal sclerosis (HS) is the most common damage seen in the patients with temporal lobe epilepsy (TLE). In the present study, the hippocampal-cortical connectivity was defined as the correlation between the hippocampal volume and cortical thickness at each vertex throughout the whole brain. We aimed to investigate the differences of ipsilateral hippocampal-cortical connectivity between the unilateral TLE-HS patients and the normal controls. In our study, the bilateral hippocampal volumes were first measured in each subject, and we found that the ipsilateral hippocampal volume significantly decreased in the left TLE-HS patients. Then, group analysis showed significant thinner average cortical thickness of the whole brain in the left TLE-HS patients compared with the normal controls. We found significantly increased ipsilateral hippocampal-cortical connectivity in the bilateral superior temporal gyrus, the right cingulate gyrus and the left parahippocampal gyrus of the left TLE-HS patients, which indicated structural vulnerability related to the hippocampus atrophy in the patient group. However, for the right TLE-HS patients, no significant differences were found between the patients and the normal controls, regardless of the ipsilateral hippocampal volume, the average cortical thickness or the patterns of hippocampal-cortical connectivity, which might be related to less atrophies observed in the MRI scans. Our study provided more evidence for the structural abnormalities in the unilateral TLE-HS patients.

  2. Hippocampal network oscillations in APP/APLP2-deficient mice.

    Directory of Open Access Journals (Sweden)

    Xiaomin Zhang

    Full Text Available The physiological function of amyloid precursor protein (APP and its two homologues APP-like protein 1 (APLP1 and 2 (APLP2 is largely unknown. Previous work suggests that lack of APP or APLP2 impairs synaptic plasticity and spatial learning. There is, however, almost no data on the role of APP or APLP at the network level which forms a critical interface between cellular functions and behavior. We have therefore investigated memory-related synaptic and network functions in hippocampal slices from three lines of transgenic mice: APPsα-KI (mice expressing extracellular fragment of APP, corresponding to the secreted APPsα ectodomain, APLP2-KO, and combined APPsα-KI/APLP2-KO (APPsα-DM for "double mutants". We analyzed two prominent patterns of network activity, gamma oscillations and sharp-wave ripple complexes (SPW-R. Both patterns were generally preserved in all strains. We find, however, a significantly reduced frequency of gamma oscillations in CA3 of APLP2-KO mice in comparison to APPsα-KI and WT mice. Network activity, basic synaptic transmission and short-term plasticity were unaltered in the combined mutants (APPsα-DM which showed, however, reduced long-term potentiation (LTP. Together, our data indicate that APLP2 and the intracellular domain of APP are not essential for coherent activity patterns in the hippocampus, but have subtle effects on synaptic plasticity and fine-tuning of network oscillations.

  3. Impaired Hippocampal Glutamate and Glutamine Metabolism in the db/db Mouse Model of Type 2 Diabetes Mellitus

    DEFF Research Database (Denmark)

    Andersen, Jens Velde; Nissen, Jakob Dahl; Christensen, Sofie Kjellerup

    2017-01-01

    Type 2 diabetes mellitus (T2DM) is a risk factor for the development of Alzheimer's disease, and changes in brain energy metabolism have been suggested as a causative mechanism. The aim of this study was to investigate the cerebral metabolism of the important amino acids glutamate and glutamine...... significantly reduced 13C labeling in glutamate, glutamine, GABA, citrate, and aspartate from metabolism of [U-13C]glutamate. Additionally, reduced 13C labeling were observed in GABA, citrate, and aspartate from [U-13C]glutamine metabolism in hippocampal slices of db/db mice when compared to controls. None...

  4. Cavernous angioma associated with ipsilateral hippocampal sclerosis

    International Nuclear Information System (INIS)

    Okujava, M.; Ebner, A.; Schmitt, J.; Woermann, F.G.

    2002-01-01

    We report two cases with extratemporal cavernous angioma (CA) and coexisting ipsilateral hippocampal sclerosis. Classically dual pathology is defined as the association of hippocampal sclerosis with an extrahippocampal lesion. Subtle changes in hippocampus might be overlooked in the presence of an unequivocal extrahippocampal abnormality. Seizure outcome after epilepsy surgery in cases with dual pathology is less favourable if only one of the lesions is removed. Dual pathology must always be considered in diagnostic imaging of patients with intractable epilepsy and CA. (orig.)

  5. Cavernous angioma associated with ipsilateral hippocampal sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Okujava, M [Institute of Radiology and Interventional Diagnostics, Tbilisi (Georgia); Ebner, A; Schmitt, J; Woermann, F G [Bethel Epilepsy Centre, Mara Hospital, Bielefeld (Germany)

    2002-07-01

    We report two cases with extratemporal cavernous angioma (CA) and coexisting ipsilateral hippocampal sclerosis. Classically dual pathology is defined as the association of hippocampal sclerosis with an extrahippocampal lesion. Subtle changes in hippocampus might be overlooked in the presence of an unequivocal extrahippocampal abnormality. Seizure outcome after epilepsy surgery in cases with dual pathology is less favourable if only one of the lesions is removed. Dual pathology must always be considered in diagnostic imaging of patients with intractable epilepsy and CA. (orig.)

  6. Morphological Variations of Hippocampal Formation in Epilepsy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2013-02-01

    Full Text Available Researchers at Hospital Sao Paulo and other centers in Brazil compared the hippocampal formation (HF morphology of healthy asymptomatic individuals (n=30 with that of patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS(n=68, of patients with malformations of cortical development (MCD(n=34, and of patients with morphological HF variations without other structural signs (pure MVHF(n=12.

  7. The hypothalamic slice approach to neuroendocrinology.

    Science.gov (United States)

    Hatton, G I

    1983-07-01

    The magnocellular peptidergic cells of the supraoptic and paraventricular nuclei comprise much of what is known as the hypothalamo-neurohypophysial system and is involved in several functions, including body fluid balance, parturition and lactation. While we have learned much from experiments in vivo, they have not produced a clear understanding of some of the crucial features associated with the functioning of this system. In particular, questions relating to the osmosensitivity of magnocellular neurones and the mechanism(s) by which their characteristic firing patterns are generated have not been answered using the older approaches. Electrophysiological studies with brain slices present direct evidence for osmosensitivity, and perhaps even osmoreceptivity, of magnocellular neurones. Other evidence indicates that the phasic bursting patterns of activity associated with vasopressin-releasing neurones (a) occur in the absence of patterned chemical synaptic input, (b) may be modulated by electrotonic conduction across gap junctions connecting magnocellular neurones and (c) are likely to be generated by endogenous membrane currents. These results make untenable the formerly held idea that phasic bursting activity is dependent upon recurrent synaptic inhibition.

  8. Effects of endogenous pyrogen and prostaglandin E2 on hypothalamic neurons in rat brain slices.

    Science.gov (United States)

    Watanabe, T; Morimoto, A; Murakami, N

    1987-06-01

    We investigated the effects of endogenous pyrogen and prostaglandin E2 (PGE2) on the preoptic and anterior hypothalamic (POAH) neurons using brain slice preparations from the rat. Partially purified endogenous pyrogen did not change the activities of most of the neurons in the POAH region when applied locally through a micropipette attached to the recording electrode in proximity to the neurons. This indicates that partially purified endogenous pyrogen does not act directly on the neuronal activity in the POAH region. The partially purified endogenous pyrogen, applied into a culture chamber containing a brain slice, facilitated the activities in 24% of the total neurons tested, regardless of the thermal specificity of the neurons. Moreover, PGE2 added to the culture chamber facilitated 48% of the warm-responsive, 33% of the cold-responsive, and 29% of the thermally insensitive neurons. The direction of change in neuronal activity induced by partially purified endogenous pyrogen appears to be almost the same as that induced by PGE2 when these substances were applied by perfusion to the same neuron in the culture chamber. These results suggest that partially purified pyrogen applied to the perfusate of the culture chamber stimulates some constituents of brain tissue to synthesize and release prostaglandin, which in turn affects the neuronal activity of the POAH region.

  9. Influence of the slice thickness in CT to clinical effect

    International Nuclear Information System (INIS)

    Kimura, Kazue; Katakura, Toshihiko; Ito, Masami; Okuaki, Okihisa; Suzuki, Kenji

    1980-01-01

    CT is a kind of tomography. Therefore, what thickness of tissue is being observed in the picture - this is important in the clinical application of CT. The influence of slice thickness on the pictures, especially its clinical effect, was examined. The apparatus used is EMI CT 5005. For varying the slice thickness, it cannot be any larger than the thickness essential to the apparatus. Therefore, to make it thinner than the essential 14 mm, collimators were specially prepared, which were used on the sides of an X-ray tube and a detector. As basic observation, the revelation ability of form owing to the difference of slice thickness using acryl pipes, and the revelation ability of slice face owing to the difference of slice thickness, were examined. About clinical observation, the results for certain cases of cancer were compared with the CT images for the slice thickness of 14 mm essential to EMI CT 5005 and the slice thickness of 7 mm achieved by means of the collimators. (J.P.N.)

  10. The Slice Algorithm For Irreducible Decomposition of Monomial Ideals

    DEFF Research Database (Denmark)

    Roune, Bjarke Hammersholt

    2009-01-01

    Irreducible decomposition of monomial ideals has an increasing number of applications from biology to pure math. This paper presents the Slice Algorithm for computing irreducible decompositions, Alexander duals and socles of monomial ideals. The paper includes experiments showing good performance...

  11. Study of Energy Consumption of Potato Slices During Drying Process

    Directory of Open Access Journals (Sweden)

    Hafezi Negar

    2015-06-01

    Full Text Available One of the new methods of food drying using infrared heating under vacuum is to increase the drying rate and maintain the quality of dried product. In this study, potato slices were dried using vacuum-infrared drying. Experiments were performed with the infrared lamp power levels 100, 150 and 200 W, absolute pressure levels 20, 80, 140 and 760 mmHg, and with three thicknesses of slices 1, 2 and 3 mm, in three repetitions. The results showed that the infrared lamp power, absolute pressure and slice thickness have important effects on the drying of potato. With increasing the radiation power, reducing the absolute pressure (acts of vacuum in the dryer chamber and also reducing the thickness of potato slices, drying time and the amount of energy consumed is reduced. In relation to thermal utilization efficiency, results indicated that with increasing the infrared radiation power and decreasing the absolute pressure, thermal efficiency increased.

  12. Moxibustion upregulates hippocampal progranulin expression

    Directory of Open Access Journals (Sweden)

    Tao Yi

    2016-01-01

    Full Text Available In China, moxibustion is reported to be useful and has few side effects for chronic fatigue syndrome, but its mechanisms are largely unknown. More recently, the focus has been on the wealth of information supporting stress as a factor in chronic fatigue syndrome, and largely concerns dysregulation in the stress-related hypothalamic-pituitary-adrenal axis. In the present study, we aimed to determine the effect of moxibustion on behavioral symptoms in chronic fatigue syndrome rats and examine possible mechanisms. Rats were subjected to a combination of chronic restraint stress and forced swimming to induce chronic fatigue syndrome. The acupoints Guanyuan (CV4 and Zusanli (ST36, bilateral were simultaneously administered moxibustion. Untreated chronic fatigue syndrome rats and normal rats were used as controls. Results from the forced swimming test, open field test, tail suspension test, real-time PCR, enzyme-linked immunosorbent assay, and western blot assay showed that moxibustion treatment decreased mRNA expression of corticotropin-releasing hormone in the hypothalamus, and adrenocorticotropic hormone and corticosterone levels in plasma, and markedly increased progranulin mRNA and protein expression in the hippocampus. These findings suggest that moxibustion may relieve the behavioral symptoms of chronic fatigue syndrome, at least in part, by modulating the hypothalamic-pituitary-adrenal axis and upregulating hippocampal progranulin.

  13. Cardiac tissue slices: preparation, handling, and successful optical mapping.

    Science.gov (United States)

    Wang, Ken; Lee, Peter; Mirams, Gary R; Sarathchandra, Padmini; Borg, Thomas K; Gavaghan, David J; Kohl, Peter; Bollensdorff, Christian

    2015-05-01

    Cardiac tissue slices are becoming increasingly popular as a model system for cardiac electrophysiology and pharmacology research and development. Here, we describe in detail the preparation, handling, and optical mapping of transmembrane potential and intracellular free calcium concentration transients (CaT) in ventricular tissue slices from guinea pigs and rabbits. Slices cut in the epicardium-tangential plane contained well-aligned in-slice myocardial cell strands ("fibers") in subepicardial and midmyocardial sections. Cut with a high-precision slow-advancing microtome at a thickness of 350 to 400 μm, tissue slices preserved essential action potential (AP) properties of the precutting Langendorff-perfused heart. We identified the need for a postcutting recovery period of 36 min (guinea pig) and 63 min (rabbit) to reach 97.5% of final steady-state values for AP duration (APD) (identified by exponential fitting). There was no significant difference between the postcutting recovery dynamics in slices obtained using 2,3-butanedione 2-monoxime or blebistatin as electromechanical uncouplers during the cutting process. A rapid increase in APD, seen after cutting, was caused by exposure to ice-cold solution during the slicing procedure, not by tissue injury, differences in uncouplers, or pH-buffers (bicarbonate; HEPES). To characterize intrinsic patterns of CaT, AP, and conduction, a combination of multipoint and field stimulation should be used to avoid misinterpretation based on source-sink effects. In summary, we describe in detail the preparation, mapping, and data analysis approaches for reproducible cardiac tissue slice-based investigations into AP and CaT dynamics. Copyright © 2015 the American Physiological Society.

