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Sample records for bdnf receptors converge

  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. BDNF released during neuropathic pain potentiates NMDA receptors in primary afferent terminals.

    Science.gov (United States)

    Chen, Wenling; Walwyn, Wendy; Ennes, Helena S; Kim, Hyeyoung; McRoberts, James A; Marvizón, Juan Carlos G

    2014-05-01

    NMDA receptors in primary afferent terminals can contribute to hyperalgesia by increasing neurotransmitter release. In rats and mice, we found that the ability of intrathecal NMDA to induce neurokinin 1 receptor (NK1R) internalization (a measure of substance P release) required a previous injection of BDNF. Selective knock-down of NMDA receptors in primary afferents decreased NMDA-induced NK1R internalization, confirming the presynaptic location of these receptors. The effect of BDNF was mediated by tropomyosin-related kinase B (trkB) receptors and not p75 neurotrophin receptors (p75(NTR) ), because it was not produced by proBDNF and was inhibited by the trkB antagonist ANA-12 but not by the p75(NTR) inhibitor TAT-Pep5. These effects are probably mediated through the truncated form of the trkB receptor as there is little expression of full-length trkB in dorsal root ganglion (DRG) neurons. Src family kinase inhibitors blocked the effect of BDNF, suggesting that trkB receptors promote the activation of these NMDA receptors by Src family kinase phosphorylation. Western blots of cultured DRG neurons revealed that BDNF increased Tyr(1472) phosphorylation of the NR2B subunit of the NMDA receptor, known to have a potentiating effect. Patch-clamp recordings showed that BDNF, but not proBDNF, increased NMDA receptor currents in cultured DRG neurons. NMDA-induced NK1R internalization was also enabled in a neuropathic pain model or by activating dorsal horn microglia with lipopolysaccharide. These effects were decreased by a BDNF scavenger, a trkB receptor antagonist and a Src family kinase inhibitor, indicating that BDNF released by microglia potentiates NMDA receptors in primary afferents during neuropathic pain. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  3. Cerebral 5-HT2A receptor and serotonin transporter binding in humans are not affected by the val66met BDNF polymorphism status or blood BDNF levels

    DEFF Research Database (Denmark)

    Klein, Anders Bue; Trajkovska, Viktorija; Erritzoe, David;

    2010-01-01

    Recent studies have proposed an interrelation between the brain-derived neurotrophic factor (BDNF) val66met polymorphism and the serotonin system. In this study, we investigated whether the BDNF val66met polymorphism or blood BDNF levels are associated with cerebral 5-hydroxytryptamine 2A (5-HT(2A......)) receptor or serotonin transporter (SERT) binding in healthy subjects. No statistically significant differences in 5-HT(2A) receptor or SERT binding were found between the val/val and met carriers, nor were blood BDNF values associated with SERT binding or 5-HT(2A) receptor binding. In conclusion, val66met...... BDNF polymorphism status is not associated with changes in the serotonergic system. Moreover, BDNF levels in blood do not correlate with either 5-HT(2A) or SERT binding....

  4. The BDNF Val66Met polymorphism impairs NMDA receptor-dependent synaptic plasticity in the hippocampus.

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    Ninan, Ipe; Bath, Kevin G; Dagar, Karishma; Perez-Castro, Rosalia; Plummer, Mark R; Lee, Francis S; Chao, Moses V

    2010-06-30

    The Val66Met polymorphism in the brain-derived neurotrophic factor (BDNF) gene results in a defect in regulated release of BDNF and affects episodic memory and affective behaviors. However, the precise role of the BDNF Val66Met polymorphism in hippocampal synaptic transmission and plasticity has not yet been studied. Therefore, we examined synaptic properties in the hippocampal CA3-CA1 synapses of BDNF(Met/Met) mice and matched wild-type mice. Although basal glutamatergic neurotransmission was normal, both young and adult mice showed a significant reduction in NMDA receptor-dependent long-term potentiation. We also found that NMDA receptor-dependent long-term depression was decreased in BDNF(Met/Met) mice. However, mGluR-dependent long-term depression was not affected by the BDNF Val66Met polymorphism. Consistent with the NMDA receptor-dependent synaptic plasticity impairment, we observed a significant decrease in NMDA receptor neurotransmission in the CA1 pyramidal neurons of BDNF(Met/Met) mice. Thus, these results show that the BDNF Val66Met polymorphism has a direct effect on NMDA receptor transmission, which may account for changes in synaptic plasticity in the hippocampus.

  5. BDNF up-regulates alpha7 nicotinic acetylcholine receptor levels on subpopulations of hippocampal interneurons.

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    Massey, Kerri A; Zago, Wagner M; Berg, Darwin K

    2006-12-01

    In the hippocampus, brain-derived neurotrophic factor (BDNF) regulates a number of synaptic components. Among these are nicotinic acetylcholine receptors containing alpha7 subunits (alpha7-nAChRs), which are interesting because of their relative abundance in the hippocampus and their high relative calcium permeability. We show here that BDNF elevates surface and intracellular pools of alpha7-nAChRs on cultured hippocampal neurons and that glutamatergic activity is both necessary and sufficient for the effect. Blocking transmission through NMDA receptors with APV blocked the BDNF effect; increasing spontaneous excitatory activity with the GABA(A) receptor antagonist bicuculline replicated the BDNF effect. BDNF antibodies blocked the BDNF-mediated increase but not the bicuculline one, consistent with enhanced glutamatergic activity acting downstream from BDNF. Increased alpha7-nAChR clusters were most prominent on interneuron subtypes known to directly innervate excitatory neurons. The results suggest that BDNF, acting through glutamatergic transmission, can modulate hippocampal output in part by controlling alpha7-nAChR levels.

  6. BDNF and its receptors in human myasthenic thymus: implications for cell fate in thymic pathology.

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    Berzi, Angela; Ayata, C Korcan; Cavalcante, Paola; Falcone, Chiara; Candiago, Elisabetta; Motta, Teresio; Bernasconi, Pia; Hohlfeld, Reinhard; Mantegazza, Renato; Meinl, Edgar; Farina, Cinthia

    2008-07-15

    Here we show that in myasthenic thymus several cell types, including thymic epithelial cells (TEC) and immune cells, were the source and the target of the neurotrophic factor brain-derived growth factor (BDNF). Interestingly, many actively proliferating medullary thymocytes expressed the receptor TrkB in vivo in involuted thymus, while this population was lost in hyperplastic or neoplastic thymuses. Furthermore, in hyperplastic thymuses the robust coordinated expression of BDNF in the germinal centers together with the receptor p75NTR on all proliferating B cells strongly suggests that this factor regulates germinal center reaction. Finally, all TEC dying of apoptosis expressed BDNF receptors, indicating that this neurotrophin is involved in TEC turnover. In thymomas both BDNF production and receptor expression in TEC were strongly hindered. This may represent an attempt of tumour escape from cell death.

  7. An AMPA receptor potentiator modulates hippocampal expression of BDNF: an in vivo study.

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    Mackowiak, Marzena; O'Neill, Michael J; Hicks, Caroline A; Bleakman, David; Skolnick, Phil

    2002-07-01

    AMPA receptor activation has been demonstrated to increase the neuronal expression of brain derived neurotrophic factor (BDNF). In the present study, we investigated the effect of a novel AMPA receptor potentiator (LY404187) and its active isomer (LY451646) on the expression of BDNF protein and mRNA, as well as TrkB mRNA in rat hippocampus. LY404187 administered for 7 days (1 mg/kg) significantly increased the number of BDNF immunopositive cells in the dentate gyrus, but not other hippocampal subfields. Chronic treatment (7 days) with LY451646 (0.5 mg/kg, comparable to 1 mg/kg of LY404187) increased the level of both BDNF and TrkB mRNA expression in the dentate gyrus, CA3 and CA4 of the hippocampus. However, chronic treatment with lower doses of LY451646 (0.125 and 0.25 mg/kg) decreased the level of BDNF and TrkB mRNA in hippocampus, whilst the highest used dose of LY451646 (1 mg/kg) had no effect on BDNF and TrkB mRNA in hippocampus. In contrast, acute treatment with LY451646 produced an increase in BDNF mRNA levels at doses of 0.125 and 0.25 mg/kg in the hippocampus (CA4, CA3 and dentate gyrus, but not in CA1). LY451646 at 0.5 mg/kg had no effect, but at 1.0 mg/kg decreased the level of BDNF mRNA in hippocampus. Acute treatment with LY451646 did not affect the TrkB receptor mRNA levels in hippocampus. Our results demonstrate that biarylpropylsulfonamide AMPA receptor potentiators are capable of modulating the expression of BDNF and TrkB mRNA in a dose- and time-dependent manner. The increase in both BDNF protein and mRNA expression in the dentate gyrus but not in CA1 indicates a specific role of AMPA receptors in the regulation of BDNF expression in this hippocampal subfield. The regulation of BDNF expression by biarylpropylsulfonamids such as LY451646 may have important therapeutical implications for this class of molecule in the treatment of depression and other CNS disorders.

  8. BDNF Up-Regulates α7 Nicotinic Acetylcholine Receptor Levels on Subpopulations of Hippocampal Interneurons

    OpenAIRE

    Massey, Kerri A; Zago, Wagner M.; Berg, Darwin K.

    2006-01-01

    In the hippocampus, brain-derived neurotrophic factor (BDNF) regulates a number of synaptic components. Among these are nicotinic acetylcholine receptors containing α7 subunits (α7-nAChRs), which are interesting because of their relative abundance in the hippocampus and their high relative calcium permeability. We show here that BDNF elevates surface and intracellular pools of α7-nAChRs on cultured hippocampal neurons and that glutamatergic activity is both necessary and sufficient for the ef...

  9. Antidepressant Drugs Transactivate TrkB Neurotrophin Receptors in the Adult Rodent Brain Independently of BDNF and Monoamine Transporter Blockade

    OpenAIRE

    Tomi Rantamäki; Liisa Vesa; Hanna Antila; Antonio Di Lieto; Päivi Tammela; Angelika Schmitt; Klaus-Peter Lesch; Maribel Rios; Eero Castrén

    2011-01-01

    BACKGROUND: Antidepressant drugs (ADs) have been shown to activate BDNF (brain-derived neurotrophic factor) receptor TrkB in the rodent brain but the mechanism underlying this phenomenon remains unclear. ADs act as monoamine reuptake inhibitors and after prolonged treatments regulate brain bdnf mRNA levels indicating that monoamine-BDNF signaling regulate AD-induced TrkB activation in vivo. However, recent findings demonstrate that Trk receptors can be transactivated independently of their ne...

  10. Hippocampal Deletion of BDNF Gene Attenuates Gamma Oscillations in Area CA1 by Up-Regulating 5-HT3 Receptor

    OpenAIRE

    Ying Huang; Alexei Morozov

    2011-01-01

    BACKGROUND: Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown. METHODOLOGY/PRINCIPAL FINDINGS: 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 recept...

  11. AT2-receptor stimulation enhances axonal plasticity after spinal cord injury by upregulating BDNF expression

    DEFF Research Database (Denmark)

    Namsolleck, Pawel; Boato, Francesco; Schwengel, Katja;

    2013-01-01

    outgrowth was absent in neurons derived from AT2R-KO mice. In primary neurons, treatment with C21 further induced RNA expression of anti-apoptotic Bcl-2 (+75.7%), brain-derived neurotrophic factor (BDNF) (+53.7%), the neurotrophin receptors TrkA (+57.4%) and TrkB (+67.9%) and a marker for neurite growth...

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

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    Ying Huang

    Full Text Available BACKGROUND: Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSION/SIGNIFICANCE: 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.

  13. Regulation of TrkB receptor translocation to lipid rafts by adenosine A2A receptors and its functional implications for BDNF-induced regulation of synaptic plasticity

    OpenAIRE

    Assaife-Lopes, Natália; Sousa, Vasco C.; Pereira, Daniela B.; Ribeiro, Joaquim A.; Sebastião, Ana M.

    2013-01-01

    Brain-derived neurotrophic factor (BDNF) signalling is critical for neuronal development and transmission. Recruitment of TrkB receptors to lipid rafts has been shown to be necessary for the activation of specific signalling pathways and modulation of neurotransmitter release by BDNF. Since TrkB receptors are known to be modulated by adenosine A2A receptor activation, we hypothesized that activation of A2A receptors could influence TrkB receptor localization among different membrane microdoma...

  14. Juvenile methylphenidate reduces prefrontal cortex plasticity via D3 receptor and BDNF in adulthood

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    Susan L Andersen

    2014-01-01

    Full Text Available Background: Early drug intervention in childhood disorders aims to maximize individual potential in the short- and long-term. Consistently, juvenile exposure to psychostimulants, such as methylphenidate (MPH, reduces risk for substance use in animals and sub-populations of individuals with attention deficit hyperactivity disorder (ADHD. We investigated the effects of MPH on brain plasticity via dopamine receptor D3 (D3R and brain-derived neurotrophic factor (BDNF expression in developing rats. Methods: Between postnatal days 20-35, rat pups were administered saline vehicle (Veh or MPH (2 mg/kg, the D3R-preferring agonist ± 7-OHDPAT, or the antagonist nafadotride (0.05 mg/kg alone, or in combination with MPH twice a day. In adulthood, subjects were challenged to Veh or cocaine (10 mg/kg for two days. The prefrontal cortex was analyzed for protein and mRNA levels of total BDNF, its splice variants I, IIc, III/IV, and IV/VI, and D3 receptors. A separate group of subjects was assessed for splice variants at 20, 35, 40 and 60 days. Results: Across age strong correlations were evident between Drd3 and Bdnf mRNA levels (r=0.65 and a negative relationship between Drd3 and exon IIc after MPH exposure (r=-0.73. BDNF protein levels did not differ between Veh- and MPH subjects at baseline, but were significantly lower in MPH-treated and cocaine challenged subjects (30.3 ± 9.7%. Bdnf mRNA was significantly higher in MPH subjects, and reversed upon exposure to cocaine. This effect was blocked by nafadotride. Furthermore, Bdnftotal and Bdnf splice variants I, IIc, III/IV, and IV/VI changed across the transitions between juvenility and late adolescence. Conclusions: These data suggest a sensitive window of vulnerability to modulations of BDNF expression around adolescence, and that compared to normal animals, juvenile exposure to MPH permanently reduces prefrontal BDNF transcription and translation upon cocaine exposure in adulthood by a D3R

  15. BDNF-induced synaptic delivery of AMPAR subunits is differentially dependent on NMDA receptors and requires ERK.

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    Li, Wei; Keifer, Joyce

    2009-03-01

    Previous studies using an in vitro model of eyeblink classical conditioning in turtles suggest that increased numbers of synaptic AMPARs supports the acquisition and expression of conditioned responses (CRs). Brain-derived neurotrophic factor (BDNF) and its associated receptor tyrosine kinase, TrkB, is also required for acquisition of CRs. Bath application of BDNF alone induces synaptic delivery of GluR1- and GluR4-containing AMPARs that is blocked by coapplication of the receptor tyrosine kinase inhibitor K252a. The molecular mechanisms involved in BDNF-induced AMPAR trafficking remain largely unknown. The aim of this study was to determine whether BDNF-induced synaptic AMPAR incorporation utilizes similar cellular mechanisms as AMPAR trafficking that occurs during in vitro classical conditioning. Using pharmacological blockade and confocal imaging, the results show that synaptic delivery of GluR1 subunits during conditioning or BDNF application does not require activity of NMDARs but is mediated by extracellular signal-regulated kinase (ERK). In contrast, synaptic delivery of GluR4-containing AMPARs during both conditioning and BDNF application is NMDAR- as well as ERK-dependent. These findings indicate that BDNF application mimics AMPAR trafficking observed during conditioning by activation of some of the same intracellular signaling pathways and suggest that BDNF is a key signal transduction element in postsynaptic events that mediate conditioning.

  16. Regulated release of BDNF by cortical oligodendrocytes is mediated through metabotropic glutamate receptors and the PLC pathway

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    Issa P Bagayogo

    2009-04-01

    Full Text Available A number of studies suggest that OLGs (oligodendrocytes), the myelinating cells of the central nervous system, are also a source of trophic molecules, such as neurotrophins that may influence survival of proximate neurons. What is less clear is how the release of these molecules may be regulated. The present study investigated the effects of BDNF (brain-derived neurotrophic factor) derived from cortical OLGs on proximate neurons, as well as regulatory mechanisms mediating BDNF release. Initial work determined that BDNF derived from cortical OLGs increased the numbers of VGLUT1 (vesicular glutamate transporter 1)-positive glutamatergic cortical neurons. Furthermore, glutamate acting through metabotropic, and not AMPA/kainate or NMDA (N-methyl-d-aspartate), receptors increased BDNF release. The PLC (phospholipase C) pathway is a key mediator of metabotropic actions to release BDNF in astrocytes and neurons. Treatment of OLGs with the PLC activator m-3M3FBS [N-(3-trifluoromethylphenyl)-2,4,6-trimethylbenzenesulfonamide] induced robust release of BDNF. Moreover, release elicited by the metabotropic receptor agonist ACPD [trans-(1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid] was inhibited by the PLC antagonist U73122, the IP3 (inositol triphosphate 3) receptor inhibitor 2-APB (2-aminoethoxydiphenylborane) and the intracellular calcium chelator BAPTA/AM [1,2-bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid tetrakis(acetoxymethyl ester)]. Taken together, these results suggest that OLG lineage cells release BDNF, a molecule trophic for proximate neurons. BDNF release is regulated by glutamate acting through mGluRs (metabotropic glutamate receptors) and the PLC pathway. Thus glutamate and BDNF may be molecules that support neuron–OLG interactions in the cortex.

  17. Divergent Roles of p75NTR and Trk Receptors in BDNF's Effects on Dendritic Spine Density and Morphology

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    Christopher A. Chapleau

    2012-01-01

    Full Text Available Activation of TrkB receptors by brain-derived neurotrophic factor (BDNF followed by MAPK/ERK signaling increases dendritic spine density and the proportion of mature spines in hippocampal CA1 pyramidal neurons. Considering the opposing actions of p75NTR and Trk receptors in several BDNF actions on CNS neurons, we tested whether these receptors also have divergent actions on dendritic spine density and morphology. A function-blocking anti-p75NTR antibody (REX did not affect spine density by itself but it prevented BDNF’s effect on spine density. Intriguingly, REX by itself increased the proportion of immature spines and prevented BDNF's effect on spine morphology. In contrast, the Trk receptor inhibitor k-252a increased spine density by itself, and prevented BDNF from further increasing spine density. However, most of the spines in k-252a-treated slices were of the immature type. These effects of k-252a on spine density and morphology required neuronal activity because they were prevented by TTX. These divergent BDNF actions on spine density and morphology are reminiscent of opposing functional signaling by p75NTR and Trk receptors and reveal an unexpected level of complexity in the consequences of BDNF signaling on dendritic morphology.

  18. HBpF-proBDNF: A New Tool for the Analysis of Pro-Brain Derived Neurotrophic Factor Receptor Signaling and Cell Biology

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    Gaub, Perrine; de Léon, Andrès; Gibon, Julien; Soubannier, Vincent; Dorval, Geneviève; Séguéla, Philippe; Barker, Philip A.

    2016-01-01

    Neurotrophins activate intracellular signaling pathways necessary for neuronal survival, growth and apoptosis. The most abundant neurotrophin in the adult brain, brain-derived neurotrophic factor (BDNF), is first synthesized as a proBDNF precursor and recent studies have demonstrated that proBDNF can be secreted and that it functions as a ligand for a receptor complex containing p75NTR and sortilin. Activation of proBDNF receptors mediates growth cone collapse, reduces synaptic activity, and facilitates developmental apoptosis of motoneurons but the precise signaling cascades have been difficult to discern. To address this, we have engineered, expressed and purified HBpF-proBDNF, an expression construct containing a 6X-HIS tag, a biotin acceptor peptide (BAP) sequence, a PreScission™ Protease cleavage site and a FLAG-tag attached to the N-terminal part of murine proBDNF. Intact HBpF-proBDNF has activities indistinguishable from its wild-type counterpart and can be used to purify proBDNF signaling complexes or to monitor proBDNF endocytosis and retrograde transport. HBpF-proBDNF will be useful for characterizing proBDNF signaling complexes and for deciphering the role of proBDNF in neuronal development, synapse function and neurodegenerative disease. PMID:26950209

  19. Peptides derived from the solvent-exposed loops 3 and 4 of BDNF bind TrkB and p75(NTR) receptors and stimulate neurite outgrowth and survival

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    Fobian, Kristina; Owczarek, Sylwia; Budtz, Christian;

    2010-01-01

    Brain-derived neurotrophic factor (BDNF) is critically involved in modeling the developing nervous system and is an important regulator of a variety of crucial functions in the mature CNS. BDNF exerts its action through interactions with two transmembrane receptors, either separately or in concert....... BDNF has been implicated in several neurological disorders, and irregularities in BDNF function may have severe consequences. Administration of BDNF as a drug has thus far yielded few practicable results, and the potential side effects when using a multifunctional protein are substantial. In an effort...... to produce more specific compounds without side effects, small peptides mimicking protein function have been developed. The present study characterized two mimetic peptides, Betrofin 3 and Betrofin 4, derived from the BDNF sequence. Both Betrofins bound the cognate BDNF receptors, TrkB and p75(NTR...

  20. Divergent Roles of p75NTR and Trk Receptors in BDNF's Effects on Dendritic Spine Density and Morphology

    OpenAIRE

    2012-01-01

    Activation of TrkB receptors by brain-derived neurotrophic factor (BDNF) followed by MAPK/ERK signaling increases dendritic spine density and the proportion of mature spines in hippocampal CA1 pyramidal neurons. Considering the opposing actions of p75NTR and Trk receptors in several BDNF actions on CNS neurons, we tested whether these receptors also have divergent actions on dendritic spine density and morphology. A function-blocking anti-p75NTR antibody (REX) did not affect spine density by ...

  1. Effects of gravity changes on gene expression of BDNF and serotonin receptors in the mouse brain.

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    Ishikawa, Chihiro; Li, Haiyan; Ogura, Rin; Yoshimura, Yuko; Kudo, Takashi; Shirakawa, Masaki; Shiba, Dai; Takahashi, Satoru; Morita, Hironobu; Shiga, Takashi

    2017-01-01

    Spaceflight entails various stressful environmental factors including microgravity. The effects of gravity changes have been studied extensively on skeletal, muscular, cardiovascular, immune and vestibular systems, but those on the nervous system are not well studied. The alteration of gravity in ground-based animal experiments is one of the approaches taken to address this issue. Here we investigated the effects of centrifugation-induced gravity changes on gene expression of brain-derived neurotrophic factor (BDNF) and serotonin receptors (5-HTRs) in the mouse brain. Exposure to 2g hypergravity for 14 days showed differential modulation of gene expression depending on regions of the brain. BDNF expression was decreased in the ventral hippocampus and hypothalamus, whereas increased in the cerebellum. 5-HT1BR expression was decreased in the cerebellum, whereas increased in the ventral hippocampus and caudate putamen. In contrast, hypergravity did not affect gene expression of 5-HT1AR, 5-HT2AR, 5-HT2CR, 5-HT4R and 5-HT7R. In addition to hypergravity, decelerating gravity change from 2g hypergravity to 1g normal gravity affected gene expression of BDNF, 5-HT1AR, 5-HT1BR, and 5-HT2AR in various regions of the brain. We also examined involvement of the vestibular organ in the effects of hypergravity. Surgical lesions of the inner ear's vestibular organ removed the effects induced by hypergravity on gene expression, which suggests that the effects of hypergravity are mediated through the vestibular organ. In summary, we showed that gravity changes induced differential modulation of gene expression of BDNF and 5-HTRs (5-HT1AR, 5-HT1BR and 5-HT2AR) in some brain regions. The modulation of gene expression may constitute molecular bases that underlie behavioral alteration induced by gravity changes.

  2. Stress induces altered CRE/CREB pathway activity and BDNF expression in the hippocampus of glucocorticoid receptor-impaired mice.

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    Alboni, Silvia; Tascedda, Fabio; Corsini, Daniela; Benatti, Cristina; Caggia, Federica; Capone, Giacomo; Barden, Nicholas; Blom, Joan M C; Brunello, Nicoletta

    2011-06-01

    The gene coding for the neurotrophin Brain-Derived Neurotrophic Factor (BDNF) is a stress-responsive gene. Changes in its expression may underlie some of the pathological effects of stress-related disorders like depression. Data on the stress-induced regulation of the expression of BDNF in pathological conditions are rare because often research is conducted using healthy animals. In our experiments, we used transgenic mice with glucocorticoid receptor impaired (GR-i) expression in the hypothalamus created as a tool to study the neuroendocrine changes occurring in stress-related disorders. First, under basal condition, GR-i mice displayed lower levels of BDNF exons IX and IV and decreased CRE(BDNF) binding activity with respect to wild-type (WT) mice in the hippocampus. Then, we exposed GR-i and WT mice to an acute restraint stress (ARS) to test the hypothesis that GR-i mice display: 1] different ARS induced expression of BDNF, and 2] altered activation of signaling pathways implicated in regulating BDNF gene expression in the hippocampus with respect to WT mice. Results indicate that ARS enhanced BDNF mRNA expression mainly in the CA3 hippocampal sub-region of GR-i mice in the presence of enhanced levels of pro-BDNF protein, while no effect was observed in WT mice. Moreover, ARS reduced CREB signaling and binding to the BDNF promoter in GR-i mice but enhanced signaling and binding, possibly through ERK1/2 activation, in WT mice. Thus, life-long central GR dysfunction resulted in an altered sensitivity at the transcriptional level that may underlie an impaired response to an acute psycho-physical stress. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'.

  3. Metabotropic glutamate receptor 2 and corticotrophin-releasing factor receptor-1 gene expression is differently regulated by BDNF in rat primary cortical neurons

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    Jørgensen, Christinna V; Klein, Anders B; El-Sayed, Mona;

    2013-01-01

    Brain-derived neurotrophic factor (BDNF) is important for neuronal survival and plasticity. Incorporation of matured receptor proteins is an integral part of synapse formation. However, whether BDNF increases synthesis and integration of receptors in functional synapses directly is unclear. We...... are particularly interested in the regulation of the 5-hydroxytryptamine receptor 2A (5-HT2A R). This receptor form a functional complex with the metabotropic glutamate receptor 2 (mGluR2) and is recruited to the cell membrane by the corticotrophin-releasing factor receptor 1 (CRF-R1). The effect of BDNF on gene...... expression for all these receptors, as well as a number of immediate-early genes, was pharmacologically characterized in primary neurons from rat frontal cortex. BDNF increased CRF-R1 mRNA levels up to fivefold, whereas mGluR2 mRNA levels were proportionally downregulated. No effect on 5-HT2A R mRNA was seen...

  4. Administration of N-acetylserotonin and melatonin alleviate chronic ketamine-induced behavioural phenotype accompanying BDNF-independent and dependent converging cytoprotective mechanisms in the hippocampus.

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    Choudhury, Arnab; Singh, Seema; Palit, Gautam; Shukla, Shubha; Ganguly, Surajit

    2016-01-15

    Though growing evidence implicates both melatonin (MLT) and its immediate precursor N-acetylserotonin (NAS) in the regulation of hippocampal neurogenesis, their comparative mechanistic relationship with core behavioural correlates of psychiatric disorders is largely unknown. To address this issue, we investigated the ability of these indoleamines to mitigate the behavioral phenotypes associated with NMDA-receptor (NMDAR) hypofunction in mice. We demonstrated that exogenous MLT and NAS treatments attenuated the NMDAR antagonist (ketamine) induced immobility in the forced swim test (FST) but not the classical striatum-related hyperlocomotor activity phenotype. The MLT/NAS-mediated protection of the phenotype in FST could be correlated to the ability of these indoleamines to counteract the deleterious effects of chronic ketamine on pro-survival molecular events by restoring the activities in MEK-ERK and PI3K-AKT pathways in the hippocampus. MLT seems to modulate these pathways by promoting accumulation of the mature form of BDNF above the control (vehicle-treated) levels, perhaps via MLT receptor-dependent mechanisms and in the process overcoming the ketamine-induced down-regulation of BDNF. In contrast, NAS appears to partly restore the ketamine-induced decrease of BDNF to the control levels. In spite of this fundamental difference in modulating BDNF levels in the upstream events, both MLT and NAS seem to overlap in the TrkB-induced downstream pro-survival mechanisms in the hippocampus, providing protection against NMDAR-hypofunction related cellular events. Perhaps, this also signifies the physiological importance of robust MLT synthesizing machinery that converts serotonin to MLT, in ensuring positive impact on hippocampus-related symptoms in psychiatric disorders.

  5. Neuronal release of proBDNF

    OpenAIRE

    Yang, Jianmin; Siao, Chia-Jen; Nagappan, Guhan; Marinic, Tina; Jing, Deqiang; McGrath, Kelly; Chen, Zhe-Yu; Mark, Willie; Tessarollo, Lino; Lee, Francis S.; Lu, Bai; Hempstead, Barbara L.

    2009-01-01

    Pro–brain-derived neurotrophic factor (proBDNF) and mature BDNF utilize distinct receptors to mediate divergent neuronal actions. Using new tools to quantitate endogenous BDNF isoforms, we found that mouse neurons secrete both proBDNF and mature BDNF. The highest levels of proBDNF and p75 were observed perinatally and declined, but were still detectable, in adulthood. Thus, BDNF actions are developmentally regulated by secretion of proBDNF or mature BDNF and by local expression of p75 and Trk...

  6. BDNF Reduces Toxic Extrasynaptic NMDA Receptor Signaling via Synaptic NMDA Receptors and Nuclear-Calcium-Induced Transcription of inhba/Activin A

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    David Lau

    2015-08-01

    Full Text Available The health of neurons is critically dependent on the relative signaling intensities of survival-promoting synaptic and death-inducing extrasynaptic NMDA receptors. Here, we show that BDNF is a regulator of this balance and promotes neuroprotection by reducing toxic NMDA receptor signaling. BDNF acts by initiating synaptic NMDA-receptor/nuclear-calcium-driven adaptogenomics, leading to increased expression of inhibin β-A (inhba. Inhibin β-A (its homodimer is known as activin A in turn reduces neurotoxic extrasynaptic NMDA-receptor-mediated calcium influx, thereby shielding neurons against mitochondrial dysfunction, a major cause of excitotoxicity. Thus, BDNF induces acquired neuroprotection by enhancing synaptic activity and lowering extrasynaptic NMDA receptor death signaling through a nuclear calcium-inhibin β-A pathway. This process, which confers protection against ischemic brain damage in a mouse stroke model, may be compromised in Huntington’s disease, Alzheimer’s disease, or aging-related neurodegenerative conditions that are associated with reduced BDNF levels and/or enhanced extrasynaptic NMDA receptor signaling.

  7. p75 neurotrophin receptor and pro-BDNF promote cell survival and migration in clear cell renal cell carcinoma

    Science.gov (United States)

    Sánchez-Prieto, Ricardo; Saada, Sofiane; Naves, Thomas; Guillaudeau, Angélique; Perraud, Aurélie; Sindou, Philippe; Lacroix, Aurélie; Descazeaud, Aurélien; Lalloué, Fabrice; Jauberteau, Marie-Odile

    2016-01-01

    p75NTR, a member of TNF receptor family, is the low affinity receptor common to several mature neurotrophins and the high affinity receptor for pro-neurotrophins. Brain-Derived Neurotrophic Factor (BDNF), a member of neurotrophin family has been described to play an important role in development and progression of several cancers, through its binding to a high affinity tyrosine kinase receptor B (TrkB) and/or p75NTR. However, the functions of these two receptors in renal cell carcinoma (RCC) have never been investigated. An overexpression of p75NTR, pro-BDNF, and to a lesser extent for TrkB and sortilin, was detected by immunohistochemistry in a cohort of 83 clear cell RCC tumors. p75NTR, mainly expressed in tumor tissues, was significantly associated with higher Fuhrman grade in multivariate analysis. In two derived-RCC lines, 786-O and ACHN cells, we demonstrated that pro-BDNF induced cell survival and migration, through p75NTR as provided by p75NTR RNA silencing or blocking anti-p75NTR antibody. This mechanism is independent of TrkB activation as demonstrated by k252a, a tyrosine kinase inhibitor for Trk neurotrophin receptors. Taken together, these data highlight for the first time an important role for p75NTR in renal cancer and indicate a putative novel target therapy in RCC. PMID:27120782

  8. Presynaptic inhibition by kainate receptors converges mechanistically with presynaptic inhibition by adenosine and GABAB receptors.

    Science.gov (United States)

    Partovi, Dara; Frerking, Matthew

    2006-11-01

    Kainate receptors are widely reported to regulate the release of neurotransmitter in the CNS, but the mechanisms involved remain controversial. Previous studies have found that the kainate receptor agonist ATPA, which selectively activates Glu(K5)-containing kainate receptors, depresses glutamate release at Schaffer-collateral synapses in the hippocampus. In the present study, we provide pharmacological evidence that this depressant effect is mediated by Glu(K5)-containing heteromers, but is distinct from a similar depressant effect engaged by the kainate receptor agonist domoate. The depressant effect of ATPA is insensitive to antagonists for GABA(A), GABA(B), and adenosine receptors, and is also unaffected by lowering the release probability by reducing extracellular calcium. However, the effect of ATPA is partly occluded by prior activation of GABA(B) receptors and completely occluded by prior activation of adenosine receptors, suggesting a mechanistic convergence of heteromeric Glu(K5) kainate receptor signaling with GABA(B) receptors and adenosine receptors. The effects of domoate are partially occluded by both adenosine and GABA(B) receptor agonists, indicating at least a partial convergence of Glu(K5)-lacking kainate receptor signaling with these other pathways. The depressant effect of ATPA is not blocked by inhibition of serine/threonine protein kinases. These results suggest that ATPA and domoate inhibit glutamate release through mechanisms that converge with those of classical metabotropic receptor agonists, although they do so through different receptors.

  9. [Research progress of BDNF and depression].

    Science.gov (United States)

    Qiao, Hui; An, Shu-Cheng; Xu, Chang

    2011-06-01

    BDNF is widespread existed in CNS and PNS, because of its function in nerve regeneration and restoration, more and more researches focused on the effect of BDNF on neural plasticity in the development of depression and the mechanisms of antidepressant. This article review the basic results and the research trends on BDNF and depression at present, more researches about the interactions of BDNF and proBDNF, BDNF and other transmitters and their receptors should be expected.

  10. Antidepressant drugs transactivate TrkB neurotrophin receptors in the adult rodent brain independently of BDNF and monoamine transporter blockade.

    Directory of Open Access Journals (Sweden)

    Tomi Rantamäki

    Full Text Available BACKGROUND: Antidepressant drugs (ADs have been shown to activate BDNF (brain-derived neurotrophic factor receptor TrkB in the rodent brain but the mechanism underlying this phenomenon remains unclear. ADs act as monoamine reuptake inhibitors and after prolonged treatments regulate brain bdnf mRNA levels indicating that monoamine-BDNF signaling regulate AD-induced TrkB activation in vivo. However, recent findings demonstrate that Trk receptors can be transactivated independently of their neurotrophin ligands. METHODOLOGY: In this study we examined the role of BDNF, TrkB kinase activity and monoamine reuptake in the AD-induced TrkB activation in vivo and in vitro by employing several transgenic mouse models, cultured neurons and TrkB-expressing cell lines. PRINCIPAL FINDINGS: Using a chemical-genetic TrkB(F616A mutant and TrkB overexpressing mice, we demonstrate that ADs specifically activate both the maturely and immaturely glycosylated forms of TrkB receptors in the brain in a TrkB kinase dependent manner. However, the tricyclic AD imipramine readily induced the phosphorylation of TrkB receptors in conditional bdnf⁻/⁻ knock-out mice (132.4±8.5% of control; P = 0.01, indicating that BDNF is not required for the TrkB activation. Moreover, using serotonin transporter (SERT deficient mice and chemical lesions of monoaminergic neurons we show that neither a functional SERT nor monoamines are required for the TrkB phosphorylation response induced by the serotonin selective reuptake inhibitors fluoxetine or citalopram, or norepinephrine selective reuptake inhibitor reboxetine. However, neither ADs nor monoamine transmitters activated TrkB in cultured neurons or cell lines expressing TrkB receptors, arguing that ADs do not directly bind to TrkB. CONCLUSIONS: The present findings suggest that ADs transactivate brain TrkB receptors independently of BDNF and monoamine reuptake blockade and emphasize the need of an intact tissue context for the

  11. Effects of castration on the immunoreactivity to NGF, BDNF and their receptors in the pelvic ganglia of the male rat

    Directory of Open Access Journals (Sweden)

    C Squillacioti

    2009-08-01

    Full Text Available Nerve growth factor (NGF and brain derived neurotrophic factor (BDNF and are members of the neurotrophin family, a family of neurotrophic factors that also includes neurotrophin (NT 3 and NT4/5. Neurotrophins have essential roles in the survival, development and differentiation of neurons in the central and peripheral nervous systems. Neurotrophins exert their effects by binding to corresponding receptors which are formed by the tyrosine protein kinases TrkA, TrkB and TrkC, and the low affinity neurotrophic receptor (p75NTR. In the present study, using immunohistochemistry and quantitative analysis, we have investigated immunoreactivity to BDNF, NGF, TrkB, p75NTR and TrkA in the pelvic ganglia of normal and castrated rats. Neurons of the pelvic ganglia expressed both these neurotrophins and their receptors. After castration the immunoreactivity persisted. However, the number of BDNF- and p75NTR–IR cells statistically significant decreased after castration. These results suggest that castration modulates the expression of neurotrophins and their receptors in pelvic autonomic neurons.

  12. Estradiol-induced modulation of estrogen receptor-beta and GABA within the adult neocortex: a potential transsynaptic mechanism for estrogen modulation of BDNF.

    Science.gov (United States)

    Blurton-Jones, Mathew; Tuszynski, Mark H

    2006-12-01

    Estrogen influences brain-derived neurotrophic factor (BDNF) expression in the neocortex. However, BDNF-producing cortical neurons do not express detectable levels of nuclear estrogen receptors; instead, the most abundant cortical nuclear estrogen receptor, ER-beta, is present in GABAergic neurons, prompting us to test the hypothesis that estrogen effects on BDNF are mediated via cortical inhibitory interneurons. Adult female ovariectomized rats were provided acute estrogen replacement and the number of cortical GABA, ER-beta, and ER-beta/GABA double-labeled neurons was examined. Within 48 hours of injection of 17-beta-estradiol, the number of perirhinal neurons double-labeled for ER-beta/GABA was reduced by 28% (PBDNF-expressing cells, brain sections were double- or triple-labeled for ER-beta, GABAergic, and BDNF immunomarkers. The findings indicated that ER-beta-bearing inhibitory neurons project onto other GABAergic neurons that lack nuclear estrogen receptors; these inhibitory neurons in turn innervate BDNF-expressing excitatory cells. High estrogen states reduce cortical GABA levels, presumably releasing inhibition on BDNF-expressing neurons. This identifies a putative two-step transsynaptic mechanism whereby estrogen availability modulates expression of inhibitory transmitters, resulting in increased BDNF expression.

  13. Mineralocorticoid receptor genotype moderates the association between physical neglect and serum BDNF.

    Science.gov (United States)

    Bortoluzzi, Andressa; Salum, Giovanni Abrahão; Blaya, Carolina; Silveira, Patrícia Pelufo; Grassi-Oliveira, Rodrigo; da Rosa, Eduarda Dias; de Aguiar, Bianca Wollenhaupt; Stertz, Laura; Bosa, Vera Lúcia; Schuch, Ilaine; Goldani, Marcelo; Kapczinski, Flavio; Leistner-Segal, Sandra; Manfro, Gisele Gus

    2014-12-01

    The objective of this study is to investigate if a polymorphism in the NR3C2 gene moderates the association between childhood trauma on serum levels of brain derived neurothrophic factor (sBDNF). sBDNF was used here as a general marker of alteration in brain function. This is a community cross sectional study comprising 90 adolescents (54 with anxiety disorders). DNA was extracted from saliva in order to genotype the MR-2G/C (rs2070951) polymorphism using real time PCR. Blood was collected for sBDNF Elisa immunoassay. The Childhood Trauma Questionnaire (CTQ) was used to evaluate childhood abuse and neglect. Main effects and gene environment interactions were tested using linear regression models. Anxiety disorders were not associated with the MR-2G/C polymorphism or with sBDNF levels, but the number of C alleles of the MR-2G/C polymorphism was significantly associated with higher sBDNF levels (b = 8.008; p-value = 0.001). Subjects with intermediate and high exposure to physical neglect showed higher sBDNF levels if compared to subjects non-exposed (b = 11.955; p = 0.004 and b = 16.186; p = 0.009, respectively). In addition, we detected a significant physical neglect by MR-2G/C C allele interaction on sBDNF levels (p = 0.005), meaning that intermediate and high exposure to childhood neglect were only associated with increased sBDNF levels in subjects with the CC genotype, but not in subjects with other genotypes. Our findings suggest that genetic variants in NR3C2 gene may partially explain plastic brain vulnerability to traumatic events. Further studies are needed to investigate the moderating effects of NR3C2 gene in more specific markers of alteration in brain function.

  14. Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence

    OpenAIRE

    Xu, R.; S.R. Duan; Zhao, J.W.; Wang, C Y

    2015-01-01

    Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable a...

  15. The brain-uterus connection: brain derived neurotrophic factor (BDNF) and its receptor (Ntrk2) are conserved in the mammalian uterus.

    Science.gov (United States)

    Wessels, Jocelyn M; Wu, Liang; Leyland, Nicholas A; Wang, Hongmei; Foster, Warren G

    2014-01-01

    The neurotrophins are neuropeptides that are potent regulators of neurite growth and survival. Although mainly studied in the brain and nervous system, recent reports have shown that neurotrophins are expressed in multiple target tissues and cell types throughout the body. Additionally, dysregulation of neurotrophins has been linked to several disease conditions including Alzheimer's, Parkinson's, Huntington's, psychiatric disorders, and cancer. Brain derived neurotrophic factor (BDNF) is a member of the neurotrophin family that elicits its actions through the neurotrophic tyrosine receptor kinase type 2 (Ntrk2). Together BDNF and Ntrk2 are capable of activating the adhesion, angiogenesis, apoptosis, and proliferation pathways. These pathways are prominently involved in reproductive physiology, yet a cross-species examination of BDNF and Ntrk2 expression in the mammalian uterus is lacking. Herein we demonstrated the conserved nature of BDNF and Ntrk2 across several mammalian species by mRNA and protein sequence alignment, isolated BDNF and Ntrk2 transcripts in the uterus by Real-Time PCR, localized both proteins to the glandular and luminal epithelium, vascular smooth muscle, and myometrium of the uterus, determined that the major isoforms expressed in the human endometrium were pro-BDNF, and truncated Ntrk2, and finally demonstrated antibody specificity. Our findings suggest that BDNF and Ntrk2 are transcribed, translated, and conserved across mammalian species including human, mouse, rat, pig, horse, and the bat.

  16. The brain-uterus connection: brain derived neurotrophic factor (BDNF and its receptor (Ntrk2 are conserved in the mammalian uterus.

    Directory of Open Access Journals (Sweden)

    Jocelyn M Wessels

    Full Text Available The neurotrophins are neuropeptides that are potent regulators of neurite growth and survival. Although mainly studied in the brain and nervous system, recent reports have shown that neurotrophins are expressed in multiple target tissues and cell types throughout the body. Additionally, dysregulation of neurotrophins has been linked to several disease conditions including Alzheimer's, Parkinson's, Huntington's, psychiatric disorders, and cancer. Brain derived neurotrophic factor (BDNF is a member of the neurotrophin family that elicits its actions through the neurotrophic tyrosine receptor kinase type 2 (Ntrk2. Together BDNF and Ntrk2 are capable of activating the adhesion, angiogenesis, apoptosis, and proliferation pathways. These pathways are prominently involved in reproductive physiology, yet a cross-species examination of BDNF and Ntrk2 expression in the mammalian uterus is lacking. Herein we demonstrated the conserved nature of BDNF and Ntrk2 across several mammalian species by mRNA and protein sequence alignment, isolated BDNF and Ntrk2 transcripts in the uterus by Real-Time PCR, localized both proteins to the glandular and luminal epithelium, vascular smooth muscle, and myometrium of the uterus, determined that the major isoforms expressed in the human endometrium were pro-BDNF, and truncated Ntrk2, and finally demonstrated antibody specificity. Our findings suggest that BDNF and Ntrk2 are transcribed, translated, and conserved across mammalian species including human, mouse, rat, pig, horse, and the bat.

  17. Oligomeric amyloid-{beta} inhibits the proteolytic conversion of brain-derived neurotrophic factor (BDNF), AMPA receptor trafficking, and classical conditioning.

    Science.gov (United States)

    Zheng, Zhaoqing; Sabirzhanov, Boris; Keifer, Joyce

    2010-11-01

    Amyloid-β (Aβ) peptide is thought to have a significant role in the progressive memory loss observed in patients with Alzheimer disease and inhibits synaptic plasticity in animal models of learning. We previously demonstrated that brain-derived neurotrophic factor (BDNF) is critical for synaptic AMPA receptor delivery in an in vitro model of eyeblink classical conditioning. Here, we report that acquisition of conditioned responses was significantly attenuated by bath application of oligomeric (200 nm), but not fibrillar, Aβ peptide. Western blotting revealed that BDNF protein expression during conditioning is significantly reduced by treatment with oligomeric Aβ, as were phosphorylation levels of cAMP-response element-binding protein (CREB), Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), Ca(2+)/calmodulin-dependent protein kinase IV (CaMKIV), and ERK. However, levels of PKA and PKCζ/λ were unaffected, as was PDK-1. Protein localization studies using confocal imaging indicate that oligomeric Aβ, but not fibrillar or scrambled forms, suppresses colocalization of GluR1 and GluR4 AMPA receptor subunits with synaptophysin, indicating that trafficking of these subunits to synapses during the conditioning procedure is blocked. In contrast, coapplication of BDNF with oligomeric Aβ significantly reversed these findings. Interestingly, a tolloid-like metalloproteinase in turtle, tTLLs (turtle tolloid-like protein), which normally processes the precursor proBDNF into mature BDNF, was found to degrade oligomeric Aβ into small fragments. These data suggest that an Aβ-induced reduction in BDNF, perhaps due to interference in the proteolytic conversion of proBDNF to BDNF, results in inhibition of synaptic AMPA receptor delivery and suppression of the acquisition of conditioning.

  18. Role of Adenosine A2A Receptors in Modulating Synaptic Functions and Brain Levels of BDNF: a Possible Key Mechanism in the Pathophysiology of Huntington's Disease

    Directory of Open Access Journals (Sweden)

    Maria Teresa Tebano

    2010-01-01

    Full Text Available In the last few years, accumulating evidence has shown the existence of an important cross-talk between adenosine A2A receptors (A2ARs and brain-derived neurotrophic factor (BDNF. Not only are A2ARs involved in the mechanism of transactivation of BDNF receptor TrkB, they also modulate the effect of BDNF on synaptic transmission, playing a facilitatory and permissive role. The cAMP-PKA pathway, the main transduction system operated by A2ARs, is involved in such effects. Furthermore, a basal tonus of A2ARs is required to allow the regulation of BDNF physiological levels in the brain, as demonstrated by the reduced protein levels measured in A2ARs KO mice. The crucial role of adenosine A2ARs in the maintenance of synaptic functions and BDNF levels will be reviewed here and discussed in the light of possible implications for Huntington's disease therapy, in which a joint impairment of BDNF and A2ARs seems to play a pathogenetic role.

  19. BDNF prevents NMDA-induced toxicity in models of Huntington's disease: the effects are genotype specific and adenosine A2A receptor is involved.

    Science.gov (United States)

    Martire, Alberto; Pepponi, Rita; Domenici, Maria Rosaria; Ferrante, Antonella; Chiodi, Valentina; Popoli, Patrizia

    2013-04-01

    NMDA receptor-mediated excitotoxicity is thought to play a pivotal role in the pathogenesis of Huntington's disease (HD). The neurotrophin brain-derived neurotrophic factor (BDNF), which is also highly involved in HD and whose effects are modulated by adenosine A2 ARs, influences the activity and expression of striatal NMDA receptors. In electrophysiology experiments, we investigated the role of BDNF toward NMDA-induced effects in HD models, and the possible involvement of A2ARs. In corticostriatal slices from wild-type mice and age-matched symptomatic R6/2 mice (a model of HD), NMDA application (75 μM) induced a transient or a permanent (i.e., toxic) reduction of field potential amplitude, respectively. BDNF (10 ng/mL) potentiated NMDA effects in wild-type, while it protected from NMDA toxicity in R6/2 mice. Both effects of BDNF were prevented by A2 AR blockade. The protective effect of BDNF against NMDA-induced toxicity was reproduced in a cellular model of HD. These findings may have very important implications for the neuroprotective potential of BDNF and A2 AR ligands in HD.

  20. Convergence

    DEFF Research Database (Denmark)

    Madsen, Ole Brun; Nielsen, Jens Frederik Dalsgaard; Schiøler, Henrik

    2002-01-01

    Convergence trends between the WAN Internet area, characterized by best effort service provision, and the real time LAN domain, with requirements for guaranteed services, are identified and discussed. A bilateral evolution is identified, where typical bulk service applications from WAN...

  1. Alteration in BDNF and its receptors, full-length and truncated TrkB and p75(NTR) following penetrating traumatic brain injury.

    Science.gov (United States)

    Rostami, Elham; Krueger, Frank; Plantman, Stefan; Davidsson, Johan; Agoston, Denes; Grafman, Jordan; Risling, Mårten

    2014-01-13

    The evidence that BDNF is involved in neuroprotection, neuronal repair and recovery after traumatic brain injury (TBI) is substantial. We have previously shown that the polymorphism of the human BDNF gene predicts cognitive recovery and outcome following penetrating TBI. The distribution of expression of BDNF and its receptors after penetrating TBI has not been investigated. In this study we examined the expression of these genes in a rat model of penetrating TBI. The injury is produced by a controlled penetration of a 2mm thick needle-shaped object, which is accelerated with a pellet from an air gun. We used in situ hybridization and investigated the mRNA expression of BDNF and its receptors: the full-length and the truncated TrkB and p75(NTR), from 1 day to 8 weeks following penetrating TBI. In addition, the protein level of BDNF in frontal cortex and hippocampus was measured by reverse phase protein microarray (RPPM). The mRNA expression of BDNF and its receptors decreased in the hippocampus in the border zone ipsilateral to the injury while there was an increase in mRNA expression at the contralateral side. The increase in BDNF mRNA expression in the hippocampus was sustained for 2 weeks following injury, with the highest expression noted in the CA3 cell layer. Furthermore, the protein analysis by RPPM showed increased levels of BDNF in the frontal cortex and the hippocampus up to 2 weeks after TBI. At 8 weeks following injury there was an intense labeling of the truncated TrkB receptor and the p75(NTR) in the area surrounding the cavity. Our study is the first report on the expression of BDNF and its receptors following penetrating TBI and suggests that their expression is altered long after the acute phase of injury. Further studies are needed to investigate if the late expressions of these receptors are beneficial or deleterious. In either case it indicates the possibility to influence the recovery after brain injury during the chronic phase and the

  2. Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence

    Energy Technology Data Exchange (ETDEWEB)

    Xu, R.; Duan, S.R.; Zhao, J.W.; Wang, C.Y. [Neurology Ward of Internal Medicine, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province (China)

    2015-06-23

    Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.

  3. Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence.

    Science.gov (United States)

    Xu, R; Duan, S R; Zhao, J W; Wang, C Y

    2015-08-01

    Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.

  4. Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence

    Directory of Open Access Journals (Sweden)

    R. Xu

    2015-08-01

    Full Text Available Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB and p75 neurotrophin receptor (p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory, at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG, and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4. Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.

  5. Convergence

    Science.gov (United States)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-09-01

    Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and

  6. Expression and physiological regulation of BDNF receptors in the neuroendocrine melanotrope cell of Xenopus laevis

    NARCIS (Netherlands)

    Kidane, A.H.; Dooren, S.H. van; Roubos, E.W.; Jenks, B.G.

    2007-01-01

    Brain-derived neurotrophic factor (BDNF) and alpha-melanophore-stimulating hormone (alpha-MSH) are co-sequestered in secretory granules in melanotrope cells of the pituitary pars intermedia of the amphibian Xenopus laevis. alpha-MSH is responsible for pigment dispersion in dermal melanophores during

  7. Effects of chronic forced swim stress on hippocampal brain-derived neutrophic factor (BDNF) and its receptor (TrkB) immunoreactive cells in juvenile and aged rats.

    Science.gov (United States)

    Badowska-Szalewska, Ewa; Spodnik, Edyta; Klejbor, Ilona; Morys, Janusz

    2010-01-01

    A type of stress stimulation and age are claimed to affect the expression of brain-derived neurotrophic factor (BDNF) and its receptor - tyrosine kinase B (TrkB) in the hippocampal regions differentially. This study aimed to explore the influence of chronic (15 min daily for 21 days) forced swim stress (FS) exposure on the BDNF and TrkB containing neurons in the hippocampal CA1, CA3 pyramidal cell layers and dentate gyrus (DG) granule cell layer in juvenile (P28) and aged (P360) rats. An immunofluorescence (-ir) method was used to detect BDNF-ir and TrkB-ir cells. Under chronic FS exposure, in the group of juvenile rats a significant decrease in the density of BDNF immunoreactive neurons was observed in CA1 and DG (P less than CA3, where it remained unaltered just as the density of TrkB-ir cells in CA1 and DG, but in CA3 the number of TrkB-ir cells was found to grow (P less than 0.05) in comparison with control groups. After chronic FS exposure of aged (P360) rats, the density of BDNF-ir and TrkB-ir cells did not decline in any of the subregions of the hippocampus. In all subfields of the hippocampus, the denseness of BDNF-positive neurons was significantly higher in P360 stressed group, compared with P28 stressed group, but the density of TrkB-ir fell more markedly in P360 than in P28. In conclusion, chronic FS stress influenced the number of BDNF and TrkB immunoreactive neurons only in juvenile animals. The age of rats tested in the chronic forced swim test was a decisive factor determining changes in the density of BDNF-ir and TrkB-ir in the hippocampal structures.

  8. Gene expression of BDNF and its receptors, TrkB and p75 in the uterus and oviduct of pregnant and non-pregnant ewes.

    Science.gov (United States)

    Mirshokraei, P; Hassanpour, H; Rahnama, A; Foster, W G

    2013-08-01

    To compare genes expression of BDNF and its receptors, TrkB and p75 between pregnant and non-pregnant uterine and oviductal tissues of ewes, semi-quantitative RT-PCR was performed. BDNF, TrkB and p75 genes are normally expressed in the ovine uterus and oviduct. The relative amounts of BDNF mRNA were increased in the uterine segments of the pregnant samples with compared to non-pregnant samples. This increasing was only significant (Ppregnant samples. In contrast, the relative amounts of BDNF mRNA were decreased in the oviductal segments of the pregnant samples and were undetectable in the isthmus. Variations of the relative amounts of TrkB and p75 mRNAs between the pregnant and non-pregnant samples were not significant (P>0.05) although TrkB mRNA in the caruncle and cervix and p75 mRNA in the cervix of pregnant samples were too less to be detected by RT-PCR method. It is probably that these changes of BDNF/receptors genes expression are necessary for normal pregnancy, and abnormal variations in the expression of these genes may be involved in the pathophysiological conditions.

  9. Convergence

    DEFF Research Database (Denmark)

    Prasad, Ramjee

    2009-01-01

    This paper presents the main conclusions which can be drawn from the discussions on Future Communication Systems and lessons on Unpredictable Future of Wireless Communication Systems. Future systems beyond the third generation are already under discussions in international bodies, such as ITU, WW...... and R&D programmes worldwide. The incoming era is characterized by the convergence of networks and access technology and the divergence of applications. Future mobile communication systems should bring something more than only faster data or wireless internet access....

  10. Deletion of the BDNF truncated receptor TrkB.T1 delays disease onset in a mouse model of amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    Sudhirkumar U Yanpallewar

    Full Text Available Brain Derived Neurotrophic Factor (BDNF exerts strong pro-survival effects on developing and injured motoneurons. However, in clinical trials, BDNF has failed to benefit patients with amyotrophic lateral sclerosis (ALS. To date, the cause of this failure remains unclear. Motoneurons express the TrkB kinase receptor but also high levels of the truncated TrkB.T1 receptor isoform. Thus, we investigated whether the presence of this receptor may affect the response of diseased motoneurons to endogenous BDNF. We deleted TrkB.T1 in the hSOD1(G93A ALS mouse model and evaluated the impact of this mutation on motoneuron death, muscle weakness and disease progression. We found that TrkB.T1 deletion significantly slowed the onset of motor neuron degeneration. Moreover, it delayed the development of muscle weakness by 33 days. Although the life span of the animals was not affected we observed an overall improvement in the neurological score at the late stage of the disease. To investigate the effectiveness of strategies aimed at bypassing the TrkB.T1 limit to BDNF signaling we treated SOD1 mutant mice with the adenosine A2A receptor agonist CGS21680, which can activate motoneuron TrkB receptor signaling independent of neurotrophins. We found that CGS21680 treatment slowed the onset of motor neuron degeneration and muscle weakness similarly to TrkB.T1 removal. Together, our data provide evidence that endogenous TrkB.T1 limits motoneuron responsiveness to BDNF in vivo and suggest that new strategies such as Trk receptor transactivation may be used for therapeutic intervention in ALS or other neurodegenerative disorders.

  11. Loss of BDNF or Its Receptors in Three Mouse Models Has Unpredictable Consequences for Anxiety and Fear Acquisition

    Science.gov (United States)

    Olsen, Ditte; Kaas, Mathias; Schwartz, Ole; Nykjaer, Anders; Glerup, Simon

    2013-01-01

    BDNF-induced signaling is essential for the development of the central nervous system and critical for plasticity in adults. Mature BDNF signals through TrkB, while its precursor proBDNF employs p75[superscript NTR], resulting in activation of signaling cascades with opposite effects on neuronal survival, growth cone decisions, and synaptic…

  12. Loss of BDNF or Its Receptors in Three Mouse Models Has Unpredictable Consequences for Anxiety and Fear Acquisition

    Science.gov (United States)

    Olsen, Ditte; Kaas, Mathias; Schwartz, Ole; Nykjaer, Anders; Glerup, Simon

    2013-01-01

    BDNF-induced signaling is essential for the development of the central nervous system and critical for plasticity in adults. Mature BDNF signals through TrkB, while its precursor proBDNF employs p75[superscript NTR], resulting in activation of signaling cascades with opposite effects on neuronal survival, growth cone decisions, and synaptic…

  13. Effect of δ-Opioid Receptor Activation on BDNF-TrkB vs. TNF-α in the Mouse Cortex Exposed to Prolonged Hypoxia

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    Ying Xia

    2013-07-01

    Full Text Available We investigated whether δ-opioid receptor (DOR-induced neuroprotection involves the brain-derived neurotrophic factor (BDNF pathway. We studied the effect of DOR activation on the expression of BDNF and other proteins in the cortex of C57BL/6 mice exposed to hypoxia (10% of oxygen for 1–10 days. The results showed that: (1 1-day hypoxia had no appreciable effect on BDNF expression, while 3- and 10-day hypoxia progressively decreased BDNF expression, resulting in 37.3% reduction (p < 0.05 after 10-day exposure; (2 DOR activation with UFP-512 (1 mg/kg, i.p., daily partially reversed the hypoxia-induced reduction of BDNF expression in the 3- or 10-day exposed cortex; (3 DOR activation partially reversed the hypoxia-induced reduction in functional TrkB (140-kDa and attenuated hypoxia-induced increase in truncated TrkB (90-kDa in the 3- or 10-day hypoxic cortex; and (4 prolonged hypoxia (10 days significantly increased TNF-α level and decreased CD11b expression in the cortex, which was completely reversed following DOR activation; and (5 there was no significant change in pCREB and pATF-1 levels in the hypoxic cortex. We conclude that prolonged hypoxia down-regulates BDNF-TrkB signaling leading to an increase in TNF-α in the cortex, while DOR activation up-regulates BDNF-TrkB signaling thereby decreasing TNF-α levels in the hypoxic cortex.

  14. Neurokinin-1 (NK-1 receptor and brain-derived neurotrophic factor (BDNF gene expression is differentially modulated in the rat spinal dorsal horn and hippocampus during inflammatory pain

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    McCarson Kenneth E

    2007-10-01

    Full Text Available Abstract Persistent pain produces complex alterations in sensory pathways of the central nervous system (CNS through activation of various nociceptive mechanisms. However, the effects of pain on higher brain centers, particularly the influence of the stressful component of pain on the limbic system, are poorly understood. Neurokinin-1 (NK-1 receptors and brain-derived neurotrophic factor (BDNF, known neuromediators of hyperalgesia and spinal central sensitization, have also been implicated in the plasticity and neurodegeneration occurring in the hippocampal formation during exposures to various stressors. Results of this study showed that injections of complete Freund's adjuvant (CFA into the hind paw increased NK-1 receptor and BDNF mRNA levels in the ipsilateral dorsal horn, supporting an important role for these nociceptive mediators in the amplification of ascending pain signaling. An opposite effect was observed in the hippocampus, where CFA down-regulated NK-1 receptor and BDNF gene expression, phenomena previously observed in immobilization models of stress and depression. Western blot analyses demonstrated that in the spinal cord, CFA also increased levels of phosphorylated cAMP response element-binding protein (CREB, while in the hippocampus the activation of this transcription factor was significantly reduced, further suggesting that tissue specific transcription of either NK-1 or BDNF genes may be partially regulated by common intracellular transduction mechanisms mediated through activation of CREB. These findings suggest that persistent nociception induces differential regional regulation of NK-1 receptor and BDNF gene expression and CREB activation in the CNS, potentially reflecting varied roles of these neuromodulators in the spinal cord during persistent sensory activation vs. modulation of the higher brain structures such as the hippocampus.

  15. Neurokinin-1 (NK-1) receptor and brain-derived neurotrophic factor (BDNF) gene expression is differentially modulated in the rat spinal dorsal horn and hippocampus during inflammatory pain.

    Science.gov (United States)

    Duric, Vanja; McCarson, Kenneth E

    2007-10-31

    Persistent pain produces complex alterations in sensory pathways of the central nervous system (CNS) through activation of various nociceptive mechanisms. However, the effects of pain on higher brain centers, particularly the influence of the stressful component of pain on the limbic system, are poorly understood. Neurokinin-1 (NK-1) receptors and brain-derived neurotrophic factor (BDNF), known neuromediators of hyperalgesia and spinal central sensitization, have also been implicated in the plasticity and neurodegeneration occurring in the hippocampal formation during exposures to various stressors. Results of this study showed that injections of complete Freund's adjuvant (CFA) into the hind paw increased NK-1 receptor and BDNF mRNA levels in the ipsilateral dorsal horn, supporting an important role for these nociceptive mediators in the amplification of ascending pain signaling. An opposite effect was observed in the hippocampus, where CFA down-regulated NK-1 receptor and BDNF gene expression, phenomena previously observed in immobilization models of stress and depression. Western blot analyses demonstrated that in the spinal cord, CFA also increased levels of phosphorylated cAMP response element-binding protein (CREB), while in the hippocampus the activation of this transcription factor was significantly reduced, further suggesting that tissue specific transcription of either NK-1 or BDNF genes may be partially regulated by common intracellular transduction mechanisms mediated through activation of CREB. These findings suggest that persistent nociception induces differential regional regulation of NK-1 receptor and BDNF gene expression and CREB activation in the CNS, potentially reflecting varied roles of these neuromodulators in the spinal cord during persistent sensory activation vs. modulation of the higher brain structures such as the hippocampus.

  16. Regionally specific induction of BDNF and truncated trkB.T1 receptors in the hippocampal formation after intraseptal injection of kainic acid.

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    Venero, J L; Hefti, F

    1998-04-20

    The septo-hippocampal cholinergic and GABAergic systems were lesioned with single unilateral injections of kainic acid (KA) into the septum to further characterize the role of these afferents in the regulation of hippocampal brain-derived neurotrophic factor (BDNF) expression. Nearly all cells expressing choline acetyltransferase, trkA or glutamic acid decarboxylase mRNA disappeared in the medial septum 7 days after the neurotoxin administration. The lesion resulted in a complete loss of CA3 pyramidal cells, and robust increases in BDNF mRNA levels in hippocampal granular dentate cells and in the amygdala. There were rapid transient increases of BDNF mRNA levels in the hippocampal formation and cortex. In addition, we found a strong induction of truncated trkB.T1 mRNA receptors in the stratum radiatum and stratum oriens of the CA3 subfield. The prolonged induction of BDNF mRNA levels suggests an important role of this neurotrophin, possibly mediated by truncated trkB receptors, in the regulation of hippocampal plasticity following injury.

  17. Brain ischaemia induces shedding of a BDNF-scavenger ectodomain from TrkB receptors by excitotoxicity activation of metalloproteinases and γ-secretases.

    Science.gov (United States)

    Tejeda, Gonzalo S; Ayuso-Dolado, Sara; Arbeteta, Raquel; Esteban-Ortega, Gema M; Vidaurre, Oscar G; Díaz-Guerra, Margarita

    2016-04-01

    Stroke remains a leading cause of death and disability in the world with limited therapies available to restrict brain damage or improve functional recovery after cerebral ischaemia. A promising strategy currently under investigation is the promotion of brain-derived neurotrophic factor (BDNF) signalling through tropomyosin-related kinase B (TrkB) receptors, a pathway essential for neuronal survival and function. However, TrkB and BDNF-signalling are impaired by excitotoxicity, a primary pathological process in stroke also associated with neurodegenerative diseases. Pathological imbalance of TrkB isoforms is critical in neurodegeneration and is caused by calpain processing of BDNF high affinity full-length receptor (TrkB-FL) and an inversion of the transcriptional pattern of the Ntrk2 gene, to favour expression of the truncated isoform TrkB-T1 over TrkB-FL. We report here that both TrkB-FL and neuronal TrkB-T1 also undergo ectodomain shedding by metalloproteinases activated after ischaemic injury or excitotoxic damage of cortical neurons. Subsequently, the remaining membrane-bound C-terminal fragments (CTFs) are cleaved by γ-secretases within the transmembrane region, releasing their intracellular domains (ICDs) into the cytosol. Therefore, we identify TrkB-FL and TrkB-T1 as new substrates of regulated intramembrane proteolysis (RIP), a mechanism that highly contributes to TrkB-T1 regulation in ischaemia but is minor for TrkB-FL which is mainly processed by calpain. However, since the secreted TrkB ectodomain acts as a BDNF scavenger and significantly alters BDNF/TrkB signalling, the mechanism of RIP could contribute to neuronal death in excitotoxicity. These results are highly relevant since they reveal new targets for the rational design of therapies to treat stroke and other pathologies with an excitotoxic component.

  18. Immunolocalization of pro- and mature-brain derived neurotrophic factor (BDNF) and receptor TrkB in the human brainstem and hippocampus.

    Science.gov (United States)

    Tang, Samantha; Machaalani, Rita; Waters, Karen A

    2010-10-01

    Brain-derived neurotrophic factor (BDNF) and its receptor TrkB are essential in promoting normal development of the central nervous system. Specific functions that are affected in knockout models include respiratory control, coordination of movement and balance, and feeding activities. The expression of these markers has not yet been studied in the human infant brain. This study provides a detailed account of the distribution and localization of both pro- and mature-recombinant human (rh) forms of BDNF, and of TrkB in the human infant brainstem and hippocampus, and qualitatively compares this expression to that seen in the human adult. Using commercially available antibodies, we applied immunohistochemistry on formalin fixed and paraffin embedded human brain tissue [n=8 for infant, n=6 for adult], and qualitatively analyzed the expression of proBDNF, rhBDNF and TrkB. Amongst the brainstem regions studied, the greatest expression of the markers was in the mesencephalic trigeminal of the pons, and in the medulla, the inferior olive and arcuate nucleus. The lowest expression was in the substantia nigra of the midbrain and pontine locus coeruleus. Compared to adults, all the studied markers had a higher expression in the infant brainstem nuclei of the hypoglossal, vestibular, dorsal motor nucleus of the vagus, prepositus, cuneate, and dorsal raphe. In the hippocampus, only TrkB showed a higher expression in infants compared to adults. We conclude that BDNF and TrkB play important roles in controlling respiration, movement, balance and feeding in the brainstem and that the TrkB receptor is the most age-sensitive component of this system, especially in the hippocampus.

  19. Molecular mechanism linking BDNF/TrkB signaling with the NMDA receptor in memory: the role of Girdin in the CNS.

    Science.gov (United States)

    Itoh, Norimichi; Enomoto, Atsushi; Nagai, Taku; Takahashi, Masahide; Yamada, Kiyofumi

    2016-07-01

    It is well known that synaptic plasticity is the cellular mechanism underlying learning and memory. Activity-dependent synaptic changes in electrical properties and morphology, including synaptogenesis, lead to alterations of synaptic strength, which is associated with long-term potentiation (LTP). Brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) signaling is involved in learning and memory formation by regulating synaptic plasticity. The phosphatidylinositol 3-kinase (PI3-K)/Akt pathway is one of the key signaling cascades downstream BDNF/TrkB and is believed to modulate N-methyl-d-aspartate (NMDA) receptor-mediated synaptic plasticity. However, the molecular mechanism underlying the connection between these two key players in synaptic plasticity remains largely unknown. Girders of actin filament (Girdin), an Akt substrate that directly binds to actin filaments, has been shown to play a role in neuronal migration and neuronal development. Recently, we identified Girdin as a key molecule involved in regulating long-term memory. It was demonstrated that phosphorylation of Girdin by Akt contributed to the maintenance of LTP by linking the BDNF/TrkB signaling pathway with NMDA receptor activity. These findings indicate that Girdin plays a pivotal role in a variety of processes in the CNS. Here, we review recent advances in our understanding about the roles of Girdin in the CNS and focus particularly on neuronal migration and memory.

  20. Reciprocal regulation of very low density lipoprotein receptors (VLDLRs) in neurons by brain-derived neurotrophic factor (BDNF) and Reelin: involvement of the E3 ligase Mylip/Idol.

    Science.gov (United States)

    Do, Hai Thi; Bruelle, Céline; Tselykh, Timofey; Jalonen, Pilvi; Korhonen, Laura; Lindholm, Dan

    2013-10-11

    BDNF positively influences various aspects of neuronal migration, maturation, and survival in the developing brain. Reelin in turn mediates inhibitory signals to migrating neuroblasts, which is crucial for brain development. The interplay between BDNF and Reelin signaling in neurodevelopment is not fully understood. We show here that BDNF increased the levels of the Reelin receptor (VLDL receptor (VLDLR)) in hippocampal neurons by increasing gene expression. In contrast, Reelin decreased VLDLRs, which was accompanied by an increase in the levels of the E3 ligase Mylip/Idol in neurons. Down-regulation of Mylip/Idol using shRNAs abrogated the decrease in VLDLRs induced by Reelin. These results show that VLDLRs are tightly regulated in hippocampal neurons by both transcriptional and post-transcriptional mechanisms. The regulation of VLDLR by BDNF and Reelin may affect the migration of neurons and contribute to neurodevelopmental disorders in the nervous system.