  14. Resource slicing in virtual wireless networks: a survey

    OpenAIRE

    Richart, Matias; Baliosian De Lazzari, Javier Ernesto; Serrat Fernández, Juan; Gorricho Moreno, Juan Luis

    2016-01-01

    New architectural and design approaches for radio access networks have appeared with the introduction of network virtualization in the wireless domain. One of these approaches splits the wireless network infrastructure into isolated virtual slices under their own management, requirements, and characteristics. Despite the advances in wireless virtualization, there are still many open issues regarding the resource allocation and isolation of wireless slices. Because of the dynamics and share...

  15. Geometry Processing of Conventionally Produced Mouse Brain Slice Images.

    Science.gov (United States)

    Agarwal, Nitin; Xu, Xiangmin; Gopi, M

    2018-04-21

    Brain mapping research in most neuroanatomical laboratories relies on conventional processing techniques, which often introduce histological artifacts such as tissue tears and tissue loss. In this paper we present techniques and algorithms for automatic registration and 3D reconstruction of conventionally produced mouse brain slices in a standardized atlas space. This is achieved first by constructing a virtual 3D mouse brain model from annotated slices of Allen Reference Atlas (ARA). Virtual re-slicing of the reconstructed model generates ARA-based slice images corresponding to the microscopic images of histological brain sections. These image pairs are aligned using a geometric approach through contour images. Histological artifacts in the microscopic images are detected and removed using Constrained Delaunay Triangulation before performing global alignment. Finally, non-linear registration is performed by solving Laplace's equation with Dirichlet boundary conditions. Our methods provide significant improvements over previously reported registration techniques for the tested slices in 3D space, especially on slices with significant histological artifacts. Further, as one of the application we count the number of neurons in various anatomical regions using a dataset of 51 microscopic slices from a single mouse brain. To the best of our knowledge the presented work is the first that automatically registers both clean as well as highly damaged high-resolutions histological slices of mouse brain to a 3D annotated reference atlas space. This work represents a significant contribution to this subfield of neuroscience as it provides tools to neuroanatomist for analyzing and processing histological data. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. NMR surprizes with thin slices and strong gradients

    Energy Technology Data Exchange (ETDEWEB)

    Gaedke, Achim; Kresse, Benjamin [Institute of Condensed Matter Physics, Technische Universitaet Darmstadt (Germany); Nestle, Nikolaus

    2008-07-01

    In the context of our work on diffusion-relaxation-coupling in thin excited slices, we perform NMR experiments in static magnetic field gradients up to 200 T/m. For slice thicknesses in the range of 10{mu}m, the frequency bandwidth of the excited slices becomes sufficiently narrow that free induction decays (FIDs) become observable despite the presence of the strong static gradient. The observed FIDs were also simulated using standard methods from MRI physics. Possible effects of diffusion during the FID duration are still minor at this slice thickness in water but might become dominant for smaller slices or more diffusive media. Furthermore, the detailed excitation structure of the RF pulses was studied in profiling experiments over the edge of a plane liquid cell. Side lobe effects to the slices will be discussed along with approaches to control them. The spatial resolution achieved in the profiling experiments furthermore allows the identification of thermal expansion phenomena in the NMR magnet. Measures to reduce the temperature drift problems are presented.

  17. Generalized Fourier slice theorem for cone-beam image reconstruction.

    Science.gov (United States)

    Zhao, Shuang-Ren; Jiang, Dazong; Yang, Kevin; Yang, Kang

    2015-01-01

    The cone-beam reconstruction theory has been proposed by Kirillov in 1961, Tuy in 1983, Feldkamp in 1984, Smith in 1985, Pierre Grangeat in 1990. The Fourier slice theorem is proposed by Bracewell 1956, which leads to the Fourier image reconstruction method for parallel-beam geometry. The Fourier slice theorem is extended to fan-beam geometry by Zhao in 1993 and 1995. By combining the above mentioned cone-beam image reconstruction theory and the above mentioned Fourier slice theory of fan-beam geometry, the Fourier slice theorem in cone-beam geometry is proposed by Zhao 1995 in short conference publication. This article offers the details of the derivation and implementation of this Fourier slice theorem for cone-beam geometry. Especially the problem of the reconstruction from Fourier domain has been overcome, which is that the value of in the origin of Fourier space is 0/0. The 0/0 type of limit is proper handled. As examples, the implementation results for the single circle and two perpendicular circle source orbits are shown. In the cone-beam reconstruction if a interpolation process is considered, the number of the calculations for the generalized Fourier slice theorem algorithm is O(N^4), which is close to the filtered back-projection method, here N is the image size of 1-dimension. However the interpolation process can be avoid, in that case the number of the calculations is O(N5).

  18. CRMPs colocalize and interact with cytoskeleton in hippocampal neurons

    Science.gov (United States)

    Yang, Yuhao; Zhao, Bo; Ji, Zhisheng; Zhang, Guowei; Zhang, Jifeng; Li, Sumei; Guo, Guoqing; Lin, Hongsheng

    2015-01-01

    CRMP family proteins (CRMPs) are widely expressed in the developing neurons, mediating a variety of fundamental functions such as growth cone guidance, neuronal polarity and axon elongation. However, whether all the CRMP proteins interact with cytoskeleton remains unknown. In this study, we found that in cultured hippocampal neurons, CRMPs mainly colocalized with tubulin and actin network in neurites. In growth cones, CRMPs colocalized with tubulinmainly in the central (C-) domain and transition zone (T-zone), less in the peripheral (P-) domain and colocalized with actin in all the C-domain, T-zone and P-domain. The correlation efficiency of CRMPs between actin was significantly higher than that between tubulin, especially in growth cones. We successfully constructed GST-CRMPs plasmids, expressed and purified the GST-CRMP proteins. By GST-pulldown assay, all the CRMP family proteins were found to beinteracted with cytoskeleton proteins. Taken together, we revealed that CRMPs were colocalized with cytoskeleton in hippocampal neurons, especially in growth cones. CRMPs can interact with both tubulin and actin, thus mediating neuronal development. PMID:26885211

  19. Synaptically evoked Ca2+ release from intracellular stores is not influenced by vesicular zinc in CA3 hippocampal pyramidal neurones.

    Science.gov (United States)

    Evstratova, Alesya; Tóth, Katalin

    2011-12-01

    The co-release of neuromodulatory substances in combination with classic neurotransmitters such as glutamate and GABA from individual presynaptic nerve terminals has the capacity to dramatically influence synaptic efficacy and plasticity. At hippocampal mossy fibre synapses vesicular zinc is suggested to serve as a cotransmitter capable of regulating calcium release from internal stores in postsynaptic CA3 pyramidal cells. Here we investigated this possibility using combined intracellular ratiometric calcium imaging and patch-clamp recording techniques. In acute hippocampal slices a brief train of mossy fibre stimulation produced a large, delayed postsynaptic Ca(2+) wave that was spatially restricted to the proximal apical dendrites of CA3 pyramidal cells within stratum lucidum. This calcium increase was sensitive to intracellularly applied heparin indicating reliance upon release from internal stores and was triggered by activation of both group I metabotropic glutamate and NMDA receptors. Importantly, treatment of slices with the membrane-impermeant zinc chelator CaEDTA did not influence the synaptically evoked postsynaptic Ca(2+) waves. Moreover, mossy fibre stimulus evoked postsynaptic Ca(2+) signals were not significantly different between wild-type and zinc transporter 3 (ZnT3) knock-out animals. Considered together our data do not support a role for vesicular zinc in regulating mossy fibre evoked Ca(2+) release from CA3 pyramidal cell internal stores.

  20. Efficacy of a new charge-balanced biphasic electrical stimulus in the isolated sciatic nerve and the hippocampal slice

    NARCIS (Netherlands)

    Cappaert, N.L.M.; Ramekers, D.; Martens, H.C.F.; Wadman, W.J.

    2013-01-01

    Most deep brain stimulators apply rectangular monophasic voltage pulses. By modifying the stimulus shape, it is possible to optimize stimulus efficacy and find the best compromise between clinical effect, minimal side effects and power consumption of the stimulus generator. In this study, we

  1. Long-Term Plasticity of Astrocytic Metabotropic Neurotransmitter Receptors Driven by Changes in Neuronal Activity in Hippocampal Slices

    OpenAIRE

    Xie, Xiaoqiao

    2011-01-01

    In addition to synaptic communication between neurons, there is now strong evidence for neuron-to-astrocyte receptor signaling in the brain. During trains of action potentials or repetitive stimulation, neurotransmitter spills out of the synapse to activate astrocytic Gq protein-coupled receptors (Gq GPCRs). To date, very little is known about the ability of astrocytic receptors to exhibit plasticity as a result of long-term changes in neuronal firing rates. Here we describe for the first tim...

  2. Radiation exposure in multi-slice versus single-slice spiral CT: results of a nationwide survey

    International Nuclear Information System (INIS)

    Brix, G.; Nagel, H.D.; Stamm, G.; Veit, R.; Lechel, U.; Griebel, J.; Galanski, M.

    2003-01-01

    Multi-slice (MS) technology increases the efficacy of CT procedures and offers new promising applications. The expanding use of MSCT, however, may result in an increase in both frequency of procedures and levels of patient exposure. It was, therefore, the aim of this study to gain an overview of MSCT examinations conducted in Germany in 2001. All MSCT facilities were requested to provide information about 14 standard examinations with respect to scan parameters and frequency. Based on this data, dosimetric quantities were estimated using an experimentally validated formalism. Results are compared with those of a previous survey for single-slice (SS) spiral CT scanners. According to the data provided for 39 dual- and 73 quad-slice systems, the average annual number of patients examined at MSCT is markedly higher than that examined at SSCT scanners (5500 vs 3500). The average effective dose to patients was changed from 7.4 mSv at single-slice to 5.5 mSv and 8.1 mSv at dual- and quad-slice scanners, respectively. There is a considerable potential for dose reduction at quad-slice systems by an optimisation of scan protocols and better education of the personnel. To avoid an increase in the collective effective dose from CT procedures, a clear medical justification is required in each case. (orig.)

  3. Taurine increases hippocampal neurogenesis in aging mice

    Directory of Open Access Journals (Sweden)

    Elias Gebara

    2015-05-01

    Full Text Available Aging is associated with increased inflammation and reduced hippocampal neurogenesis, which may in turn contribute to cognitive impairment. Taurine is a free amino acid found in numerous diets, with anti-inflammatory properties. Although abundant in the young brain, the decrease in taurine concentration with age may underlie reduced neurogenesis. Here, we assessed the effect of taurine on hippocampal neurogenesis in middle-aged mice. We found that taurine increased cell proliferation in the dentate gyrus through the activation of quiescent stem cells, resulting in increased number of stem cells and intermediate neural progenitors. Taurine had a direct effect on stem/progenitor cells proliferation, as observed in vitro, and also reduced activated microglia. Furthermore, taurine increased the survival of newborn neurons, resulting in a net increase in adult neurogenesis. Together, these results show that taurine increases several steps of adult neurogenesis and support a beneficial role of taurine on hippocampal neurogenesis in the context of brain aging.

  4. Amyloid beta-peptide(25-35) changes [Ca2+] in hippocampal neurons

    DEFF Research Database (Denmark)

    Mogensen, Helle Smidt; Beatty, D M; Morris, S J

    1998-01-01

    of A beta(25-35) on [Ca2+]i and intracellular H+ concentration ([H+]i) in single hippocampal neurons by real time fluorescence imaging using the Ca(2+)- and H(+)-specific ratio dyes, indo-1 and SNARF-1. Incubation of these cultures with A beta(25-35) for 3-12 days in vitro increased [Ca2+]i and [H......+]i in large, NMDA-responsive neurons....

  5. Adult hippocampal neurogenesis and cognitive aging

    Directory of Open Access Journals (Sweden)

    Román Darío Moreno Fernández

    2013-12-01

    Full Text Available Aging is a normal developmental process associated with neurobiological changes leading to cognitive alterations with preserved, impaired, and enhanced functions. Evidence from animal and human studies is reviewed to explore the potential role of hippocampal plasticity on age-related cognitive changes with special attention to adult hippocampal neurogenesis. Results from lesion and stimulation strategies, as well as correlation data, support either a direct or modulatory role for adult newborn neurons in cognition at advanced ages. Further research on this topic may help to develop new treatments and to improve the quality of life of older people.

  6. Disinhibition mediates a form of hippocampal long-term potentiation in area CA1.

    Directory of Open Access Journals (Sweden)

    Jake Ormond

    Full Text Available The hippocampus plays a central role in memory formation in the mammalian brain. Its ability to encode information is thought to depend on the plasticity of synaptic connections between neurons. In the pyramidal neurons constituting the primary hippocampal output to the cortex, located in area CA1, firing of presynaptic CA3 pyramidal neurons produces monosynaptic excitatory postsynaptic potentials (EPSPs followed rapidly by feedforward (disynaptic inhibitory postsynaptic potentials (IPSPs. Long-term potentiation (LTP of the monosynaptic glutamatergic inputs has become the leading model of synaptic plasticity, in part due to its dependence on NMDA receptors (NMDARs, required for spatial and temporal learning in intact animals. Using whole-cell recording in hippocampal slices from adult rats, we find that the efficacy of synaptic transmission from CA3 to CA1 can be enhanced without the induction of classic LTP at the glutamatergic inputs. Taking care not to directly stimulate inhibitory fibers, we show that the induction of GABAergic plasticity at feedforward inhibitory inputs results in the reduced shunting of excitatory currents, producing a long-term increase in the amplitude of Schaffer collateral-mediated postsynaptic potentials. Like classic LTP, disinhibition-mediated LTP requires NMDAR activation, suggesting a role in types of learning and memory attributed primarily to the former and raising the possibility of a previously unrecognized target for therapeutic intervention in disorders linked to memory deficits, as well as a potentially overlooked site of LTP expression in other areas of the brain.

  7. Disrupted Co-activation of Interneurons and Hippocampal Network after Focal Kainate Lesion

    Directory of Open Access Journals (Sweden)

    Lim-Anna Sieu

    2017-11-01

    Full Text Available GABAergic interneurons are known to control activity balance in physiological conditions and to coordinate hippocampal networks during cognitive tasks. In temporal lobe epilepsy interneuron loss and consecutive network imbalance could favor pathological hypersynchronous epileptic discharges. We tested this hypothesis in mice by in vivo unilateral epileptogenic hippocampal kainate lesion followed by in vitro recording of extracellular potentials and patch-clamp from GFP-expressing interneurons in CA3, in an optimized recording chamber. Slices from lesioned mice displayed, in addition to control synchronous events, larger epileptiform discharges. Despite some ipsi/contralateral and layer variation, interneuron density tended to decrease, average soma size to increase. Their membrane resistance decreased, capacitance increased and contralateral interneuron required higher current intensity to fire action potentials. Examination of synchronous discharges of control and larger amplitudes, revealed that interneurons were biased to fire predominantly with the largest population discharges. Altogether, these observations suggest that the overall effect of reactive cell loss, hypertrophy and reduced contralateral excitability corresponds to interneuron activity tuning to fire with larger population discharges. Such cellular and network mechanisms may contribute to a runaway path toward epilepsy.

  8. Dopamine receptor activation reorganizes neuronal ensembles during hippocampal sharp waves in vitro.

    Directory of Open Access Journals (Sweden)

    Takeyuki Miyawaki

    Full Text Available Hippocampal sharp wave (SW/ripple complexes are thought to contribute to memory consolidation. Previous studies suggest that behavioral rewards facilitate SW occurrence in vivo. However, little is known about the precise mechanism underlying this enhancement. Here, we examined the effect of dopaminergic neuromodulation on spontaneously occurring SWs in acute hippocampal slices. Local field potentials were recorded from the CA1 region. A brief (1 min treatment with dopamine led to a persistent increase in the event frequency and the magnitude of SWs. This effect lasted at least for our recording period of 45 min and did not occur in the presence of a dopamine D1/D5 receptor antagonist. Functional multineuron calcium imaging revealed that dopamine-induced SW augmentation was associated with an enriched repertoire of the firing patterns in SW events, whereas the overall tendency of individual neurons to participate in SWs and the mean number of cells participating in a single SW were maintained. Therefore, dopaminergic activation is likely to reorganize cell assemblies during SWs.

  9. Neural 17β-estradiol facilitates long-term potentiation in the hippocampal CA1 region.

    Science.gov (United States)

    Grassi, S; Tozzi, A; Costa, C; Tantucci, M; Colcelli, E; Scarduzio, M; Calabresi, P; Pettorossi, V E

    2011-09-29

    In the hippocampal formation many neuromodulators are possibly implied in the synaptic plasticity such as the long-term potentiation (LTP) induced by high-frequency stimulation (HFS) of afferent fibers. We investigated the involvement of locally synthesized neural 17β-estradiol (nE(2)) in the induction of HFS-LTP in hippocampal slices from male rats by stimulating the Schaffer collateral fibers and recording the evoked field excitatory postsynaptic potential (fEPSP) in the CA1 region. We demonstrated that either the blockade of nE(2) synthesis by the aromatase inhibitor letrozole, or the antagonism of E(2) receptors (ERs) by ICI 182,780 did not prevent the induction of HFS-LTP, but reduced its amplitude by ∼60%, without influencing its maintenance. Moreover, letrozole and ICI 182,780 did not affect the first short-term post-tetanic component of LTP and the paired-pulse facilitation (PPF). These findings demonstrate that nE(2) plays an important role in the induction phase of HFS-dependent LTP. Since the basal responses were not affected by the blocking agents, we suggest that the synthesis of nE(2) is induced or enhanced by HFS through aromatase activation. In this context, the local production of nE(2) seems to be a very effective mechanism to modulate the amplitude of LTP. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Learning, memory and hippocampal LTP in genetically obese rodents

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We have found that leptin, at physiological concentrations of 10-12 mol/L, facilitates learning and memory and LTP maintenance in Wistar rats. To explore the role of leptin recepors in learning, memory and synaptic plasticity, experiments were carried out using Zucker rats (Z), db/db mice (db), and ob/ob mice(ob). The former two have defects in leptin receptors and the latter cannot produce normal leptin. Unlike the effects observed in normal rats, high or low frequency stimulation of Schaffer collateral-CA1 synapses in hippocampal slices prepared from Z, db and ob animals failed to induce the learning and memory relevant long-term potentiation or depression in CA1 neurons. However, LTP in ob CA1 synapses was facilitated by leptin at 10-12 mol/L concentration. Moreover, the paired-pulse facilitation of CA1 synaptic potentials and intracellularly recorded postsynaptic responses to the neurotransmitters AMPA, NMDA and GABA, applied electrophoretically to the apical dendrites of CA1 neurons, were approximately the same compared to the control lean animals. In addition, unlike the second messenger responses observed in Wistar rats, calmodulin kinase Ⅱ activity in the CA1 area of Z and db animals was not activated after tetanic stimulation of the Schaffer collaterals. It has been shown that all three strains, Z, db and ob display impaired spatial learning and memory when tested in the Morris water maze. The results of these experiments indicate a close relationship between spatial learning and memory, facilitation of LTP, and calmodulin kinase Ⅱ activity.

  11. Estrogen Regulates Protein Synthesis and Actin Polymerization in Hippocampal Neurons through Different Molecular Mechanisms

    Science.gov (United States)

    Briz, Victor; Baudry, Michel

    2014-01-01

    Estrogen rapidly modulates hippocampal synaptic plasticity by activating selective membrane-associated receptors. Reorganization of the actin cytoskeleton and stimulation of mammalian target of rapamycin (mTOR)-mediated protein synthesis are two major events required for the consolidation of hippocampal long-term potentiation and memory. Estradiol regulates synaptic plasticity by interacting with both processes, but the underlying molecular mechanisms are not yet fully understood. Here, we used acute rat hippocampal slices to analyze the mechanisms underlying rapid changes in mTOR activity and actin polymerization elicited by estradiol. Estradiol-induced mTOR phosphorylation was preceded by rapid and transient activation of both extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) and by phosphatase and tensin homolog (PTEN) degradation. These effects were prevented by calpain and ERK inhibitors. Estradiol-induced mTOR stimulation did not require activation of classical estrogen receptors (ER), as specific ERα and ERβ agonists (PPT and DPN, respectively) failed to mimic this effect, and ER antagonists could not block it. Estradiol rapidly activated both RhoA and p21-activated kinase (PAK). Furthermore, a specific inhibitor of RhoA kinase (ROCK), H1152, and a potent and specific PAK inhibitor, PF-3758309, blocked estradiol-induced cofilin phosphorylation and actin polymerization. ER antagonists also blocked these effects of estrogen. Consistently, both PPT and DPN stimulated PAK and cofilin phosphorylation as well as actin polymerization. Finally, the effects of estradiol on actin polymerization were insensitive to protein synthesis inhibitors, but its stimulation of mTOR activity was impaired by latrunculin A, a drug that disrupts actin filaments. Taken together, our results indicate that estradiol regulates local protein synthesis and cytoskeletal reorganization via different molecular mechanisms and signaling pathways. PMID:24611062

  12. Altered hippocampal plasticity by prenatal kynurenine administration, kynurenine-3-monoxygenase (KMO) deletion or galantamine.

    Science.gov (United States)

    Forrest, C M; McNair, K; Pisar, M; Khalil, O S; Darlington, L G; Stone, T W

    2015-12-03

    Glutamate receptors sensitive to N-methyl-D-aspartate (NMDA) are involved in embryonic brain development but their activity may be modulated by the kynurenine pathway of tryptophan metabolism which includes an agonist (quinolinic acid) and an antagonist (kynurenic acid) at these receptors. Our previous work has shown that prenatal inhibition of the pathway produces abnormalities of brain development. In the present study kynurenine and probenecid (both 100mg/kg, doses known to increase kynurenic acid levels in the brain) were administered to female Wistar rats on embryonic days E14, E16 and E18 of gestation and the litter was allowed to develop to post-natal day P60. Western blotting revealed no changes in hippocampal expression of several proteins previously found to be altered by inhibition of the kynurenine pathway including the NMDA receptor subunits GluN1, GluN2A and GluN2B, as well as doublecortin, Proliferating Cell Nuclear Antigen (PCNA), sonic hedgehog and unco-ordinated (unc)-5H1 and 5H3. Mice lacking the enzyme kynurenine-3-monoxygenase (KMO) also showed no changes in hippocampal expression of several of these proteins or the 70-kDa and 100-kDa variants of Disrupted in Schizophrenia-1 (DISC1). Electrical excitability of pyramidal neurons in the CA1 region of hippocampal slices was unchanged, as was paired-pulse facilitation and inhibition. Long-term potentiation was decreased in the kynurenine-treated rats and in the KMO(-/-) mice, but galantamine reversed this effect in the presence of nicotinic receptor antagonists, consistent with evidence that it can potentiate glutamate at NMDA receptors. It is concluded that interference with the kynurenine pathway in utero can have lasting effects on brain function of the offspring, implying that the kynurenine pathway is involved in the regulation of early brain development. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Stretch-induced Ca2+ independent ATP release in hippocampal astrocytes.

    Science.gov (United States)

    Xiong, Yingfei; Teng, Sasa; Zheng, Lianghong; Sun, Suhua; Li, Jie; Guo, Ning; Li, Mingli; Wang, Li; Zhu, Feipeng; Wang, Changhe; Rao, Zhiren; Zhou, Zhuan

    2018-02-28

    Similar to neurons, astrocytes actively participate in synaptic transmission via releasing gliotransmitters. The Ca 2+ -dependent release of gliotransmitters includes glutamate and ATP. Following an 'on-cell-like' mechanical stimulus to a single astrocyte, Ca 2+ independent single, large, non-quantal, ATP release occurs. Astrocytic ATP release is inhibited by either selective antagonist treatment or genetic knockdown of P2X7 receptor channels. Our work suggests that ATP can be released from astrocytes via two independent pathways in hippocampal astrocytes; in addition to the known Ca 2+ -dependent vesicular release, larger non-quantal ATP release depends on P2X7 channels following mechanical stretch. Astrocytic ATP release is essential for brain functions such as synaptic long-term potentiation for learning and memory. However, whether and how ATP is released via exocytosis remains hotly debated. All previous studies of non-vesicular ATP release have used indirect assays. By contrast, two recent studies report vesicular ATP release using more direct assays. In the present study, using patch clamped 'ATP-sniffer cells', we re-investigated astrocytic ATP release at single-vesicle resolution in hippocampal astrocytes. Following an 'on-cell-like' mechanical stimulus of a single astrocyte, a Ca 2+ independent single large non-quantal ATP release occurred, in contrast to the Ca 2+ -dependent multiple small quantal ATP release in a chromaffin cell. The mechanical stimulation-induced ATP release from an astrocyte was inhibited by either exposure to a selective antagonist or genetic knockdown of P2X7 receptor channels. Functional P2X7 channels were expressed in astrocytes in hippocampal brain slices. Thus, in addition to small quantal ATP release, larger non-quantal ATP release depends on P2X7 channels in astrocytes. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

  14. Long-term plasticity in identified hippocampal GABAergic interneurons in the CA1 area in vivo.

    Science.gov (United States)

    Lau, Petrina Yau-Pok; Katona, Linda; Saghy, Peter; Newton, Kathryn; Somogyi, Peter; Lamsa, Karri P

    2017-05-01

    Long-term plasticity is well documented in synapses between glutamatergic principal cells in the cortex both in vitro and in vivo. Long-term potentiation (LTP) and -depression (LTD) have also been reported in glutamatergic connections to hippocampal GABAergic interneurons expressing parvalbumin (PV+) or nitric oxide synthase (NOS+) in brain slices, but plasticity in these cells has not been tested in vivo. We investigated synaptically-evoked suprathreshold excitation of identified hippocampal neurons in the CA1 area of urethane-anaesthetized rats. Neurons were recorded extracellularly with glass microelectrodes, and labelled with neurobiotin for anatomical analyses. Single-shock electrical stimulation of afferents from the contralateral CA1 elicited postsynaptic action potentials with monosynaptic features showing short delay (9.95 ± 0.41 ms) and small jitter in 13 neurons through the commissural pathway. Theta-burst stimulation (TBS) generated LTP of the synaptically-evoked spike probability in pyramidal cells, and in a bistratified cell and two unidentified fast-spiking interneurons. On the contrary, PV+ basket cells and NOS+ ivy cells exhibited either LTD or LTP. An identified axo-axonic cell failed to show long-term change in its response to stimulation. Discharge of the cells did not explain whether LTP or LTD was generated. For the fast-spiking interneurons, as a group, no correlation was found between plasticity and local field potential oscillations (1-3 or 3-6 Hz components) recorded immediately prior to TBS. The results demonstrate activity-induced long-term plasticity in synaptic excitation of hippocampal PV+ and NOS+ interneurons in vivo. Physiological and pathological activity patterns in vivo may generate similar plasticity in these interneurons.