  1. Neuregulin and BDNF induce a switch to NMDA receptor-dependent myelination by oligodendrocytes.

    Directory of Open Access Journals (Sweden)

    Iben Lundgaard

    2013-12-01

    Full Text Available Myelination is essential for rapid impulse conduction in the CNS, but what determines whether an individual axon becomes myelinated remains unknown. Here we show, using a myelinating coculture system, that there are two distinct modes of myelination, one that is independent of neuronal activity and glutamate release and another that depends on neuronal action potentials releasing glutamate to activate NMDA receptors on oligodendrocyte lineage cells. Neuregulin switches oligodendrocytes from the activity-independent to the activity-dependent mode of myelination by increasing NMDA receptor currents in oligodendrocyte lineage cells 6-fold. With neuregulin present myelination is accelerated and increased, and NMDA receptor block reduces myelination to far below its level without neuregulin. Thus, a neuregulin-controlled switch enhances the myelination of active axons. In vivo, we demonstrate that remyelination after white matter damage is NMDA receptor-dependent. These data resolve controversies over the signalling regulating myelination and suggest novel roles for neuregulin in schizophrenia and in remyelination after white matter damage.

  2. Dietary supplementation of soy germ phytoestrogens or estradiol improves spatial memory performance and increases gene expression of BDNF, TrkB receptor and synaptic factors in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Li Zhuoneng

    2010-09-01

    Full Text Available Abstract Background Estrogen or phytoestrogens treatment has been suggested to improve cognitive function of the brain in postmenopausal women. However, there is lack of information on the mechanism of such treatment on the central nervous system. The present study aimed to determine the effects of estradiol and soy germ phytoestrogens on spatial memory performance in ovariectomized rats and to explore the underlying mechanisms affecting the central nervous system. Methods Ovariectomized Sprague-Dawley rats were fed a basic diet supplemented with soy germ phytoestrogens (0.4 g/kg or 1.6 g/kg or 17β-estradiol (0.15 g/kg for 12 weeks. At the end of the experiment, animals were evaluated for their spatial learning and memory performance by the Morris Water Maze task. The expressions of brain-derived neurotrophic factor (BDNF and synaptic formation proteins in the hippocampal tissue were estimated using RT-PCR and ELISA. Results It was found that rats supplemented with soy germ phytoestrogens or estradiol performed significantly better in spatial memory acquisition and retention when compared to the rats fed on the control diet. Estradiol or the high dose of phytoestrogens treatment significantly increased BDNF concentration and the mRNA levels for BDNF and its TrkB receptors as well as the synaptic formation proteins, synaptophysin, spinophilin, synapsin 1 and PSD-95, in the hippocampal tissue of the experimental animals. It was also found that phytoestrogens, in contrast to estradiol, did not show any significant effect on the vaginal and uteri. Conclusion Soy germ phytoestrogens, which may be a substitute of estradiol, improved spatial memory performance in ovariectomized rats without significant side-effects on the vaginal and uteri. The memory enhancement effect may relate to the increase in BDNF and the synaptic formation proteins expression in the hippocampus of the brain.

  3. Anxiolytic effects of muscarinic acetylcholine receptors agonist oxotremorine in chronically stressed rats and related changes in BDNF and FGF2 levels in the hippocampus and prefrontal cortex.

    Science.gov (United States)

    Di Liberto, Valentina; Frinchi, Monica; Verdi, Vincenzo; Vitale, Angela; Plescia, Fulvio; Cannizzaro, Carla; Massenti, Maria F; Belluardo, Natale; Mudò, Giuseppa

    2017-02-01

    In depressive disorders, one of the mechanisms proposed for antidepressant drugs is the enhancement of synaptic plasticity in the hippocampus and cerebral cortex. Previously, we showed that the muscarinic acetylcholine receptor (mAChR) agonist oxotremorine (Oxo) increases neuronal plasticity in hippocampal neurons via FGFR1 transactivation. Here, we aimed to explore (a) whether Oxo exerts anxiolytic effect in the rat model of anxiety-depression-like behavior induced by chronic restraint stress (CRS), and (b) if the anxiolytic effect of Oxo is associated with the modulation of neurotrophic factors, brain-derived neurotrophic factor (BDNF) and fibroblast growth factor-2 (FGF2), and phosphorylated Erk1/2 (p-Erk1/2) levels in the dorsal or ventral hippocampus and in the medial prefrontal cortex. The rats were randomly divided into four groups: control unstressed, CRS group, CRS group treated with 0.2 mg/kg Oxo, and unstressed group treated with Oxo. After 21 days of CRS, the groups were treated for 10 days with Oxo or saline. The anxiolytic role of Oxo was tested by using the following: forced swimming test, novelty suppressed feeding test, elevated plus maze test, and light/dark box test. The hippocampi and prefrontal cortex were used to evaluate BDNF and FGF2 protein levels and p-Erk1/2 levels. Oxo treatment significantly attenuated anxiety induced by CRS. Moreover, Oxo treatment counteracted the CRS-induced reduction of BDNF and FGF2 levels in the ventral hippocampus and medial prefrontal cerebral cortex CONCLUSIONS: The present study showed that Oxo treatment ameliorates the stress-induced anxiety-like behavior and rescues FGF2 and BDNF levels in two brain regions involved in CRS-induced anxiety, ventral hippocampal formation, and medial prefrontal cortex.

  4. Mature BDNF, but not proBDNF, reduces excitability of fast-spiking interneurons in mouse dentate gyrus.

    Science.gov (United States)

    Holm, Mai Marie; Nieto-Gonzalez, Jose Luis; Vardya, Irina; Vaegter, Christian Bjerggaard; Nykjaer, Anders; Jensen, Kimmo

    2009-10-07

    Mature BDNF and its precursor proBDNF may both be secreted to exert opposite effects on synaptic plasticity in the hippocampus. However, it is unknown how proBDNF and mature BDNF affect the excitability of GABAergic interneurons and thereby regulate GABAergic inhibition. We made recordings of GABAergic spontaneous IPSCs (sIPSCs) in mouse dentate gyrus granule cells and found that chronic or acute BDNF reductions led to large increases in the sIPSC frequencies, which were TTX (tetrodotoxin) sensitive and therefore action-potential driven. Conversely, addition of mature BDNF, but not proBDNF, within minutes led to a decrease in the sIPSC frequency to 44%. Direct recordings from fast-spiking GABAergic interneurons revealed that mature BDNF reduced their excitability and depressed their action potential firing, whereas proBDNF had no effect. Using the TrkB inhibitor K-252a, or mice deficient for the common neurotrophin receptor p75(NTR), the regulation of GABAergic activity was shown specifically to be mediated by BDNF binding to the neurotrophin receptor TrkB. In agreement, immunohistochemistry demonstrated that TrkB, but not p75(NTR), was expressed in parvalbumin-positive interneurons. Our results suggest that mature BDNF decreases the excitability of GABAergic interneurons via activation of TrkB, while proBDNF does not impact on GABAergic activity. Thus, by affecting the firing of GABAergic interneurons, mature BDNF may play an important role in regulating network oscillations in the hippocampus.

  5. Brain adaptation to stressful stimuli: a new perspective on potential therapeutic approaches based on BDNF and NMDA receptors.

    Science.gov (United States)

    Marini, Ann M; Popolo, Margherita; Pan, Hongna; Blondeau, Nicolas; Lipsky, Robert H

    2008-10-01

    A variety of sublethal or stressful stimuli induce a phenomenon in the brain known as tolerance, an adaptive response that protects the brain against the same stress, or against a different stress (cross-tolerance). Understanding the molecular mechanisms of brain preconditioning holds promise in developing innovative therapies to prevent and treat neurodegenerative disorders, particularly ischemic stroke. Many of the detailed steps involved in tolerance and cross-tolerance are unknown. It is also likely that different stressors differentially regulate sets of genes, transcription factors, and signal transduction pathways that depend upon the molecules that are released in response to the stressor, activation of particular receptors, and the surrounding milieu. The focus of this review is to highlight a few examples of stimuli that induce tolerance: 1) cortical spreading depression; 2) 3-nitropropionic acid; and 3) 2-deoxy-D-glucose. We will summarize by discussing one pathway where intracellular mediators may converge to upregulate intrinsic neuronal survival pathways to promote survival by resisting damage. This mechanism, activation of N-methyl-D-aspartate receptors and its integral relationship with brain-derived neurotrophic factor, may be a critical and general mechanism developed in brain to respond to stressful stimuli.

  6. BDNF isoforms: a round trip ticket between neurogenesis and serotonin?

    Science.gov (United States)

    Foltran, Rocío Beatriz; Diaz, Silvina Laura

    2016-07-01

    The brain-derived neurotrophic factor, BDNF, was discovered more than 30 years ago and, like other members of the neurotrophin family, this neuropeptide is synthetized as a proneurotrophin, the pro-BDNF, which is further cleaved to yield mature BDNF. The myriad of actions of these two BDNF isoforms in the central nervous system is constantly increasing and requires the development of sophisticated tools and animal models to refine our understanding. This review is focused on BDNF isoforms, their participation in the process of neurogenesis taking place in the hippocampus of adult mammals, and the modulation of their expression by serotonergic agents. Interestingly, around this triumvirate of BDNF, serotonin, and neurogenesis, a series of recent research has emerged with apparently counterintuitive results. This calls for an exhaustive analysis of the data published so far and encourages thorough work in the quest for new hypotheses in the field. BDNF is synthetized as a pre-proneurotrophin. After removal of the pre-region, proBDNF can be cleaved by intracellular or extracellular proteases. Mature BDNF can bind TrkB receptors, promoting their homodimerization and intracellular phosphorylation. Phosphorylated-TrkB can activate three different signaling pathways. Whereas G-protein-coupled receptors can transactivate TrkB receptors, truncated forms can inhibit mBDNF signaling. Pro-BDNF binds p75(NTR) by its mature domain, whereas the pro-region binds co-receptors. © 2016 International Society for Neurochemistry.

  7. Wnt5a uses CD146 as a receptor to regulate cell motility and convergent extension

    Science.gov (United States)

    Ye, Zhongde; Zhang, Chunxia; Tu, Tao; Sun, Min; Liu, Dan; Lu, Di; Feng, Jing; Yang, Dongling; Liu, Feng; Yan, Xiyun

    2013-12-01

    Dysregulation of Wnt signalling leads to developmental defects and diseases. Non-canonical Wnt signalling via planar cell polarity proteins regulates cell migration and convergent extension; however, the underlying mechanisms are poorly understood. Here we report that Wnt5a uses CD146 as a receptor to regulate cell migration and zebrafish embryonic convergent extension. CD146 binds to Wnt5a with the high affinity required for Wnt5a-induced activation of Dishevelled (Dvl) and c-jun amino-terminal kinase (JNK). The interaction between CD146 and Dvl2 is enhanced on Wnt5a treatment. Mutation of the Dvl2-binding region impairs its ability to activate JNK, promote cell migration and facilitate the formation of cell protrusions. Knockdown of Dvls impairs CD146-induced cell migration. Interestingly, CD146 inhibits canonical Wnt signalling by promoting β-catenin degradation. Our results suggest a model in which CD146 acts as a functional Wnt5a receptor in regulating cell migration and convergent extension, turning off the canonical Wnt signalling branch.

  8. Dietary omega-3 deficiency reduces BDNF content and activation NMDA receptor and Fyn in dorsal hippocampus: implications on persistence of long-term memory in rats.

    Science.gov (United States)

    Bach, Simone Azevedo; de Siqueira, Letícia V; Müller, Alexandre P; Oses, Jean P; Quatrim, Andreia; Emanuelli, Tatiana; Vinadé, Lúcia; Souza, Diogo O; Moreira, Júlia D

    2014-07-01

    Omega-3 (n-3) fatty acids are important for adequate brain function and cognition. The aim of the present study was to evaluate how n-3 fatty acids influence the persistence of long-term memory (LTM) in an aversive memory task and to explore the putative mechanism involved. Female rats received isocaloric diets that included n-3 (n-3 group) or not (D group). The adult litters were subjected to an inhibitory avoidance task (0.7 mA, 1.0 seconds foot shock) to elicit persistent LTM. Twelve hours after the training session, the fatty acid profile and the brain derived neurotrophic factor (BDNF) content of the dorsal hippocampus were assessed. In addition, we measured the activation of the NR2B subunit of the N-methyl-d-aspartate (NMDA) receptor and the SRC family protein Fyn. Despite pronounced learning in both groups, the persistence of LTM was abolished in the D group 7 days after the training session. We also observed that the D group presented reductions in hippocampal DHA (22:6 n-3) and BDNF content. Twelve hours after the training session, the D group showed decreased NR2B and Fyn phosphorylation in the dorsal hippocampus, with no change in the total content of these proteins. Further, there was a decrease in the interaction of Fyn with NR2B in the D group, as observed by co-immunoprecipitation. Taken together, these data suggest that n-3 fatty acids influence the persistence of LTM by maintaining adequate levels of DHA and BDNF as well as by influencing the activation of NR2B and Fyn during the period of memory formation.

  9. Persistent inflammation-induced up-regulation of brain-derived neurotrophic factor (BDNF) promotes synaptic delivery of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor GluA1 subunits in descending pain modulatory circuits.

    Science.gov (United States)

    Tao, Wenjuan; Chen, Quan; Zhou, Wenjie; Wang, Yunping; Wang, Lu; Zhang, Zhi

    2014-08-08

    The enhanced AMPA receptor phosphorylation at GluA1 serine 831 sites in the central pain-modulating system plays a pivotal role in descending pain facilitation after inflammation, but the underlying mechanisms remain unclear. We show here that, in the rat brain stem, in the nucleus raphe magnus, which is a critical relay in the descending pain-modulating system of the brain, persistent inflammatory pain induced by complete Freund adjuvant (CFA) can enhance AMPA receptor-mediated excitatory postsynaptic currents and the GluA2-lacking AMPA receptor-mediated rectification index. Western blot analysis showed an increase in GluA1 phosphorylation at Ser-831 but not at Ser-845. This was accompanied by an increase in distribution of the synaptic GluA1 subunit. In parallel, the level of histone H3 acetylation at bdnf gene promoter regions was reduced significantly 3 days after CFA injection, as indicated by ChIP assays. This was correlated with an increase in BDNF mRNA levels and BDNF protein levels. Sequestering endogenous extracellular BDNF with TrkB-IgG in the nucleus raphe magnus decreased AMPA receptor-mediated synaptic transmission and GluA1 phosphorylation at Ser-831 3 days after CFA injection. Under the same conditions, blockade of TrkB receptor functions, phospholipase C, or PKC impaired GluA1 phosphorylation at Ser-831 and decreased excitatory postsynaptic currents mediated by GluA2-lacking AMPA receptors. Taken together, these results suggest that epigenetic up-regulation of BDNF by peripheral inflammation induces GluR1 phosphorylation at Ser-831 sites through activation of the phospholipase C-PKC signaling cascade, leading to the trafficking of GluA1 to pain-modulating neuronal synapses.

  10. DNA methylation and single nucleotide variants in the brain-derived neurotrophic factor (BDNF and oxytocin receptor (OXTR genes are associated with anxiety/depression in older women

    Directory of Open Access Journals (Sweden)

    Yvon eChagnon

    2015-06-01

    Full Text Available Background: Environmental effects and personal experiences could be expressed in individuals through epigenetic non-structural changes such as DNA methylation. This methylation could up- regulate or down-regulate corresponding gene expressions and modify related phenotypes. DNA methylation increases with ageing and could be related to the late expression of some forms of mental disease. The objective of this study was to evaluate the association between anxiety disorders and/or depression in older women and DNA methylation for four genes related to anxiety or depression. Methods: Women aged 65 and older with (n =19 or without (n =24 anxiety disorders and/or major depressive episode (DSM-IV, were recruited. DNA methylation and single nucleotide variant (SNV were evaluated from saliva, respectively by pyrosequencing and by PCR, for the following genes: brain-derived neurotrophic factor (BDNF; rs6265, oxytocin receptor (OXTR; rs53576, serotonin transporter (SLC6A4; rs25531 and apolipoprotein E (APOE; rs429358 and rs7412. Results: A greater BDNF DNA methylation was observed in subjects with anxiety/depression compared to control group subjects(Mean: 2.92 SD: 0.74 vs. 2.34 SD: 0.42; p=0.0026.This difference was more pronounced in subjects carrying the BDNF rs6265 CT genotype (2.99 SD: 0.41 vs.2.27 SD: 0.26; p=0.0006 than those carrying the CC genotype (p=0.0332; no subjects with the TT genotype were observed. For OXTR, a greater DNA methylation was observed in subjects with anxiety/depression, but only for those carrying the AA genotype of the OXTR rs53576SNV, more particularly at one out of the seven CpGs studied (7.01 SD: 0.94 vs. 4.44 SD: 1.11; p=0.0063. No significant differences were observed for APOE and SLC6A4.Conclusion: These results suggest that DNA methylation in interaction with SNV variations in BDNF and OXTR, are associated with the occurrence of anxiety/depression in older women.

  11. Effect of FK506 and cyclosporine A on the expression of BDNF, tyrosine kinase B and p75 neurotrophin receptors in astrocytes exposed to simulated ischemia in vitro.

    Science.gov (United States)

    Gabryel, Bozena; Bernacki, Jacek

    2009-07-01

    We investigated whether the immunosuppressive drugs, FK506 and cyclosporine A, increase BDNF protein and/or mRNA expression in ischemic astrocytes and if an increase could be related to changes in the nuclear expression of p-CREB, p-Erk1/2 and p-Akt. The influence of these immunosuppressants on protein and mRNA levels of TrkB and p75(NTR) receptors was also examined. On day 21, cultures of rat astrocytes were subjected to ischemic conditions simulated in vitro (combined oxygen glucose deprivation, OGD) for 8h and exposed to FK506 (10-1000nM) and cyclosporine A (0.25-10microM). FK506 and cyclosporine A (at 1000nM and 0.25microM, respectively) stimulated the expression and release of BDNF in cultured rat cerebral cortical astrocytes exposed to OGD. The immunosuppressants at these doses simultaneously increased p-CREB and p-Erk1/2 expression in the nuclear fraction of astrocytes. The results RT-PCR and Western blot analysis provided further evidence of a modulating influence of the drugs on the expression of trkB and p75(NTR) genes and their protein products in ischemic astrocytes.

  12. A flavonoid agonist of the TrkB receptor for BDNF improves hippocampal neurogenesis and hippocampus-dependent memory in the Ts65Dn mouse model of DS.

    Science.gov (United States)

    Stagni, Fiorenza; Giacomini, Andrea; Guidi, Sandra; Emili, Marco; Uguagliati, Beatrice; Salvalai, Maria Elisa; Bortolotto, Valeria; Grilli, Mariagrazia; Rimondini, Roberto; Bartesaghi, Renata

    2017-09-04

    Intellectual disability is the unavoidable hallmark of Down syndrome (DS), with a heavy impact on public health. Reduced neurogenesis and impaired neuron maturation are considered major determinants of altered brain function in DS. Since the DS brain starts at a disadvantage, attempts to rescue neurogenesis and neuron maturation should take place as soon as possible. The brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays a key role in brain development by specifically binding to tropomyosin-related kinase receptor B (TrkB). Systemic BDNF administration is impracticable because BDNF has a poor blood-brain barrier penetration. Recent screening of a chemical library has identified a flavone derivative, 7,8-dihydroxyflavone (7,8-DHF), a small-molecule that crosses the blood-brain barrier and binds with high affinity and specificity to the TrkB receptor. The therapeutic potential of TrkB agonists for neurogenesis improvement in DS has never been examined. The goal of our study was to establish whether it is possible to restore brain development in the Ts65Dn mouse model of DS by targeting the TrkB receptor with 7,8-DHF. Ts65Dn mice subcutaneously injected with 7,8-DHF in the neonatal period P3-P15 exhibited a large increase in the number of neural precursor cells in the dentate gyrus and restoration of granule cell number, density of dendritic spines and levels of the presynaptic protein synaptophysin. In order to establish the functional outcome of treatment, mice were treated with 7,8-DHF from P3 to adolescence (P45-50) and were tested with the Morris Water Maze. Treated Ts65Dn mice exhibited improvement of learning and memory, indicating that the recovery of the hippocampal anatomy translated into a functional rescue. Our study in a mouse model of DS provides novel evidence that treatment with 7,8-DHF during the early postnatal period restores the major trisomy-linked neurodevelopmental defects, suggesting that therapy with 7,8-DHF may represent a

  13. Role of pro-brain-derived neurotrophic factor (proBDNF) to mature BDNF conversion in activity-dependent competition at developing neuromuscular synapses.

    Science.gov (United States)

    Je, H Shawn; Yang, Feng; Ji, Yuanyuan; Nagappan, Guhan; Hempstead, Barbara L; Lu, Bai

    2012-09-25

    Formation of specific neuronal connections often involves competition between adjacent axons, leading to stabilization of the active terminal, while retraction of the less active ones. The underlying molecular mechanisms remain unknown. We show that activity-dependent conversion of pro-brain-derived neurotrophic factor (proBDNF) to mature (m)BDNF mediates synaptic competition. Stimulation of motoneurons triggers proteolytic conversion of proBDNF to mBDNF at nerve terminals. In Xenopus nerve-muscle cocultures, in which two motoneurons innervate one myocyte, proBDNF-p75(NTR) signaling promotes retraction of the less active terminal, whereas mBDNF-tyrosine-related kinase B (TrkB) p75NTR (p75 neurotrophin receptor) facilitates stabilization of the active one. Thus, proBDNF and mBDNF may serve as potential "punishment" and "reward" signals for inactive and active terminals, respectively, and activity-dependent conversion of proBDNF to mBDNF may regulate synapse elimination.

  14. Brain-derived neurotrophic factor (BDNF) induces sustained intracellular Ca2+ elevation through the up-regulation of surface transient receptor potential 3 (TRPC3) channels in rodent microglia.

    Science.gov (United States)

    Mizoguchi, Yoshito; Kato, Takahiro A; Seki, Yoshihiro; Ohgidani, Masahiro; Sagata, Noriaki; Horikawa, Hideki; Yamauchi, Yusuke; Sato-Kasai, Mina; Hayakawa, Kohei; Inoue, Ryuji; Kanba, Shigenobu; Monji, Akira

    2014-06-27

    Microglia are immune cells that release factors, including proinflammatory cytokines, nitric oxide (NO), and neurotrophins, following activation after disturbance in the brain. Elevation of intracellular Ca(2+) concentration ([Ca(2+)]i) is important for microglial functions such as the release of cytokines and NO from activated microglia. There is increasing evidence suggesting that pathophysiology of neuropsychiatric disorders is related to the inflammatory responses mediated by microglia. Brain-derived neurotrophic factor (BDNF) is a neurotrophin well known for its roles in the activation of microglia as well as in pathophysiology and/or treatment of neuropsychiatric disorders. In this study, we sought to examine the underlying mechanism of BDNF-induced sustained increase in [Ca(2+)]i in rodent microglial cells. We observed that canonical transient receptor potential 3 (TRPC3) channels contribute to the maintenance of BDNF-induced sustained intracellular Ca(2+) elevation. Immunocytochemical technique and flow cytometry also revealed that BDNF rapidly up-regulated the surface expression of TRPC3 channels in rodent microglial cells. In addition, pretreatment with BDNF suppressed the production of NO induced by tumor necrosis factor α (TNFα), which was prevented by co-adiministration of a selective TRPC3 inhibitor. These suggest that BDNF induces sustained intracellular Ca(2+) elevation through the up-regulation of surface TRPC3 channels and TRPC3 channels could be important for the BDNF-induced suppression of the NO production in activated microglia. We show that TRPC3 channels could also play important roles in microglial functions, which might be important for the regulation of inflammatory responses and may also be involved in the pathophysiology and/or the treatment of neuropsychiatric disorders.

  15. The transfection of BDNF to dopamine neurons potentiates the effect of dopamine D3 receptor agonist recovering the striatal innervation, dendritic spines and motor behavior in an aged rat model of Parkinson's disease.

    Science.gov (United States)

    Razgado-Hernandez, Luis F; Espadas-Alvarez, Armando J; Reyna-Velazquez, Patricia; Sierra-Sanchez, Arturo; Anaya-Martinez, Veronica; Jimenez-Estrada, Ismael; Bannon, Michael J; Martinez-Fong, Daniel; Aceves-Ruiz, Jorge

    2015-01-01

    The progressive degeneration of the dopamine neurons of the pars compacta of substantia nigra and the consequent loss of the dopamine innervation of the striatum leads to the impairment of motor behavior in Parkinson's disease. Accordingly, an efficient therapy of the disease should protect and regenerate the dopamine neurons of the substantia nigra and the dopamine innervation of the striatum. Nigral neurons express Brain Derived Neurotropic Factor (BDNF) and dopamine D3 receptors, both of which protect the dopamine neurons. The chronic activation of dopamine D3 receptors by their agonists, in addition, restores, in part, the dopamine innervation of the striatum. Here we explored whether the over-expression of BDNF by dopamine neurons potentiates the effect of the activation of D3 receptors restoring nigrostriatal innervation. Twelve-month old Wistar rats were unilaterally injected with 6-hydroxydopamine into the striatum. Five months later, rats were treated with the D3 agonist 7-hydroxy-N,N-di-n-propy1-2-aminotetralin (7-OH-DPAT) administered i.p. during 4½ months via osmotic pumps and the BDNF gene transfection into nigral cells using the neurotensin-polyplex nanovector (a non-viral transfection) that selectively transfect the dopamine neurons via the high-affinity neurotensin receptor expressed by these neurons. Two months after the withdrawal of 7-OH-DPAT when rats were aged (24 months old), immunohistochemistry assays were made. The over-expression of BDNF in rats receiving the D3 agonist normalized gait and motor coordination; in addition, it eliminated the muscle rigidity produced by the loss of dopamine. The recovery of motor behavior was associated with the recovery of the nigral neurons, the dopamine innervation of the striatum and of the number of dendritic spines of the striatal neurons. Thus, the over-expression of BDNF in dopamine neurons associated with the chronic activation of the D3 receptors appears to be a promising strategy for restoring

  16. Regulation of brain-derived neurotrophic factor (BDNF) expression and release from hippocampal neurons is mediated by non-NMDA type glutamate receptors.

    Science.gov (United States)

    Wetmore, C; Olson, L; Bean, A J

    1994-03-01

    We have examined the influence of glutamate on cortical brain-derived neurotrophic factor (BDNF) expression using in situ hybridization and immunohistochemistry. Kainic acid (KA) produced an upregulation of hippocampal and neocortical BDNF mRNA as well as BDNF protein that was blocked by a non-NMDA antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX), but was not affected by the NMDA antagonist 2-amino-7-phosphonoheptanoic acid (AP7). Basal levels of BDNF mRNA were not affected by NMDA, DNQX, or AP7 treatment. BDNF protein was also increased after kainate exposure with a spatial and temporal course distinct from that seen for the expression of BDNF mRNA. A dramatic shift in BDNF immunoreactivity (-IR) was observed from intracellular compartments to the neuropil surrounding CA3 pyramidal cells 2-3 hr after KA exposure. This shift in localization of BDNF-IR suggests a constitutive release of BDNF at the level of the cell body and dendrites. Moreover, we have localized mRNAs for full-length and truncated trkB, to a co-incident population of neurons and glia. These data suggest the neurons that produce BDNF also express components necessary for a biological response to the same neurotrophic factor. The present study also demonstrates increased BDNF-IR in the mossy fiber terminal zone of hippocampus after exposure to KA, as well as an increase in trkB mRNA, and provides evidence of local release of this neurotrophin into the surrounding neuropil where it would be available for local utilization. The synthesis and putative release of BDNF from somatic and/or dendritic sites within the hippocampus provide evidence of a potential autocrine or paracrine role for BDNF, and establish a local source of trophic support for the maintenance of synaptic plasticity and anatomic reorganization in the mature nervous system.

  17. Postnatal development of brain-derived neurotrophic factor (BDNF) and tyrosine protein kinase B (TrkB) receptor immunoreactivity in multiple brain stem respiratory-related nuclei of the rat.

    Science.gov (United States)

    Liu, Qiuli; Wong-Riley, Margaret T T

    2013-01-01

    Previously, we found a transient imbalance between suppressed excitation and enhanced inhibition in the respiratory network of the rat around postnatal days (P) 12-13, a critical period when the hypoxic ventilatory response is at its weakest. The mechanism underlying the imbalance is poorly understood. Brain-derived neurotrophic factor (BDNF) and its tyrosine protein kinase B (TrkB) receptors are known to potentiate glutamatergic and attenuate gamma-aminobutyric acid (GABA)ergic neurotransmission, and BDNF is essential for respiratory development. We hypothesized that the excitation-inhibition imbalance during the critical period stemmed from a reduced expression of BDNF and TrkB at that time within respiratory-related nuclei of the brain stem. An in-depth, semiquantitative immunohistochemical study was undertaken in seven respiratory-related brain stem nuclei and one nonrespiratory nucleus in P0-21 rats. The results indicate that the expressions of BDNF and TrkB: 1) in the pre-Bötzinger complex, nucleus ambiguus, commissural and ventrolateral subnuclei of solitary tract nucleus, and retrotrapezoid nucleus/parafacial respiratory group were significantly reduced at P12, but returned to P11 levels by P14; 2) in the lateral paragigantocellular nucleus and parapyramidal region were increased from P0 to P7, but were strikingly reduced at P10 and plateaued thereafter; and 3) in the nonrespiratory cuneate nucleus showed a gentle plateau throughout the first 3 postnatal weeks, with only a slight decline of BDNF expression after P11. Thus, the significant downregulation of both BDNF and TrkB in respiratory-related nuclei during the critical period may form the basis of, or at least contribute to, the inhibitory-excitatory imbalance within the respiratory network during this time.

  18. Topiramate via NMDA, AMPA/kainate, GABAA and Alpha2 receptors and by modulation of CREB/BDNF and Akt/GSK3 signaling pathway exerts neuroprotective effects against methylphenidate-induced neurotoxicity in rats.

    Science.gov (United States)

    Motaghinejad, Majid; Motevalian, Manijeh; Fatima, Sulail; Beiranvand, Tabassom; Mozaffari, Shiva

    2017-08-09

    Chronic abuse of methylphenidate (MPH) often causes neuronal cell death. Topiramate (TPM) carries neuroprotective effects, but its exact mechanism of action remains unclear. In the present study, the role of various doses of TPM and its possible mechanisms, receptors and signaling pathways involved against MPH-induced hippocampal neurodegeneration were evaluated in vivo. Thus, domoic acid (DOM) was used as AMPA/kainate receptor agonist, bicuculline (BIC) as GABAA receptor antagonist, ketamine (KET) as NMDA receptor antagonist, yohimbine (YOH) as α2 adrenergic receptor antagonist and haloperidol (HAL) was used as dopamine D2 receptor antagonist. Open field test (OFT) was used to investigate the disturbances in motor activity. Hippocampal neurodegenerative parameters were evaluated. Protein expressions of CREB/BDNF and Akt/GSK3 signaling pathways were also evaluated. Cresyl violet staining was performed to show and confirm the changes in the shape of the cells. TPM (70 and 100 mg/kg) reduced MPH-induced rise in lipid peroxidation, oxidized form of glutathione (GSSG), IL-1β and TNF-α levels, Bax expression and motor activity disturbances. In addition, TPM treatment increased Bcl-2 expression, the level of reduced form of glutathione (GSH) and the levels and activities of superoxide dismutase, glutathione peroxidase and glutathione reductase enzymes. TPM also inhibited MPH-induced hippocampal degeneration. Pretreatment of animals with DOM, BIC, KET and YOH inhibited TPM-induced neuroprotection and increased oxidative stress, neuroinflammation, neuroapoptosis and neurodegeneration while reducing CREB, BDNF and Akt protein expressions. Also pretreatment with DOM, BIC, KET and YOH inhibited TPM-induced decreases in GSK3. It can be concluded that the mentioned receptors by modulation of CREB/BDNF and Akt/GSK3 pathways, are involved in neuroprotection of TPM against MPH-induced neurodegeneration.

  19. Glioactive ATP controls BDNF recycling in cortical astrocytes

    Science.gov (United States)

    Vignoli, Beatrice; Canossa, Marco

    2017-01-01

    ABSTRACT We have recently reported that long-term memory retention requires synaptic glia for proBDNF uptake and recycling. Through the recycling course, glial cells release endocytic BDNF, a mechanism that is activated in response to glutamate via AMPA and mGluRI/II receptors. Cortical astrocytes express receptors for many different transmitters suggesting for a complex signaling controlling endocytic BDNF secretion. Here, we demonstrated that the extracellular nucleotide ATP, activating P2X and P2Y receptors, regulates endocytic BDNF secretion in cultured astrocytes. Our data indicate that distinct glioactive molecules can participate in BDNF glial recycling and suggest that cortical astrocytes contributing to neuronal plasticity can be influenced by neurotransmitters in tune with synaptic needs.

  20. Blockade of Cannabinoid CB1 receptor attenuates the acquisition of morphine-induced conditioned place preference along with a downregulation of ERK, CREB phosphorylation, and BDNF expression in the nucleus accumbens and hippocampus.

    Science.gov (United States)

    Zhang, Jianbo; Wang, Na; Chen, Bo; Wang, Yi'nan; He, Jing; Cai, Xintong; Zhang, Hongbo; Wei, Shuguang; Li, Shengbin

    2016-09-06

    Cannabinoid CB1 receptor (CB1R) is highly expressed in the mesocorticolimbic system and associated with drug craving and relapse. Clinical trials suggest that CB1R antagonists may represent new therapies for drug addiction. However, the downstream signaling of CB1R is not fully elucidated. In the present study, we investigated the relationship between CB1R and the extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB), brain-derived neurotrophic factor (BDNF) signaling in the nucleus accumbens (NAc) and hippocampus in morphine-induced conditioned place preference (CPP), which is used to assess the morphine-induced reward memory. The protein level of CB1R, ERK, CREB, and BDNF were detected by western blotting. Additionally, a CB1R antagonist, AM251, was used to study whether blockade of CB1R altered the CPP and above-mentioned molecules. We found an increase of CB1R expression in the NAc and hippocampus of the mice following morphine CPP, but not those after repeated morphine in home cage without context exposure (NO-CPP). Both morphine CPP and NO-CPP induced an upregulation of ERK, CREB phosphorylation and BDNF expression. Furthermore, pretreatment with AM251 before morphine attenuated the CPP acquisition and CB1R expression as well as the activation of ERK-CREB-BDNF cascade. Collectively, these findings demonstrate that (1) Repeated morphine with context exposures but not merely the pharmacological effects of morphine increased CB1R expression both in the NAc and hippocampus. (2) CB1R antagonist mediated blockade of ERK-CREB-BDNF signaling activation in the NAc and hippocampus may be an important mechanism underlying the attenuation of morphine CPP.