  15. Memory impairment in multiple sclerosis: Relevance of hippocampal activation and hippocampal connectivity

    NARCIS (Netherlands)

    Hulst, H.E.; Schoonheim, M.M.; van Geest, Q.; Uitdehaag, B.M.J.; Barkhof, F.; Geurts, J.J.G.

    2015-01-01

    Background: Memory impairment is frequent in multiple sclerosis (MS), but it is unclear what functional brain changes underlie this cognitive deterioration. Objective: To investigate functional hippocampal activation and connectivity, in relation to memory performance in MS. Methods: Structural and

  16. Improved biochemical preservation of heart slices during cold storage.

    Science.gov (United States)

    Bull, D A; Reid, B B; Connors, R C; Albanil, A; Stringham, J C; Karwande, S V

    2000-01-01

    Development of myocardial preservation solutions requires the use of whole organ models which are animal and labor intensive. These models rely on physiologic rather than biochemical endpoints, making accurate comparison of the relative efficacy of individual solution components difficult. We hypothesized that myocardial slices could be used to assess preservation of biochemical function during cold storage. Whole rat hearts were precision cut into slices with a thickness of 200 microm and preserved at 4 degrees C in one of the following solutions: Columbia University (CU), University of Wisconsin (UW), D5 0.2% normal saline with 20 meq/l KCL (QNS), normal saline (NS), or a novel cardiac preservation solution (NPS) developed using this model. Myocardial biochemical function was assessed by ATP content (etamoles ATP/mg wet weight) and capacity for protein synthesis (counts per minute (cpm)/mg protein) immediately following slicing (0 hours), and at 6, 12, 18, and 24 hours of cold storage. Six slices were assayed at each time point for each solution. The data were analyzed using analysis of variance and are presented as the mean +/- standard deviation. ATP content was higher in the heart slices stored in the NPS compared to all other solutions at 6, 12, 18 and 24 hours of cold storage (p cold storage (p cold storage.

  17. Improved biochemical preservation of lung slices during cold storage.

    Science.gov (United States)

    Bull, D A; Connors, R C; Reid, B B; Albanil, A; Stringham, J C; Karwande, S V

    2000-05-15

    Development of lung preservation solutions typically requires whole-organ models which are animal and labor intensive. These models rely on physiologic rather than biochemical endpoints, making accurate comparison of the relative efficacy of individual solution components difficult. We hypothesized that lung slices could be used to assess preservation of biochemical function during cold storage. Whole rat lungs were precision cut into slices with a thickness of 500 microm and preserved at 4 degrees C in the following solutions: University of Wisconsin (UW), Euro-Collins (EC), low-potassium-dextran (LPD), Kyoto (K), normal saline (NS), or a novel lung preservation solution (NPS) developed using this model. Lung biochemical function was assessed by ATP content (etamol ATP/mg wet wt) and capacity for protein synthesis (cpm/mg protein) immediately following slicing (0 h) and at 6, 12, 18, and 24 h of cold storage. Six slices were assayed at each time point for each solution. The data were analyzed using analysis of variance and are presented as means +/- SD. ATP content was significantly higher in the lung slices stored in NPS compared with all other solutions at each time point (P cold storage. Copyright 2000 Academic Press.

  18. [Standardization of production of process Notopterygii Rhizoma et Radix slices].

    Science.gov (United States)

    Sun, Zhen-Yang; Wang, Ying-Zi; Nie, Rui-Jie; Zhang, Jing-Zhen; Wang, Si-Yu

    2017-12-01

    Notopterol, isoimperatorin, volatile oil and extract (water and ethanol) were used as the research objects in this study to investigate the effects of different softening method, slice thickness and drying methods on the quality of Notopterygii Rhizoma et Radix slices, and the experimental data were analyzed by homogeneous distance evaluation method. The results showed that different softening, cutting and drying processes could affect the content of five components in Notopterygii Rhizoma et Radix incisum. The best processing technology of Notopterygii Rhizoma et Radix slices was as follows: non-medicinal parts were removed; mildewed and rot as well as moth-eaten parts were removed; washed by the flowing drinking water; stacked in the drug pool; moistening method was used for softening, where 1/8 volume of water was sprayed for every 1 kg of herbs every 2 h; upper part of herbs covered with clean and moist cotton, and cut into thick slices (2-4 mm) after 12 h moistening until appropriate softness, then received blast drying for 4 h at 50 ℃, and turned over for 2 times during the drying. The process is practical and provides the experimental basis for the standardization of the processing of Notopterygii Rhizoma et Radix, with great significance to improve the quality of Notopterygii Rhizoma et Radix slices. Copyright© by the Chinese Pharmaceutical Association.

  19. Effect of acetylcholine receptors on the pain-related electrical activities in the hippocampal CA3 region of morphine-addicted rats

    Directory of Open Access Journals (Sweden)

    Guan Zeng Li

    2015-07-01

    Full Text Available Objective(s:To determine the effect of acetylcholine (ACh, pilocarpine, and atropine on pain evoked responses of pain excited neurons (PEN and pain inhibited neurons (PIN in hippocampal CA3 region of morphine addicted rats. Materials and Methods:Female Wistar rats, weighing between 230-260 g were used in this study. Morphine addicted rats were generated by subcutaneous injection of increasing concentrations of morphine hydrochloride for six days. Trains of electrical impulses applied to the sciatic nerve were used as noxious stimulation and the evoked electrical activities of PEN or PIN in hippocampal CA3 area were recorded using extracellular electrophysiological recording techniques in hippocampal slices. The effect of acetylcholine receptor stimulation byACh, the muscarinic agonist pilocarpine, and the muscarinic antagonist atropine on the pain evoked responses of pain related electrical activities was analyzed in hippocampal CA3 area of morphine addicted rats. Results:Intra-CA3 microinjection of ACh (2 μg/1 μl or pilocarpine (2 μg/1 μl decreased the discharge frequency and prolonged the firing latency of PEN, but increased the discharge frequency and shortened the firing inhibitory duration (ID of PIN. The intra-CA3 administration of atropine (0.5 μg/1 μl produced opposite effect. The peak activity of cholinergic modulators was 2 to 4 min later in morphine addicted rats compared to peak activity previously observed in normal rats. Conclusion: ACh dependent modulation of noxious stimulation exists in hippocampal CA3 area of morphine addicted rats. Morphine treatment may shift the sensitivity of pain related neurons towards a delayed response to muscarinergic neurotransmission in hippocampal CA3 region.

  20. Effect of acetylcholine receptors on the pain-related electrical activities in the hippocampal CA3 region of morphine-addicted rats.

    Science.gov (United States)

    Li, Guan Zeng; Liu, Zhe Hui; Wei, XinYa; Zhao, Pan; Yang, Chun Xiao; Xu, Man Ying

    2015-07-01

    To determine the effect of acetylcholine (ACh), pilocarpine, and atropine on pain evoked responses of pain excited neurons (PEN) and pain inhibited neurons (PIN) in hippocampal CA3 region of morphine addicted rats. Female Wistar rats, weighing between 230-260 g were used in this study. Morphine addicted rats were generated by subcutaneous injection of increasing concentrations of morphine hydrochloride for six days. Trains of electrical impulses applied to the sciatic nerve were used as noxious stimulation and the evoked electrical activities of PEN or PIN in hippocampal CA3 area were recorded using extracellular electrophysiological recording techniques in hippocampal slices. The effect of acetylcholine receptor stimulation by ACh, the muscarinic agonist pilocarpine, and the muscarinic antagonist atropine on the pain evoked responses of pain related electrical activities was analyzed in hippocampal CA3 area of morphine addicted rats. Intra-CA3 microinjection of ACh (2 μg/1 μl) or pilocarpine (2 μg/1 μl) decreased the discharge frequency and prolonged the firing latency of PEN, but increased the discharge frequency and shortened the firing inhibitory duration (ID) of PIN. The intra-CA3 administration of atropine (0.5 μg/1 μl) produced opposite effect. The peak activity of cholinergic modulators was 2 to 4 min later in morphine addicted rats compared to peak activity previously observed in normal rats. ACh dependent modulation of noxious stimulation exists in hippocampal CA3 area of morphine addicted rats. Morphine treatment may shift the sensitivity of pain related neurons towards a delayed response to muscarinergic neurotransmission in hippocampal CA3 region.

  1. Hippocampal insulin resistance and cognitive dysfunction

    NARCIS (Netherlands)

    Biessels, Geert Jan; Reagan, Lawrence P.

    2015-01-01

    Clinical studies suggest a link between type 2 diabetes mellitus (T2DM) and insulin resistance (IR) and cognitive dysfunction, but there are significant gaps in our knowledge of the mechanisms underlying this relationship. Animal models of IR help to bridge these gaps and point to hippocampal IR as

  2. Hippocampal Abnormalities after Prolonged Febrile Convulsions

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2003-11-01

    Full Text Available Hippocampal volume and T2 relaxation times were determined in an MRI study of 14 children with prolonged febrile convulsions (PFC who were investigated, 1 within 5 days of a PFC, and 2 at follow-up 4-8 months after the acute study, at the Institute of Child Health, University College, and Great Ormond Street Hospital, London, UK.

  3. Amnesia due to bilateral hippocampal glioblastoma

    International Nuclear Information System (INIS)

    Shimauchi, M.; Wakisaka, S.; Kinoshita, K.

    1989-01-01

    The authors report a unique case of glioblastoma which caused permanent amnesia. Magnetic resonance imaging showed the lesion to be limited to the hippocampal formation bilaterally. Although glioblastoma extends frequently into fiber pathways and expands into the opposite cerebral hemisphere, making a 'butterfly' lesion, it is unusual for it to invade the limbic system selectively to this extent. (orig.)

  4. Hippocampal theta frequency shifts and operant behaviour

    NARCIS (Netherlands)

    Lopes da Silva, F.H.; Kamp, A.

    1. 1. A shift of hippocampal dominant theta frequency to 6 c/sec has been demonstrated in the post-reward period in two dogs, which occurs consistently related in time to a well defined behavioural pattern in the course of an operant conditioning paradigm. 2. 2. The frequency shift was detected and

  5. Hippocampal gamma oscillations increase with memory load

    NARCIS (Netherlands)

    Van Vugt, Marieke K.; Schulze-Bonhage, Andreas; Litt, Brian; Brandt, Armin; Kahana, Michael J.

    2010-01-01

    Although the hippocampus plays a crucial role in encoding and retrieval of contextually mediated episodic memories, considerable controversy surrounds the role of the hippocampus in short-term or working memory. To examine both hippocampal and neocortical contributions to working memory function, we

  6. Single fluoxetine treatment before but not after stress prevents stress-induced hippocampal long-term depression and spatial memory retrieval impairment in rats

    Science.gov (United States)

    Han, Huili; Dai, Chunfang; Dong, Zhifang

    2015-01-01

    A growing body of evidence has shown that chronic treatment with fluoxetine, a widely prescribed medication for treatment of depression, can affect synaptic plasticity in the adult central nervous system. However, it is not well understood whether acute fluoxetine influences synaptic plasticity, especially on hippocampal CA1 long-term depression (LTD), and if so, whether it subsequently impacts hippocampal-dependent spatial memory. Here, we reported that LTD facilitated by elevated-platform stress in hippocampal slices was completely prevented by fluoxetine administration (10 mg/kg, i.p.) 30 min before stress. The LTD was not, however, significantly inhibited by fluoxetine administration immediately after stress. Similarly, fluoxetine incubation (10 μM) during electrophysiological recordings also displayed no influence on the stress-facilitated LTD. In addition, behavioral results showed that a single fluoxetine treatment 30 min before but not after acute stress fully reversed the impairment of spatial memory retrieval in the Morris water maze paradigm. Taken together, these results suggest that acute fluoxetine treatment only before, but not after stress, can prevent hippocampal CA1 LTD and spatial memory retrieval impairment caused by behavioral stress in adult animals. PMID:26218751

  7. Chelation of hippocampal zinc enhances long-term potentiation and synaptic tagging/capture in CA1 pyramidal neurons of aged rats: implications to aging and memory.

    Science.gov (United States)

    Shetty, Mahesh Shivarama; Sharma, Mahima; Sajikumar, Sreedharan

    2017-02-01

    Aging is associated with decline in cognitive functions, prominently in the memory consolidation and association capabilities. Hippocampus plays a crucial role in the formation and maintenance of long-term associative memories, and a significant body of evidence shows that impairments in hippocampal function correlate with aging-related memory loss. A number of studies have implicated alterations in hippocampal synaptic plasticity, such as long-term potentiation (LTP), in age-related cognitive decline although exact mechanisms underlying are not completely clear. Zinc deficiency and the resultant adverse effects on cognition have been well studied. However, the role of excess of zinc in synaptic plasticity, especially in aging, is not addressed well. Here, we have investigated the hippocampal zinc levels and the impairments in synaptic plasticity, such as LTP and synaptic tagging and capture (STC), in the CA1 region of acute hippocampal slices from 82- to 84-week-old male Wistar rats. We report increased zinc levels in the hippocampus of aged rats and also deficits in the tetani-induced and dopaminergic agonist-induced late-LTP and STC. The observed deficits in synaptic plasticity were restored upon chelation of zinc using a cell-permeable chelator. These data suggest that functional plasticity and associativity can be successfully established in aged neural networks by chelating zinc with cell-permeable chelating agents. © 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  8. Color changes and acrylamide formation in fried potato slices

    DEFF Research Database (Denmark)

    Pedreschi, Franco; Moyano, Pedro; Kaack, Karl

    2005-01-01

    The objective of this work was to study the kinetics of browning during deep-fat frying of blanched and unblanched potato chips by using the dynamic method and to find a relationship between browning development and acrylamide formation. Prior to frying, potato slices were blanched in hot water...... at 85degreesC for 3.5 min. Unblanched slices were used as the control. Control and blanched potato slices (Panda variety, diameter: 37 mm, width: 2.2 mm) were fried at 120, 150 and 180degreesC until reaching moisture contents of similar to1.8% (total basis) and their acrylamide content and final color...... were measured. Color changes were recorded at different sampling times during frying at the three mentioned temperatures using the chromatic redness parameter a(*). Experimental data of surface temperature, moisture content and color change in potato chips during frying were fit to empirical...

  9. An overview of 5G network slicing architecture

    Science.gov (United States)

    Chen, Qiang; Wang, Xiaolei; Lv, Yingying

    2018-05-01

    With the development of mobile communication technology, the traditional single network model has been unable to meet the needs of users, and the demand for differentiated services is increasing. In order to solve this problem, the fifth generation of mobile communication technology came into being, and as one of the key technologies of 5G, network slice is the core technology of network virtualization and software defined network, enabling network slices to flexibly provide one or more network services according to users' needs[1]. Each slice can independently tailor the network functions according to the requirements of the business scene and the traffic model and manage the layout of the corresponding network resources, to improve the flexibility of network services and the utilization of resources, and enhance the robustness and reliability of the whole network [2].

  10. Hippocampal sclerosis in advanced age: clinical and pathological features.

    Science.gov (United States)

    Nelson, Peter T; Schmitt, Frederick A; Lin, Yushun; Abner, Erin L; Jicha, Gregory A; Patel, Ela; Thomason, Paula C; Neltner, Janna H; Smith, Charles D; Santacruz, Karen S; Sonnen, Joshua A; Poon, Leonard W; Gearing, Marla; Green, Robert C; Woodard, John L; Van Eldik, Linda J; Kryscio, Richard J

    2011-05-01

    Hippocampal sclerosis is a relatively common neuropathological finding (∼10% of individuals over the age of 85 years) characterized by cell loss and gliosis in the hippocampus that is not explained by Alzheimer's disease. Hippocampal sclerosis pathology can be associated with different underlying causes, and we refer to hippocampal sclerosis in the aged brain as hippocampal sclerosis associated with ageing. Much remains unknown about hippocampal sclerosis associated with ageing. We combined three different large autopsy cohorts: University of Kentucky Alzheimer's Disease Centre, the Nun Study and the Georgia Centenarian Study to obtain a pool of 1110 patients, all of whom were evaluated neuropathologically at the University of Kentucky. We focused on the subset of cases with neuropathology-confirmed hippocampal sclerosis (n=106). For individuals aged≥95 years at death (n=179 in our sample), each year of life beyond the age of 95 years correlated with increased prevalence of hippocampal sclerosis pathology and decreased prevalence of 'definite' Alzheimer's disease pathology. Aberrant TAR DNA protein 43 immunohistochemistry was seen in 89.9% of hippocampal sclerosis positive patients compared with 9.7% of hippocampal sclerosis negative patients. TAR DNA protein 43 immunohistochemistry can be used to demonstrate that the disease is usually bilateral even when hippocampal sclerosis pathology is not obvious by haematoxylin and eosin stains. TAR DNA protein 43 immunohistochemistry was negative on brain sections from younger individuals (n=10) after hippocampectomy due to seizures, who had pathologically confirmed hippocampal sclerosis. There was no association between cases with hippocampal sclerosis associated with ageing and apolipoprotein E genotype. Age of death and clinical features of hippocampal sclerosis associated with ageing (with or without aberrant TAR DNA protein 43) were distinct from previously published cases of frontotemporal lobar degeneration TAR

  11. Preservation of low slice emittance in bunch compressors

    Directory of Open Access Journals (Sweden)

    S. Bettoni

    2016-03-01

    Full Text Available Minimizing the dilution of the electron beam emittance is crucial for the performance of accelerators, in particular for free electron laser facilities, where the length of the machine and the efficiency of the lasing process depend on it. Measurements performed at the SwissFEL Injector Test Facility revealed an increase in slice emittance after compressing the bunch even for moderate compression factors. The phenomenon was experimentally studied by characterizing the dependence of the effect on beam and machine parameters relevant for the bunch compression. The reproduction of these measurements in simulation required the use of a 3D beam dynamics model along the bunch compressor that includes coherent synchrotron radiation. Our investigations identified transverse effects, such as coherent synchrotron radiation and transverse space charge as the sources of the observed emittance dilution, excluding other effects, such as chromatic effects on single slices or spurious dispersion. We also present studies, both experimental and simulation based, on the effect of the optics mismatch of the slices on the variation of the slice emittance along the bunch. After a corresponding reoptimization of the beam optics in the test facility we reached slice emittances below 200 nm for the central slices along the longitudinal dimension with a moderate increase up to 300 nm in the head and tail for a compression factor of 7.5 and a bunch charge of 200 pC, equivalent to a final current of 150 A, at about 230 MeV energy.

  12. ASIC-like, proton-activated currents in rat hippocampal neurons.

    Science.gov (United States)

    Baron, Anne; Waldmann, Rainer; Lazdunski, Michel

    2002-03-01

    The expression of mRNA for acid sensing ion channels (ASIC) subunits ASIC1a, ASIC2a and ASIC2b has been reported in hippocampal neurons, but the presence of functional hippocampal ASIC channels was never assessed. We report here the first characterization of ASIC-like currents in rat hippocampal neurons in primary culture. An extracellular pH drop induces a transient Na(+) current followed by a sustained non-selective cation current. This current is highly sensitive to pH with an activation threshold around pH 6.9 and a pH(0.5) of 6.2. About half of the total peak current is inhibited by the spider toxin PcTX1, which is specific for homomeric ASIC1a channels. The remaining PcTX1-resistant ASIC-like current is increased by 300 microM Zn(2+) and, whereas not fully activated at pH 5, it shows a pH(0.5) of 6.0 between pH 7.4 and 5. We have previously shown that Zn(2+) is a co-activator of ASIC2a-containing channels. Thus, the hippocampal transient ASIC-like current appears to be generated by a mixture of homomeric ASIC1a channels and ASIC2a-containing channels, probably heteromeric ASIC1a+2a channels. The sustained non-selective current suggests the involvement of ASIC2b-containing heteromeric channels. Activation of the hippocampal ASIC-like current by a pH drop to 6.9 or 6.6 induces a transient depolarization which itself triggers an initial action potential (AP) followed by a sustained depolarization and trains of APs. Zn(2+) increases the acid sensitivity of ASIC channels, and consequently neuronal excitability. It is probably an important co-activator of ASIC channels in the central nervous system.

  13. Insulin modulates hippocampally-mediated spatial working memory via glucose transporter-4.

    Science.gov (United States)

    Pearson-Leary, J; Jahagirdar, V; Sage, J; McNay, E C

    2018-02-15

    The insulin-regulated glucose transporter, GluT4, is a key molecule in peripheral insulin signaling. Although GluT4 is abundantly expressed in neurons of specific brain regions such as the hippocampus, the functional role of neuronal GluT4 is unclear. Here, we used pharmacological inhibition of GluT4-mediated glucose uptake to determine whether GluT4 mediates insulin-mediated glucose uptake in the hippocampus. Consistent with previous reports, we found that glucose utilization increased in the dorsal hippocampus of male rats during spontaneous alternation (SA), a hippocampally-mediated spatial working memory task. We previously showed that insulin signaling within the hippocampus is required for processing this task, and that administration of exogenous insulin enhances performance. At baseline levels of hippocampal insulin, inhibition of GluT4-mediated glucose uptake did not affect SA performance. However, inhibition of an upstream regulator of GluT4, Akt, did impair SA performance. Conversely, when a memory-enhancing dose of insulin was delivered to the hippocampus prior to SA-testing, inhibition of GluT4-mediated glucose transport prevented cognitive enhancement. These data suggest that baseline hippocampal cognitive processing does not require functional hippocampal GluT4, but that cognitive enhancement by supra-baseline insulin does. Consistent with these findings, we found that in neuronal cell culture, insulin increases glucose utilization in a GluT4-dependent manner. Collectively, these data demonstrate a key role for GluT4 in transducing the procognitive effects of elevated hippocampal insulin. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. (Non)perturbative gravity, nonlocality, and nice slices

    International Nuclear Information System (INIS)

    Giddings, Steven B.

    2006-01-01

    Perturbative dynamics of gravity is investigated for high-energy scattering and in black hole backgrounds. In the latter case, a straightforward perturbative analysis fails, in a close parallel to the failure of the former when the impact parameter reaches the Schwarzschild radius. This suggests a flaw in a semiclassical description of physics on spatial slices that intersect both outgoing Hawking radiation and matter that has carried information into a black hole; such slices are instrumental in a general argument for black hole information loss. This indicates a possible role for the proposal that nonperturbative gravitational physics is intrinsically nonlocal

  15. Verification-Driven Slicing of UML/OCL Models

    DEFF Research Database (Denmark)

    Shaikh, Asadullah; Clarisó Viladrosa, Robert; Wiil, Uffe Kock

    2010-01-01

    computational complexity can limit their scalability. In this paper, we consider a specific static model (UML class diagrams annotated with unrestricted OCL constraints) and a specific property to verify (satisfiability, i.e., “is it possible to create objects without violating any constraint?”). Current...... approaches to this problem have an exponential worst-case runtime. We propose a technique to improve their scalability by partitioning the original model into submodels (slices) which can be verified independently and where irrelevant information has been abstracted. The definition of the slicing procedure...

  16. Investigation of the slice sensitivity profile for step-and-shoot mode multi-slice computed tomography

    International Nuclear Information System (INIS)

    Hsieh Jiang

    2001-01-01

    Multislice computed tomography (MCT) is one of the recent technology advancements in CT. Compared to single slice CT, MCT significantly improves examination time, x-ray tube efficiency, and contrast material utilization. Although the scan mode of MCT is predominately helical, step-and-shoot (axial) scans continue to be an important part of routine clinical protocols. In this paper, we present a detailed investigation on the slice sensitivity profile (SSP) of MCT in the step-and-shoot mode. Our investigation shows that, unlike single slice CT, the SSP for MCT exhibits multiple peaks and valleys resulting from intercell gaps between detector rows. To fully understand the characteristics of the SSP, we developed an analytical model to predict the behavior of MCT. We propose a simple experimental technique that can quickly and accurately measure SSP. The impact of the SSP on image artifacts and low contrast detectability is also investigated

  17. Imaging skeletal anatomy of injured cervical spine specimens: comparison of single-slice vs multi-slice helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Obenauer, S.; Alamo, L.; Herold, T.; Funke, M.; Kopka, L.; Grabbe, E. [Department of Radiology, Georg August-University Goettingen, Robert-Koch-Strasse 40, 37075 Goettingen (Germany)

    2002-08-01

    Our objective was to compare a single-slice CT (SS-CT) scanner with a multi-slice CT (MS-CT) scanner in the depiction of osseous anatomic structures and fractures of the upper cervical spine. Two cervical spine specimens with artificial trauma were scanned with a SS-CT scanner (HighSpeed, CT/i, GE, Milwaukee, Wis.) by using various collimations (1, 3, 5 mm) and pitch factors (1, 1.5, 2, 3) and a four-slice helical CT scanner (LightSpeed, QX/i, GE, Milwaukee, Wis.) by using various table speeds ranging from 3.75 to 15 mm/rotation for a pitch of 0.75 and from 7.5 to 30 mm/rotation for a pitch of 1.5. Images were reconstructed with an interval of 1 mm. Sagittal and coronal multiplanar reconstructions of the primary and reconstructed data set were performed. For MS-CT a tube current resulting in equivalent image noise as with SS-CT was used. All images were judged by two observers using a 4-point scale. The best image quality for SS-CT was achieved with the smallest slice thickness (1 mm) and a pitch smaller than 2 resulting in a table speed of up to 2 mm per gantry rotation (4 points). A reduction of the slice thickness rather than of the table speed proved to be beneficial at MS-CT. Therefore, the optimal scan protocol in MS-CT included a slice thickness of 1.25 mm with a table speed of 7.5 mm/360 using a pitch of 1.5 (4 points), resulting in a faster scan time than when a pitch of 0.75 (4 points) was used. This study indicates that MS-CT could provide equivalent image quality at approximately four times the volume coverage speed of SS-CT. (orig.)