  1. The transfection of BDNF to dopamine neurons potentiates the effect of dopamine D3 receptor agonist recovering the striatal innervation, dendritic spines and motor behavior in an aged rat model of Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Luis F Razgado-Hernandez

    Full Text Available The progressive degeneration of the dopamine neurons of the pars compacta of substantia nigra and the consequent loss of the dopamine innervation of the striatum leads to the impairment of motor behavior in Parkinson's disease. Accordingly, an efficient therapy of the disease should protect and regenerate the dopamine neurons of the substantia nigra and the dopamine innervation of the striatum. Nigral neurons express Brain Derived Neurotropic Factor (BDNF and dopamine D3 receptors, both of which protect the dopamine neurons. The chronic activation of dopamine D3 receptors by their agonists, in addition, restores, in part, the dopamine innervation of the striatum. Here we explored whether the over-expression of BDNF by dopamine neurons potentiates the effect of the activation of D3 receptors restoring nigrostriatal innervation. Twelve-month old Wistar rats were unilaterally injected with 6-hydroxydopamine into the striatum. Five months later, rats were treated with the D3 agonist 7-hydroxy-N,N-di-n-propy1-2-aminotetralin (7-OH-DPAT administered i.p. during 4½ months via osmotic pumps and the BDNF gene transfection into nigral cells using the neurotensin-polyplex nanovector (a non-viral transfection that selectively transfect the dopamine neurons via the high-affinity neurotensin receptor expressed by these neurons. Two months after the withdrawal of 7-OH-DPAT when rats were aged (24 months old, immunohistochemistry assays were made. The over-expression of BDNF in rats receiving the D3 agonist normalized gait and motor coordination; in addition, it eliminated the muscle rigidity produced by the loss of dopamine. The recovery of motor behavior was associated with the recovery of the nigral neurons, the dopamine innervation of the striatum and of the number of dendritic spines of the striatal neurons. Thus, the over-expression of BDNF in dopamine neurons associated with the chronic activation of the D3 receptors appears to be a promising strategy

  2. The Transfection of BDNF to Dopamine Neurons Potentiates the Effect of Dopamine D3 Receptor Agonist Recovering the Striatal Innervation, Dendritic Spines and Motor Behavior in an Aged Rat Model of Parkinson’s Disease

    Science.gov (United States)

    Razgado-Hernandez, Luis F.; Espadas-Alvarez, Armando J.; Reyna-Velazquez, Patricia; Sierra-Sanchez, Arturo; Anaya-Martinez, Veronica; Jimenez-Estrada, Ismael; Bannon, Michael J.; Martinez-Fong, Daniel; Aceves-Ruiz, Jorge

    2015-01-01

    The progressive degeneration of the dopamine neurons of the pars compacta of substantia nigra and the consequent loss of the dopamine innervation of the striatum leads to the impairment of motor behavior in Parkinson’s disease. Accordingly, an efficient therapy of the disease should protect and regenerate the dopamine neurons of the substantia nigra and the dopamine innervation of the striatum. Nigral neurons express Brain Derived Neurotropic Factor (BDNF) and dopamine D3 receptors, both of which protect the dopamine neurons. The chronic activation of dopamine D3 receptors by their agonists, in addition, restores, in part, the dopamine innervation of the striatum. Here we explored whether the over-expression of BDNF by dopamine neurons potentiates the effect of the activation of D3 receptors restoring nigrostriatal innervation. Twelve-month old Wistar rats were unilaterally injected with 6-hydroxydopamine into the striatum. Five months later, rats were treated with the D3 agonist 7-hydroxy-N,N-di-n-propy1-2-aminotetralin (7-OH-DPAT) administered i.p. during 4½ months via osmotic pumps and the BDNF gene transfection into nigral cells using the neurotensin-polyplex nanovector (a non-viral transfection) that selectively transfect the dopamine neurons via the high-affinity neurotensin receptor expressed by these neurons. Two months after the withdrawal of 7-OH-DPAT when rats were aged (24 months old), immunohistochemistry assays were made. The over-expression of BDNF in rats receiving the D3 agonist normalized gait and motor coordination; in addition, it eliminated the muscle rigidity produced by the loss of dopamine. The recovery of motor behavior was associated with the recovery of the nigral neurons, the dopamine innervation of the striatum and of the number of dendritic spines of the striatal neurons. Thus, the over-expression of BDNF in dopamine neurons associated with the chronic activation of the D3 receptors appears to be a promising strategy for restoring

  3. Neuropeptide S receptor gene -- converging evidence for a role in panic disorder.

    Science.gov (United States)

    Domschke, K; Reif, A; Weber, H; Richter, J; Hohoff, C; Ohrmann, P; Pedersen, A; Bauer, J; Suslow, T; Kugel, H; Heindel, W; Baumann, C; Klauke, B; Jacob, C; Maier, W; Fritze, J; Bandelow, B; Krakowitzky, P; Rothermundt, M; Erhardt, A; Binder, E B; Holsboer, F; Gerlach, A L; Kircher, T; Lang, T; Alpers, G W; Ströhle, A; Fehm, L; Gloster, A T; Wittchen, H-U; Arolt, V; Pauli, P; Hamm, A; Deckert, J

    2011-09-01

    Animal studies have suggested neuropeptide S (NPS) and its receptor (NPSR) to be involved in the pathogenesis of anxiety-related behavior. In this study, a multilevel approach was applied to further elucidate the role of NPS in the etiology of human anxiety. The functional NPSR A/T (Asn¹⁰⁷Ile) variant (rs324981) was investigated for association with (1) panic disorder with and without agoraphobia in two large, independent case-control studies, (2) dimensional anxiety traits, (3) autonomic arousal level during a behavioral avoidance test and (4) brain activation correlates of anxiety-related emotional processing in panic disorder. The more active NPSR rs324981 T allele was found to be associated with panic disorder in the female subgroup of patients in both samples as well as in a meta-analytic approach. The T risk allele was further related to elevated anxiety sensitivity, increased heart rate and higher symptom reports during a behavioral avoidance test as well as decreased activity in the dorsolateral prefrontal, lateral orbitofrontal and anterior cingulate cortex during processing of fearful faces in patients with panic disorder. The present results provide converging evidence for a female-dominant role of NPSR gene variation in panic disorder potentially through heightened autonomic arousal and distorted processing of anxiety-relevant emotional stimuli.

  4. Orchestrated regulation of Nogo receptors, LOTUS, AMPA receptors and BDNF in an ECT model suggests opening and closure of a window of synaptic plasticity.

    Directory of Open Access Journals (Sweden)

    Max Nordgren

    Full Text Available Electroconvulsive therapy (ECT is an efficient and relatively fast acting treatment for depression. However, one severe side effect of the treatment is retrograde amnesia, which in certain cases can be long-term. The mechanisms behind the antidepressant effect and the amnesia are not well understood. We hypothesized that ECT causes transient downregulation of key molecules needed to stabilize synaptic structure and to prevent Ca2+ influx, and a simultaneous increase in neurotrophic factors, thus providing a short time window of increased structural synaptic plasticity. Here we followed regulation of NgR1, NgR3, LOTUS, BDNF, and AMPA subunits GluR1 and GluR2 flip and flop mRNA levels in hippocampus at 2, 4, 12, 24, and 72 hours after a single episode of induced electroconvulsive seizures (ECS in rats. NgR1 and LOTUS mRNA levels were transiently downregulated in the dentate gyrus 2, 4, 12 and 4, 12, 24 h after ECS treatment, respectively. GluR2 flip, flop and GluR1 flop were downregulated at 4 h. GluR2 flip remained downregulated at 12 h. In contrast, BDNF, NgR3 and GluR1 flip mRNA levels were upregulated. Thus, ECS treatment induces a transient regulation of factors important for neuronal plasticity. Our data provide correlations between ECS treatment and molecular events compatible with the hypothesis that both effects and side effects of ECT may be caused by structural synaptic rearrangements.

  5. BDNF pro-peptide actions facilitate hippocampal LTD and are altered by the common BDNF polymorphism Val66Met.

    Science.gov (United States)

    Mizui, Toshiyuki; Ishikawa, Yasuyuki; Kumanogoh, Haruko; Lume, Maria; Matsumoto, Tomoya; Hara, Tomoko; Yamawaki, Shigeto; Takahashi, Masami; Shiosaka, Sadao; Itami, Chiaki; Uegaki, Koichi; Saarma, Mart; Kojima, Masami

    2015-06-09

    Most growth factors are initially synthesized as precursor proteins and subsequently processed into their mature form by proteolytic cleavage, resulting in simultaneous removal of a pro-peptide. However, compared with that of mature form, the biological role of the pro-peptide is poorly understood. Here, we investigated the biological role of the pro-peptide of brain-derived neurotrophic factor (BDNF) and first showed that the pro-peptide is expressed and secreted in hippocampal tissues and cultures, respectively. Interestingly, we found that the BDNF pro-peptide directly facilitates hippocampal long-term depression (LTD), requiring the activation of GluN2B-containing NMDA receptors and the pan-neurotrophin receptor p75(NTR). The BDNF pro-peptide also enhances NMDA-induced α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor endocytosis, a mechanism crucial for LTD expression. Thus, the BDNF pro-peptide is involved in synaptic plasticity that regulates a mechanism responsible for promoting LTD. The well-known BDNF polymorphism valine for methionine at amino acid position 66 (Val66Met) affects human memory function. Here, the BDNF pro-peptide with Met mutation completely inhibits hippocampal LTD. These findings demonstrate functional roles for the BDNF pro-peptide and a naturally occurring human BDNF polymorphism in hippocampal synaptic depression.

  6. Acute exercise modulates BDNF and pro-BDNF protein content in immune cells.

    Science.gov (United States)

    Brunelli, Andrea; Dimauro, Ivan; Sgrò, Paolo; Emerenziani, Gian Pietro; Magi, Fiorenza; Baldari, Carlo; Guidetti, Laura; Di Luigi, Luigi; Parisi, Paolo; Caporossi, Daniela

    2012-10-01

    Although several studies have shown that immune cells stimulated by in vitro stress are capable to produce neurotrophins, there is still no evidence whether physiological stress, such as exercise, can modulate the in vivo levels of brain-derived neurotrophic factor (BDNF) in peripheral blood mononuclear cells (PBMCs). This work investigated whether acute exercise modulates the expression of BDNF, pro-BDNF, and p75(NTR) in the PBMCs of 10 healthy young men who performed a cycling incremental test to exhaustion (MAX) or exercised at individual anaerobic threshold (IAT). The PBMC expression of stress response proteins and the level of circulating BDNF, vascular endothelial growth growth factor, platelet-derived growth factor subunit B, basic fibroblast growth factor pro-inflammatory, and anti-inflammatory cytokines were analyzed as well. A major finding is that both sessions of acute exercise regulated the content of BDNF isoforms within PBMCs in a manner related to the physiological stress exerted. Although the pro-BDNF increased after both MAX and IAT protocols, BDNF showed a kinetics dependent on exercise type: MAX induced a 54% protein increase immediately after exercise, followed by a significant drop 60 min after its conclusion (38% lower than the baseline). Differently, in the IAT, BDNF increased significantly up to 75% from the baseline throughout the recovery phase. All physiological parameters, as well as the p75(NTR) receptor and the stress-inducible proteins, were also differently regulated by the two exercise conditions. These data supported the hypothesis that PBMCs might produce and secrete BDNF isoforms, as well as modulate the proteins p75(NTR) , Bcl-xL, hsp90, hsp27, and αB-crystallin, as part of the physiological stress response induced by acute exercise, offering a novel example of bidirectional interaction between nervous and immune systems.

  7. Childhood maternal care is associated with DNA methylation of the genes for brain-derived neurotrophic factor (BDNF) and oxytocin receptor (OXTR) in peripheral blood cells in adult men and women.

    Science.gov (United States)

    Unternaehrer, Eva; Meyer, Andrea Hans; Burkhardt, Susan C A; Dempster, Emma; Staehli, Simon; Theill, Nathan; Lieb, Roselind; Meinlschmidt, Gunther

    2015-01-01

    In adults, reporting low and high maternal care in childhood, we compared DNA methylation in two stress-associated genes (two target sequences in the oxytocin receptor gene, OXTR; one in the brain-derived neurotrophic factor gene, BDNF) in peripheral whole blood, in a cross-sectional study (University of Basel, Switzerland) during 2007-2008. We recruited 89 participants scoring  33 (n = 42, 35 women) on the maternal care subscale of the Parental Bonding Instrument (PBI) at a previous assessment of a larger group (N = 709, range PBI maternal care = 0-36, age range = 19-66 years; median 24 years). 85 participants gave blood for DNA methylation analyses (Sequenom(R) EpiTYPER, San Diego, CA) and cell count (Sysmex PocH-100i™, Kobe, Japan). Mixed model statistical analysis showed greater DNA methylation in the low versus high maternal care group, in the BDNF target sequence [Likelihood-Ratio (1) = 4.47; p = 0.035] and in one OXTR target sequence Likelihood-Ratio (1) = 4.33; p = 0.037], but not the second OXTR target sequence [Likelihood-Ratio (1) BDNF (estimate = -0.005, 95% CI = -0.025 to 0.015; p = 0.626) or OXTR DNA methylation (estimate = -0.015, 95% CI = -0.038 to 0.008; p = 0.192). Hence, low maternal care in childhood was associated with greater DNA methylation in an OXTR and a BDNF target sequence in blood cells in adulthood. Although the study has limitations (cross-sectional, a wide age range, only three target sequences in two genes studied, small effects, uncertain relevance of changes in blood cells to gene methylation in brain), the findings may indicate components of the epiphenotype from early life stress.

  8. Ethanol-BDNF interactions: still more questions than answers.

    Science.gov (United States)

    Davis, Margaret I

    2008-04-01

    Brain-derived neurotrophic factor (BDNF) has emerged as a regulator of development, plasticity and, recently, addiction. Decreased neurotrophic activity may be involved in ethanol-induced neurodegeneration in the adult brain and in the etiology of alcohol-related neurodevelopmental disorders. This can occur through decreased expression of BDNF or through inability of the receptor to transduce signals in the presence of ethanol. In contrast, recent studies implicate region-specific up-regulation of BDNF and associated signaling pathways in anxiety, addiction and homeostasis after ethanol exposure. Anxiety and depression are precipitating factors for substance abuse and these disorders also involve region-specific changes in BDNF in both pathogenesis and response to pharmacotherapy. Polymorphisms in the genes coding for BDNF and its receptor TrkB are linked to affective, substance abuse and appetitive disorders and therefore may play a role in the development of alcoholism. This review summarizes historical and pre-clinical data on BDNF and TrkB as it relates to ethanol toxicity and addiction. Many unresolved questions about region-specific changes in BDNF expression and the precise role of BDNF in neuropsychiatric disorders and addiction remain to be elucidated. Resolution of these questions will require significant integration of the literature on addiction and comorbid psychiatric disorders that contribute to the development of alcoholism.

  9. Multiple functions of precursor BDNF to CNS neurons: negative regulation of neurite growth, spine formation and cell survival

    Directory of Open Access Journals (Sweden)

    Koshimizu Hisatsugu

    2009-08-01

    Full Text Available Abstract Background Proneurotrophins and mature neurotrophins elicit opposite effects via the p75 neurotrophin receptor (p75NTR and Trk tyrosine kinase receptors, respectively; however the molecular roles of proneurotrophins in the CNS are not fully understood. Results Based on two rare single nucleotide polymorphisms (SNPs of the human brain-derived neurotrophic factor (BDNF gene, we generated R125M-, R127L- and R125M/R127L-BDNF, which have amino acid substitution(s near the cleavage site between the pro- and mature-domain of BDNF. Western blot analyses demonstrated that these BDNF variants are poorly cleaved and result in the predominant secretion of proBDNF. Using these cleavage-resistant proBDNF (CR-proBDNF variants, the molecular and cellular roles of proBDNF on the CNS neurons were examined. First, CR-proBDNF showed normal intracellular distribution and secretion in cultured hippocampal neurons, suggesting that inhibition of proBDNF cleavage does not affect intracellular transportation and secretion of BDNF. Second, we purified recombinant CR-proBDNF and tested its biological effects using cultured CNS neurons. Treatment with CR-proBDNF elicited apoptosis of cultured cerebellar granule neurons (CGNs, while treatment with mature BDNF (matBDNF promoted cell survival. Third, we examined the effects of CR-proBDNF on neuronal morphology using more than 2-week cultures of basal forebrain cholinergic neurons (BFCNs and hippocampal neurons. Interestingly, in marked contrast to the action of matBDNF, which increased the number of cholinergic fibers and hippocampal dendritic spines, CR-proBDNF dramatically reduced the number of cholinergic fibers and hippocampal dendritic spines, without affecting the survival of these neurons. Conclusion These results suggest that proBDNF has distinct functions in different populations of CNS neurons and might be responsible for specific physiological cellular processes in the brain.

  10. Physiology of BDNF: focus on hypothalamic function.

    Science.gov (United States)

    Tapia-Arancibia, Lucia; Rage, Florence; Givalois, Laurent; Arancibia, Sandor

    2004-07-01

    Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family which interacts with high-affinity protein kinase receptors (Trk) and the unselective p75(NGFR) receptor. The BDNF gene has a complex structure with multiple regulatory elements and four promoters that are differentially expressed in central or peripheral tissue. BDNF expression is regulated by neuronal activity or peripheral hormones. Neurotrophins regulate the survival and differentiation of neurons during development but growing evidence indicates that they are also involved in several functions in adulthood, including plasticity processes. BDNF expression in the central nervous system (CNS) is modified by various kinds of brain insult (stress, ischemia, seizure activity, hypoglycemia, etc.) and alterations in its expression may contribute to some pathologies such as depression, epilepsy, Alzheimer's, and Parkinson's disease. Apart from very traumatic situations, the brain functioning is resilient to stress and capable of adaptive plasticity. Neurotrophins might act as plasticity mediators enhancing this trait which seems to be crucial in adaptive processes. In addition to documenting all of the topics mentioned above in the CNS, we review the state of the art concerning neurotrophins and their receptors, including our personal contribution which is essentially focused on the stress response.

  11. BDNF-mediated modulation of glycine transmission on rat spinal motoneurons.

    Science.gov (United States)

    Ding, Jian-Dong; Tang, Xian-Ye; Shi, Jian-Gang; Jia, Lian-Shun

    2014-08-22

    BDNF has a widespread distribution in the central and peripheral nervous systems, suggesting that BDNF may play a role in the regulation of motor control. However, the direct actions of BDNF on the motoneurons and their underlying mechanisms are still largely unknown to date. Therefore, by using whole-cell patch clamp recordings, quantitative RT-PCR and immunocytochemistry, the present study was designed to investigate the effects of BDNF on electrical activity and glycinergic transmission on the motoneurons and the underlying receptor mechanism. The results reveal: (i) BDNF did not produce a direct excitatory or inhibitory effect on the motoneurons; (ii) BDNF dose-dependently increased the glycinergic transmission on the motoneurons; (iii) glycinergic transmission on motoneurons was a direct postsynaptic effect; (iv) BDNF-induced enhancement of the glycinergic transmission was mediated by the activation of TrkB receptors; and (v) BDNF and its receptors TrkB had an extensive expression in the motoneurons. These results suggest that BDNF is directly involved in the regulation of glycinergic transmission on the motoneurons through postsynaptic TrkB receptors. Considering that the glycinergic synaptic transmission of motoneurons mainly comes from Renshaw cells, the important inhibitory interneurons of spinal cord, we speculate that BDNF may play an important role in the information integration in the spinal cord and participate in the sensitivity of motoneurons.

  12. THE ROLE OF BDNF IN THE DEVELOPMENT OF FEAR LEARNING

    Science.gov (United States)

    Dincheva, Iva; Lynch, Niccola B.; Lee, Francis S.

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is a growth factor that is dynamically expressed in the brain across postnatal development, regulating neuronal differentiation and synaptic plasticity. The neurotrophic hypothesis of psychiatric mood disorders postulates that in the adult brain, decreased BDNF levels leads to altered neural plasticity, contributing to disease. Although BDNF has been established as a key factor regulating the critical period plasticity in the developing visual system, it has recently been shown to also play a role in fear circuitry maturation, which has implications for the emergence of fear-related mood disorders. This review provides a detailed overview of developmental changes in expression of BDNF isoforms, as well as their receptors across postnatal life. In addition, recent developmental studies utilizing a genetic BDNF single nucleotide polymorphism (Val66Met) knock-in mouse highlight the impact of BDNF on fear learning during a sensitive period spanning the transition into adolescent time frame. We hypothesize that BDNF in the developing brain regulates fear circuit plasticity during a sensitive period in early adolescence, and alterations in BDNF expression (genetic or environmental) have a persistent impact on fear behavior and fear-related disorders. PMID:27699937

  13. 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.

  14. Ethanol-BDNF interactions: Still More Questions than Answers

    OpenAIRE

    Davis, Margaret I.

    2008-01-01

    Brain Derived Neurotrophic Factor (BDNF) has emerged as a regulator of development, plasticity and, recently, addiction. Decreased neurotrophic activity may be involved in ethanol-induced neurodegeneration in the adult brain and in the etiology of alcohol-related neurodevelopmental disorders. This can occur through decreased expression of BDNF or through inability of the receptor to transduce signals in the presence of ethanol. In contrast, recent studies implicate region-specific up-regulati...

  15. BDNF promotes differentiation and maturation of adult-born neurons through GABAergic transmission.

    Science.gov (United States)

    Waterhouse, Emily G; An, Juan Ji; Orefice, Lauren L; Baydyuk, Maryna; Liao, Guey-Ying; Zheng, Kang; Lu, Bai; Xu, Baoji

    2012-10-10

    Brain-derived neurotrophic factor (BDNF) has been implicated in regulating adult neurogenesis in the subgranular zone (SGZ) of the dentate gyrus; however, the mechanism underlying this regulation remains unclear. In this study, we found that Bdnf mRNA localized to distal dendrites of dentate gyrus granule cells isolated from wild-type (WT) mice, but not from Bdnf(klox/klox) mice where the long 3' untranslated region (UTR) of Bdnf mRNA is truncated. KCl-induced membrane depolarization stimulated release of dendritic BDNF translated from long 3' UTR Bdnf mRNA in cultured hippocampal neurons, but not from short 3' UTR Bdnf mRNA. Bdnf(klox/klox) mice exhibited reduced expression of glutamic acid decarboxylase 65 (a GABA synthase), increased proliferation of progenitor cells, and impaired differentiation and maturation of newborn neurons in the SGZ. These deficits in adult neurogenesis were rescued with administration of phenobarbital, an enhancer of GABA(A) receptor activity. Furthermore, we observed similar neurogenesis deficits in mice where the receptor for BDNF, TrkB, was selectively abolished in parvalbumin (PV)-expressing GABAergic interneurons. Thus, our data suggest that locally synthesized BDNF in dendrites of granule cells promotes differentiation and maturation of progenitor cells in the SGZ by enhancing GABA release, at least in part, from PV-expressing GABAergic interneurons.

  16. The neurotrophin-receptor-related protein NRH1 is essential for convergent extension movements.

    Science.gov (United States)

    Sasai, Noriaki; Nakazawa, Yoko; Haraguchi, Tomoko; Sasai, Yoshiki

    2004-08-01

    Early spherical Xenopus laevis embryos are transformed into a streamlined shape through convergent extension movements. Here we report that a p75(NTR)-related transmembrane protein, NRH1, has an essential function in the regulation of these movements. NRH1 was expressed in marginal zone tissues of the gastrula and in the posterior ectoderm of the neurula. Attenuation of the NRH1 function inhibited convergent extension movements in the embryo and in activin-treated animal caps. NRH1 activated downstream effectors of the Wnt/planar cell polarity pathway: small GTPases and the cascade of MKK7-JNK. Furthermore, gain- and loss-of-function phenotypes of NRH1 were rescued by co-injection of dominant-negative and constitutively active forms of these downstream effectors, respectively, suggesting that NRH1 functions as a positive modulator of planar cell polarity signalling. Interestingly, NRH1 does not require Dishevelled (Xdsh) for the activation of these downstream effectors or translocation of Xdsh to the membrane, suggesting that NRH1 signalling interacts with planar cell polarity signalling downstream of Xdsh. This demonstrates an essential role for p75(NTR)-related signalling in early embryonic morphogenesis.

  17. BDNF regulates the KCC2-dependent switch from depolarizing to hyperpolarizing GABA action

    OpenAIRE

    Akyeli, Jan

    2010-01-01

    The depolarising action of the neurotransmitter GABA enables a route for local Ca2+ entry into immature neurons and therefore plays an important role in neuronal maturation. We have characterised neuronal GABAA receptor activity in slices comprising the superficial gray layer of the late embryonic and early postnatal mouse superior colliculus and compared wild type (bdnf+/+) and BDNF-deficient (bdnf-/-) preparations. Whole-cell or gramicidin-perforated patch recordings and Ca2+ imaging exper...

  18. Oxytocin receptor gene methylation : converging multilevel evidence for a role in social anxiety

    NARCIS (Netherlands)

    Ziegler, Christiane; Dannlowski, Udo; Bräuer, David; Stevens, Stephan; Laeger, Inga; Wittmann, Hannah; Kugel, Harald; Dobel, Christian; Hurlemann, René; Reif, Andreas; Lesch, Klaus-Peter; Heindel, Walter; Kirschbaum, Clemens; Arolt, Volker; Gerlach, Alexander L; Hoyer, Jürgen; Deckert, Jürgen; Zwanzger, Peter; Domschke, Katharina

    2015-01-01

    Social anxiety disorder (SAD) is a commonly occurring and highly disabling disorder. The neuropeptide oxytocin and its receptor (OXTR) have been implicated in social cognition and behavior. This study-for the first time applying a multilevel epigenetic approach-investigates the role of OXTR gene met

  19. Functional interactions between steroid hormones and neurotrophin BDNF

    Institute of Scientific and Technical Information of China (English)

    Tadahiro; Numakawa; Daisaku; Yokomaku; Misty; Richards; Hiroaki; Hori; Naoki; Adachi; Hiroshi; Kunugi

    2010-01-01

    Brain-derived neurotrophic factor(BDNF),a critical neurotrophin,regulates many neuronal aspects including cell differentiation,cell survival,neurotransmission,and synaptic plasticity in the central nervous system(CNS) .Though BDNF has two types of receptors,high affinity tropomyosin-related kinase(Trk) B and low affinity p75 receptors,BDNF positively exerts its biological effects on neurons via activation of TrkB and of resultant intracellular signaling cascades including mitogenactivated protein kinase/extracellular signal-regulated protein kinase,phospholipase Cγ,and phosphoinositide 3-kinase pathways.Notably,it is possible that alteration in the expression and/or function of BDNF in the CNS is involved in the pathophysiology of various brain diseases such as stroke,Parkinson’s disease,Alzheimer’s disease,and mental disorders.On the other hand,glucocorticoids,stress-induced steroid hormones,also putatively contribute to the pathophysiology of depression.Interestingly,in addition to the reduction in BDNF levels due to increased glucocorticoid exposure,current reports demonstrate possible interactions between glucocorticoids and BDNF-mediated neuronal functions. Other steroid hormones,such as estrogen,are involved in not only sexual differentiation in the brain,but also numerous neuronal events including cell survival and synaptic plasticity.Furthermore,it is well known that estrogen plays a role in the pathophysiology of Parkinson’s disease,Alzheimer’s disease,and mental illness,while serving to regulate BDNF expression and/or function.Here,we present a broad overview of the current knowledge concerning the association between BDNF expression/function and steroid hormones(glucocorticoids and estrogen).

  20. The BDNF Val66Met polymorphism enhances glutamatergic transmission but diminishes activity-dependent synaptic plasticity in the dorsolateral striatum.

    Science.gov (United States)

    Jing, Deqiang; Lee, Francis S; Ninan, Ipe

    2017-01-01

    The Val66Met polymorphism in the brain-derived neurotrophic factor (BDNF) gene disrupts the activity-dependent release of BDNF, which might underlie its involvement in several neuropsychiatric disorders. Consistent with the potential role of regulated release of BDNF in synaptic functions, earlier studies have demonstrated that the BDNF Val66Met polymorphism impairs NMDA receptor-mediated synaptic transmission and plasticity in the hippocampus, the medial prefrontal cortex and the central amygdala. However, it is unknown whether the BDNF Val66Met polymorphism affects synapses in the dorsal striatum, which depends on cortical afferents for BDNF. Electrophysiological experiments revealed an enhanced glutamatergic transmission in the dorsolateral striatum (DLS) of knock-in mice containing the variant polymorphism (BDNF(Met/Met)) compared to the wild-type (BDNF(Val/Val)) mice. This increase in glutamatergic transmission is mediated by a potentiation in glutamate release and NMDA receptor transmission in the medium spiny neurons without any alterations in non-NMDA receptor-mediated transmission. We also observed an impairment of synaptic plasticity, both long-term potentiation and depression in the DLS neurons, in BDNF(Met/Met) mice. Thus, the BDNF Val66Met polymorphism exerts an increase in glutamatergic transmission but impairs synaptic plasticity in the dorsal striatum, which might play a role in its effect on neuropsychiatric symptoms. This article is part of the Special Issue entitled 'Ionotropic glutamate receptors'.

  1. Converging action of alcohol consumption and cannabinoid receptor activation on adult hippocampal neurogenesis.

    Science.gov (United States)

    Alén, Francisco; Mouret, Aurélie; Viveros, Maria-Paz; Llorente, Ricardo; Lepousez, Gabriel; Lledo, Pierre-Marie; López-Moreno, José Antonio

    2010-03-01

    Alcoholism is characterized by successive periods of abstinence and relapse, resulting from long-lasting changes in various circuits of the central nervous system. Accumulating evidence points to the endocannabinoid system as one of the most relevant biochemical systems mediating alcohol addiction. The endocannabinoid system regulates adult neurogenesis, a form of long-lasting adult plasticity that occurs in a few areas of the brain, including the dentate gyrus. Because exposure to psychotropic drugs regulates adult neurogenesis, it is possible that neurogenesis might be implicated in the pathophysiology, and hence treatment, of neurobiological illnesses related to drugs of abuse. Here, we investigated the sensitivity of adult hippocampal neurogenesis to alcohol and the cannabinoid receptor agonist WIN 55,212-2 (WIN). Specifically, we analysed the potential link between alcohol relapse, cannabinoid receptor activation, and adult neurogenesis. Adult rats were exposed to subchronic alcohol binge intoxication and received the cannabinoid receptor agonist WIN. Another group of rats were subjected to an alcohol operant self-administration task. Half of these latter animals had continuous access to alcohol, while the other half were subjected to alcohol deprivation, with or without WIN administration. WIN treatment, when administered during alcohol deprivation, resulted in the greatest increase in alcohol consumption during relapse. Together, forced alcohol binge intoxication and WIN administration dramatically reduced hippocampal neurogenesis. Furthermore, adult neurogenesis inversely correlated with voluntary consumption of alcohol. These findings suggest that adult hippocampal neurogenesis is a key factor involved in drug abuse and that it may provide a new strategy for the treatment of alcohol addiction and dependence.

  2. Involvement of BDNF signaling transmission from basolateral amygdala to infralimbic prefrontal cortex in conditioned taste aversion extinction.

    Science.gov (United States)

    Xin, Jian; Ma, Ling; Zhang, Tian-Yi; Yu, Hui; Wang, Yue; Kong, Liang; Chen, Zhe-Yu

    2014-05-21

    Brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase receptor B (TrkB), play a critical role in memory extinction. However, the detailed role of BDNF in memory extinction on the basis of neural circuit has not been fully understood. Here, we aim to investigate the role of BDNF signaling circuit in mediating conditioned taste aversion (CTA) memory extinction of the rats. We found region-specific changes in BDNF gene expression during CTA extinction. CTA extinction led to increased BDNF gene expression in the basolateral amygdala (BLA) and infralimbic prefrontal cortex (IL) but not in the central amygdaloid nucleus (CeA) and hippocampus (HIP). Moreover, blocking BDNF signaling or exogenous microinjection of BDNF into the BLA or IL could disrupt or enhance CTA extinction, which suggested that BDNF signaling in the BLA and IL is necessary and sufficient for CTA extinction. Interestingly, we found that microinjection of BDNF-neutralizing antibody into the BLA could abolish the extinction training-induced BDNF mRNA level increase in the IL, but not vice versa, demonstrating that BDNF signaling is transmitted from the BLA to IL during extinction. Finally, the accelerated extinction learning by infusion of exogenous BDNF in the BLA could also be blocked by IL infusion of BDNF-neutralizing antibody rather than vice versa, indicating that the IL, but not BLA, is the primary action site of BDNF in CTA extinction. Together, these data suggest that BLA-IL circuit regulates CTA memory extinction by identifying BDNF as a key regulator.

  3. BDNF Evokes Release of Endogenous Cannabinoids at Layer 2/3 Inhibitory Synapses in the Neocortex

    OpenAIRE

    2010-01-01

    The neurotrophin brain-derived neurotrophic factor (BDNF) is a potent regulator of inhibitory synaptic transmission, although the locus of this effect and the underlying mechanisms are controversial. We explored a potential interaction between BDNF and endogenous cannabinoid (endocannabinoid) signaling because activation of type 1 cannabinoid (CB1) receptors potently regulates γ-aminobutyric acid (GABA) release and both trkB tyrosine kinase receptors and CB1 receptors are highly expressed at ...

  4. Definition of a Bidirectional Activity-Dependent Pathway Involving BDNF and Narp

    Directory of Open Access Journals (Sweden)

    Abigail Mariga

    2015-12-01

    Full Text Available One of the cardinal features of neural development and adult plasticity is the contribution of activity-dependent signaling pathways. However, the interrelationships between different activity-dependent genes are not well understood. The immediate early gene neuronal-activity-regulated pentraxin (NPTX2 or Narp encodes a protein that has been associated with excitatory synaptogenesis, AMPA receptor aggregation, and the onset of critical periods. Here, we show that Narp is a direct transcriptional target of brain-derived neurotrophic factor (BDNF, another highly regulated activity-dependent gene involved in synaptic plasticity. Unexpectedly, Narp is bidirectionally regulated by BDNF. Acute BDNF withdrawal results in downregulation of Narp, whereas transcription of Narp is greatly enhanced by BDNF. Furthermore, our results show that BDNF directly regulates Narp to mediate glutamatergic transmission and mossy fiber plasticity. Hence, Narp serves as a significant epistatic target of BDNF to regulate synaptic plasticity during periods of dynamic activity.

  5. Chronic BDNF deficiency leads to an age-dependent impairment in spatial learning.

    Science.gov (United States)

    Petzold, Anne; Psotta, Laura; Brigadski, Tanja; Endres, Thomas; Lessmann, Volkmar

    2015-04-01

    Brain-derived neurotrophic factor (BDNF) is a crucial mediator of neural plasticity and, consequently, of memory formation. In hippocampus-dependent learning tasks BDNF also seems to play an essential role. However, there are conflicting results concerning the spatial learning ability of aging BDNF(+/-) mice in the Morris water maze paradigm. To evaluate the effect of chronic BDNF deficiency in the hippocampus on spatial learning throughout life, we conducted a comprehensive study to test differently aged BDNF(+/-) mice and their wild type littermates in the Morris water maze and to subsequently quantify their hippocampal BDNF protein levels as well as expression levels of TrkB receptors. We observed an age-dependent learning deficit in BDNF(+/-) animals, starting at seven months of age, despite stable hippocampal BDNF protein expression and continual decline of TrkB receptor expression throughout aging. Furthermore, we detected a positive correlation between hippocampal BDNF protein levels and learning performance during the probe trial in animals that showed a good learning performance during the long-term memory test.