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

    Science.gov (United States)

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

    2015-01-01

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

  19. A slice through a prototype LHC bending magnet

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    This slice through a prototype LHC magnet clearly shows the superconducting cable in several blocks around the central hole – the beam pipe in which the LHC’s accelerated beams will travel. Magnet design is crucial to the LHC’s success and this sample is among the first to be built to the final cable configuration.

  20. Continuous Slice Functional Calculus in Quaternionic Hilbert Spaces

    Science.gov (United States)

    Ghiloni, Riccardo; Moretti, Valter; Perotti, Alessandro

    2013-04-01

    The aim of this work is to define a continuous functional calculus in quaternionic Hilbert spaces, starting from basic issues regarding the notion of spherical spectrum of a normal operator. As properties of the spherical spectrum suggest, the class of continuous functions to consider in this setting is the one of slice quaternionic functions. Slice functions generalize the concept of slice regular function, which comprises power series with quaternionic coefficients on one side and that can be seen as an effective generalization to quaternions of holomorphic functions of one complex variable. The notion of slice function allows to introduce suitable classes of real, complex and quaternionic C*-algebras and to define, on each of these C*-algebras, a functional calculus for quaternionic normal operators. In particular, we establish several versions of the spectral map theorem. Some of the results are proved also for unbounded operators. However, the mentioned continuous functional calculi are defined only for bounded normal operators. Some comments on the physical significance of our work are included.

  1. Blanching, salting and sun drying of different pumpkin fruit slices.

    Science.gov (United States)

    Workneh, T S; Zinash, A; Woldetsadik, K

    2014-11-01

    The study was aimed at assessing the quality of pumpkin (Cucuribita Spp.) slices that were subjected to pre-drying treatments and drying using two drying methods (uncontrolled sun and oven) fruit accessions. Pre-drying had significant (P ≤ 0.05) effect on the quality of dried pumpkin slices. 10 % salt solution dipped pumpkin fruit slices had good chemical quality. The two-way interaction between drying methods and pre-drying treatments had significant (P ≤ 0.05) effect on chemical qualities. Pumpkin subjected to salt solution dipping treatment and oven dried had higher chemical concentrations. Among the pumpkin fruit accessions, pumpkin accession 8007 had the superior TSS, total sugar and sugar to acid ratio after drying. Among the three pre-drying treatment, salt solution dipping treatment had significant (P ≤ 0.05) effect and the most efficient pre-drying treatment to retain the quality of dried pumpkin fruits without significant chemical quality deterioration. Salt dipping treatment combined with low temperature (60 °C) oven air circulation drying is recommended to maintain quality of dried pumpkin slices. However, since direct sun drying needs extended drying time due to fluctuation in temperature, it is recommended to develop or select best successful solar dryer for use in combination with pre-drying salt dipping or blanching treatments.

  2. A slicing-based approach for locating type errors

    NARCIS (Netherlands)

    T.B. Dinesh; F. Tip (Frank)

    1998-01-01

    htmlabstractThe effectiveness of a type checking tool strongly depends on the accuracy of the positional information that is associated with type errors. We present an approach where the location associated with an error message e is defined as a slice P_e of the program P being type checked. We

  3. A slicing-based approach for locating type errors

    NARCIS (Netherlands)

    T.B. Dinesh; F. Tip (Frank)

    1998-01-01

    textabstractThe effectiveness of a type checking tool strongly depends on the accuracy of the positional information that is associated with type errors. We present an approach where the location associated with an error message e is defined as a slice P_e of the program P being type checked. We

  4. Bacteriological Quality of Dried Sliced Beef (Kilishi) Sold In Ilorin ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    ABSTRACT: The bacteriological quality of dried sliced beef (kilishi) obtained from three selling points in. Ilorin metropolis was determined in order to ascertain its safety. The total bacterial count, Enterobacteriaceae count, Staphylococcus aureus count and E.coli counts were used as index of bacteriological quality. Samples.

  5. Thin slice impressions : How advertising evaluation depends on exposure duration

    NARCIS (Netherlands)

    Pieters, Rik; Elsen, M.; Wedel, M.

    The duration of exposures to advertising is often brief. Then, consumers can only obtain “thin slices” of information from the ads, such as which product and brand are being promoted. This research is the first to examine the influence that such thin slices of information have on ad and brand

  6. A novel lung slice system with compromised antioxidant defenses

    Energy Technology Data Exchange (ETDEWEB)

    Hardwick, S.J.; Adam, A.; Cohen, G.M. (Univ. of London (England)); Smith, L.L. (Imperial Chemical Industries PLC, Cheshire (England))

    1990-04-01

    In order to facilitate the study of oxidative stress in lung tissue, rat lung slices with impaired antioxidant defenses were prepared and used. Incubation of lung slices with the antineoplastic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (100 {mu}M) in an amino acid-rich medium for 45 min produced a near-maximal (approximately 85%), irreversible inhibition of glutathione reductase, accompanied by only a modest (approximately 15%) decrease in pulmonary nonprotein sulfhydryls (NPSH) and no alteration in intracellular ATP, NADP{sup +}, and NADPH levels. The amounts of NADP(H), ATP, and NPSH were stable over a 4-hr incubation period following the removal from BCNU. The viability of the system was further evaluated by measuring the rate of evolution of {sup 14}CO{sub 2} from D-({sup 14}C(U))-glucose. The rates of evolution were almost identical in the compromised system when compared with control slices over a 4-hr time period. By using slices with compromised oxidative defenses, preliminary results have been obtained with paraquat, nitrofurantoin, and 2,3-dimethoxy-1,4-naphthoquinone.

  7. Automatic Solitary Lung Nodule Detection in Computed Tomography Images Slices

    Science.gov (United States)

    Sentana, I. W. B.; Jawas, N.; Asri, S. A.

    2018-01-01

    Lung nodule is an early indicator of some lung diseases, including lung cancer. In Computed Tomography (CT) based image, nodule is known as a shape that appears brighter than lung surrounding. This research aim to develop an application that automatically detect lung nodule in CT images. There are some steps in algorithm such as image acquisition and conversion, image binarization, lung segmentation, blob detection, and classification. Data acquisition is a step to taking image slice by slice from the original *.dicom format and then each image slices is converted into *.tif image format. Binarization that tailoring Otsu algorithm, than separated the background and foreground part of each image slices. After removing the background part, the next step is to segment part of the lung only so the nodule can localized easier. Once again Otsu algorithm is use to detect nodule blob in localized lung area. The final step is tailoring Support Vector Machine (SVM) to classify the nodule. The application has succeed detecting near round nodule with a certain threshold of size. Those detecting result shows drawback in part of thresholding size and shape of nodule that need to enhance in the next part of the research. The algorithm also cannot detect nodule that attached to wall and Lung Chanel, since it depend the searching only on colour differences.

  8. The Sliced Pineapple Grid Feature for Predicting Grasping Affordances

    DEFF Research Database (Denmark)

    Thomsen, Mikkel Tang; Kraft, Dirk; Krüger, Norbert

    2017-01-01

    The problem of grasping unknown objects utilising vision is addressed in this work by introducing a novel feature, the Sliced Pineapple Grid Feature (SPGF). The SPGF encode semi-local surfaces and allows for distinguishing structures such as “walls”,“edges” and “rims”. These structures are shown...

  9. Water-activity of dehydrated guava slices sweeteners

    International Nuclear Information System (INIS)

    Ayub, M.; Zeb, A.; Ullah, J.

    2005-01-01

    A study was carried out to investigate the individual and combined effect of caloric sweeteners (sucrose, glucose and fructose) and non-caloric sweeteners (saccharine, cyclamate and aspartame) along with antioxidants (citric acid and ascorbic acid) and chemical preservatives (potassium metabisulphite and potassium sorbate) on the water-activity (a/sub w/) of dehydrated guava slices. Different dilutions of caloric sweeteners (20, 30, 40 and 50 degree brix (bx) and non-caloric sweeteners (equivalent to sucrose sweetness) were used. Guava slices were osmotically dehydrated in these solutions and then dehydrated initially at 0 and then at 60 degree C to final moisture-content of 20-25%. Guava slices prepared with sucrose: glucose 7:3 potassium metabisulphite, ascorbic acid and citric acid produced best quality products, which have minimum (a/sub w/) and best overall sensory characteristics. The analysis showed that treatments and their various concentrations had a significant effect (p=0.05) on (a/sub w/) of dehydrated guava slices. (author)

  10. Colour behaviour on mango ( Mangifera indica ) slices self ...

    African Journals Online (AJOL)

    The effect of the syrup composition on behaviour colour of self stabilized mango slices in glass jars by hurdle technology during 180 days of storage was studied through 26-2 fractional factorial design. L* (lightness), a* (redness and greenness), and b* (yellowness and blueness) values were measured with a colorimeter ...

  11. A novel lung slice system with compromised antioxidant defenses

    International Nuclear Information System (INIS)

    Hardwick, S.J.; Adam, A.; Cohen, G.M.; Smith, L.L.

    1990-01-01

    In order to facilitate the study of oxidative stress in lung tissue, rat lung slices with impaired antioxidant defenses were prepared and used. Incubation of lung slices with the antineoplastic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (100 μM) in an amino acid-rich medium for 45 min produced a near-maximal (approximately 85%), irreversible inhibition of glutathione reductase, accompanied by only a modest (approximately 15%) decrease in pulmonary nonprotein sulfhydryls (NPSH) and no alteration in intracellular ATP, NADP + , and NADPH levels. The amounts of NADP(H), ATP, and NPSH were stable over a 4-hr incubation period following the removal from BCNU. The viability of the system was further evaluated by measuring the rate of evolution of 14 CO 2 from D-[ 14 C(U)]-glucose. The rates of evolution were almost identical in the compromised system when compared with control slices over a 4-hr time period. By using slices with compromised oxidative defenses, preliminary results have been obtained with paraquat, nitrofurantoin, and 2,3-dimethoxy-1,4-naphthoquinone

  12. Gravitational clustering of galaxies in the CfA slice

    International Nuclear Information System (INIS)

    Crane, P.; Saslaw, W.C.

    1988-01-01

    The clustering properties of the Galaxies in the CfA slice have been analyzed by comparing the properties of the neighbor distributions to the predictions of gravitational clustering theory. The agreement is excellent and implies that the observed structures can be explained by gravitational effects alone and do not require exotic explanations

  13. [Protective effect of Uncaria rhynchophylla total alkaloids pretreatment on hippocampal neurons after acute hypoxia].

    Science.gov (United States)

    Liu, Wei; Zhang, Zhao-qin; Zhao, Xiao-min; Gao, Yun-sheng

    2006-05-01

    To investigate the effect of Uncaria rhynchophylla total alkaloids (RTA) pretreatment on the voltage-gated sodium currents of the rat hippocampal neurons after acute hypoxia. Primary cultured hippocampal neurons were divided into RTA pre-treated and non-pretreated groups. Patch clamp whole-cell recording was used to compare the voltage-gated sodium current amplitude and threshold with those before hypoxia. After acute hypoxia, sodium current amplitude was significantly decreased and its threshold was upside. RTA pretreatment could inhibit the reduction of sodium current amplitude. RTA pretreatment alleviates the acute hypoxia-induced change of sodium currents, which may be one of the mechanisms for protective effect of RTA on cells.

  14. Fan beam image reconstruction with generalized Fourier slice theorem.

    Science.gov (United States)

    Zhao, Shuangren; Yang, Kang; Yang, Kevin

    2014-01-01

    For parallel beam geometry the Fourier reconstruction works via the Fourier slice theorem (or central slice theorem, projection slice theorem). For fan beam situation, Fourier slice can be extended to a generalized Fourier slice theorem (GFST) for fan-beam image reconstruction. We have briefly introduced this method in a conference. This paper reintroduces the GFST method for fan beam geometry in details. The GFST method can be described as following: the Fourier plane is filled by adding up the contributions from all fanbeam projections individually; thereby the values in the Fourier plane are directly calculated for Cartesian coordinates such avoiding the interpolation from polar to Cartesian coordinates in the Fourier domain; inverse fast Fourier transform is applied to the image in Fourier plane and leads to a reconstructed image in spacial domain. The reconstructed image is compared between the result of the GFST method and the result from the filtered backprojection (FBP) method. The major differences of the GFST and the FBP methods are: (1) The interpolation process are at different data sets. The interpolation of the GFST method is at projection data. The interpolation of the FBP method is at filtered projection data. (2) The filtering process are done in different places. The filtering process of the GFST is at Fourier domain. The filtering process of the FBP method is the ramp filter which is done at projections. The resolution of ramp filter is variable with different location but the filter in the Fourier domain lead to resolution invariable with location. One advantage of the GFST method over the FBP method is in short scan situation, an exact solution can be obtained with the GFST method, but it can not be obtained with the FBP method. The calculation of both the GFST and the FBP methods are at O(N^3), where N is the number of pixel in one dimension.

  15. Prediction of dementia by hippocampal shape analysis

    DEFF Research Database (Denmark)

    Achterberg, Hakim C.; van der Lijn, Fedde; den Heijer, Tom

    2010-01-01

    This work investigates the possibility of predicting future onset of dementia in subjects who are cognitively normal, using hippocampal shape and volume information extracted from MRI scans. A group of 47 subjects who were non-demented normal at the time of the MRI acquisition, but were diagnosed...... with dementia during a 9 year follow-up period, was selected from a large population based cohort study. 47 Age and gender matched subjects who stayed cognitively intact were selected from the same cohort study as a control group. The hippocampi were automatically segmented and all segmentations were inspected...... and, if necessary, manually corrected by a trained observer. From this data a statistical model of hippocampal shape was constructed, using an entropy-based particle system. This shape model provided the input for a Support Vector Machine classifier to predict dementia. Cross validation experiments...

  16. Relationships between hippocampal activity and breathing patterns

    DEFF Research Database (Denmark)

    Harper, R M; Poe, G R; Rector, D M

    1998-01-01

    Single cell discharge, EEG activity, and optical changes accompanying alterations in breathing patterns, as well as the knowledge that respiratory musculature is heavily involved in movement and other behavioral acts, implicate hippocampal regions in some aspects of breathing control. The control...... is unlikely to reside in oscillatory breathing movements, because such patterns emerge in preparations retaining only the medulla (and perhaps only the spinal cord). However, momentary changes in breathing patterns induced by affect, startle, whole-body movement changes, or compensatory ventilatory changes...... of hippocampal contributions to breathing control should be viewed in the context that significant interactions exist between blood pressure changes and ventilation, and that modest breathing challenges, such as exposure to hypercapnia or to increased resistive loads, bring into action a vast array of brain...

  17. Hippocampal Processing of Ambiguity Enhances Fear Memory.

    Science.gov (United States)

    Amadi, Ugwechi; Lim, Seh Hong; Liu, Elizabeth; Baratta, Michael V; Goosens, Ki A

    2017-02-01

    Despite the ubiquitous use of Pavlovian fear conditioning as a model for fear learning, the highly predictable conditions used in the laboratory do not resemble real-world conditions, in which dangerous situations can lead to unpleasant outcomes in unpredictable ways. In the current experiments, we varied the timing of aversive events after predictive cues in rodents and discovered that temporal ambiguity of aversive events greatly enhances fear. During fear conditioning with unpredictably timed aversive events, pharmacological inactivation of the dorsal hippocampus or optogenetic silencing of cornu ammonis 1 cells during aversive negative prediction errors prevented this enhancement of fear without affecting fear learning for predictable events. Dorsal hippocampal inactivation also prevented ambiguity-related enhancement of fear during auditory fear conditioning under a partial-reinforcement schedule. These results reveal that information about the timing and occurrence of aversive events is rapidly acquired and that unexpectedly timed or omitted aversive events generate hippocampal signals to enhance fear learning.

  18. Hippocampal Neurogenesis, Depressive Disorders, and Antidepressant Therapy

    Directory of Open Access Journals (Sweden)

    Eleni Paizanis

    2007-01-01

    Full Text Available There is a growing body of evidence that neural stem cells reside in the adult central nervous system where neurogenesis occurs throughout lifespan. Neurogenesis concerns mainly two areas in the brain: the subgranular zone of the dentate gyrus in the hippocampus and the subventricular zone, where it is controlled by several trophic factors and neuroactive molecules. Neurogenesis is involved in processes such as learning and memory and accumulating evidence implicates hippocampal neurogenesis in the physiopathology of depression. We herein review experimental and clinical data demonstrating that stress and antidepressant treatments affect neurogenesis in opposite direction in rodents. In particular, the stimulation of hippocampal neurogenesis by all types of antidepressant drugs supports the view that neuroplastic phenomena are involved in the physiopathology of depression and underlie—at least partly—antidepressant therapy.

  19. A Compressed Sensing Perspective of Hippocampal Function

    Directory of Open Access Journals (Sweden)

    Panagiotis ePetrantonakis

    2014-08-01

    Full Text Available Hippocampus is one of the most important information processing units in the brain. Input from the cortex passes through convergent axon pathways to the downstream hippocampal subregions and, after being appropriately processed, is fanned out back to the cortex. Here, we review evidence of the hypothesis that information flow and processing in the hippocampus complies with the principles of Compressed Sensing (CS. The CS theory comprises a mathematical framework that describes how and under which conditions, restricted sampling of information (data set can lead to condensed, yet concise, forms of the initial, subsampled information entity (i.e. of the original data set. In this work, hippocampus related regions and their respective circuitry are presented as a CS-based system whose different components collaborate to realize efficient memory encoding and decoding processes. This proposition introduces a unifying mathematical framework for hippocampal function and opens new avenues for exploring coding and decoding strategies in the brain.

  20. Contamination of knives and graters by bacterial foodborne pathogens during slicing and grating of produce.

    Science.gov (United States)

    Erickson, Marilyn C; Liao, Jean; Cannon, Jennifer L; Ortega, Ynes R

    2015-12-01

    Poor hygiene and improper food preparation practices in consumers' homes have previously been demonstrated as contributing to foodborne diseases. To address potential cross-contamination by kitchen utensils in the home, a series of studies was conducted to determine the extent to which the use of a knife or grater on fresh produce would lead to the utensil's contamination with Escherichia coli O157:H7 or Salmonella enterica. When shredding inoculated carrots (ca. 5.3 log CFU/carrot), all graters became contaminated and the number of E. coli O157:H7 present on the utensil was significantly greater than Salmonella (p Contamination of knives after slicing inoculated produce (4.9-5.4 log CFU/produce item) could only be detected by enrichment culture. After slicing tomatoes, honeydew melons, strawberries, cucumbers, and cantaloupes, the average prevalence of knife contamination by the two pathogens was 43%, 17%, 15%, 7%, and 3%, respectively. No significant increase in the incidence or level of contamination occurred on the utensils when residues were present (p > 0.05); however, subsequent contamination of 7 produce items processed with the contaminated utensils did occur. These results highlight the necessity of proper sanitization of these utensils when used in preparation of raw produce. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Effect of simultaneous infrared dry-blanching and dehydration on quality characteristics of carrot slices

    Science.gov (United States)

    This study investigated the effects of various processing parameters on carrot slices exposed to infrared (IR) radiation heating for achieving simultaneous infrared dry-blanching and dehydration (SIRDBD). The investigated parameters were product surface temperature, slice thickness and processing ti...

  2. Calcium current homeostasis and synaptic deficits in hippocampal neurons from Kelch-like 1 knockout mice

    Directory of Open Access Journals (Sweden)

    Paula Patricia Perissinotti

    2015-01-01

    Full Text Available Kelch-like 1 (KLHL1 is a neuronal actin-binding protein that modulates voltage-gated CaV2.1 (P/Q-type and CaV3.2 (α1H T-type calcium channels; KLHL1 knockdown experiments (KD cause down-regulation of both channel types and altered synaptic properties in cultured rat hippocampal neurons (Perissinotti et al., 2014. Here, we studied the effect of ablation of KLHL1 on calcium channel function and synaptic properties in cultured hippocampal neurons from KLHL1 knockout (KO mice. Western blot data showed the P/Q-type channel α1A subunit was less abundant in KO hippocampus compared to wildtype (WT; and PQ-type calcium currents were smaller in KO neurons than WT during early days in vitro, although this decrease was compensated for at late stages by increases in L-type calcium current. In contrast, T-type currents did not change in culture. However, biophysical properties and western blot analysis revealed a differential contribution of T-type channel isoforms in the KO, with CaV3.2 α1H subunit being down-regulated and CaV3.1 α1G up-regulated. Synapsin I levels were reduced in the KO hippocampus; cultured neurons displayed a concomitant reduction in synapsin I puncta and decreased miniature excitatory postsynaptic current (mEPSC frequency. In summary, genetic ablation of the calcium channel modulator resulted in compensatory mechanisms to maintain calcium current homeostasis in hippocampal KO neurons; however, synaptic alterations resulted in a reduction of excitatory synapse number, causing an imbalance of the excitatory-inhibitory synaptic input ratio favoring inhibition.

  3. Reduction of acrylamide formation in potato slices during frying

    DEFF Research Database (Denmark)

    Pedreschi, Franco; Kaack, K.; Granby, Kit

    2004-01-01

    and 40 min; 90degreesC for 2 and 9 min); (iii) immersed in citric acid solutions of different concentrations (10 and 20 g/l) for half an hour. Glucose and asparagine concentration was determined in potato slices before frying, whereas acrylamide content was determined in the resultant fried potato chips...... on average 76% and 68% of the glucose and asparagine content compared to the control. Potato slices blanched at 50degreesC for 70 min surprisingly had a very low acrylamide content (28 mum/kg) even when they were fried at 190degreesC. Potato immersion in citric acid solutions of 10 and 20 g/l reduced...

  4. The physiology of rodent beta-cells in pancreas slices.

    Science.gov (United States)

    Rupnik, M

    2009-01-01

    Beta-cells in pancreatic islets form complex syncytia. Sufficient cell-to-cell electrical coupling seems to ensure coordinated depolarization pattern and insulin release that can be further modulated by rich innervation. The complex structure and coordinated action develop after birth during fast proliferation of the endocrine tissue. These emergent properties can be lost due to various reasons later in life and can lead to glucose intolerance and diabetes mellitus. Pancreas slice is a novel method of choice to study the physiology of beta-cells still embedded in their normal cellulo-social context. I present major advantages, list drawbacks and provide an overview on recent advances in our understanding of the physiology of beta-cells using the pancreas slice approach.

  5. Microbiological quality of sliced and block mozzarella cheese

    Directory of Open Access Journals (Sweden)

    Mariana Fontanetti Marinheiro

    2015-06-01

    Full Text Available The aim of this study was to verify the microbiological quality of mozzarella cheese sold in retail markets of Pelotas, Rio Grande do Sul, Brazil. Forty samples of mozzarella cheese were analyzed, comprising 20 samples of block cheese and 20 of sliced cheese. The cheese samples were analyzed for thermotolerant coliform counts and coagulase positive staphylococci counts, and presence of Salmonella spp and Listeria monocytogenes. The percentage of 12,5% and 5% of the sliced and block cheese samples analyzed, respectively, exceeded the microbiological standards accepted by Brazilian legislation. These results indicate the need for a better product monitoring and more concern with hygiene and sanitary practices during industrial process.

  6. Comparison between powder and slices diffraction methods in teeth samples

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, Marcos V.; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (IF/UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada; Porto, Isabel M. [Universidade Estadual de Campinas (FOP/UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia; Gerlach, Raquel F. [Universidade de Sao Paulo (FORP/USP), Rieirao Preto, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia, Estomatologia e Fisiologia; Costa, Fanny N. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LIN/COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2011-07-01

    Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10{sup -1}0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

  7. Analysis of aliasing artifacts in 16-slice helical CT

    International Nuclear Information System (INIS)

    Chen Wei; Liu Jingkang; Ou Xiaoguang; Li Wenzheng; Liao Weihua; Yan Ang

    2006-01-01

    Objective: To recognize the features of aliasing artifacts on CT images, and to investigate the effects of imaging parameters on the magnitude of this artifacts. Methods: An adult dry skull was placed in a plastic water-filled container and scanned with a PHILIPS 16-slice helical CT. All the acquired transaxial images by using several different acquisition or reconstruction parameters were examined for comparative assessment of the aliasing artifacts. Results: The aliasing artifacts could be seen in most instances and characterized as the spokewise patterns emanating from the edges of high contrast structure as its radius varies sharply in the longitudinal direction. The images that scanned with pitch of 0.3, 0.6 and 0.9, respectively, showed aliasing artifacts, and its severities increased with pitches escalated (detector combination 16 x 1.5, reconstruction thickness 2 mm); There were more significant aliasing artifacts on the images reconstructed with 0.8 mm slice width compared with 1-mm slice width, and no aliasing artifacts were observed on the images reconstructed with 2-mm slice width (detector combination 16 x 0.75, pitch 0.6); No artifacts were perceived on the images scanned with detector combination 16 x 0.75, while presented evidently with the use of detector combination 16 x 1.5 (pitch 0.6, reconstruction thickness 2 mm); The degrees of aliasing artifacts were unaltered when reconstruction interval and tube current changed. Conclusions: Aliasing artifacts are caused by undersampling. When the operator choose the thinner sampling thickness, lower pitch and a much wider reconstruction thickness judiciously, aliasing artifacts could be effectively mitigated or suppressed. (authors)

  8. On the concordance genus of topologically slice knots

    OpenAIRE

    Hom, Jennifer

    2012-01-01

    The concordance genus of a knot K is the minimum Seifert genus of all knots smoothly concordant to K. Concordance genus is bounded below by the 4-ball genus and above by the Seifert genus. We give a lower bound for the concordance genus of K coming from the knot Floer complex of K. As an application, we prove that there are topologically slice knots with 4-ball genus equal to one and arbitrarily large concordance genus.