  6. BDNF/TrkB signaling protects HT-29 human colon cancer cells from EGFR inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Brunetto de Farias, Caroline [Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS (Brazil); Children' s Cancer Institute, 90420-140 Porto Alegre, RS (Brazil); Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90050-170 Porto Alegre, RS (Brazil); National Institute for Translational Medicine (INCT-TM), 90035-003 Porto Alegre, RS (Brazil); Heinen, Tiago Elias; Pereira dos Santos, Rafael [Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS (Brazil); Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90050-170 Porto Alegre, RS (Brazil); National Institute for Translational Medicine (INCT-TM), 90035-003 Porto Alegre, RS (Brazil); Abujamra, Ana Lucia [Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS (Brazil); Children' s Cancer Institute, 90420-140 Porto Alegre, RS (Brazil); National Institute for Translational Medicine (INCT-TM), 90035-003 Porto Alegre, RS (Brazil); Schwartsmann, Gilberto [Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS (Brazil); National Institute for Translational Medicine (INCT-TM), 90035-003 Porto Alegre, RS (Brazil); Department of Internal Medicine, School of Medicine, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS (Brazil); and others

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer BDNF protected HT-29 colorectal cancer cells from the antitumor effect of cetuximab. Black-Right-Pointing-Pointer TrkB inhibition potentiated the antitumor effect of cetuximab. Black-Right-Pointing-Pointer BDNF/TrkB signaling might be involved in resistance to anti-EGFR therapy. -- Abstract: The clinical success of targeted treatment of colorectal cancer (CRC) is often limited by resistance to anti-epidermal growth factor receptor (EGFR) therapy. The neurotrophin brain-derived neurotrophic factor (BDNF) and its receptor TrkB have recently emerged as anticancer targets, and we have previously shown increased BDNF levels in CRC tumor samples. Here we report the findings from in vitro experiments suggesting that BDNF/TrkB signaling can protect CRC cells from the antitumor effects of EGFR blockade. The anti-EGFR monoclonal antibody cetuximab reduced both cell proliferation and the mRNA expression of BDNF and TrkB in human HT-29 CRC cells. The inhibitory effect of cetuximab on cell proliferation and survival was counteracted by the addition of human recombinant BDNF. Finally, the Trk inhibitor K252a synergistically enhanced the effect of cetuximab on cell proliferation, and this effect was blocked by BDNF. These results provide the first evidence that increased BDNF/TrkB signaling might play a role in resistance to EGFR blockade. Moreover, it is possible that targeting TrkB could potentiate the anticancer effects of anti-EGFR therapy.

  7. BDNF heightens the sensitivity of motor neurons to excitotoxic insults through activation of TrkB

    Science.gov (United States)

    Hu, Peter; Kalb, Robert G.; Walton, K. D. (Principal Investigator)

    2003-01-01

    The survival promoting and neuroprotective actions of brain-derived neurotrophic factor (BDNF) are well known but under certain circumstances this growth factor can also exacerbate excitotoxic insults to neurons. Prior exploration of the receptor through which BDNF exerts this action on motor neurons deflects attention away from p75. Here we investigated the possibility that BDNF acts through the receptor tyrosine kinase, TrkB, to confer on motor neurons sensitivity to excitotoxic challenge. We blocked BDNF activation of TrkB using a dominant negative TrkB mutant or a TrkB function blocking antibody, and found that this protected motor neurons against excitotoxic insult in cultures of mixed spinal cord neurons. Addition of a function blocking antibody to BDNF to mixed spinal cord neuron cultures is also neuroprotective indicating that endogenously produced BDNF participates in vulnerability to excitotoxicity. We next examined the intracellular signaling cascades that are engaged upon TrkB activation. Previously we found that inhibition of the phosphatidylinositide-3'-kinase (PI3'K) pathway blocks BDNF-induced excitotoxic sensitivity. Here we show that expression of a constitutively active catalytic subunit of PI3'K, p110, confers excitotoxic sensitivity (ES) upon motor neurons not incubated with BDNF. Parallel studies with purified motor neurons confirm that these events are likely to be occuring specifically within motor neurons. The abrogation of BDNF's capacity to accentuate excitotoxic insults may make it a more attractive neuroprotective agent.

  8. Brain-derived neurotrophic factor (BDNF)-induced mitochondrial motility arrest and presynaptic docking contribute to BDNF-enhanced synaptic transmission.

    Science.gov (United States)

    Su, Bo; Ji, Yun-Song; Sun, Xu-lu; Liu, Xiang-Hua; Chen, Zhe-Yu

    2014-01-17

    Appropriate mitochondrial transport and distribution are essential for neurons because of the high energy and Ca(2+) buffering requirements at synapses. Brain-derived neurotrophic factor (BDNF) plays an essential role in regulating synaptic transmission and plasticity. However, whether and how BDNF can regulate mitochondrial transport and distribution are still unclear. Here, we find that in cultured hippocampal neurons, application of BDNF for 15 min decreased the percentage of moving mitochondria in axons, a process dependent on the activation of the TrkB receptor and its downstream PI3K and phospholipase-Cγ signaling pathways. Moreover, the BDNF-induced mitochondrial stopping requires the activation of transient receptor potential canonical 3 and 6 (TRPC3 and TRPC6) channels and elevated intracellular Ca(2+) levels. The Ca(2+) sensor Miro1 plays an important role in this process. Finally, the BDNF-induced mitochondrial stopping leads to the accumulation of more mitochondria at presynaptic sites. Mutant Miro1 lacking the ability to bind Ca(2+) prevents BDNF-induced mitochondrial presynaptic accumulation and synaptic transmission, suggesting that Miro1-mediated mitochondrial motility is involved in BDNF-induced mitochondrial presynaptic docking and neurotransmission. Together, these data suggest that mitochondrial transport and distribution play essential roles in BDNF-mediated synaptic transmission.

  9. Cross-Generational trans Fat Consumption Favors Self-Administration of Amphetamine and Changes Molecular Expressions of BDNF, DAT, and D1/D2 Receptors in the Cortex and Hippocampus of Rats.

    Science.gov (United States)

    Kuhn, Fábio Teixeira; Dias, Verônica Tironi; Roversi, Karine; Vey, Luciana Taschetto; de Freitas, Daniele Leão; Pase, Camila Simonetti; Roversi, Katiane; Veit, Juliana Cristina; Emanuelli, Tatiana; Bürger, Marilise Escobar

    2015-11-01

    Amphetamine (AMPH) is an addictive psychostimulant drug whose use has been related to neurotoxicity. Experimentally, AMPH increases anxiety-like symptoms, showing addictive properties. In the last decades, the growing consumption of processed foods has provided an excess of saturated and trans fats in detriment of essential fatty acids, which may modify the lipid profile of brain membranes, thus modifying its permeability and dopaminergic neurotransmission. Here, we assessed the influence of brain incorporation of different fatty acids (FA) on AMPH self-administration. Three groups of young male rats were orally supplemented from weaning with a mixture of soybean oil (SO, rich in n-6 FA) and fish oil (FO, rich in n-3 FA), hydrogenated vegetable fat (HVF, rich in trans fatty acids--TFA), or water (control group). These animals were born from dams that were supplemented with the same fat from pregnancy to lactation. Anxiety-like symptoms and locomotor index were assessed in elevated plus maze and open-field (OF), respectively, while brain molecular expressions of dopaminergic receptors, dopamine transporter (DAT), and BDNF were determined in the cortex and hippocampus. HVF increased the frequency of AMPH self-administration and was associated with reinforcement and withdrawal signs as observed by increased anxiety-like symptoms. Contrarily, SO/FO decreased these parameters. Increased BDNF protein together with decreased DAT expression was observed in the hippocampus of HVF group. Based on these findings, our study points to a harmful influence of trans fats on drug addiction and craving symptoms, whose mechanism may be related to changes in the dopaminergic neurotransmission.

  10. BDNF — EDRN Public Portal

    Science.gov (United States)

    BDNF (brain-derived neurotrophic factor) is a member of the nerve growth factor family. It is induced by cortical neurons, and is necessary for survival of striatal neurons in the brain. During development, BDNF promotes the survival and differentiation of selected neuronal populations of the peripheral and central nervous systems. Decreased expression of the BDNF gene is seen in both Alzheimer's and Huntington disease patients. BDNF may play a role in the regulation of stress response and in the biology of mood disorders. Multiple transcript variants encoding distinct isoforms have been described for this gene.

  11. Requirement for BDNF in the reconsolidation of fear extinction.

    Science.gov (United States)

    Radiske, Andressa; Rossato, Janine I; Köhler, Cristiano A; Gonzalez, Maria Carolina; Medina, Jorge H; Cammarota, Martín

    2015-04-22

    Therapies based on the impairment of reconsolidation or the enhancement of extinction offer the possibility of decreasing the persistent recollection of distressing memories. However, the direct interplay between reconsolidation and extinction has rarely been considered. Previously, we reported that reactivation induces reconsolidation of fear extinction memory. Here, using a step-down inhibitory avoidance learning paradigm in rats, we show that intrahippocampus infusion of function-blocking anti-BDNF antibody immediately or 6 h after extinction memory reactivation impairs the reconsolidation of extinction. Extinction memory reactivation increases proBDNF, BDNF, and tropomyosin receptor kinase B (TrkB) phosphorylation levels in dorsal CA1, while blocking BDNF maturation in the hippocampus with plasminogen activator inhibitor 1 hinders the persistence of extinction and induces the recurrence of fear. Moreover, coinfusion of recombinant BDNF (0.25 μg/side) after extinction memory reactivation impedes the recovery of the avoidance response induced by inhibiting gene expression and protein synthesis in the dorsal hippocampus. Our findings unravel a new role for BDNF, suggesting that this neurotrophin is necessary and sufficient to maintain the reactivated fear extinction engram.

  12. NMDA-Dependent Switch of proBDNF Actions on Developing GABAergic Synapses

    Science.gov (United States)

    Langlois, Anais; Diabira, Diabe; Ferrand, Nadine; Porcher, Christophe

    2013-01-01

    The brain-derived neurotrophic factor (BDNF) has emerged as an important messenger for activity-dependent development of neuronal network. Recent findings have suggested that a significant proportion of BDNF can be secreted as a precursor (proBDNF) and cleaved by extracellular proteases to yield the mature form. While the actions of proBDNF on maturation and plasticity of excitatory synapses have been studied, the effect of the precursor on developing GABAergic synapses remains largely unknown. Here, we show that regulated secretion of proBDNF exerts a bidirectional control of GABAergic synaptic activity with NMDA receptors driving the polarity of the plasticity. When NMDA receptors are activated during ongoing synaptic activity, regulated Ca2+-dependent secretion of proBDNF signals via p75NTR to depress GABAergic synaptic activity, while in the absence of NMDA receptors activation, secreted proBDNF induces a p75NTR-dependent potentiation of GABAergic synaptic activity. These results revealed a new function for proBDNF-p75NTR signaling in synaptic plasticity and a novel mechanism by which synaptic activity can modulate the development of GABAergic synaptic connections. PMID:22510533

  13. 左归丸对惊恐伤肾 MCAO大鼠 BDNF及其受体的影响%Effect of Zuogui Wan on BDNF and Its Receptor in MCAO Model Rats with“Panic Injured Kidney”

    Institute of Scientific and Technical Information of China (English)

    刘宏; 贾彦; 仲丽丽; 孙世晓; 张雨薇; 郝迪; 刘爽; 叶阳; 黄树明

    2015-01-01

    group,and the ischemia-reperfusion was used after 2 hours of MCAO.“Cat scaring mouse”model group and the treatment group were adopted to reproduce the animal models of“panic injured kidney”with 10 days prior to the operation of MCAO.The treatment group was given Zuogui Wan decoction one time a day for consecutively 10 days with 3 days before MCAO surgery.Immunohistochem-istry was used to assess the protein expressions of BDNF and P -TrkB/TrkB in MCAO rats.Results: Comparedwith the sham operation group, the protein expressions of BDNF and p -TrkB/TrkB increased in themodel group.Compared with the model group,the protein expressions of BDNF and p -TrkB/TrkB descendedin the“cat scaring mouse”model group.Compared with the“cat scaring mouse”model group, the protein expressionsof BDNF and p -TrkB/TrkB increased in the treatment group.Conclusion: The protein expressionsof BDNF and its receptor increase after cerebral ischemia,which may be a protective response of the body afterinjury.Kidney deficiency induced by panic can significantly attenuate the body's self -protection function aftercerebral injury and Zuogui Wan can prevent the impairment,which is likely to be achieved by upregulation ofthe protein expressions of BDNF and activation of TrkB.

  14. Converging evolution leads to near maximal junction diversity through parallel mechanisms in B and T cell receptors

    Science.gov (United States)

    Benichou, Jennifer I. C.; van Heijst, Jeroen W. J.; Glanville, Jacob; Louzoun, Yoram

    2017-08-01

    T and B cell receptor (TCR and BCR) complementarity determining region 3 (CDR3) genetic diversity is produced through multiple diversification and selection stages. Potential holes in the CDR3 repertoire were argued to be linked to immunodeficiencies and diseases. In contrast with BCRs, TCRs have practically no Dβ germline genetic diversity, and the question emerges as to whether they can produce a diverse CDR3 repertoire. In order to address the genetic diversity of the adaptive immune system, appropriate quantitative measures for diversity and large-scale sequencing are required. Such a diversity method should incorporate the complex diversification mechanisms of the adaptive immune response and the BCR and TCR loci structure. We combined large-scale sequencing and diversity measures to show that TCRs have a near maximal CDR3 genetic diversity. Specifically, TCR have a larger junctional and V germline diversity, which starts more 5‧ in Vβ than BCRs. Selection decreases the TCR repertoire diversity, but does not affect BCR repertoire. As a result, TCR is as diverse as BCR repertoire, with a biased CDR3 length toward short TCRs and long BCRs. These differences suggest parallel converging evolutionary tracks to reach the required diversity to avoid holes in the CDR3 repertoire.

  15. Peripherally-derived BDNF promotes regeneration of ascending sensory neurons after spinal cord injury.

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    Xing-Yun Song

    Full Text Available BACKGROUND: The blood brain barrier (BBB and truncated trkB receptor on astrocytes prevent the penetration of brain derived neurotrophic factor (BDNF applied into the peripheral (PNS and central nervous system (CNS thus restrict its application in the treatment of nervous diseases. As BDNF is anterogradely transported by axons, we propose that peripherally derived and/or applied BDNF may act on the regeneration of central axons of ascending sensory neurons. METHODOLOGY/PRINCIPAL FINDINGS: The present study aimed to test the hypothesis by using conditioning lesion of the sciatic nerve as a model to increase the expression of endogenous BDNF in sensory neurons and by injecting exogenous BDNF into the peripheral nerve or tissues. Here we showed that most of regenerating sensory neurons expressed BDNF and p-CREB but not p75NTR. Conditioning-lesion induced regeneration of ascending sensory neuron and the increase in the number of p-Erk positive and GAP-43 positive neurons was blocked by the injection of the BDNF antiserum in the periphery. Enhanced neurite outgrowth of dorsal root ganglia (DRG neurons in vitro by conditioning lesion was also inhibited by the neutralization with the BDNF antiserum. The delivery of exogenous BDNF into the sciatic nerve or the footpad significantly increased the number of regenerating DRG neurons and regenerating sensory axons in the injured spinal cord. In a contusion injury model, an injection of BDNF into the footpad promoted recovery of motor functions. CONCLUSIONS/SIGNIFICANCE: Our data suggest that endogenous BDNF in DRG and spinal cord is required for the enhanced regeneration of ascending sensory neurons after conditioning lesion of sciatic nerve and peripherally applied BDNF may have therapeutic effects on the spinal cord injury.

  16. Cooperation between BDNF and glutamate in the regulation of synaptic transmission and neuronal development.

    Science.gov (United States)

    Martin, Jean-Luc; Finsterwald, Charles

    2011-01-01

    Ample evidence supports a role of brain-derived neurotrophic factor (BDNF) in the survival and differentiation of selective populations of neurons in the peripheral and central nervous systems. In addition to its trophic actions, BDNF exerts acute effects on synaptic transmission and plasticity. In particular, BDNF enhances excitatory synaptic transmission through pre- and postsynaptic mechanisms. In this regard, BDNF enhances glutamate release, the frequency of miniature excitatory postsynaptic currents (mEPSCs), NMDA receptor activity and the phosphorylation of NMDA receptor subunits. Our recent studies revealed a novel cooperative interaction between BDNF and glutamate in the regulation of dendritic development. Indeed, we found that the effects of BDNF on dendritic growth of cortical neurons require both the stimulation of cAMP response element-binding protein (CREB) phosphorylation by BDNF and the activation of the CREB-regulated transcription coactivator 1 (CRTC1) by glutamate. Together, these studies highlight the importance of the cooperation between BDNF and glutamate in the regulation of synaptic transmission and neuronal development.

  17. Essential Role for Vav GEFs in Brain-derived Neurotrophic Factor (BDNF)-induced Dendritic Spine Growth and Synapse Plasticity

    OpenAIRE

    Hale, Carly F.; Dietz, Karen C.; Varela, Juan A.; Wood, Cody B.; Zirlin, Benjamin C.; Leah S. Leverich; Greene, Robert W.; Cowan, Christopher W.

    2011-01-01

    Brain-derived neurotrophic factor (BDNF) and its cognate receptor, TrkB, regulate a wide range of cellular processes, including dendritic spine formation and functional synapse plasticity. However, the signaling mechanisms that link BDNF-activated TrkB to F-actin remodeling enzymes and dendritic spine morphological plasticity remain poorly understood. We report here that BDNF/TrkB signaling in neurons activates the Vav family of Rac/RhoA guanine nucleotide exchange factors (GEFs) through a no...

  18. 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

  19. Silencing Status Epilepticus-Induced BDNF Expression with Herpes Simplex Virus Type-1 Based Amplicon Vectors.

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    Chiara Falcicchia

    Full Text Available Brain-derived neurotrophic factor (BDNF has been found to produce pro- but also anti-epileptic effects. Thus, its validity as a therapeutic target must be verified using advanced tools designed to block or to enhance its signal. The aim of this study was to develop tools to silence the BDNF signal. We generated Herpes simplex virus type 1 (HSV-1 derived amplicon vectors, i.e. viral particles containing a genome of 152 kb constituted of concatameric repetitions of an expression cassette, enabling the expression of the gene of interest in multiple copies. HSV-1 based amplicon vectors are non-pathogenic and have been successfully employed in the past for gene delivery into the brain of living animals. Therefore, amplicon vectors should represent a logical choice for expressing a silencing cassette, which, in multiple copies, is expected to lead to an efficient knock-down of the target gene expression. Here, we employed two amplicon-based BDNF silencing strategies. The first, antisense, has been chosen to target and degrade the cytoplasmic mRNA pool of BDNF, whereas the second, based on the convergent transcription technology, has been chosen to repress transcription at the BDNF gene. Both these amplicon vectors proved to be effective in down-regulating BDNF expression in vitro, in BDNF-expressing mesoangioblast cells. However, only the antisense strategy was effective in vivo, after inoculation in the hippocampus in a model of status epilepticus in which BDNF mRNA levels are strongly increased. Interestingly, the knocking down of BDNF levels induced with BDNF-antisense was sufficient to produce significant behavioral effects, in spite of the fact that it was produced only in a part of a single hippocampus. In conclusion, this study demonstrates a reliable effect of amplicon vectors in knocking down gene expression in vitro and in vivo. Therefore, this approach may find broad applications in neurobiological studies.

  20. BDNF regulation in the rat dorsal vagal complex during stress-induced anorexia.

    Science.gov (United States)

    Charrier, Céline; Chigr, Fatiha; Tardivel, Catherine; Mahaut, Stéphanie; Jean, André; Najimi, Mohamed; Moyse, Emmanuel

    2006-08-30

    The dorsal vagal complex (DVC) is the satiety reflex-integrating center of adult mammals. Immobilization stress (IS) is known to elicit anorexia and to up-regulate BDNF expression in adult rat forebrain; intra-DVC delivery of BDNF was shown to elicit anorexia. Therefore, we addressed here whether IS would increase BDNF signaling in rat DVC by using PCR and western-blot on microdissected tissue extracts. Significant variations of BDNF expression in DVC after IS include exon V mRNA increase at 3 h, decreases of both protein and exon III mRNA at 24 h, and exon I mRNA decrease at 72 h. At the receptor level, IS elicited a highly significant induction of both full-length and truncated-1 TrkB mRNAs at 24 h after IS. In vivo recruitment of BDNF signaling in DVC during stress thus differs from hypothalamus, the relevance of which to anorexia is discussed.

  1. Blood BDNF concentrations reflect brain-tissue BDNF levels across species

    DEFF Research Database (Denmark)

    Klein, Anders B; Williamson, Rebecca; Santini, Martin A

    2011-01-01

    Brain-derived neurotrophic factor (BDNF) is involved in synaptic plasticity, neuronal differentiation and survival of neurons. Observations of decreased serum BDNF levels in patients with neuropsychiatric disorders have highlighted the potential of BDNF as a biomarker, but so far there have been...... positive correlation between frontal cortex and hippocampal BDNF levels in mice (r2=0.81, p=0.0139). Our data support the view that measures of blood and plasma BDNF levels reflect brain-tissue BDNF levels....

  2. Disruption of glucocorticoid receptors in the noradrenergic system leads to BDNF up-regulation and altered serotonergic transmission associated with a depressive-like phenotype in female GR(DBHCre) mice.

    Science.gov (United States)

    Chmielarz, Piotr; Kreiner, Grzegorz; Kot, Marta; Zelek-Molik, Agnieszka; Kowalska, Marta; Bagińska, Monika; Daniel, Władysława Anna; Nalepa, Irena

    2015-10-01

    Recently, we have demonstrated that conditional inactivation of glucocorticoid receptors (GRs) in the noradrenergic system, may evoke depressive-like behavior in female but not male mutant mice (GR(DBHCre) mice). The aim of the current study was to dissect how selective ablation of glucocorticoid signaling in the noradrenergic system influences the previously reported depressive-like phenotype and whether it might be linked to neurotrophic alterations or secondary changes in the serotonergic system. We demonstrated that selective depletion of GRs enhances brain derived neurotrophic factor (BDNF) expression in female but not male GR(DBHCre) mice on both the mRNA and protein levels. The possible impact of the mutation on brain noradrenergic and serotonergic systems was addressed by investigating the tissue neurotransmitter levels under basal conditions and after acute restraint stress. The findings indicated a stress-provoked differential response in tissue noradrenaline content in the GR(DBHCre) female but not male mutant mice. An analogous gender-specific effect was identified in the diminished content of 5-hydroxyindoleacetic acid, the main metabolite of serotonin, in the prefrontal cortex, which suggests down-regulation of this monoamine system in female GR(DBHCre) mice. The lack of GR also resulted in an up-regulation of alpha2-adrenergic receptor (α2-AR) density in the female but not male mutants in the locus coeruleus. We have also confirmed the utility of the investigated model in pharmacological studies, which demonstrates that the depressive-like phenotype of GR(DBHCre) female mice can be reversed by antidepressant treatment with desipramine or fluoxetine, with the latter drug evoking more pronounced effects. Overall, our study validates the use of female GR(DBHCre) mice as an interesting and novel genetic tool for the investigation of the cross-connected mechanisms of depression that is not only based on behavioral phenotypes.

  3. Activity-dependent release of endogenous BDNF from mossy fibers evokes a TRPC3 current and Ca2+ elevations in CA3 pyramidal neurons.

    Science.gov (United States)

    Li, Yong; Calfa, Gaston; Inoue, Takafumi; Amaral, Michelle D; Pozzo-Miller, Lucas

    2010-05-01

    Multiple studies have demonstrated that brain-derived neurotrophic factor (BDNF) is a potent modulator of neuronal structure and function in the hippocampus. However, the majority of studies to date have relied on the application of recombinant BDNF. We herein report that endogenous BDNF, released via theta burst stimulation of mossy fibers (MF), elicits a slowly developing cationic current and intracellular Ca(2+) elevations in CA3 pyramidal neurons with the same pharmacological profile of the transient receptor potential canonical 3 (TRPC3)-mediated I(BDNF) activated in CA1 neurons by brief localized applications of recombinant BDNF. Indeed, sensitivity to both the extracellular BDNF scavenger tropomyosin-related kinase B (TrkB)-IgG and small hairpin interference RNA-mediated TRPC3 channel knockdown confirms the identity of this conductance as such, henceforth-denoted MF-I(BDNF). Consistent with such activity-dependent release of BDNF, these MF-I(BDNF) responses were insensitive to manipulations of extracellular Zn(2+) concentration. Brief theta burst stimulation of MFs induced a long-lasting depression in the amplitude of excitatory postsynaptic currents (EPSCs) mediated by both AMPA and N-methyl-d-aspartate (NMDA) receptors without changes in the NMDA receptor/AMPA receptor ratio, suggesting a reduction in neurotransmitter release. This depression of NMDAR-mediated EPSCs required activity-dependent release of endogenous BDNF from MFs and activation of Trk receptors, as it was sensitive to the extracellular BDNF scavenger TrkB-IgG and the tyrosine kinase inhibitor k-252b. These results uncovered the most immediate response to endogenously released--native--BDNF in hippocampal neurons and lend further credence to the relevance of BDNF signaling for synaptic function in the hippocampus.

  4. Dendritically targeted Bdnf mRNA is essential for energy balance and response to leptin.

    Science.gov (United States)

    Liao, Guey-Ying; An, Juan Ji; Gharami, Kusumika; Waterhouse, Emily G; Vanevski, Filip; Jones, Kevin R; Xu, Baoji

    2012-03-18

    Mutations in the Bdnf gene, which produces transcripts with either short or long 3' untranslated regions (3' UTRs), cause human obesity; however, the precise role of brain-derived neurotrophic factor (BDNF) in the regulation of energy balance is unknown. Here we show the relationship between Bdnf mRNA with a long 3' UTR (long 3' UTR Bdnf mRNA), leptin, neuronal activation and body weight. We found that long 3' UTR Bdnf mRNA was enriched in the dendrites of hypothalamic neurons and that insulin and leptin could stimulate its translation in dendrites. Furthermore, mice harboring a truncated long Bdnf 3' UTR developed severe hyperphagic obesity, which was completely reversed by viral expression of long 3' UTR Bdnf mRNA in the hypothalamus. In these mice, the ability of leptin to activate hypothalamic neurons and inhibit food intake was compromised despite normal activation of leptin receptors. These results reveal a novel mechanism linking leptin action to BDNF expression during hypothalamic-mediated regulation of body weight, while also implicating dendritic protein synthesis in this process.

  5. BDNF-TrkB axis regulates migration of the lateral line primordium and modulates the maintenance of mechanoreceptor progenitors.

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    Eugene V Gasanov

    Full Text Available BDNF and its specialized receptor TrkB are expressed in the developing lateral line system of zebrafish, but their role in this organ is unknown. To tackle this problem in vivo, we used transgenic animals expressing fluorescent markers in different cell types of the lateral line and combined a BDNF gain-of-function approach by BDNF mRNA overexpression and by soaking embryos in a solution of BDNF, with a loss-of-function approach by injecting the antisence ntrk2b-morpholino and treating embryos with the specific Trk inhibitor K252a. Subsequent analysis demonstrated that the BDNF-TrkB axis regulates migration of the lateral line primordium. In particular, BDNF-TrkB influences the expression level of components of chemokine signaling including Cxcr4b, and the generation of progenitors of mechanoreceptors, at the level of expression of Atoh1a-Atp2b1a.

  6. Exogenous t-PA administration increases hippocampal mature BDNF levels. plasmin- or NMDA-dependent mechanism?

    Science.gov (United States)

    Rodier, Marion; Prigent-Tessier, Anne; Béjot, Yannick; Jacquin, Agnès; Mossiat, Claude; Marie, Christine; Garnier, Philippe

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) through TrkB activation is central for brain functioning. Since the demonstration that plasmin is able to process pro-BDNF to mature BDNF and that these two forms have opposite effects on neuronal survival and plasticity, a particular attention has been paid to the link between tissue plasminogen activator (tPA)/plasmin system and BDNF metabolism. However, t-PA via its action on different N-methyl-D-aspartate (NMDA) receptor subunits is also considered as a neuromodulator of glutamatergic transmission. In this context, the aim of our study was to investigate the effect of recombinant (r)t-PA administration on brain BDNF metabolism in rats. In the hippocampus, we found that rt-PA (10 mg/kg) administration induced a progressive increase in mature BDNF levels associated with TrkB activation. In order to delineate the mechanistic involved, plasmin activity was assessed and its inhibition was attempted using tranexamic acid (30 or 300 mg/kg, i.v.) while NMDA receptors were antagonized with MK801 (0.3 or 3 mg/kg, i.p.) in combination with rt-PA treatment. Our results showed that despite a rise in rt-PA activity, rt-PA administration failed to increase hippocampal plasmin activity suggesting that the plasminogen/plasmin system is not involved whereas MK801 abrogated the augmentation in mature BDNF levels observed after rt-PA administration. All together, our results show that rt-PA administration induces increase in hippocampal mature BDNF expression and suggests that rt-PA contributes to the control of brain BDNF synthesis through a plasmin-independent potentiation of NMDA receptors signaling.

  7. Exogenous t-PA administration increases hippocampal mature BDNF levels. plasmin- or NMDA-dependent mechanism?

    Directory of Open Access Journals (Sweden)

    Marion Rodier

    Full Text Available Brain-derived neurotrophic factor (BDNF through TrkB activation is central for brain functioning. Since the demonstration that plasmin is able to process pro-BDNF to mature BDNF and that these two forms have opposite effects on neuronal survival and plasticity, a particular attention has been paid to the link between tissue plasminogen activator (tPA/plasmin system and BDNF metabolism. However, t-PA via its action on different N-methyl-D-aspartate (NMDA receptor subunits is also considered as a neuromodulator of glutamatergic transmission. In this context, the aim of our study was to investigate the effect of recombinant (rt-PA administration on brain BDNF metabolism in rats. In the hippocampus, we found that rt-PA (10 mg/kg administration induced a progressive increase in mature BDNF levels associated with TrkB activation. In order to delineate the mechanistic involved, plasmin activity was assessed and its inhibition was attempted using tranexamic acid (30 or 300 mg/kg, i.v. while NMDA receptors were antagonized with MK801 (0.3 or 3 mg/kg, i.p. in combination with rt-PA treatment. Our results showed that despite a rise in rt-PA activity, rt-PA administration failed to increase hippocampal plasmin activity suggesting that the plasminogen/plasmin system is not involved whereas MK801 abrogated the augmentation in mature BDNF levels observed after rt-PA administration. All together, our results show that rt-PA administration induces increase in hippocampal mature BDNF expression and suggests that rt-PA contributes to the control of brain BDNF synthesis through a plasmin-independent potentiation of NMDA receptors signaling.

  8. PACAP enhances axon outgrowth in cultured hippocampal neurons to a comparable extent as BDNF.

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    Katsuya Ogata

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP exerts neurotrophic activities including modulation of synaptic plasticity and memory, hippocampal neurogenesis, and neuroprotection, most of which are shared with brain-derived neurotrophic factor (BDNF. Therefore, the aim of this study was to compare morphological effects of PACAP and BDNF on primary cultured hippocampal neurons. At days in vitro (DIV 3, PACAP increased neurite length and number to similar levels by BDNF, but vasoactive intestinal polypeptide showed much lower effects. In addition, PACAP increased axon, but not dendrite, length, and soma size at DIV 3 similarly to BDNF. The PACAP antagonist PACAP6-38 completely blocked the PACAP-induced increase in axon, but not dendrite, length. Interestingly, the BDNF-induced increase in axon length was also inhibited by PACAP6-38, suggesting a mechanism involving PACAP signaling. K252a, a TrkB receptor inhibitor, inhibited axon outgrowth induced by PACAP and BDNF without affecting dendrite length. These results indicate that in primary cultured hippocampal neurons, PACAP shows morphological actions via its cognate receptor PAC1, stimulating neurite length and number, and soma size to a comparable extent as BDNF, and that the increase in total neurite length is ascribed to axon outgrowth.

  9. Hippocampal BDNF signaling restored with chronic asiaticoside treatment in depression-like mice.

    Science.gov (United States)

    Luo, Liu; Liu, Xiao-Long; Mu, Rong-Hao; Wu, Yong-Jing; Liu, Bin-Bin; Geng, Di; Liu, Qing; Yi, Li-Tao

    2015-05-01

    Brain-derived neurotrophic factor (BDNF) plays a key role in the regulation of depression in the brain. Recently, increasing studies have focused on the antidepressant-like mechanism of BDNF and its downstream signaling pathway. A previous study has shown that asiaticoside produced an antidepressant-like action in the mouse tail suspension test and forced swimming test. However, the neurotrophic mechanism that is affected by asiaticoside is unclear. Our present study aimed to verify whether asiaticoside produces an antidepressant-like effect through the activation of BDNF signaling in chronic unpredictable mild stress (CUMS). The results showed that mice treated with asiaticoside for four weeks reversed the decreased sucrose preference and increased immobility time that was observed in CUMS mice. In addition, we found that asiaticoside up-regulated BDNF, PSD-95 and synapsin I expression only in the hippocampus but not in the frontal cortex in both non-stressed and CUMS mice. However, K252a, an inhibitor of BDNF receptor tropomyosin-related kinase receptor B (TrkB), completely abolished the antidepressant-like effect of asiaticoside. Moreover, the expression of hippocampal BDNF, PSD-95 and synapsin I that had increased with asiaticoside also declined with K252a pretreatment. In conclusion, our study implies that it is possible that asiaticoside exerts its antidepressant-like action by activating BDNF signaling in the hippocampus.

  10. Convergence Insufficiency

    Science.gov (United States)

    ... from convergence insufficiency? Symptoms of convergence insufficiency include diplopia (double vision) and headaches when reading. Many patients ... another time or simply watched for symptoms of diplopia or headaches with near work. A patient who ...

  11. GPR39 (zinc receptor) knockout mice exhibit depression-like behavior and CREB/BDNF down-regulation in the hippocampus

    DEFF Research Database (Denmark)

    Młyniec, Katarzyna; Budziszewska, Bogusława; Holst, Birgitte

    2015-01-01

    Background: Zinc may act as a neurotransmitter in the central nervous system by activation of the GPR39 metabotropic receptors. Methods: In the present study, we investigated whether GPR39 knockout would cause depressive-like and/or anxiety-like behavior, as measured by the forced swim test, tail...... to the forced swim test, as measured by Western-blot analysis. Results: In this study, GPR39 knockout mice showed an increased immobility time in both the forced swim test and tail suspension test, indicating depressive-like behavior and displayed anxiety-like phenotype. GPR39 knockout mice had lower CREB...... mice in comparison with the wild-type control mice, which does not support a role of GPR39 in hypothalamus-pituitary-adrenal axis regulation. The results of this study indicate the involvement of the GPR39 Zn2+-sensing receptor in the pathophysiology of depression with component of anxiety....

  12. Dopamine D1-D2 receptor heteromer in dual phenotype GABA/glutamate-coexpressing striatal medium spiny neurons: regulation of BDNF, GAD67 and VGLUT1/2.

    Directory of Open Access Journals (Sweden)

    Melissa L Perreault

    Full Text Available In basal ganglia a significant subset of GABAergic medium spiny neurons (MSNs coexpress D1 and D2 receptors (D1R and D2R along with the neuropeptides dynorphin (DYN and enkephalin (ENK. These coexpressing neurons have been recently shown to have a region-specific distribution throughout the mesolimbic and basal ganglia circuits. While the functional relevance of these MSNs remains relatively unexplored, they have been shown to exhibit the unique property of expressing the dopamine D1-D2 receptor heteromer, a novel receptor complex with distinct pharmacology and cell signaling properties. Here we showed that MSNs coexpressing the D1R and D2R also exhibited a dual GABA/glutamate phenotype. Activation of the D1R-D2R heteromer in these neurons resulted in the simultaneous, but differential regulation of proteins involved in GABA and glutamate production or vesicular uptake in the nucleus accumbens (NAc, ventral tegmental area (VTA, caudate putamen and substantia nigra (SN. Additionally, activation of the D1R-D2R heteromer in NAc shell, but not NAc core, differentially altered protein expression in VTA and SN, regions rich in dopamine cell bodies. The identification of a MSN with dual inhibitory and excitatory intrinsic functions provides new insights into the neuroanatomy of the basal ganglia and demonstrates a novel source of glutamate in this circuit. Furthermore, the demonstration of a dopamine receptor complex with the potential to differentially regulate the expression of proteins directly involved in GABAergic inhibitory or glutamatergic excitatory activation in VTA and SN may potentially provide new insights into the regulation of dopamine neuron activity. This could have broad implications in understanding how dysregulation of neurotransmission within basal ganglia contributes to dopamine neuronal dysfunction.

  13. Production of high quality brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) RNA from isolated populations of rat spinal cord motor neurons obtained by Laser Capture Microdissection (LCM).

    Science.gov (United States)

    Mehta, Prachi; Premkumar, Brian; Morris, Renée

    2016-08-03

    The mammalian central nervous system (CNS) is composed of multiple cellular elements, making it challenging to segregate one particular cell type to study their gene expression profile. For instance, as motor neurons represent only 5-10% of the total cell population of the spinal cord, meaningful transcriptional analysis on these neurons is almost impossible to achieve from homogenized spinal cord tissue. A major challenge faced by scientists is to obtain good quality RNA from small amounts of starting material. In this paper, we used Laser Capture Microdissection (LCM) techniques to identify and isolate spinal cord motor neurons. The present analysis revealed that perfusion with paraformaldehyde (PFA) does not alter RNA quality. RNA integrity numbers (RINs) of tissue samples from rubrospinal tract (RST)-transected, intact spinal cord or from whole spinal cord homogenate were all above 8, which indicates intact, high-quality RNA. Levels of mRNA for brain-derived neurotrophic factor (BDNF) or for its tropomyosin receptor kinase B (TrkB) were not affected by rubrospinal tract (RST) transection, a surgical procedure that deprive motor neurons from one of their main supraspinal input. The isolation of pure populations of neurons with LCM techniques allows for robust transcriptional characterization that cannot be achieved with spinal cord homogenates. Such preparations of pure population of motor neurons will provide valuable tools to advance our understanding of the molecular mechanisms underlying spinal cord injury and neuromuscular diseases. In the near future, LCM techniques might be instrumental to the success of gene therapy for these debilitating conditions.

  14. TrkB/BDNF Signaling Regulates Photoreceptor Progenitor Cell Fate Decisions

    OpenAIRE

    Turner, Brian A.; Sparrow, Janet; Cai, Bolin; Monroe, Julie; Mikawa, Takashi; Hempstead, Barbara L.

    2006-01-01

    Neurotrophins, via activation of Trk receptor tyrosine kinases, serve as mitogens, survival factors and regulators of arborization during retinal development. Brain-derived neurotrophic factor (BDNF) and TrkB regulate neuronal arborization and survival in late retinal development. However, TrkB is expressed during early retinal developmet where its functions are unclear. To assess TrkB/BDNF actions in the early chick retina, replication-incompetent retroviruses were utilized to over-express a...

  15. Effect of voluntary exercise on BDNF/TrkB gene expression and alcohol intake.

    OpenAIRE

    Jonsson, Josefine

    2012-01-01

    Voluntary wheel running is rewarding and believed to activate the same brain reward system as in alcohol and drug addiction. Brain-derived neurotrophic factor (BDNF), a well-known growth factor widely expressed in the brain, is modulated by both voluntary exercise and alcohol consumption. The aim of this study was to evaluate how voluntary exercise affects the expression levels of BDNF and its receptor TrkB in brain regions involved in positive and negative reinforcement. Additionally we want...

  16. BDNF及其受体TrkB在慢性应激大鼠结肠动力紊乱中的调节作用及其机制%Modulatory role and mechanism of BDNF and its receptor TrkB in colonic motility disorder in chronic stress rat

    Institute of Scientific and Technical Information of China (English)

    樊菡; 罗和生; 全晓静; 唐勤彩; 余光

    2015-01-01

    Objective To investigate the role and mechanism of BDNF and its receptor TrkB in the disorder of colonic motility in chronic stress rats.Methods A total of 20 male Wistar rats were randomly divided into two groups using to completely random method after weighed,with 10 rats in each group.Chronic water avoidance stress model was established.Then the fecal pellets of water avoidance stress (WAS) group and sham water avoidance stress (SWAS) group were recorded.Enzyme linked immunosorbent assay (ELISA),real time PCR,Western blot and immunohistochemistry were used to detect the expression of BDNF and TrkB in serum and colon muscle.The amplitudes of contractions of circular smooth muscle strips of each group were recorded after the treatment of TTX,BDNF and K252a.Results The number of fecal pellets had obviously increased in WAS group comparing with SWAS group (P < 0.05).The level of serum BDNF in WAS group was higher than that of SWAS group ((158.30 ± 9.82) vs (84.68 ± 7.80) pg/ml).And the expression of TrkB in the colon muscle in WAS group was higher than that in SWAS group (0.44 ± 0.03 vs 0.30 ± 0.02,P < 0.05).There was no significant difference between the two groups in expression of BDNF mRNA in colon muscle (P > 0.05).TrkB was mainly expressed in the cell nucleus of muscular layer neurons,and the expression of TrkB had obviously increased in WAS rats.The amplitudes of contractions of circular smooth muscle in WAS rats had significantly increased compared with SWAS rats ((0.35 ±0.02) vs(0.22 ±0.03) g,P <0.05).After adding TTX to block the function of enteric nervous,the difference was remaining ((0.89 ± 0.07) vs (0.53 ± 0.06) g,P < 0.05).BDNF was added to the bath and the R value at different time was recorded.The difference had statistically significant at 6 min and 12 min (both P < 0.05).BDNF could induced the contraction peak of the circular smooth muscle.The contraction peak induced by BDNF was delayed and reduced when K252a was added to the

  17. Convergent evolution in European and Rroma populations reveals pressure exerted by plague on Toll-like receptors

    NARCIS (Netherlands)

    Laayouni, Hafid; Oosting, Marije; Luisi, Pierre; Ioana, Mihai; Alonso, Santos; Ricaño Ponce, Isis; Trynka, Gosia; Zhernakova, Alexandra; Plantinga, Theo S.; Cheng, Shih-Chin; van der Meer, Jos W. M.; Popp, Radu; Sood, Ajit; Thelma, B. K.; Wijmenga, Cisca; Joosten, Leo A. B.; Bertranpetit, Jaume; Netea, Mihai G.

    2014-01-01

    Recent historical periods in Europe have been characterized by severe epidemic events such as plague, smallpox, or influenza that shaped the immune system of modern populations. This study aims to identify signals of convergent evolution of the immune system, based on the peculiar demographic

  18. Blood BDNF concentrations reflect brain-tissue BDNF levels across species

    DEFF Research Database (Denmark)

    Klein, Anders B; Williamson, Rebecca; Santini, Martin A;

    2011-01-01

    Brain-derived neurotrophic factor (BDNF) is involved in synaptic plasticity, neuronal differentiation and survival of neurons. Observations of decreased serum BDNF levels in patients with neuropsychiatric disorders have highlighted the potential of BDNF as a biomarker, but so far there have been...... no studies directly comparing blood BDNF levels to brain BDNF levels in different species. We examined blood, serum, plasma and brain-tissue BDNF levels in three different mammalian species: rat, pig, and mouse, using an ELISA method. As a control, we included an analysis of blood and brain tissue from...... conditional BDNF knockout mice and their wild-type littermates. Whereas BDNF could readily be measured in rat blood, plasma and brain tissue, it was undetectable in mouse blood. In pigs, whole-blood levels of BDNF could not be measured with a commercially available ELISA kit, but pig plasma BDNF levels (mean...

  19. Fear extinction and BDNF: translating animal models of PTSD to the clinic.

    Science.gov (United States)

    Andero, R; Ressler, K J

    2012-07-01

    Brain-derived neurotrophic factor (BDNF) is the most studied neurotrophin involved in synaptic plasticity processes that are required for long-term learning and memory. Specifically, BDNF gene expression and activation of its high-affinity tropomyosin-related kinase B (TrkB) receptor are necessary in the amygdala, hippocampus and prefrontal cortex for the formation of emotional memories, including fear memories. Among the psychiatric disorders with altered fear processing, there is post-traumatic stress disorder (PTSD) which is characterized by an inability to extinguish fear memories. Since BDNF appears to enhance extinction of fear, targeting impaired extinction in anxiety disorders such as PTSD via BDNF signalling may be an important and novel way to enhance treatment efficacy. The aim of this review is to provide a translational point of view that stems from findings in the BDNF regulation of synaptic plasticity and fear extinction. In addition, there are different systems that seem to alter fear extinction through BDNF modulation like the endocannabinoid system and the hypothalamic-pituitary adrenal axis. Recent work also finds that the pituitary adenylate cyclase-activating polypeptide and PAC1 receptor, which are upstream of BDNF activation, may be implicated in PTSD. Especially interesting are data that exogenous fear extinction enhancers such as antidepressants, histone deacetylases inhibitors and D-cycloserine, a partial N-methyl d-aspartate agonist, may act through or in concert with the BDNF-TrkB system. Finally, we review studies where recombinant BDNF and a putative TrkB agonist, 7,8-dihydroxyflavone, may enhance extinction of fear. These approaches may lead to novel agents that improve extinction in animal models and eventually humans.

  20. Stress and trauma: BDNF control of dendritic-spine formation and regression.

    Science.gov (United States)

    Bennett, M R; Lagopoulos, J

    2014-01-01

    Chronic restraint stress leads to increases in brain derived neurotrophic factor (BDNF) mRNA and protein in some regions of the brain, e.g. the basal lateral amygdala (BLA) but decreases in other regions such as the CA3 region of the hippocampus and dendritic spine density increases or decreases in line with these changes in BDNF. Given the powerful influence that BDNF has on dendritic spine growth, these observations suggest that the fundamental reason for the direction and extent of changes in dendritic spine density in a particular region of the brain under stress is due to the changes in BDNF there. The most likely cause of these changes is provided by the stress initiated release of steroids, which readily enter neurons and alter gene expression, for example that of BDNF. Of particular interest is how glucocorticoids and mineralocorticoids tend to have opposite effects on BDNF gene expression offering the possibility that differences in the distribution of their receptors and of their downstream effects might provide a basis for the differential transcription of the BDNF genes. Alternatively, differences in the extent of methylation and acetylation in the epigenetic control of BDNF transcription are possible in different parts of the brain following stress. Although present evidence points to changes in BDNF transcription being the major causal agent for the changes in spine density in different parts of the brain following stress, steroids have significant effects on downstream pathways from the TrkB receptor once it is acted upon by BDNF, including those that modulate the density of dendritic spines. Finally, although glucocorticoids play a canonical role in determining BDNF modulation of dendritic spines, recent studies have shown a role for corticotrophin releasing factor (CRF) in this regard. There is considerable improvement in the extent of changes in spine size and density in rodents with forebrain specific knockout of CRF receptor 1 (CRFR1) even when

  1. BDNF pro-peptide regulates dendritic spines via caspase-3

    OpenAIRE

    Guo, J.; Ji, Y.; Y. Ding; Jiang, W.; Sun, Y.; B. Lu; Nagappan, G

    2016-01-01

    The precursor of brain-derived neurotrophic factor (BDNF) (proBDNF) is enzymatically cleaved, by either intracellular (furin/PC1) or extracellular proteases (tPA/plasmin/MMP), to generate mature BDNF (mBDNF) and its pro-peptide (BDNF pro-peptide). Little is known about the function of BDNF pro-peptide. We have developed an antibody that specifically detects cleaved BDNF pro-peptide, but not proBDNF or mBDNF. Neuronal depolarization elicited a marked increase in extracellular BDNF pro-peptide,...

  2. Neurochemical properties of BDNF-containing neurons projecting to rostral ventromedial medulla in the ventrolateral periaqueductal gray

    Directory of Open Access Journals (Sweden)

    Jun-Bin eYin

    2014-11-01

    Full Text Available The periaqueductal gray (PAG modulates nociception via a descending pathway that relays in the rostral ventromedial medulla (RVM and terminates in the spinal cord. Previous behavioral pharmacology and electrophysiological evidence suggests that brain-derived neurotrophic factor (BDNF plays an important role in descending pain modulation, likely through the PAG-RVM pathway. However, there still lacks detailed information on the distribution of BDNF, activation of BDNF-containing neurons projecting to RVM in the condition of pain, and neurochemical properties of these neurons within the PAG. Through fluorescent in situ hybridization (FISH and immunofluorescent staining, the homogenous distributions of BDNF mRNA and protein were observed in the four subregions of PAG. Both neurons and astrocytes expressed BDNF, but not microglias. By combining retrograde tracing methods and formalin pain model, there were more BDNF-containing neurons projecting to RVM being activated in the ventrolateral PAG (vlPAG than other subregions of PAG. The neurochemical properties of BDNF-containing projection neurons in the vlPAG were investigated. BDNF-containing projection neurons expressed auto receptor Tropomyosin-related kinase B (TrkB in addition to serotonin (5-HT, neurotensin (NT, substance P (SP, calcitonin gene related peptide (CGRP, nitric oxide synthase (NOS, and parvalbumin (PV but not tyrosine decarboxylase (TH. It is speculated that BDNF released from projection neurons in the vlPAG might participate in the descending pain modulation through enhancing the presynaptic release of other neuroactive substances (NSs in the RVM.

  3. In vivo BDNF modulation of hippocampal mossy fiber plasticity induced by high frequency stimulation.

    Science.gov (United States)

    Schjetnan, Andrea Gómez-Palacio; Escobar, Martha L

    2012-01-01

    Changes in synaptic efficacy and morphology have been proposed as mechanisms underlying learning and memory processes. In our previous studies, high frequency stimulation (HFS) sufficient to induce LTP at the hippocampal mossy fiber (MF) pathway, leads to MF synaptogenesis, in a prominent contralateral form, at the stratum oriens of hippocampal CA3 area. Recently we reported that acute intrahippocampal microinfusion of BDNF induces a lasting potentiation of synaptic efficacy at the MF projection accompanied by a structural reorganization at the CA3 area within the stratum oriens region in a prominent ipsilateral form. It is considered that the capacity of synapses to express plastic changes is itself subject to variation dependent on previous experience. Here we used intrahippocampal microinfusion of BDNF to analyze its effects on functional and structural synaptic plasticity induced by subsequent mossy fiber HFS sufficient to induce LTP in adult rats, in vivo. Our results show that BDNF modifies the ability of the MF pathway to present LTP by HFS. Moreover BDNF modified the structural reorganization pattern produced by HFS, presenting a balanced bilateral appearance. Microinfusion of K252a blocks the functional and morphological effects produced by BDNF, revealing that the BDNF modulation is dependent on its TrkB receptor activation. These findings support the idea that BDNF actions modify subsequent synaptic plasticity; a homeostatic mechanism thought to be essential for synaptic integration among prolonged temporal domains in the adult mammalian brain.

  4. Direct current stimulation promotes BDNF-dependent synaptic plasticity: potential implications for motor learning.

    Science.gov (United States)

    Fritsch, Brita; Reis, Janine; Martinowich, Keri; Schambra, Heidi M; Ji, Yuanyuan; Cohen, Leonardo G; Lu, Bai

    2010-04-29

    Despite its increasing use in experimental and clinical settings, the cellular and molecular mechanisms underlying transcranial direct current stimulation (tDCS) remain unknown. Anodal tDCS applied to the human motor cortex (M1) improves motor skill learning. Here, we demonstrate in mouse M1 slices that DCS induces a long-lasting synaptic potentiation (DCS-LTP), which is polarity specific, NMDA receptor dependent, and requires coupling of DCS with repetitive low-frequency synaptic activation (LFS). Combined DCS and LFS enhance BDNF-secretion and TrkB activation, and DCS-LTP is absent in BDNF and TrkB mutant mice, suggesting that BDNF is a key mediator of this phenomenon. Moreover, the BDNF val66met polymorphism known to partially affect activity-dependent BDNF secretion impairs motor skill acquisition in humans and mice. Motor learning is enhanced by anodal tDCS, as long as activity-dependent BDNF secretion is in place. We propose that tDCS may improve motor skill learning through augmentation of synaptic plasticity that requires BDNF secretion and TrkB activation within M1.

  5. Increased BDNF protein expression after ischemic or PKC epsilon preconditioning promotes electrophysiologic changes that lead to neuroprotection.

    Science.gov (United States)

    Neumann, Jake T; Thompson, John W; Raval, Ami P; Cohan, Charles H; Koronowski, Kevin B; Perez-Pinzon, Miguel A

    2015-01-01

    Ischemic preconditioning (IPC) via protein kinase C epsilon (PKCɛ) activation induces neuroprotection against lethal ischemia. Brain-derived neurotrophic factor (BDNF) is a pro-survival signaling molecule that modulates synaptic plasticity and neurogenesis. Interestingly, BDNF mRNA expression increases after IPC. In this study, we investigated whether IPC or pharmacological preconditioning (PKCɛ activation) promoted BDNF-induced neuroprotection, if neuroprotection by IPC or PKCɛ activation altered neuronal excitability, and whether these changes were BDNF-mediated. We used both in vitro (hippocampal organotypic cultures and cortical neuronal-glial cocultures) and in vivo (acute hippocampal slices 48 hours after preconditioning) models of IPC or PKCɛ activation. BDNF protein expression increased 24 to 48 hours after preconditioning, where inhibition of the BDNF Trk receptors abolished neuroprotection against oxygen and glucose deprivation (OGD) in vitro. In addition, there was a significant decrease in neuronal firing frequency and increase in threshold potential 48 hours after preconditioning in vivo, where this threshold modulation was dependent on BDNF activation of Trk receptors in excitatory cortical neurons. In addition, 48 hours after PKCɛ activation in vivo, the onset of anoxic depolarization during OGD was significantly delayed in hippocampal slices. Overall, these results suggest that after IPC or PKCɛ activation, there are BDNF-dependent electrophysiologic modifications that lead to neuroprotection.

  6. The gut-brain axis, BDNF, NMDA and CNS disorders

    OpenAIRE

    Maqsood, Raeesah; Stone, Trevor W.

    2016-01-01

    Gastro-intestinal (GI) microbiota and the ‘gut-brain axis’ are proving to be increasingly relevant to early brain development and the emergence of psychiatric disorders. This review focuses on the influence of the GI tract on Brain-Derived Neurotrophic Factor (BDNF) and its relationship with receptors for N-methyl-d-aspartate (NMDAR), as these are believed to be involved in synaptic plasticity and cognitive function. NMDAR may be associated with the development of schizophrenia and a range of...

  7. Vergleichende Studie zur Expression von Neuropeptiden und von Calcium-bindenden Proteinen im Hippocampus von BDNF Knock-out Mäusen und den entsprechenden Wildtyp Geschwistertieren

    OpenAIRE

    Herrmann-Schwartzkopff, Katharina Helene

    2010-01-01

    Brain derived neurotrophic factor (BDNF) is well known for its positive effects on survival, development and differentiation of neurons in the central nervous system. It exerts its action through binding to its high (TrkB) and low (p75) affinity receptors. This work examines the expression of neuropeptides and calcium-binding proteins in the hippocampus of BDNF knockout mice (BDNF -/-) and their corresponding wild type littermates. With the use of highly specific antibodies the hippoca...

  8. Effect of oxymatrine on the expression of BDNF and its receptor TrkB after focal cerebral ischemia-reperfusion in rats%氧化苦参碱对大鼠局灶性脑缺血再灌注损伤BDNF及其受体TrkB表达的影响

    Institute of Scientific and Technical Information of China (English)

    付燕燕; 段静雨; 段昌柱

    2011-01-01

    Objective:To study the effects of oxymatrine(OMT) on brain-derived neurotrophic factor(BDNF) and its receptor tyrosinekinase(TrkB) in cerebral cortex after focal cerebral ischemia -reperfusion in rats,and explore the neuroprotective mechanism of oxymatrine. Methods-The rat middle cerebral artery occlu-sion models with filament of focal cerebral ischemia-reperfusion were established.SD male rats were divided randomly into sham group,cerebral ischemia-reperfusion model group,nimodipine(Nim) group and the oxymatrine group.the oxymatrine group was futher divided into three sub-groups which were dealt with the low,middle and high dose of oxymatrine.The neurological scores were used after 2 h ischemia followed by 24 h reperfusion.The expression of BDNF positive neurons,BDNF and TrkB proteins were respectively detected by immunohistochemistry and western blot. Results:Compared with the sham group,the neurological scores decreased, while the expression of BDNF positive neurons,BDNF and its receptor TrkB protein significantly increased in middle and high dose of oxymatrine groups(P<0.05;P<0.01). Conclusion: OMT protects the rats from the ischemia injury following focal cerebral ischemia-reperfusion, the mechanism of which may partly be due to up-regulating the expression of BDNF and TrkB.%目的:观察氧化苦参碱(Oxymatrine,OMT)对大鼠局灶性脑缺血再灌注后皮质脑源性神经生长因子(Brain -derived neurotrophic factor,BDNF)及其受体酪氨酸激酶B(Tyrosine kinase B,TrkB)表达的影响,探讨OMT神经保护作用的机制.方法:采用线栓法建立大鼠大脑中动脉缺血再灌注模型.SD雄性大鼠随机分为假手术组、模型组、阳性药尼莫地平组和OMT低、中、高剂量给药组6组,缺血2h再灌注24h后进行神经功能评分.免疫组化法检测BDNF阳性细胞,Western blot检测BDNF和TrkB蛋白表达.结果:与模型组比,OMT中、高剂量组神经学评分均减低,BDNF阳性细胞数以及BDNF和其受体TrkB

  9. Deltamethrin, a type II pyrethroid insecticide, has neurotrophic effects on neurons with continuous activation of the Bdnf promoter.

    Science.gov (United States)

    Ihara, Daisuke; Fukuchi, Mamoru; Honma, Daisuke; Takasaki, Ichiro; Ishikawa, Mitsuru; Tabuchi, Akiko; Tsuda, Masaaki

    2012-02-01

    Pyrethroids, widely used insecticides with low acute toxicity in mammals, affect sodium channels in neurons. In a primary culture of rat cortical neurons, deltamethrin (DM), a type II pyrethroid, markedly enhanced the expression of brain-derived neurotrophic factor (BDNF) exon IV-IX (Bdnf eIV-IX) mRNA. In this study, we found that DM has a neurotrophic effect on cultured neurons and investigated the mechanisms responsible for it. One μM DM increased cell survival, neurite complexity and length. Neurite complexity and length were reduced not only by a blockade of cellular excitation with GABA or Ca(2+) influx via L-type voltage-dependent calcium channels with nicardipine, but also by a blockade of TrkB, a specific receptor for BDNF, with TrkB/Fc. These data indicate DM has neurotrophic actions. DM-induced Bdnf eIV-IX mRNA expression through the calcineurin and ERK/MAPK pathways, the increase of which was reduced by GABA(A) receptor activation. Using a promoter assay, we found that Ca(2+)-responsive elements including a CRE are involved in the DM-induced activation of the Bdnf promoter IV (Bdnf-pIV). The intracellular concentration of Ca(2+) and activation of Bdnf-pIV remained elevated for, at least, 1 and 24 h, respectively. Moreover, GABA(A) receptor activation or a blockade of Ca(2+) influx even after starting the incubation with DM reduced the elevated activity of Bdnf-pIV. These data demonstrated that the prolonged activation of Bdnf-pIV occurred because of this continuous increase in the intracellular Ca(2+) concentration. Thus, DM has neurotrophic effects on neurons, likely due to prolonged activation of Bdnf promoter in neurons. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.

  10. Mature brain-derived neurotrophic factor and its receptor TrkB are upregulated in human glioma tissues.

    Science.gov (United States)

    Xiong, Jing; Zhou, L I; Lim, Yoon; Yang, Miao; Zhu, Yu-Hong; Li, Zhi-Wei; Fu, Deng-Li; Zhou, Xin-Fu

    2015-07-01

    There are two forms of brain-derived neurotrophic factor (BDNF), precursor of BDNF (proBDNF) and mature BDNF, which each exert opposing effects through two different transmembrane receptor signaling systems, consisting of p75 neurotrophin receptor (p75NTR) and tyrosine receptor kinase B (TrkB). Previous studies have demonstrated that proBDNF promotes cell death and inhibits the growth and migration of C6 glioma cells through p75NTR in vitro, while mature BDNF has opposite effects on C6 glioma cells. It is hypothesized that mature BDNF is essential in the development of malignancy in gliomas. However, histological data obtained in previous studies were unable distinguish mature BDNF from proBDNF due to the lack of specific antibodies. The present study investigated the expression of mature BDNF using a specific sheep monoclonal anti-mature BDNF antibody in 42 human glioma tissues of different grades and 10 control tissues. The correlation between mature BDNF and TrkB was analyzed. Mature BDNF expression was significantly increased in high-grade gliomas, and was positively correlated with the malignancy of the tumor and TrkB receptor expression. The present data have demonstrated that increased levels of mature BDNF contribute markedly to the development of malignancy of human gliomas through the primary BDNF receptor TrkB.

  11. The BDNF effects on dendritic spines of mature hippocampal neurons depend on neuronal activity

    Directory of Open Access Journals (Sweden)

    Yves eKellner

    2014-03-01

    Full Text Available The fine tuning of neural networks during development and learning relies upon both functional and structural plastic processes. Changes in the number as well as in the size and shape of dendritic spines are associated to long-term activity-dependent synaptic plasticity. However, the molecular mechanisms translating functional into structural changes are still largely unknown. In this context, neurotrophins, like Brain-Derived Neurotrophic Factor (BDNF, are among promising candidates. Specifically BDNF-TrkB receptor signaling is crucial for activity-dependent strengthening of synapses in different brain regions. BDNF application has been shown to positively modulate dendritic and spine architecture in cortical and hippocampal neurons as well as structural plasticity in vitro. However, a global BDNF deprivation throughout the central nervous system (CNS resulted in very mild structural alterations of dendritic spines, questioning the relevance of the endogenous BDNF signaling in modulating the development and the mature structure of neurons in vivo. Here we show that a loss-of-function approach, blocking BDNF results in a significant reduction in dendritic spine density, associated with an increase in spine length and a decrease in head width. These changes are associated with a decrease in F-actin levels within spine heads. On the other hand, a gain-of-function approach, applying exogenous BDNF, could not reproduce the increase in spine density or the changes in spine morphology previously described. Taken together, we show here that the effects exerted by BDNF on the dendritic architecture of hippocampal neurons are dependent on the neuron’s maturation stage. Indeed, in mature hippocampal neurons in vitro as shown in vivo BDNF is specifically required for the activity-dependent maintenance of the mature spine phenotype.

  12. Involvement of brain-derived neurotrophic factor (BDNF) in the functional elimination of synaptic contacts at polyinnervated neuromuscular synapses during development.

    Science.gov (United States)

    Garcia, N; Santafe, M M; Tomàs, M; Lanuza, M A; Besalduch, N; Tomàs, J

    2010-05-15

    We use immunohistochemistry to describe the localization of brain-derived neurotrophic factor (BDNF) and its receptors trkB and p75(NTR) in the neuromuscular synapses of postnatal rats (P6-P7) during the synapse elimination period. The receptor protein p75(NTR) is present in the nerve terminal, muscle cell and glial Schwann cell whereas BDNF and trkB proteins can be detected mainly in the pre- and postsynaptic elements. Exogenously applied BDNF (10 nM for 3 hr or 50 nM for 1 hr) increases ACh release from singly and dually innervated synapses. This effect may be specific for BDNF because the neurotrophin NT-4 (2-8 nM) does not modulate release at P6-P7. Blocking the receptors trkB and p75(NTR) (with K-252a and anti-p75-192-IgG, respectively) completely abolishes the potentiating effect of exogenous BDNF. In addition, exogenous BDNF transiently recruits functionally depressed silent terminals, and this effect seems to be mediated by trkB. Calcium ions, the L-type voltage-dependent calcium channels and protein kinase C are involved in BDNF-mediated nerve ending recruitment. Blocking experiments suggest that endogenous BDNF could operate through p75(NTR) receptors coupled to potentiate ACh release in all nerve terminals because the anti-p75-192-IgG reduces release. However, blocking the trkB receptor (K-252a) or neutralizing endogenous BDNF with the trkB-IgG fusion protein reveals a trkB-mediated release inhibition on almost mature strong endings in dual junctions. Taken together these results suggest that a BDNF-induced p75(NTR)-mediated ACh release potentiating mechanism and a BDNF-induced trkB-mediated release inhibitory mechanism may contribute to developmental synapse disconnection.

  13. Why the honey badger don't care: Convergent evolution of venom-targeted nicotinic acetylcholine receptors in mammals that survive venomous snake bites.

    Science.gov (United States)

    Drabeck, Danielle H; Dean, Antony M; Jansa, Sharon A

    2015-06-01

    Honey badgers (Mellivora capensis) prey upon and survive bites from venomous snakes (Family: Elapidae), but the molecular basis of their venom resistance is unknown. The muscular nicotinic cholinergic receptor (nAChR), targeted by snake α-neurotoxins, has evolved in some venom-resistant mammals to no longer bind these toxins. Through phylogenetic analysis of mammalian nAChR sequences, we show that honey badgers, hedgehogs, and pigs have independently acquired functionally equivalent amino acid replacements in the toxin-binding site of this receptor. These convergent amino acid changes impede toxin binding by introducing a positively charged amino acid in place of an uncharged aromatic residue. In venom-resistant mongooses, different replacements at these same sites are glycosylated, which is thought to disrupt binding through steric effects. Thus, it appears that resistance to snake venom α-neurotoxin has evolved at least four times among mammals through two distinct biochemical mechanisms operating at the same sites on the same receptor.

  14. The interaction of BDNF and NTRK2 gene increases the susceptibility of paranoid schizophrenia.

    Directory of Open Access Journals (Sweden)

    Zheng Lin

    Full Text Available The association between BDNF gene functional Val66Met polymorphism rs6265 and the schizophrenia is far from being consistent. In addition to the heterogeneous in schizophrenia per se leading to the inconsistent results, the interaction among multi-genes is probably playing the main role in the pathogenesis of schizophrenia, but not a single gene. Neurotrophic tyrosine kinase receptor 2 (NTRK2 is the high-affinity receptor of BDNF, and was reported to be associated with mood disorders, though no literature reported the association with schizophrenia. Thus, in the present study, total 402 patients with paranoid schizophrenia (the most common subtype of schizophrenia and matched 406 healthy controls were recruited to investigate the role of rs6265 in BDNF, three polymorphisms in NTRK2 gene (rs1387923, rs2769605 and rs1565445 and their interaction in the susceptibility to paranoid schizophrenia in a Chinese Han population. We did not observe significant differences in allele and genotype frequencies between patients and healthy controls for all four polymorphisms separately. The haplotype analysis also showed no association between haplotype of NTRK2 genes (rs1387923, rs2769605, and rs1565445 and paranoid schizophrenia. However, we found the association between the interaction of BDNF and NTRK2 with paranoid schizophrenia by using the MDR method followed by conventional statistical analysis. The best gene-gene interaction model was a three-locus model (BDNF rs6265, NTRK2 rs1387923 and NTRK2 rs2769605, in which one low-risk and three high-risk four-locus genotype combinations were identified. Our findings implied that single polymorphism of rs6265 rs1387923, rs2769605, and rs1565445 in BDNF and NTRK2 were not associated with the development of paranoid schizophrenia in a Han population, however, the interaction of BDNF and NTRK2 genes polymorphisms (BDNF-rs6265, NTRK2-rs1387923 and NTRK2-rs2769605 may be involved in the susceptibility to paranoid

  15. The interaction of BDNF and NTRK2 gene increases the susceptibility of paranoid schizophrenia.

    Science.gov (United States)

    Lin, Zheng; Su, Yousong; Zhang, Chengfang; Xing, Mengjuan; Ding, Wenhua; Liao, Liwei; Guan, Yangtai; Li, Zezhi; Cui, Donghong

    2013-01-01

    The association between BDNF gene functional Val66Met polymorphism rs6265 and the schizophrenia is far from being consistent. In addition to the heterogeneous in schizophrenia per se leading to the inconsistent results, the interaction among multi-genes is probably playing the main role in the pathogenesis of schizophrenia, but not a single gene. Neurotrophic tyrosine kinase receptor 2 (NTRK2) is the high-affinity receptor of BDNF, and was reported to be associated with mood disorders, though no literature reported the association with schizophrenia. Thus, in the present study, total 402 patients with paranoid schizophrenia (the most common subtype of schizophrenia) and matched 406 healthy controls were recruited to investigate the role of rs6265 in BDNF, three polymorphisms in NTRK2 gene (rs1387923, rs2769605 and rs1565445) and their interaction in the susceptibility to paranoid schizophrenia in a Chinese Han population. We did not observe significant differences in allele and genotype frequencies between patients and healthy controls for all four polymorphisms separately. The haplotype analysis also showed no association between haplotype of NTRK2 genes (rs1387923, rs2769605, and rs1565445) and paranoid schizophrenia. However, we found the association between the interaction of BDNF and NTRK2 with paranoid schizophrenia by using the MDR method followed by conventional statistical analysis. The best gene-gene interaction model was a three-locus model (BDNF rs6265, NTRK2 rs1387923 and NTRK2 rs2769605), in which one low-risk and three high-risk four-locus genotype combinations were identified. Our findings implied that single polymorphism of rs6265 rs1387923, rs2769605, and rs1565445 in BDNF and NTRK2 were not associated with the development of paranoid schizophrenia in a Han population, however, the interaction of BDNF and NTRK2 genes polymorphisms (BDNF-rs6265, NTRK2-rs1387923 and NTRK2-rs2769605) may be involved in the susceptibility to paranoid schizophrenia.

  16. Antidepressant, Antipsychotic, and Hallucinogen Drugs for the Treatment of Psychiatric Disorders: A Convergence at the Serotonin-2A Receptor.

    Science.gov (United States)

    Howland, Robert H

    2016-07-01

    Antidepressant, atypical antipsychotic, and hallucinogen drugs mediate their actions in part by interactions with the serotonin-2A (5HT2A) receptor. Serotonergic hallucinogen drugs, such as psilocybin, bind most potently as agonists at the 5HT2A receptor, producing profound changes in perception, mood, and cognition. Some of these drugs have been or are currently being investigated in small Phase 2 studies for depression, alcoholism, smoking cessation, anxiety, and posttraumatic stress disorder. However, unlike the synergistic effects of combining antidepressant and atypical antipsychotic drugs, the potential therapeutic effects of hallucinogen drugs may be attenuated by the concurrent use of these medications because antidepressant and atypical antipsychotic drugs desensitize and/or down-regulate 5HT2A receptors. This finding has important implications for optimizing the potential therapeutic use of hallucinogen drugs in psychiatry. [Journal of Psychosocial Nursing and Mental Health Services, 54(7), 21-24.]. Copyright 2016, SLACK Incorporated.

  17. Cleavage of proBDNF to BDNF by a tolloid-like metalloproteinase is required for acquisition of in vitro eyeblink classical conditioning.