  9. Comparison between powder and slices diffraction methods in teeth samples

    International Nuclear Information System (INIS)

    Colaco, Marcos V.; Barroso, Regina C.; Porto, Isabel M.; Gerlach, Raquel F.; Costa, Fanny N.

    2011-01-01

    Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10 -1 0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

  10. 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

  11. Dried fruit breadfruit slices by Refractive Window™ technique

    Directory of Open Access Journals (Sweden)

    Diego F. Tirado

    2016-01-01

    Full Text Available A large amount of products are dried due several reasons as preservation, weight reduction and improvement of stability. However, on the market are not offered low-cost and high quality products simultaneously. Although there are effective methods of dehydrating foods such as freeze drying, which preserves the flavor, color and vitamins, they are poor accessibility technologies. Therefore, alternative processes are required to be efficient and economical. The aim of this research was compare drying kinetics of sliced of breadfruit (Artocarpus communis using the technique of Refractive Window® (VR with the tray drying. To carry out this study, sliced of 1 and 2 mm thick were used. Refractive window drying was performed with the water bath temperature to 92 °C; and tray drying at 62 °C and an air velocity of 0.52 m/s. During the Refractive window drying technique, the moisture content reached the lower than tray drying levels. Similarly it happened with samples of 1 mm, which, having a smaller diameter reached lower moisture levels than samples 2 mm. The higher diffusivities were obtained during drying sliced VR 1 and 2 mm with coefficients of 6.13 and 3.90*10-9 m2/s respectively.

  12. Development of an electrically operated cassava slicing machine

    Directory of Open Access Journals (Sweden)

    I. S. Aji

    2013-08-01

    Full Text Available Labor input in manual cassava chips processing is very high and product quality is low. This paper presents the design and construction of an electrically operated cassava slicing machine that requires only one person to operate. Efficiency, portability, ease of operation, corrosion prevention of slicing component of the machine, force required to slice a cassava tuber, capacity of 10 kg/min and uniformity in the size of the cassava chips were considered in the design and fabrication of the machine. The performance of the machine was evaluated with cassava of average length and diameter of 253 mm and 60 mm respectively at an average speed of 154 rpm. The machine produced 5.3 kg of chips of 10 mm length and 60 mm diameter in 1 minute. The efficiency of the machine was 95.6% with respect to the quantity of the input cassava. The chips were found to be well chipped to the designed thickness, shape and of generally similar size. Galvanized steel sheets were used in the cutting section to avoid corrosion of components. The machine is portable and easy to operate which can be adopted for cassava processing in a medium size industry.

  13. Drying of carrot slices in a triple pass solar dryer

    Directory of Open Access Journals (Sweden)

    Seshachalam Kesavan

    2017-01-01

    Full Text Available An indirect triple pass forced convection solar dryer was developed and its performance was evaluated for drying of carrot slices. The drying experiments were carried out under the meteorological conditions of Coimbatore city in India during the year 2016. The experimental set-up consists of a blower, triple pass packed bed air collector (using sand with wire mesh absorber plate, and a drying chamber. The air mass flow rate was optimized to 0.062 kg/s. The initial moisture content of the carrot slices was reduced from 87.5% (on wet basis to the final moisture content of 10% (wet basis in 6 h duration. The thin layer drying characteristics were analyzed using twelve mathematical models available in open literature. The results showed that the pick-up efficiency of the dryer was varied in the range between 14 and 43% with an average air collector thermal efficiency of 44% during the experimentation. The drying characteristics of carrot slices was predicted with good degree of accuracy using Wang and Singh drying model.

  14. BDNF val(66)met affects hippocampal volume and emotion-related hippocampal memory activity

    NARCIS (Netherlands)

    Molendijk, M. L.; van Tol, M-J; Penninx, B. W. J. H.; van der Wee, N. J. A.; Aleman, A.; Veltman, D. J.; Spinhoven, P.; Elzinga, B. M.

    2012-01-01

    The val(66)met polymorphism on the BDNF gene has been reported to explain individual differences in hippocampal volume and memory-related activity. These findings, however, have not been replicated consistently and no studies to date controlled for the potentially confounding impact of early life

  15. Hippocampal EEG and behaviour in dog. I. Hippocampal EEG correlates of gross motor behaviour

    NARCIS (Netherlands)

    Arnolds, D.E.A.T.; Lopes da Silva, F.H.; Aitink, J.W.; Kamp, A.

    It was shown that rewarding spectral shifts (i.e. increase in amplitude or peak frequency of the hippocampal EEG) causes a solitary dog to show increased motor behaviour. Rewarded spectral shifts concurred with a variety of behavioural transitions. It was found that statistically significant

  16. Preservation of hippocampal neuron numbers and hippocampal subfield volumes in behaviorally characterized aged tree shrews

    NARCIS (Netherlands)

    Keuker, J.I.H.; de Biurrun, G.; Luiten, P.G.M.; Fuchs, E.

    2004-01-01

    Aging is associated with a decreased ability to store and retrieve information. The hippocampal formation plays a critical role in such memory processes, and its integrity is affected during normal aging. We used tree shrews (Tupaia belangeri) as an animal model of aging, because in many

  17. Normal mediastinal and hilar lymph nodes evaluated by 5 mm slice bolus injection CT scan

    International Nuclear Information System (INIS)

    Yamamoto, Takako; Tsukada, Hiroshi; Koizumi, Naoya; Akita, Shinichi; Oda, Junichi; Sakai, Kunio

    1995-01-01

    We evaluated the number and size of normal mediastinal and hilar lymph nodes by 5 mm slice bolus injection CT (12 patients), compared with 10 mm slice CT (12 patients). More lymph nodes were clearly demonstrated by 5 mm slice CT than by 10 mm slice CT. Especially left-sided tracheobronchial (no.4), subaortic (no.5), subcarinal (no.7) and hilar lymph nodes were clearly visible. We concluded 5 mm slice bolus injection CT was useful to evaluate mediastinal and hilar lymph nodes. (author)

  18. Involvement of glucocorticoid-mediated Zn2+ signaling in attenuation of hippocampal CA1 LTP by acute stress.

    Science.gov (United States)

    Takeda, Atsushi; Suzuki, Miki; Tamano, Haruna; Takada, Shunsuke; Ide, Kazuki; Oku, Naoto

    2012-03-01

    Glucocorticoid-glutamatergic interactions have been proposed as a potential model to explain stress-mediated impairment of cognition. However, it is unknown whether glucocorticoid-zincergic interactions are involved in this impairment. Histochemically reactive zinc (Zn(2+)) is co-released with glutamate from zincergic neurons. In the present study, involvement of synaptic Zn(2+) in stress-induced attenuation of CA1 LTP was examined in hippocampal slices from young rats after exposure to tail suspension stress for 30s, which significantly increased serum corticosterone. Stress-induced attenuation of CA1 LTP was ameliorated by administration of clioquinol, a membrane permeable zinc chelator, to rats prior to exposure to stress, implying that the reduction of synaptic Zn(2+) by clioquinol participates in this amelioration. To pursue the involvement of corticosterone-mediated Zn(2+) signal in the attenuated CA1 LTP by stress, dynamics of synaptic Zn(2+) was checked in hippocampal slices exposed to corticosterone. Corticosterone increased extracellular Zn(2+) levels measured with ZnAF-2 dose-dependently, as well as the intracellular Ca(2+) levels measured with calcium orange AM, suggesting that corticosterone excites zincergic neurons in the hippocampus and increases Zn(2+) release from the neuron terminals. Intracellular Zn(2+) levels measured with ZnAF-2DA were also increased dose-dependently, but not in the coexistence of CaEDTA, a membrane-impermeable zinc chelator, suggesting that intracellular Zn(2+) levels is increased by the influx of extracellular Zn(2+). Furthermore, corticosterone-induced attenuation of CA1 LTP was abolished in the coexistence of CaEDTA. The present study suggests that corticosterone-mediated increase in postsynaptic Zn(2+) signal in the cytosolic compartment is involved in the attenuation of CA1 LTP after exposure to acute stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Diazinon and diazoxon impair the ability of astrocytes to foster neurite outgrowth in primary hippocampal neurons

    International Nuclear Information System (INIS)

    Pizzurro, Daniella M.; Dao, Khoi; Costa, Lucio G.

    2014-01-01

    Evidence from in vivo and epidemiological studies suggests that organophosphorus insecticides (OPs) are developmental neurotoxicants, but possible underlying mechanisms are still unclear. Astrocytes are increasingly recognized for their active role in normal neuronal development. This study sought to investigate whether the widely-used OP diazinon (DZ), and its oxygen metabolite diazoxon (DZO), would affect glial–neuronal interactions as a potential mechanism of developmental neurotoxicity. Specifically, we investigated the effects of DZ and DZO on the ability of astrocytes to foster neurite outgrowth in primary hippocampal neurons. The results show that both DZ and DZO adversely affect astrocyte function, resulting in inhibited neurite outgrowth in hippocampal neurons. This effect appears to be mediated by oxidative stress, as indicated by OP-induced increased reactive oxygen species production in astrocytes and prevention of neurite outgrowth inhibition by antioxidants. The concentrations of OPs were devoid of cytotoxicity, and cause limited acetylcholinesterase inhibition in astrocytes (18 and 25% for DZ and DZO, respectively). Among astrocytic neuritogenic factors, the most important one is the extracellular matrix protein fibronectin. DZ and DZO decreased levels of fibronectin in astrocytes, and this effect was also attenuated by antioxidants. Underscoring the importance of fibronectin in this context, adding exogenous fibronectin to the co-culture system successfully prevented inhibition of neurite outgrowth caused by DZ and DZO. These results indicate that DZ and DZO increase oxidative stress in astrocytes, and this in turn modulates astrocytic fibronectin, leading to impaired neurite outgrowth in hippocampal neurons. - Highlights: • DZ and DZO inhibit astrocyte-mediated neurite outgrowth in rat hippocampal neurons. • Oxidative stress is involved in inhibition of neuritogenesis by DZ and DZO. • DZ and DZO decrease expression of the neuritogenic

  20. Diazinon and diazoxon impair the ability of astrocytes to foster neurite outgrowth in primary hippocampal neurons

    Energy Technology Data Exchange (ETDEWEB)

    Pizzurro, Daniella M.; Dao, Khoi [Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Costa, Lucio G. [Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Department of Neuroscience, University of Parma, Parma (Italy)

    2014-02-01

    Evidence from in vivo and epidemiological studies suggests that organophosphorus insecticides (OPs) are developmental neurotoxicants, but possible underlying mechanisms are still unclear. Astrocytes are increasingly recognized for their active role in normal neuronal development. This study sought to investigate whether the widely-used OP diazinon (DZ), and its oxygen metabolite diazoxon (DZO), would affect glial–neuronal interactions as a potential mechanism of developmental neurotoxicity. Specifically, we investigated the effects of DZ and DZO on the ability of astrocytes to foster neurite outgrowth in primary hippocampal neurons. The results show that both DZ and DZO adversely affect astrocyte function, resulting in inhibited neurite outgrowth in hippocampal neurons. This effect appears to be mediated by oxidative stress, as indicated by OP-induced increased reactive oxygen species production in astrocytes and prevention of neurite outgrowth inhibition by antioxidants. The concentrations of OPs were devoid of cytotoxicity, and cause limited acetylcholinesterase inhibition in astrocytes (18 and 25% for DZ and DZO, respectively). Among astrocytic neuritogenic factors, the most important one is the extracellular matrix protein fibronectin. DZ and DZO decreased levels of fibronectin in astrocytes, and this effect was also attenuated by antioxidants. Underscoring the importance of fibronectin in this context, adding exogenous fibronectin to the co-culture system successfully prevented inhibition of neurite outgrowth caused by DZ and DZO. These results indicate that DZ and DZO increase oxidative stress in astrocytes, and this in turn modulates astrocytic fibronectin, leading to impaired neurite outgrowth in hippocampal neurons. - Highlights: • DZ and DZO inhibit astrocyte-mediated neurite outgrowth in rat hippocampal neurons. • Oxidative stress is involved in inhibition of neuritogenesis by DZ and DZO. • DZ and DZO decrease expression of the neuritogenic

  1. Human limbic encephalitis serum enhances hippocampal mossy fiber-CA3 pyramidal cell synaptic transmission.

    Science.gov (United States)

    Lalic, Tatjana; Pettingill, Philippa; Vincent, Angela; Capogna, Marco

    2011-01-01

    Limbic encephalitis (LE) is a central nervous system (CNS) disease characterized by subacute onset of memory loss and epileptic seizures. A well-recog