    Science.gov (United States)

    Keifer, Joyce; Sabirzhanov, Boris E; Zheng, Zhaoqing; Li, Wei; Clark, Timothy G

    2009-11-25

    The tolloid/bone morphogenetic protein-1 family of metalloproteinases have an important role in the regulation of embryonic pattern formation and tissue morphogenesis. Studies suggest that they participate in mechanisms of synaptic plasticity in adults, but very little is known about their function. Recently, we isolated a reptilian ortholog of the tolloid gene family designated turtle tolloid-like gene (tTll). Here, we examined the role of tTLL in an in vitro model of eyeblink classical conditioning using an isolated brainstem preparation to assess its role in synaptic plasticity during conditioning. Analysis by real-time reverse transcription-PCR shows that an extracellularly secreted form of tTLL, tTLLs, is transiently expressed in the early stages of conditioning during conditioned response acquisition, whereas a cytosolic form, tTLLc, is not. Short interfering RNA (siRNA)-directed gene knockdown and rescue of tTLL expression demonstrate that it is required for conditioning. Significantly, we show that tTLLs cleaves the precursor proBDNF into mature BDNF in cleavage assay studies, and application of recombinant tTLLs protein alone to preparations results in induction of mature BDNF expression. The mature form of BDNF is minimally expressed in preparations treated with anti-tTLL siRNA, and the synaptic incorporation of both GluR1- and GluR4-containing AMPA receptors is significantly reduced, resulting in suppression of conditioning. This is the first study to demonstrate that expression of an extracellularly secreted tolloid-like metalloproteinase is regulated in the early stages of classical conditioning and functions in the conversion of proBDNF to mature BDNF. The mature form of BDNF is required for synaptic delivery of AMPA receptors and acquisition of conditioned responses.

  18. BDNF in sleep, insomnia, and sleep deprivation.

    Science.gov (United States)

    Schmitt, Karen; Holsboer-Trachsler, Edith; Eckert, Anne

    2016-01-01

    The protein brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family of growth factors involved in plasticity of neurons in several brain regions. There are numerous evidence that BDNF expression is decreased by experiencing psychological stress and that, accordingly, a lack of neurotrophic support causes major depression. Furthermore, disruption in sleep homeostatic processes results in higher stress vulnerability and is often associated with stress-related mental disorders. Recently, we reported, for the first time, a relationship between BDNF and insomnia and sleep deprivation (SD). Using a biphasic stress model as explanation approach, we discuss here the hypothesis that chronic stress might induce a deregulation of the hypothalamic-pituitary-adrenal system. In the long-term it leads to sleep disturbance and depression as well as decreased BDNF levels, whereas acute stress like SD can be used as therapeutic intervention in some insomniac or depressed patients as compensatory process to normalize BDNF levels. Indeed, partial SD (PSD) induced a fast increase in BDNF serum levels within hours after PSD which is similar to effects seen after ketamine infusion, another fast-acting antidepressant intervention, while traditional antidepressants are characterized by a major delay until treatment response as well as delayed BDNF level increase. Key messages Brain-derived neurotrophic factor (BDNF) plays a key role in the pathophysiology of stress-related mood disorders. The interplay of stress and sleep impacts on BDNF level. Partial sleep deprivation (PSD) shows a fast action on BDNF level increase.

  19. Genetic moderation of child maltreatment effects on depression and internalizing symptoms by serotonin transporter linked polymorphic region (5-HTTLPR), brain-derived neurotrophic factor (BDNF), norepinephrine transporter (NET), and corticotropin releasing hormone receptor 1 (CRHR1) genes in African American children.

    Science.gov (United States)

    Cicchetti, Dante; Rogosch, Fred A

    2014-11-01

    Genetic moderation of the effects of child maltreatment on depression and internalizing symptoms was investigated in a sample of low-income maltreated and nonmaltreated African American children (N = 1,096). Lifetime child maltreatment experiences were independently coded from Child Protective Services records and maternal report. Child depression and internalizing problems were assessed in the context of a summer research camp by self-report on the Children's Depression Inventory and adult counselor report on the Teacher Report Form. DNA was obtained from buccal cell or saliva samples and genotyped for polymorphisms of the following genes: serotonin transporter linked polymorphic region (5-HTTLPR), brain-derived neurotrophic factor (BDNF), norepinephrine transporter, and corticotropin releasing hormone receptor 1. Analyses of covariance with age and gender as covariates were conducted, with maltreatment status and respective polymorphism as main effects and their Gene × Environment (G × E) interactions. Maltreatment consistently was associated with higher Children's Depression Inventory and Teacher Report Form symptoms. The results for child self-report symptoms indicated a G × E interaction for BDNF and maltreatment. In addition, BDNF and triallelic 5-HTTLPR interacted with child maltreatment in a G × G × E interaction. Analyses for counselor report of child anxiety/depression symptoms on the Teacher Report Form indicated moderation of child maltreatment effects by triallelic 5-HTTLPR. These effects were elaborated based on variation in developmental timing of maltreatment experiences. Norepinephrine transporter was found to further moderate the G × E interaction of 5-HTTLPR and maltreatment status, revealing a G × G × E interaction. This G × G × E was extended by consideration of variation in maltreatment subtype experiences. Finally, G × G × E effects were observed for the co-action of BDNF and the corticotropin releasing hormone receptor 1

  20. Pharmacological profile of brain-derived neurotrophic factor (BDNF) splice variant translation using a novel drug screening assay: a "quantitative code".

    Science.gov (United States)

    Vaghi, Valentina; Polacchini, Alessio; Baj, Gabriele; Pinheiro, Vera L M; Vicario, Annalisa; Tongiorgi, Enrico

    2014-10-03

    The neurotrophin brain-derived neurotrophic factor (BDNF) is a key regulator of neuronal development and plasticity. BDNF is a major pharmaceutical target in neurodevelopmental and psychiatric disorders. However, pharmacological modulation of this neurotrophin is challenging because BDNF is generated by multiple, alternatively spliced transcripts with different 5'- and 3'UTRs. Each BDNF mRNA variant is transcribed independently, but translation regulation is unknown. To evaluate the translatability of BDNF transcripts, we developed an in vitro luciferase assay in human neuroblastoma cells. In unstimulated cells, each BDNF 5'- and 3'UTR determined a different basal translation level of the luciferase reporter gene. However, constructs with either a 5'UTR or a 3'UTR alone showed poor translation modulation by BDNF, KCl, dihydroxyphenylglycine, AMPA, NMDA, dopamine, acetylcholine, norepinephrine, or serotonin. Constructs consisting of the luciferase reporter gene flanked by the 5'UTR of one of the most abundant BDNF transcripts in the brain (exons 1, 2c, 4, and 6) and the long 3'UTR responded selectively to stimulation with the different receptor agonists, and only transcripts 2c and 6 were increased by the antidepressants desipramine and mirtazapine. We propose that BDNF mRNA variants represent "a quantitative code" for regulated expression of the protein. Thus, to discriminate the efficacy of drugs in stimulating BDNF synthesis, it is appropriate to use variant-specific in vitro screening tests.

  1. Brain-derived neurotrophic factor (BDNF) enhances GABA transport by modulating the trafficking of GABA transporter-1 (GAT-1) from the plasma membrane of rat cortical astrocytes

    DEFF Research Database (Denmark)

    Vaz, Sandra H; Jørgensen, Trine Nygaard; Cristóvão-Ferreira, Sofia

    2011-01-01

    /MAPK pathway and requires active adenosine A(2A) receptors. Transport through GAT-3 is not affected by BDNF. To elucidate if BDNF affects trafficking of GAT-1 in astrocytes, we generated and infected astrocytes with a functional mutant of the rat GAT-1 (rGAT-1) in which the hemagglutinin (HA) epitope...

  2. Interplay between thyroxin, BDNF and GABA in injured neurons.

    Science.gov (United States)

    Shulga, A; Rivera, C

    2013-06-03

    Accumulating experimental evidence suggests that groups of neurons in the CNS might react to pathological insults by activating developmental-like programs for survival, regeneration and re-establishment of lost connections. For instance, in cell and animal models it was shown that after trauma mature central neurons become dependent on brain-derived neurotrophic factor (BDNF) trophic support for survival. This event is preceded by a shift of postsynaptic GABAA receptor-mediated responses from hyperpolarization to developmental-like depolarization. These profound functional changes in GABAA receptor-mediated transmission and the requirement of injured neurons for BDNF trophic support are interdependent. Thyroid hormones (THs) play a crucial role in the development of the nervous system, having significant effects on dendritic branching, synaptogenesis and axonal growth to name a few. In the adult nervous system TH thyroxin has been shown to have a neuroprotective effect and to promote regeneration in experimental trauma models. Interestingly, after trauma there is a qualitative change in the regulatory effect of thyroxin on BDNF expression as well as on GABAergic transmission. In this review we provide an overview of the post-traumatic changes in these signaling systems and discuss the potential significance of their interactions for the development of novel therapeutic strategies.

  3. Research Progress of BDNF and Depression%BDNF与抑郁症的研究现状及进展

    Institute of Scientific and Technical Information of China (English)

    乔卉; 安书成; 徐畅

    2011-01-01

    BDNF is widespread existed in CNS and PNS, because of its function in nerve regeneration and restoration, more and more researches focused on the effect of BDNF on neural plasticity in the development of depression and the mechanisms of antidepressant. This article review the basic results and the research trends on BDNF and depression at present, more researches about the interactions of BDNF and proBDNF, BDNF and other transmitters and their receptors should be expected.%脑源性神经营养因子(brain-derived neurothrophic factor,BDNF)在中枢和外周均广泛存在,基于对其神经再生和修复功能的普遍认识,越来越多的研究开始关注BDNF在抑郁发生过程中对神经可塑性的影响以及BDNF在抗抑郁药物治疗中发挥的作用.本文综述了BDNF与抑郁症关系的基础性研究成果,以及近两年的相关研究趋势,更多的关于BDNF与其前体(precursor of brain derived neurothrophic factor,proBDNF)以及BDNF与其它神经递质在神经网络中的相互作用的研究需要被深入开展.

  4. BDNF impairment is associated with age-related changes in the inner retina and exacerbates experimental glaucoma.

    Science.gov (United States)

    Gupta, Vivek; You, Yuyi; Li, Jonathan; Gupta, Veer; Golzan, Mojtaba; Klistorner, Alexander; van den Buuse, Maarten; Graham, Stuart

    2014-09-01

    Brain-derived neurotrophic factor (BDNF) stimulation of its high-affinity receptor TrkB results in activation of pro-survival cell-signalling pathways that can afford neuroprotection to the retina. Reduction in retrograde axonal transport of neurotrophic factors such as BDNF from the brain to the neuronal cell bodies in the retina has been suggested as a critical factor underlying progressive and selective degeneration of ganglion cell layer and optic nerve in glaucoma. We investigated the role of BDNF in preserving inner retinal homeostasis in normal and glaucoma states using BDNF(+/-) mice and compared it with wild type controls. This study demonstrated that BDNF(+/-) animals were more susceptible to functional, morphological and molecular degenerative changes in the inner retina caused by age as well as upon exposure to experimental glaucoma caused by increased intraocular pressure. Glaucoma induced a down regulation of BDNF/TrkB signalling and an increase in levels of neurotoxic amyloid β 1-42 in the optic nerve head which were exacerbated in BDNF(+/-) mice. Similar results were obtained upon analysing the human optic nerve head tissues. Our data highlighted the role of BDNF in maintaining the inner retinal integrity under normal conditions and the detrimental effects of its insufficiency on the retina and optic nerve in glaucoma. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Convergent Signaling Pathways Controlled by LRP1 (Receptor-related Protein 1) Cytoplasmic and Extracellular Domains Limit Cellular Cholesterol Accumulation.

    Science.gov (United States)

    El Asmar, Zeina; Terrand, Jérome; Jenty, Marion; Host, Lionel; Mlih, Mohamed; Zerr, Aurélie; Justiniano, Hélène; Matz, Rachel L; Boudier, Christian; Scholler, Estelle; Garnier, Jean-Marie; Bertaccini, Diego; Thiersé, Danièle; Schaeffer, Christine; Van Dorsselaer, Alain; Herz, Joachim; Bruban, Véronique; Boucher, Philippe

    2016-03-04

    The low density lipoprotein receptor-related protein 1 (LRP1) is a ubiquitously expressed cell surface receptor that protects from intracellular cholesterol accumulation. However, the underlying mechanisms are unknown. Here we show that the extracellular (α) chain of LRP1 mediates TGFβ-induced enhancement of Wnt5a, which limits intracellular cholesterol accumulation by inhibiting cholesterol biosynthesis and by promoting cholesterol export. Moreover, we demonstrate that the cytoplasmic (β) chain of LRP1 suffices to limit cholesterol accumulation in LRP1(-/-) cells. Through binding of Erk2 to the second of its carboxyl-terminal NPXY motifs, LRP1 β-chain positively regulates the expression of ATP binding cassette transporter A1 (ABCA1) and of neutral cholesterol ester hydrolase (NCEH1). These results highlight the unexpected functions of LRP1 and the canonical Wnt5a pathway and new therapeutic potential in cholesterol-associated disorders including cardiovascular diseases.

  6. Association Between Smoking, Nicotine Dependence, and BDNF Val(66)Met Polymorphism with BDNF Concentrations in Serum

    NARCIS (Netherlands)

    Jamal, Mumtaz; Van der Does, Willem; Elzinga, Bernet M.; Molendijk, Marc L.; Penninx, Brenda W. J. H.

    2015-01-01

    Introduction: Nicotine use is associated with the upregulation of brain-derived neurotrophic factor (BDNF) in serum. An association between smoking and the BDNF Val(66)Met polymorphism has also been found. The aim of this study is to examine the levels of serum BDNF in never-smokers, former smokers,

  7. Association Between Smoking, Nicotine Dependence, and BDNF Val(66)Met Polymorphism with BDNF Concentrations in Serum

    NARCIS (Netherlands)

    Jamal, Mumtaz; Van der Does, Willem; Elzinga, Bernet M.; Molendijk, Marc L.; Penninx, Brenda W. J. H.

    Introduction: Nicotine use is associated with the upregulation of brain-derived neurotrophic factor (BDNF) in serum. An association between smoking and the BDNF Val(66)Met polymorphism has also been found. The aim of this study is to examine the levels of serum BDNF in never-smokers, former smokers,

  8. Intracellular Ca2+ stores and Ca2+ influx are both required for BDNF to rapidly increase quantal vesicular transmitter release.

    Science.gov (United States)

    Amaral, Michelle D; Pozzo-Miller, Lucas

    2012-01-01

    Brain-derived neurotrophic factor (BDNF) is well known as a survival factor during brain development as well as a regulator of adult synaptic plasticity. One potential mechanism to initiate BDNF actions is through its modulation of quantal presynaptic transmitter release. In response to local BDNF application to CA1 pyramidal neurons, the frequency of miniature excitatory postsynaptic currents (mEPSC) increased significantly within 30 seconds; mEPSC amplitude and kinetics were unchanged. This effect was mediated via TrkB receptor activation and required both full intracellular Ca(2+) stores as well as extracellular Ca(2+). Consistent with a role of Ca(2+)-permeable plasma membrane channels of the TRPC family, the inhibitor SKF96365 prevented the BDNF-induced increase in mEPSC frequency. Furthermore, labeling presynaptic terminals with amphipathic styryl dyes and then monitoring their post-BDNF destaining in slice cultures by multiphoton excitation microscopy revealed that the increase in frequency of mEPSCs reflects vesicular fusion events. Indeed, BDNF application to CA3-CA1 synapses in TTX rapidly enhanced FM1-43 or FM2-10 destaining with a time course that paralleled the phase of increased mEPSC frequency. We conclude that BDNF increases mEPSC frequency by boosting vesicular fusion through a presynaptic, Ca(2+)-dependent mechanism involving TrkB receptors, Ca(2+) stores, and TRPC channels.

  9. Intracellular Ca2+ Stores and Ca2+ Influx Are Both Required for BDNF to Rapidly Increase Quantal Vesicular Transmitter Release

    Directory of Open Access Journals (Sweden)

    Michelle D. Amaral

    2012-01-01

    Full Text Available Brain-derived neurotrophic factor (BDNF is well known as a survival factor during brain development as well as a regulator of adult synaptic plasticity. One potential mechanism to initiate BDNF actions is through its modulation of quantal presynaptic transmitter release. In response to local BDNF application to CA1 pyramidal neurons, the frequency of miniature excitatory postsynaptic currents (mEPSC increased significantly within 30 seconds; mEPSC amplitude and kinetics were unchanged. This effect was mediated via TrkB receptor activation and required both full intracellular Ca2+ stores as well as extracellular Ca2+. Consistent with a role of Ca2+-permeable plasma membrane channels of the TRPC family, the inhibitor SKF96365 prevented the BDNF-induced increase in mEPSC frequency. Furthermore, labeling presynaptic terminals with amphipathic styryl dyes and then monitoring their post-BDNF destaining in slice cultures by multiphoton excitation microscopy revealed that the increase in frequency of mEPSCs reflects vesicular fusion events. Indeed, BDNF application to CA3-CA1 synapses in TTX rapidly enhanced FM1-43 or FM2-10 destaining with a time course that paralleled the phase of increased mEPSC frequency. We conclude that BDNF increases mEPSC frequency by boosting vesicular fusion through a presynaptic, Ca2+-dependent mechanism involving TrkB receptors, Ca2+ stores, and TRPC channels.

  10. The impact of Bdnf gene deficiency to the memory impairment and brain pathology of APPswe/PS1dE9 mouse model of Alzheimer's disease.

    Science.gov (United States)

    Rantamäki, Tomi; Kemppainen, Susanna; Autio, Henri; Stavén, Saara; Koivisto, Hennariikka; Kojima, Masami; Antila, Hanna; Miettinen, Pasi O; Kärkkäinen, Elisa; Karpova, Nina; Vesa, Liisa; Lindemann, Lothar; Hoener, Marius C; Tanila, Heikki; Castrén, Eero

    2013-01-01

    Brain-derived neurotrophic factor (BDNF) importantly regulates learning and memory and supports the survival of injured neurons. Reduced BDNF levels have been detected in the brains of Alzheimer's disease (AD) patients but the exact role of BDNF in the pathophysiology of the disorder remains obscure. We have recently shown that reduced signaling of BDNF receptor TrkB aggravates memory impairment in APPswe/PS1dE9 (APdE9) mice, a model of AD. The present study examined the influence of Bdnf gene deficiency (heterozygous knockout) on spatial learning, spontaneous exploratory activity and motor coordination/balance in middle-aged male and female APdE9 mice. We also studied brain BDNF protein levels in APdE9 mice in different ages showing progressive amyloid pathology. Both APdE9 and Bdnf mutations impaired spatial learning in males and showed a similar trend in females. Importantly, the effect was additive, so that double mutant mice performed the worst. However, APdE9 and Bdnf mutations influenced spontaneous locomotion in contrasting ways, such that locomotor hyperactivity observed in APdE9 mice was normalized by Bdnf deficiency. Obesity associated with Bdnf deficiency did not account for the reduced hyperactivity in double mutant mice. Bdnf deficiency did not alter amyloid plaque formation in APdE9 mice. Before plaque formation (3 months), BDNF protein levels where either reduced (female) or unaltered (male) in the APdE9 mouse cortex. Unexpectedly, this was followed by an age-dependent increase in mature BDNF protein. Bdnf mRNA and phospho-TrkB levels remained unaltered in the cortical tissue samples of middle-aged APdE9 mice. Immunohistological studies revealed increased BDNF immunoreactivity around amyloid plaques indicating that the plaques may sequester BDNF protein and prevent it from activating TrkB. If similar BDNF accumulation happens in human AD brains, it would suggest that functional BDNF levels in the AD brains are even lower than reported, which could

  11. The impact of Bdnf gene deficiency to the memory impairment and brain pathology of APPswe/PS1dE9 mouse model of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Tomi Rantamäki

    Full Text Available Brain-derived neurotrophic factor (BDNF importantly regulates learning and memory and supports the survival of injured neurons. Reduced BDNF levels have been detected in the brains of Alzheimer's disease (AD patients but the exact role of BDNF in the pathophysiology of the disorder remains obscure. We have recently shown that reduced signaling of BDNF receptor TrkB aggravates memory impairment in APPswe/PS1dE9 (APdE9 mice, a model of AD. The present study examined the influence of Bdnf gene deficiency (heterozygous knockout on spatial learning, spontaneous exploratory activity and motor coordination/balance in middle-aged male and female APdE9 mice. We also studied brain BDNF protein levels in APdE9 mice in different ages showing progressive amyloid pathology. Both APdE9 and Bdnf mutations impaired spatial learning in males and showed a similar trend in females. Importantly, the effect was additive, so that double mutant mice performed the worst. However, APdE9 and Bdnf mutations influenced spontaneous locomotion in contrasting ways, such that locomotor hyperactivity observed in APdE9 mice was normalized by Bdnf deficiency. Obesity associated with Bdnf deficiency did not account for the reduced hyperactivity in double mutant mice. Bdnf deficiency did not alter amyloid plaque formation in APdE9 mice. Before plaque formation (3 months, BDNF protein levels where either reduced (female or unaltered (male in the APdE9 mouse cortex. Unexpectedly, this was followed by an age-dependent increase in mature BDNF protein. Bdnf mRNA and phospho-TrkB levels remained unaltered in the cortical tissue samples of middle-aged APdE9 mice. Immunohistological studies revealed increased BDNF immunoreactivity around amyloid plaques indicating that the plaques may sequester BDNF protein and prevent it from activating TrkB. If similar BDNF accumulation happens in human AD brains, it would suggest that functional BDNF levels in the AD brains are even lower than reported

  12. THE GENE EXPRESSION OF BDNF IN NORMAL RABBIT RETINA

    Institute of Scientific and Technical Information of China (English)

    王建明; 胡海涛; 马东亮; 孙乃学; 赵世平; 冯海晓

    2004-01-01

    Objective To investigate the distribution of brain-derived neurotrophic factor(BDNF) protein in the rabbit retina. Methods Immune response material in the retina was observed using BDNF antibody by the method of immunohistochemistry. Results BDNF gene expression was mainly found in the RGCs, also in innernuclei cells and outernuclei cells in rabbit retina. Conclusion RGC is not only the target cell of BDNF, but also express the BDNF protein. BDNF from multi-sources participates in the regulation of RGCs.

  13. Brain-derived neurotrophic factor (BDNF) expression in normal and regenerating olfactory epithelium of Xenopus laevis.

    Science.gov (United States)

    Frontera, Jimena Laura; Cervino, Ailen Soledad; Jungblut, Lucas David; Paz, Dante Agustín

    2015-03-01

    Olfactory epithelium has the capability to continuously regenerate olfactory receptor neurons throughout life. Adult neurogenesis results from proliferation and differentiation of neural stem cells, and consequently, olfactory neuroepithelium offers an excellent opportunity to study neural regeneration and the factors involved in the maintenance and regeneration of all their cell types. We analyzed the expression of BDNF in the olfactory system under normal physiological conditions as well as during a massive regeneration induced by chemical destruction of the olfactory epithelium in Xenopus laevis larvae. We described the expression and presence of BDNF in the olfactory epithelium and bulb. In normal physiological conditions, sustentacular (glial) cells and a few scattered basal (stem) cells express BDNF in the olfactory epithelium as well as the granular cells in the olfactory bulb. Moreover, during massive regeneration, we demonstrated a drastic increase in basal cells expressing BDNF as well as an increase in BDNF in the olfactory bulb and nerve. Together these results suggest an important role of BDNF in the maintenance and regeneration of the olfactory system.

  14. BDNF-dependent consolidation of fear memories in the perirhinal cortex

    Directory of Open Access Journals (Sweden)

    Brigitte eSchulz-Klaus

    2013-12-01

    Full Text Available In the recent years the perirhinal cortex (PRh has been identified as a crucial brain area in fear learning. Since the neurotrophin BDNF (brain-derived neurotrophic factor is an important mediator of synaptic plasticity and also crucially involved in memory consolidation of several learning paradigms, we analyzed now whether fear conditioning influences the expression of BDNF protein in the PRh. Here we observed a specific increase of BDNF protein 120 minutes after fear conditioning training. In order to test whether this increase of BDNF protein level is also required for the consolidation of the fear memory, we locally applied the Trk receptor inhibitor k252a into the PRh during this time window in a second series of experiments. By interfering with BDNF-TrkB-signaling during this critical time window, the formation of a long-term fear memory was completely blocked, indicated by a complete lack of fear potentiated startle one day later. In conclusion the present study further emphasizes the important role of the PRh in cued fear learning and identified BDNF as an important mediator for fear memory consolidation in the PRh.

  15. Increased expression of BDNF and proliferation of dentate granule cells after bacterial meningitis.

    Science.gov (United States)

    Tauber, Simone C; Stadelmann, Christine; Spreer, Annette; Brück, Wolfgang; Nau, Roland; Gerber, Joachim

    2005-09-01

    Proliferation and differentiation of neural progenitor cells is increased after bacterial meningitis. To identify endogenous factors involved in neurogenesis, expression of brain-derived neurotrophic factor (BDNF), TrkB, nerve growth factor (NGF), and glial cell line-derived neurotrophic factor (GDNF) was investigated. C57BL/6 mice were infected by intracerebral injection of Streptococcus pneumoniae. Mice were killed 30 hours later or treated with ceftriaxone and killed 4 days after infection. Hippocampal BDNF mRNA levels were increased 2.4-fold 4 days after infection (p = 0.026). Similarly, BDNF protein levels in the hippocampal formation were higher in infected mice than in control animals (p = 0.0003). This was accompanied by an elevated proliferation of dentate granule cells (p = 0.0002). BDNF protein was located predominantly in the hippocampal CA3/4 area and the hilus of the dentate gyrus. The density of dentate granule cells expressing the BDNF receptor TrkB as well as mRNA levels of TrkB in the hippocampal formation were increased 4 days after infection (p = 0.027 and 0.0048, respectively). Conversely, NGF mRNA levels at 30 hours after infection were reduced by approximately 50% (p = 0.004). No significant changes in GDNF expression were observed. In conclusion, increased synthesis of BDNF and TrkB suggests a contribution of this neurotrophic factor to neurogenesis after bacterial meningitis.

  16. Acupuncture Improved Neurological Recovery after Traumatic Brain Injury by Activating BDNF/TrkB Pathway

    Science.gov (United States)

    Li, Xiaohong; Chen, Chong; Yang, Xiping; Wang, Jingjing; Zhao, Ming-liang; Sun, Hongtao

    2017-01-01

    How to promote neural repair following traumatic brain injury (TBI) has long been an intractable problem. Although acupuncture has been demonstrated to facilitate the neurological recovery, the underlying mechanism is elusive. Brain-derived neurotrophic factor (BDNF) exerts substantial protective effects for neurological disorders. In this study, we found that the level of BDNF and tropomyosin receptor kinase B (TrkB) was elevated spontaneously after TBI and reached up to the peak at 12 h. Nevertheless, this enhancement is quickly declined to the normal at 48 h. After combined stimulation at the acupoints of Baihui, Renzhong, Hegu, and Zusanli, we found that BDNF and TrkB were still significantly elevated at 168 h. We also observed that the downstream molecular p-Akt and p-Erk1/2 were significantly increased, suggesting that acupuncture could persistently activate the BDNF/TrkB pathway. To further verify that acupuncture improved recovery through activating BDNF/TrkB pathway, K252a (specific inhibitor of TrkB) was treated by injection stereotaxically into lateral ventricle. We observed that K252a could significantly prevent the acupuncture-induced amelioration of motor, sensation, cognition, and synaptic plasticity. These data indicated that acupuncture promoted the recovery of neurological impairment after TBI by activating BDNF/TrkB signaling pathway, providing new molecular mechanism for understanding traditional therapy of acupuncture. PMID:28243312

  17. Acupuncture Improved Neurological Recovery after Traumatic Brain Injury by Activating BDNF/TrkB Pathway.

    Science.gov (United States)

    Li, Xiaohong; Chen, Chong; Yang, Xiping; Wang, Jingjing; Zhao, Ming-Liang; Sun, Hongtao; Zhang, Sai; Tu, Yue

    2017-01-01

    How to promote neural repair following traumatic brain injury (TBI) has long been an intractable problem. Although acupuncture has been demonstrated to facilitate the neurological recovery, the underlying mechanism is elusive. Brain-derived neurotrophic factor (BDNF) exerts substantial protective effects for neurological disorders. In this study, we found that the level of BDNF and tropomyosin receptor kinase B (TrkB) was elevated spontaneously after TBI and reached up to the peak at 12 h. Nevertheless, this enhancement is quickly declined to the normal at 48 h. After combined stimulation at the acupoints of Baihui, Renzhong, Hegu, and Zusanli, we found that BDNF and TrkB were still significantly elevated at 168 h. We also observed that the downstream molecular p-Akt and p-Erk1/2 were significantly increased, suggesting that acupuncture could persistently activate the BDNF/TrkB pathway. To further verify that acupuncture improved recovery through activating BDNF/TrkB pathway, K252a (specific inhibitor of TrkB) was treated by injection stereotaxically into lateral ventricle. We observed that K252a could significantly prevent the acupuncture-induced amelioration of motor, sensation, cognition, and synaptic plasticity. These data indicated that acupuncture promoted the recovery of neurological impairment after TBI by activating BDNF/TrkB signaling pathway, providing new molecular mechanism for understanding traditional therapy of acupuncture.

  18. Acupuncture Improved Neurological Recovery after Traumatic Brain Injury by Activating BDNF/TrkB Pathway

    Directory of Open Access Journals (Sweden)

    Xiaohong Li

    2017-01-01

    Full Text Available How to promote neural repair following traumatic brain injury (TBI has long been an intractable problem. Although acupuncture has been demonstrated to facilitate the neurological recovery, the underlying mechanism is elusive. Brain-derived neurotrophic factor (BDNF exerts substantial protective effects for neurological disorders. In this study, we found that the level of BDNF and tropomyosin receptor kinase B (TrkB was elevated spontaneously after TBI and reached up to the peak at 12 h. Nevertheless, this enhancement is quickly declined to the normal at 48 h. After combined stimulation at the acupoints of Baihui, Renzhong, Hegu, and Zusanli, we found that BDNF and TrkB were still significantly elevated at 168 h. We also observed that the downstream molecular p-Akt and p-Erk1/2 were significantly increased, suggesting that acupuncture could persistently activate the BDNF/TrkB pathway. To further verify that acupuncture improved recovery through activating BDNF/TrkB pathway, K252a (specific inhibitor of TrkB was treated by injection stereotaxically into lateral ventricle. We observed that K252a could significantly prevent the acupuncture-induced amelioration of motor, sensation, cognition, and synaptic plasticity. These data indicated that acupuncture promoted the recovery of neurological impairment after TBI by activating BDNF/TrkB signaling pathway, providing new molecular mechanism for understanding traditional therapy of acupuncture.

  19. Weak Convergence and Weak Convergence

    Directory of Open Access Journals (Sweden)

    Narita Keiko

    2015-09-01

    Full Text Available In this article, we deal with weak convergence on sequences in real normed spaces, and weak* convergence on sequences in dual spaces of real normed spaces. In the first section, we proved some topological properties of dual spaces of real normed spaces. We used these theorems for proofs of Section 3. In Section 2, we defined weak convergence and weak* convergence, and proved some properties. By RNS_Real Mizar functor, real normed spaces as real number spaces already defined in the article [18], we regarded sequences of real numbers as sequences of RNS_Real. So we proved the last theorem in this section using the theorem (8 from [25]. In Section 3, we defined weak sequential compactness of real normed spaces. We showed some lemmas for the proof and proved the theorem of weak sequential compactness of reflexive real Banach spaces. We referred to [36], [23], [24] and [3] in the formalization.

  20. Effects of ketamine on expression of hippocampal GABAB1 receptors and BDNF in rats with diabetic neuropathic pain complicated with depression%氯胺酮对糖尿病神经痛并发抑郁大鼠海马GABAB1受体及BDNF蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    任伟; 白惠萍; 霍树平; 刘朋; 陆萍; 王倩; 郭跃先; 王秀丽

    2014-01-01

    目的 评价氯胺酮对糖尿病神经痛并发抑郁大鼠海马γ-氨基丁酸B1(GABAB1)受体及脑源性神经生长因子(BDNF)蛋白表达的影响.方法 清洁级雄性SD大鼠60只,体重180 ~ 200 g,采用腹腔注射链脲佐菌素联合强迫游泳实验的方法制备大鼠糖尿病神经痛并发抑郁模型,取模型制备成功的大鼠40只,采用随机数字表法,将其分为2组(n=20):模型对照组(NS组)和氯胺酮组(K组).K组肌肉注射氯胺酮10 mg/kg(0.5 ml),1次/d,持续1周.NS组以等容量生理盐水替代.另取20只大鼠为正常对照组(C组).于给药完成后第1天(T1)和第2周(T2)时,测定大鼠机械缩足反应阈(MWT)及记录强迫游泳实验不动时间(IMFST),测定结束后取海马,采用免疫组织化学法和Westernblot法测定海马GABAB1受体及BDNF蛋白的表达水平,采用RT-PCR法检测海马GABAB1受体及BDNFmRNA的表达水平.结果 与C组比较,NS组MWT降低,IMFST延长,海马GABAB1受体和BDNF蛋白及其mRNA表达下调(P<0.05).与NS组比较,K组MWT升高,IMFST缩短,海马GABAB1受体及BDNF蛋白及其mRNA的表达上调(P<0.05).结论 氯胺酮可通过上调糖尿病神经痛并发抑郁大鼠海马GABAB1受体及BDNF蛋白的表达,减轻神经病理性痛和抑郁状态.%Objective To evaluate the effects of ketamine on the expression of gamma-aminobutyric acid type B receptor subunit 1 (GABAB1) receptors and brain-derived neurotrophic factor (BDNF) in rats with diabetic neuropathic pain (DNP) complicated with depression.Methods Pathogen-free male Sprague-Dawley rats,weighing 180-200 g,were used in the study.The model of DNP was established by intraperitoneal injection of streptozocin,and then depression was induced by forcing the rats to swim in a narrow cylinder from which they cannot escape.Forty rats with DNP complicated with depression were randomly divided into 2 groups (n =20 each) using a random number table:model control group (NS group) and ketamine group (K group

  1. Androgen-dependent loss of muscle BDNF mRNA in two mouse models of SBMA.

    Science.gov (United States)

    Halievski, Katherine; Henley, Casey L; Domino, Laurel; Poort, Jessica E; Fu, Martina; Katsuno, Masahisa; Adachi, Hiroaki; Sobue, Gen; Breedlove, S Marc; Jordan, Cynthia L

    2015-07-01

    Transgenic expression of neurotrophic factors in skeletal muscle has been found to protect mice from neuromuscular disease, including spinal bulbar muscular atrophy (SBMA), triggering renewed interest in neurotrophic factors as therapeutic agents for treating neuromuscular disease. Because SBMA is an androgen-dependent disease, and brain-derived neurotrophic factor (BDNF) mediates effects of androgens on neuromuscular systems, we asked whether BDNF expression is impaired in two different transgenic (Tg) mouse models of SBMA, the so called "97Q" and "myogenic" SBMA models. The 97Q model globally overexpresses a full length human AR with 97 glutamine repeats whereas the myogenic model of SBMA overexpresses a wild-type rat androgen receptor (AR) only in skeletal muscle fibers. Using quantitative PCR, we find that muscle BDNF mRNA declines in an androgen-dependent manner in both models, paralleling changes in motor function, with robust deficits (6-8 fold) in both fast and slow twitch muscles of impaired Tg males. Castration rescues or reverses disease-related deficits in muscle BDNF mRNA in both models, paralleling its effect on motor function. Moreover, when disease is acutely induced in Tg females, both motor function and muscle BDNF mRNA expression plummet, with the deficit in muscle BDNF emerging before overt motor dysfunction. That androgen-dependent motor dysfunction is tightly associated with a robust and early down-regulation of muscle BDNF mRNA suggests that BDNF delivered to skeletal muscle may have therapeutic value for SBMA. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Regional differences in the expression of brain-derived neurotrophic factor (BDNF) pro-peptide, proBDNF and preproBDNF in the brain confer stress resilience.

    Science.gov (United States)

    Yang, Bangkun; Yang, Chun; Ren, Qian; Zhang, Ji-Chun; Chen, Qian-Xue; Shirayama, Yukihiko; Hashimoto, Kenji

    2016-12-01

    Using learned helplessness (LH) model of depression, we measured protein expression of brain-derived neurotrophic factor (BDNF) pro-peptide, BDNF precursors (proBDNF and preproBDNF) in the brain regions of LH (susceptible) and non-LH rats (resilience). Expression of preproBDNF, proBDNF and BDNF pro-peptide in the medial prefrontal cortex of LH rats, but not non-LH rats, was significantly higher than control rats, although expression of these proteins in the nucleus accumbens of LH rats was significantly lower than control rats. This study suggests that regional differences in conversion of BDNF precursors into BDNF and BDNF pro-peptide by proteolytic cleavage may contribute to stress resilience.

  3. The Responsiveness of TrkB to BDNF and Antidepressant Drugs Is Differentially Regulated during Mouse Development

    OpenAIRE

    Antonio Di Lieto; Tomi Rantamäki; Liisa Vesa; Sudhirkumar Yanpallewar; Hanna Antila; Jesse Lindholm; Maribel Rios; Lino Tessarollo; Eero Castrén

    2012-01-01

    BACKGROUND: Previous studies suggest that the responsiveness of TrkB receptor to BDNF is developmentally regulated in rats. Antidepressant drugs (AD) have been shown to increase TrkB signalling in the adult rodent brain, and recent findings implicate a BDNF-independent mechanism behind this phenomenon. When administered during early postnatal life, ADs produce long-lasting biochemical and behavioural alterations that are observed in adult animals. METHODOLOGY: We have here examined the respon...

  4. Tackling Glaucoma from within the Brain: An Unfortunate Interplay of BDNF and TrkB.

    Science.gov (United States)

    Dekeyster, Eline; Geeraerts, Emiel; Buyens, Tom; Van den Haute, Chris; Baekelandt, Veerle; De Groef, Lies; Salinas-Navarro, Manuel; Moons, Lieve

    2015-01-01

    According to the neurotrophin deprivation hypothesis, diminished retrograde delivery of neurotrophic support during an early stage of glaucoma pathogenesis is one of the main triggers that induce retinal ganglion cell (RGC) degeneration. Therefore, interfering with neurotrophic signaling seems an attractive strategy to achieve neuroprotection. Indeed, exogenous neurotrophin administration to the eye has been shown to reduce loss of RGCs in animal models of glaucoma; however, the neuroprotective effect was mostly insufficient for sustained RGC survival. We hypothesized that treatment at the level of neurotrophin-releasing brain areas might be beneficial, as signaling pathways activated by target-derived neurotrophins are suggested to differ from pathways that are initiated at the soma membrane. In our study, first, the spatiotemporal course of RGC degeneration was characterized in mice subjected to optic nerve crush (ONC) or laser induced ocular hypertension (OHT). Subsequently, the well-known neurotrophin brain-derived neurotrophic factor (BDNF) was chosen as the lead molecule, and the levels of BDNF and its high-affinity receptor, tropomyosin receptor kinase B (TrkB), were examined in the mouse retina and superior colliculus (SC) upon ONC and OHT. Both models differentially influenced BDNF and TrkB levels. Next, we aimed for RGC protection through viral vector-mediated upregulation of collicular BDNF, thought to boost the retrograde neurotrophin delivery. Although the previously reported temporary neuroprotective effect of intravitreally delivered recombinant BDNF was confirmed, viral vector-induced BDNF overexpression in the SC did not result in protection of the RGCs in the glaucoma models used. These findings most likely relate to decreased neurotrophin responsiveness upon vector-mediated BDNF overexpression. Our results highlight important insights concerning the complexity of neurotrophic factor treatments that should surely be considered in future

  5. Tackling Glaucoma from within the Brain: An Unfortunate Interplay of BDNF and TrkB.

    Directory of Open Access Journals (Sweden)

    Eline Dekeyster

    Full Text Available According to the neurotrophin deprivation hypothesis, diminished retrograde delivery of neurotrophic support during an early stage of glaucoma pathogenesis is one of the main triggers that induce retinal ganglion cell (RGC degeneration. Therefore, interfering with neurotrophic signaling seems an attractive strategy to achieve neuroprotection. Indeed, exogenous neurotrophin administration to the eye has been shown to reduce loss of RGCs in animal models of glaucoma; however, the neuroprotective effect was mostly insufficient for sustained RGC survival. We hypothesized that treatment at the level of neurotrophin-releasing brain areas might be beneficial, as signaling pathways activated by target-derived neurotrophins are suggested to differ from pathways that are initiated at the soma membrane. In our study, first, the spatiotemporal course of RGC degeneration was characterized in mice subjected to optic nerve crush (ONC or laser induced ocular hypertension (OHT. Subsequently, the well-known neurotrophin brain-derived neurotrophic factor (BDNF was chosen as the lead molecule, and the levels of BDNF and its high-affinity receptor, tropomyosin receptor kinase B (TrkB, were examined in the mouse retina and superior colliculus (SC upon ONC and OHT. Both models differentially influenced BDNF and TrkB levels. Next, we aimed for RGC protection through viral vector-mediated upregulation of collicular BDNF, thought to boost the retrograde neurotrophin delivery. Although the previously reported temporary neuroprotective effect of intravitreally delivered recombinant BDNF was confirmed, viral vector-induced BDNF overexpression in the SC did not result in protection of the RGCs in the glaucoma models used. These findings most likely relate to decreased neurotrophin responsiveness upon vector-mediated BDNF overexpression. Our results highlight important insights concerning the complexity of neurotrophic factor treatments that should surely be considered in

  6. Influence of brain-derived neurotrophic factor (BDNF) on serotonin neurotransmission in the hippocampus of adult rodents.

    Science.gov (United States)

    Benmansour, Saloua; Deltheil, Thierry; Piotrowski, Jonathan; Nicolas, Lorelei; Reperant, Christelle; Gardier, Alain M; Frazer, Alan; David, Denis J

    2008-06-10

    Whereas SSRIs produce rapid blockade of the serotonin transporter (SERT) in vitro and in vivo, the onset of an observable clinical effect takes longer to occur and a variety of pharmacological effects caused by antidepressants have been speculated to be involved either in initiating antidepressant effects and/or enhancing their effects on serotonergic transmission so as to cause clinical improvement. Among such secondary factors is increased activity of brain-derived neurotrophic factor (BDNF), which requires the Tropomyosine-related kinase B receptor (TrkB) for its effects. To begin an analysis of the influence of BDNF on serotonergic activity, we studied the acute effects of BDNF on SERT activity. A single BDNF injection (either intracerebroventricularly or directly into the CA3 region of hippocampus) decreased the signal amplitude and clearance rate produced by exogenously applied 5-HT compared to what was measured in control rats, shown using in vivo chronoamperometry. It also reduced the ability of a locally applied SSRI to block the clearance of 5-HT. In awake freely moving mice, acute intrahippocampal injection of BDNF decreased extracellular levels of 5-HT in the hippocampus, as measured using microdialysis. In addition, perfusion with BDNF decreased KCl-evoked elevations of 5-HT. These effects of BDNF were blocked by the non-selective antagonist of TrkB receptors, K252a. Overall, it may be inferred that in the hippocampus, through TrkB activation, a single injection of BDNF enhances SERT function. Such acute effects of BDNF would be expected to counter early effects of SSRIs, which might, in part, account for some delay in therapeutic effect.

  7. Postnatal BDNF Expression Profiles in Prefrontal Cortex and Hippocampus of a Rat Schizophrenia Model Induced by MK-801 Administration

    Directory of Open Access Journals (Sweden)

    Chunmei Guo

    2010-01-01

    Full Text Available Neonatal blockade of N-methyl-D-aspartic acid (NMDA receptors represents one of experimental animal models for schizophrenia. This study is to investigate the long-term brain-derived neurotrophic factor (BDNF expression profiles in different regions and correlation with “schizophrenia-like” behaviors in the adolescence and adult of this rat model. The NMDA receptor antagonist MK801 was administered to female Sprague-Dawley rats on postnatal days (PND 5 through 14. Open-field test was performed on PND 42, and PND 77 to examine the validity of the current model. BDNF protein levels in hippocampus and prefrontal cortex (PFC were analyzed on PND 15, PND 42, and PND 77. Results showed that neonatal challenge with MK-801 persistently elevated locomotor activity as well as BDNF expression; the alterations in BDNF expression varied at different developing stages and among brain regions. However, these findings provide neurochemical evidence that the blockade of NMDA receptors during brain development results in long-lasting alterations in BDNF expression and might contribute to neurobehavioral pathology of the present animal model for schizophrenia. Further study in the mechanisms and roles of the BDNF may lead to better understanding of the pathophysiology of schizophrenia.

  8. The Gut-Brain Axis, BDNF, NMDA and CNS Disorders.

    Science.gov (United States)

    Maqsood, Raeesah; Stone, Trevor W

    2016-11-01

    Gastro-intestinal (GI) microbiota and the 'gut-brain axis' are proving to be increasingly relevant to early brain development and the emergence of psychiatric disorders. This review focuses on the influence of the GI tract on Brain-Derived Neurotrophic Factor (BDNF) and its relationship with receptors for N-methyl-D-aspartate (NMDAR), as these are believed to be involved in synaptic plasticity and cognitive function. NMDAR may be associated with the development of schizophrenia and a range of other psychopathologies including neurodegenerative disorders, depression and dementias. An analysis of the routes and mechanisms by which the GI microbiota contribute to the pathophysiology of BDNF-induced NMDAR dysfunction could yield new insights relevant to developing novel therapeutics for schizophrenia and related disorders. In the absence of GI microbes, central BDNF levels are reduced and this inhibits the maintenance of NMDAR production. A reduction of NMDAR input onto GABA inhibitory interneurons causes disinhibition of glutamatergic output which disrupts the central signal-to-noise ratio and leads to aberrant synaptic behaviour and cognitive deficits. Gut microbiota can modulate BDNF function in the CNS, via changes in neurotransmitter function by affecting modulatory mechanisms such as the kynurenine pathway, or by changes in the availability and actions of short chain fatty acids (SCFAs) in the brain. Interrupting these cycles by inducing changes in the gut microbiota using probiotics, prebiotics or antimicrobial drugs has been found promising as a preventative or therapeutic measure to counteract behavioural deficits and these may be useful to supplement the actions of drugs in the treatment of CNS disorders.

  9. BDNF signaling and survival of striatal neurons

    Directory of Open Access Journals (Sweden)

    Maryna eBaydyuk

    2014-08-01

    Full Text Available The striatum, a major component of the basal ganglia, performs multiple functions including control of movement, reward, and addiction. Dysfunction and death of striatal neurons are the main causes for the motor disorders associated with Huntington’s disease (HD. Brain-derived neurotrophic factor (BDNF, a member of the neurotrophin family, is among factors that promote survival and proper function of this neuronal population. Here, we review recent studies showing that BDNF determines the size of the striatum by supporting survival of the immature striatal neurons at their origin, promotes maturation of striatal neurons, and facilitates establishment of striatal connections during brain development. We also examine the role of BDNF in maintaining proper function of the striatum during adulthood, summarize the mechanisms that lead to a deficiency in BDNF signaling and subsequently striatal degeneration in HD, and highlight a potential role of BDNF as a therapeutic target for HD treatment.

  10. Chronic caffeine prevents changes in inhibitory avoidance memory and hippocampal BDNF immunocontent in middle-aged rats.

    Science.gov (United States)

    Sallaberry, Cássia; Nunes, Fernanda; Costa, Marcelo S; Fioreze, Gabriela T; Ardais, Ana Paula; Botton, Paulo Henrique S; Klaudat, Bruno; Forte, Thomás; Souza, Diogo O; Elisabetsky, Elaine; Porciúncula, Lisiane O

    2013-01-01

    Beneficial effects of caffeine on memory processes have been observed in animal models relevant to neurodegenerative diseases and aging, although the underlying mechanisms remain unknown. Because brain-derived neurotrophic factor (BDNF) is associated with memory formation and BDNF's actions are modulated by adenosine receptors, the molecular targets for the psychostimulant actions of caffeine, we here compare the effects of chronic caffeine (1 mg/mL drinking solution for 30 days) on short- and long term memory and on levels of hippocampal proBDNF, mature BDNF, TrkB and CREB in young (3 month old) and middle-aged (12 month old) rats. Caffeine treatment substantially reduced i) age-related impairments in the two types of memory in an inhibitory avoidance paradigm, and ii) parallel increases in hippocampal BDNF levels. In addition, chronic caffeine increased proBDNF and CREB concentrations, and decreased TrkB levels, in hippocampus regardless of age. These data provide new evidence in favor of the hypothesis that modifications in BDNF and related proteins in the hippocampus contribute to the pro-cognitive effects of caffeine on age-associated losses in memory encoding. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

  11. Differential distribution of the expression of neuropeptides and calcium-binding proteins in the hippocampus of BDNF knock-out mice and the corresponding wild type brother and sister animals

    OpenAIRE

    Herrmann-Schwartzkopff, Katharina Helene

    2010-01-01

    Brain derived neurotrophic factor (BDNF) is well known for its positive effects on survival, development and differentiation of neurons in the central nervous system. It exerts its action through binding to its high (TrkB) and low (p75) affinity receptors. This work examines the expression of neuropeptides and calcium-binding proteins in the hippocampus of BDNF knockout mice (BDNF -/-) and their corresponding wild type littermates. With the use of highly specific antibodies the hippoca...

  12. Pgrmc1/BDNF Signaling Plays a Critical Role in Mediating Glia-Neuron Cross Talk.

    Science.gov (United States)

    Sun, Fen; Nguyen, Trinh; Jin, Xin; Huang, Renqi; Chen, Zhenglan; Cunningham, Rebecca L; Singh, Meharvan; Su, Chang

    2016-05-01

    Progesterone (P4) exerts robust cytoprotection in brain slice cultures (containing both neurons and glia), yet such protection is not as evident in neuron-enriched cultures, suggesting that glia may play an indispensable role in P4's neuroprotection. We previously reported that a membrane-associated P4 receptor, P4 receptor membrane component 1, mediates P4-induced brain-derived neurotrophic factor (BDNF) release from glia. Here, we sought to determine whether glia are required for P4's neuroprotection and whether glia's roles are mediated, at least partially, via releasing soluble factors to act on neighboring neurons. Our data demonstrate that P4 increased the level of mature BDNF (neuroprotective) while decreasing pro-BDNF (potentially neurotoxic) in the conditioned media (CMs) of cultured C6 astrocytes. We examined the effects of CMs derived from P4-treated astrocytes (P4-CMs) on 2 neuronal models: 1) all-trans retinoid acid-differentiated SH-SY5Y cells and 2) mouse primary hippocampal neurons. P4-CM increased synaptic marker expression and promoted neuronal survival against H2O2. These effects were attenuated by Y1036 (an inhibitor of neurotrophin receptor [tropomysin-related kinase] signaling), as well as tropomysin-related kinase B-IgG (a more specific inhibitor to block BDNF signaling), which pointed to BDNF as the key protective component within P4-CM. These findings suggest that P4 may exert its maximal protection by triggering a glia-neuron cross talk, in which P4 promotes mature BDNF release from glia to enhance synaptogenesis as well as survival of neurons. This recognition of the importance of glia in mediating P4's neuroprotection may also inform the design of effective therapeutic methods for treating diseases wherein neuronal death and/or synaptic deficits are noted.

  13. BDNF Signaling During Learning Is Regionally Differentiated Within Hippocampus

    OpenAIRE

    Chen, Lulu Y.; Rex, Christopher S.; Pham, Danielle T.; Lynch, Gary; Gall, Christine M.

    2010-01-01

    Learning-induced neurotrophic signaling at synapses is widely held to be critical for neuronal viability in adult brain. A previous study provided evidence that unsupervised learning of a novel environment is accompanied by activation of the TrkB receptor for Brain-Derived Neurotrophic Factor (BDNF) in hippocampal field CA1b of adult rats. Here we report that this effect is regionally differentiated, in accord with ‘engram’ type memory encoding. A 30-min exposure to a novel, complex environme...

  14. Altered balance of glutamatergic/GABAergic synaptic input and associated changes in dendrite morphology after BDNF expression in BDNF-deficient hippocampal neurons

    OpenAIRE

    Singh, B; Henneberger, C.; Betances, D.; Arevalo, M. A.; Rodriguez-Tebar, A.; Meier, J C; Grantyn, R.

    2006-01-01

    Cultured neurons from bdnf-/- mice display reduced densities of synaptic terminals, although in vivo these deficits are small or absent. Here we aimed at clarifying the local responses to postsynaptic brain-derived neurotrophic factor (BDNF). To this end, solitary enhanced green fluorescent protein (EGFP)-labeled hippocampal neurons from bdnf-/- mice were compared with bdnf-/- neurons after transfection with BDNF, bdnf-/- neurons after transient exposure to exogenous BDNF, and bdnf+/+ neurons...

  15. Convergent chaos

    Science.gov (United States)

    Pradas, Marc; Pumir, Alain; Huber, Greg; Wilkinson, Michael

    2017-07-01

    Chaos is widely understood as being a consequence of sensitive dependence upon initial conditions. This is the result of an instability in phase space, which separates trajectories exponentially. Here, we demonstrate that this criterion should be refined. Despite their overall intrinsic instability, trajectories may be very strongly convergent in phase space over extremely long periods, as revealed by our investigation of a simple chaotic system (a realistic model for small bodies in a turbulent flow). We establish that this strong convergence is a multi-facetted phenomenon, in which the clustering is intense, widespread and balanced by lacunarity of other regions. Power laws, indicative of scale-free features, characterize the distribution of particles in the system. We use large-deviation and extreme-value statistics to explain the effect. Our results show that the interpretation of the ‘butterfly effect’ needs to be carefully qualified. We argue that the combination of mixing and clustering processes makes our specific model relevant to understanding the evolution of simple organisms. Lastly, this notion of convergent chaos, which implies the existence of conditions for which uncertainties are unexpectedly small, may also be relevant to the valuation of insurance and futures contracts.

  16. Proteolytic Cleavage of ProBDNF into Mature BDNF in the Basolateral Amygdala Is Necessary for Defeat-Induced Social Avoidance

    Science.gov (United States)

    Dulka, Brooke N.; Ford, Ellen C.; Lee, Melissa A.; Donnell, Nathaniel J.; Goode, Travis D.; Prosser, Rebecca; Cooper, Matthew A.

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is essential for memory processes. The present study tested whether proteolytic cleavage of proBDNF into mature BDNF (mBDNF) within the basolateral amygdala (BLA) regulates the consolidation of defeat-related memories. We found that acute social defeat increases the expression of mBDNF, but not proBDNF, in…

  17. A Jacob/Nsmf Gene Knockout Results in Hippocampal Dysplasia and Impaired BDNF Signaling in Dendritogenesis.

    Directory of Open Access Journals (Sweden)

    Christina Spilker

    2016-03-01

    Full Text Available Jacob, the protein encoded by the Nsmf gene, is involved in synapto-nuclear signaling and docks an N-Methyl-D-Aspartate receptor (NMDAR-derived signalosome to nuclear target sites like the transcription factor cAMP-response-element-binding protein (CREB. Several reports indicate that mutations in NSMF are related to Kallmann syndrome (KS, a neurodevelopmental disorder characterized by idiopathic hypogonadotropic hypogonadism (IHH associated with anosmia or hyposmia. It has also been reported that a protein knockdown results in migration deficits of Gonadotropin-releasing hormone (GnRH positive neurons from the olfactory bulb to the hypothalamus during early neuronal development. Here we show that mice that are constitutively deficient for the Nsmf gene do not present phenotypic characteristics related to KS. Instead, these mice exhibit hippocampal dysplasia with a reduced number of synapses and simplification of dendrites, reduced hippocampal long-term potentiation (LTP at CA1 synapses and deficits in hippocampus-dependent learning. Brain-derived neurotrophic factor (BDNF activation of CREB-activated gene expression plays a documented role in hippocampal CA1 synapse and dendrite formation. We found that BDNF induces the nuclear translocation of Jacob in an NMDAR-dependent manner in early development, which results in increased phosphorylation of CREB and enhanced CREB-dependent Bdnf gene transcription. Nsmf knockout (ko mice show reduced hippocampal Bdnf mRNA and protein levels as well as reduced pCREB levels during dendritogenesis. Moreover, BDNF application can rescue the morphological deficits in hippocampal pyramidal neurons devoid of Jacob. Taken together, the data suggest that the absence of Jacob in early development interrupts a positive feedback loop between BDNF signaling, subsequent nuclear import of Jacob, activation of CREB and enhanced Bdnf gene transcription, ultimately leading to hippocampal dysplasia.

  18. Effect of Gold Belt on the BDNF and NMDA Receptor Expression and Behaviour Changes in Rats following Traumatic Spinal Cord Injury%金腰带治疗对大鼠损伤脊髓BDNF、NMDA受体表达及行为学的影响

    Institute of Scientific and Technical Information of China (English)

    许争光; 习阳彦斌; 杨峻; 吕志平; 孙艳华; 茹金; 李晓松; 刘江华; 但齐琴; 赵楠

    2012-01-01

    目的 研究中草药金腰带治疗对脊髓损伤(SCI)大鼠行为学、脑源性神经营养因子(BDNF)表达及N-甲基-D-门冬氨酸(NMDA)受体水平的影响.方法 SD成年雄性大鼠,随机分为假手术组、脊髓挫伤组(SCI组)、脊髓挫伤后金腰带治疗组[每日1次胃内灌服金腰带50mg/(kg·d),共7次].各组大鼠均在术后(0d、3d、10d、28 d)进行后肢行为学评价(BBB运动功能评分).术后13d,每组取8只大鼠麻醉后取损伤脊髓T10液氮中保存,采用[3 H]MK-801放射性配基分析法测定NMDA受体亲和力(Kd)和最大结合数量(Bmax);取术后28 d组大鼠损伤脊髓进行免疫组织化学染色,观察BDNF在脊髓的定位及表达变化.结果 BBB评分SCI组大鼠各时间点均低于假手术组(P均<0.05),而金腰带治疗组术后各时间点均高于SCI组(P均<0.05).SCI后13d,脊髓内NMDA受体Bmax较假手术组增高(P<0.05),金腰带组较SCI组减少(P<0.05);SCI后28 d损伤处脊髓腹角、背角BDNF阳性神经元数量较假手术组增加(P<0.05),金腰带治疗组BDNF阳性神经元数量较SCI组进一步增加(P<0.05).结论 金腰带治疗能有效改善SCI大鼠后肢运动功能,增加脊髓组织中BDNF的表达和通过影响脊髓NMDA受体减轻脊髓继发性损伤,对SCI有一定的治疗与保护作用.%Objective To study the effects of gold belt (GB), a Chinese Herbal, on behavioral changes and brain derived neutrophic factor (BDNF) expression and N-methyl-D-aspartic acid (NMDA) receptor level in rats subjected to spinal cord injury (SCI). Methods Adult male SD rats were randomly divided into three groups: ① Sham group; ②Spinal cord injury group (SCI group); ③Spinal cord injury followed with gold belt treatment (gold belt 50 mg/(kg · d), intragastric gavage once daily for 7 days) group (GB group). The Basso, Beattie and Bresnahan (BBB) locomotor scale method was performed to evaluate the hindlimb motor function in the days 0,3, 10 and 28. After

  19. Integral Characterization of Defective BDNF/TrkB Signalling in Neurological and Psychiatric Disorders Leads the Way to New Therapies

    Science.gov (United States)

    Tejeda, Gonzalo S.; Díaz-Guerra, Margarita

    2017-01-01

    Enhancement of brain-derived neurotrophic factor (BDNF) signalling has great potential in therapy for neurological and psychiatric disorders. This neurotrophin not only attenuates cell death but also promotes neuronal plasticity and function. However, an important challenge to this approach is the persistence of aberrant neurotrophic signalling due to a defective function of the BDNF high-affinity receptor, tropomyosin-related kinase B (TrkB), or downstream effectors. Such changes have been already described in several disorders, but their importance as pathological mechanisms has been frequently underestimated. This review highlights the relevance of an integrative characterization of aberrant BDNF/TrkB pathways for the rational design of therapies that by combining BDNF and TrkB targets could efficiently promote neurotrophic signalling. PMID:28134845

  20. BDNF mediates neuroprotection against oxygen-glucose deprivation by the cardiac glycoside oleandrin.

    Science.gov (United States)

    Van Kanegan, Michael J; He, Dong Ning; Dunn, Denise E; Yang, Peiying; Newman, Robert A; West, Anne E; Lo, Donald C

    2014-01-15

    We have previously shown that the botanical drug candidate PBI-05204, a supercritical CO2 extract of Nerium oleander, provides neuroprotection in both in vitro and in vivo brain slice-based models for focal ischemia (Dunn et al., 2011). Intriguingly, plasma levels of the neurotrophin BDNF were increased in patients treated with PBI-05204 in a phase I clinical trial (Bidyasar et al., 2009). We thus tested the hypothesis that neuroprotection provided by PBI-05204 to rat brain slices damaged by oxygen-glucose deprivation (OGD) is mediated by BDNF. We found, in fact, that exogenous BDNF protein itself is sufficient to protect brain slices against OGD, whereas downstream activation of TrkB receptors for BDNF is necessary for neuroprotection provided by PBI-05204, using three independent methods. Finally, we provide evidence that oleandrin, the principal cardiac glycoside component of PBI-05204, can quantitatively account for regulation of BDNF at both the protein and transcriptional levels. Together, these findings support further investigation of cardiac glycosides in providing neuroprotection in the context of ischemic stroke.

  1. BDNF Depresses Excitability of Parvalbumin-Positive Interneurons through an M-Like Current in Rat Dentate Gyrus.

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    Jose Luis Nieto-Gonzalez

    Full Text Available In addition to their classical roles in neuronal growth, survival and differentiation, neurotrophins are also rapid regulators of excitability, synaptic transmission and activity-dependent synaptic plasticity. We have recently shown that mature BDNF (Brain Derived Neurotrophic Factor, but not proBDNF, modulates the excitability of interneurons in dentate gyrus within minutes. Here, we used brain slice patch-clamp recordings to study the mechanisms through which BDNF modulates the firing of interneurons in rat dentate gyrus by binding to TrkB receptors. Bath application of BDNF (15 ng/ml under current-clamp decreased the firing frequency (by 80% and input resistance, blocking the delayed firing observed at near-threshold voltage ranges, with no changes in resting membrane potential or action potential waveform. Using TEA (tetraethylammonium, or XE991(a Kv7/KCNQ channel antagonist, the effect of BDNF was abolished, whereas application of retigabine (a Kv7/KCNQ channel opener mimicked the effect of BDNF, suggesting that the M-current could be implicated in the modulation of the firing. In voltage-clamp experiments, BDNF increased the M-like current amplitude with no change in holding current. This effect was again blocked by XE991 and mimicked by retigabine, the latter accompanied with a change in holding current. In agreement with the electrophysiology, parvalbumin-positive interneurons co-expressed TrkB receptors and Kv7.2/KCNQ2 channels. In conclusion, BDNF depresses the excitability of interneurons by activating an M-like current and possibly blocking Kv1 channels, thereby controlling interneuron resting membrane potential and excitability.

  2. BDNF Depresses Excitability of Parvalbumin-Positive Interneurons through an M-Like Current in Rat Dentate Gyrus.

    Science.gov (United States)

    Nieto-Gonzalez, Jose Luis; Jensen, Kimmo

    2013-01-01

    In addition to their classical roles in neuronal growth, survival and differentiation, neurotrophins are also rapid regulators of excitability, synaptic transmission and activity-dependent synaptic plasticity. We have recently shown that mature BDNF (Brain Derived Neurotrophic Factor), but not proBDNF, modulates the excitability of interneurons in dentate gyrus within minutes. Here, we used brain slice patch-clamp recordings to study the mechanisms through which BDNF modulates the firing of interneurons in rat dentate gyrus by binding to TrkB receptors. Bath application of BDNF (15 ng/ml) under current-clamp decreased the firing frequency (by 80%) and input resistance, blocking the delayed firing observed at near-threshold voltage ranges, with no changes in resting membrane potential or action potential waveform. Using TEA (tetraethylammonium), or XE991(a Kv7/KCNQ channel antagonist), the effect of BDNF was abolished, whereas application of retigabine (a Kv7/KCNQ channel opener) mimicked the effect of BDNF, suggesting that the M-current could be implicated in the modulation of the firing. In voltage-clamp experiments, BDNF increased the M-like current amplitude with no change in holding current. This effect was again blocked by XE991 and mimicked by retigabine, the latter accompanied with a change in holding current. In agreement with the electrophysiology, parvalbumin-positive interneurons co-expressed TrkB receptors and Kv7.2/KCNQ2 channels. In conclusion, BDNF depresses the excitability of interneurons by activating an M-like current and possibly blocking Kv1 channels, thereby controlling interneuron resting membrane potential and excitability.

  3. Estrogen receptor α functions in the regulation of motivation and spatial cognition in young male rats.

    Directory of Open Access Journals (Sweden)

    Katrin Meyer

    Full Text Available Estrogenic functions in regulating behavioral states such as motivation, mood, anxiety, and cognition are relatively well documented in female humans and animals. In males, however, although the entire enzymatic machinery for producing estradiol and the corresponding receptors are present, estrogenic functions have been largely neglected. Therefore, and as a follow-up study to previous research, we sub-chronically applied a specific estrogen receptor α (ERα antagonist in young male rats before and during a spatial learning task (holeboard. The male rats showed a dose-dependent increase in motivational, but not cognitive, behavior. The expression of hippocampal steroid receptor genes, such as glucocorticoid (GR, mineralocorticoid (MR, androgen (AR, and the estrogen receptor ERα but not ERβ was dose-dependently reduced. The expression of the aromatase but not the brain-derived neurotrophic factor (BDNF encoding gene was also suppressed. Reduced gene expression and increased behavioral performance converged at an antagonist concentration of 7.4 µmol. The hippocampal and blood serum hormone levels (corticosterone, testosterone, and 17β-estradiol did not differ between the experimental groups and controls. We conclude that steroid receptors (and BDNF act in a concerted, network-like manner to affect behavior and mutual gene expression. Therefore, the isolated view on single receptor types is probably insufficient to explain steroid effects on behavior. The steroid network may keep motivation in homeostasis by supporting and constraining the behavioral expression of motivation.

  4. Brain-derived neurotrophic factor (BDNF)-induced tropomyosin-related kinase B (Trk B) signaling is a potential therapeutic target for peritoneal carcinomatosis arising from colorectal cancer.

    Science.gov (United States)

    Tanaka, Koji; Okugawa, Yoshinaga; Toiyama, Yuji; Inoue, Yasuhiro; Saigusa, Susumu; Kawamura, Mikio; Araki, Toshimitsu; Uchida, Keiichi; Mohri, Yasuhiko; Kusunoki, Masato

    2014-01-01

    Tropomyosin-related receptor kinase B (TrkB) signaling, stimulated by brain-derived neurotrophic factor (BDNF) ligand, promotes tumor progression, and is related to the poor prognosis of various malignancies. We sought to examine the clinical relevance of BDNF/TrkB expression in colorectal cancer (CRC) tissues, its prognostic value for CRC patients, and its therapeutic potential in vitro and in vivo. Two hundred and twenty-three CRC patient specimens were used to determine both BDNF and TrkB mRNA levels. The expression of these proteins in their primary and metastatic tumors was investigated by immunohistochemistry. CRC cell lines and recombinant BDNF and K252a (a selective pharmacological pan-Trk inhibitor) were used for in vitro cell viability, migration, invasion, anoikis resistance and in vivo peritoneal metastasis assays. Tissue BDNF mRNA was associated with liver and peritoneal metastasis. Tissue TrkB mRNA was also associated with lymph node metastasis. The co-expression of BDNF and TrkB was associated with liver and peritoneal metastasis. Patients with higher BDNF, TrkB, and co-expression of BDNF and TrkB had a significantly poor prognosis. BDNF increased tumor cell viability, migration, invasion and inhibited anoikis in the TrkB-expressing CRC cell lines. These effects were suppressed by K252a. In mice injected with DLD1 co-expressing BDNF and TrkB, and subsequently treated with K252a, peritoneal metastatic nodules was found to be reduced, as compared with control mice. BDNF/TrkB signaling may thus be a potential target for treating peritoneal carcinomatosis arising from colorectal cancer.

  5. Brain-derived neurotrophic factor (BDNF) and its precursor (proBDNF) in genetically defined fear-induced aggression.

    Science.gov (United States)

    Ilchibaeva, Tatiana V; Kondaurova, Elena M; Tsybko, Anton S; Kozhemyakina, Rimma V; Popova, Nina K; Naumenko, Vladimir S

    2015-09-01

    The brain-derived neurotrophic factor (BDNF), its precursor (proBDNF) and BDNF mRNA levels were studied in the brain of wild rats selectively bred for more than 70 generations for either high level or for the lack of affective aggressiveness towards man. Significant increase of BDNF mRNA level in the frontal cortex and increase of BDNF level in the hippocampus of aggressive rats was revealed. In the midbrain and hippocampus of aggressive rats proBDNF level was increased, whereas BDNF/proBDNF ratio was reduced suggesting the prevalence and increased influence of proBDNF in highly aggressive rats. In the frontal cortex, proBDNF level in aggressive rats was decreased. Thus, considerable structure-specific differences in BDNF and proBDNF levels as well as in BDNF gene expression between highly aggressive and nonaggressive rats were shown. The data suggested the implication of BDNF and its precursor proBDNF in the mechanism of aggressiveness and in the creation of either aggressive or nonaggressive phenotype.

  6. Apoptosis signal-regulating kinase 1 is involved in brain-derived neurotrophic factor (BDNF)-enhanced cell motility and matrix metalloproteinase 1 expression in human chondrosarcoma cells.

    Science.gov (United States)

    Lin, Chih-Yang; Chang, Sunny Li-Yun; Fong, Yi-Chin; Hsu, Chin-Jung; Tang, Chih-Hsin

    2013-07-25

    Chondrosarcoma is the primary malignancy of bone that is characterized by a potent capacity to invade locally and cause distant metastasis, and is therefore associated with poor prognoses. Chondrosarcoma further shows a predilection for metastasis to the lungs. The brain-derived neurotrophic factor (BDNF) is a small molecule in the neurotrophin family of growth factors that is associated with the disease status and outcome of cancers. However, the effect of BDNF on cell motility in human chondrosarcoma cells is mostly unknown. Here, we found that human chondrosarcoma cell lines had significantly higher cell motility and BDNF expression compared to normal chondrocytes. We also found that BDNF increased cell motility and expression of matrix metalloproteinase-1 (MMP-1) in human chondrosarcoma cells. BDNF-mediated cell motility and MMP-1 up-regulation were attenuated by Trk inhibitor (K252a), ASK1 inhibitor (thioredoxin), JNK inhibitor (SP600125), and p38 inhibitor (SB203580). Furthermore, BDNF also promoted Sp1 activation. Our results indicate that BDNF enhances the migration and invasion activity of chondrosarcoma cells by increasing MMP-1 expression through a signal transduction pathway that involves the TrkB receptor, ASK1, JNK/p38, and Sp1. BDNF thus represents a promising new target for treating chondrosarcoma metastasis.

  7. Potentiation of Methylmercury-Induced Death in Rat Cerebellar Granular Neurons Occurs by Further Decrease of Total Intracellular GSH with BDNF via TrkB in Vitro.

    Science.gov (United States)

    Sakaue, Motoharu; Maki, Takehiro; Kaneko, Takuya; Hemmi, Natsuko; Sekiguchi, Hitomi; Horio, Tomoyo; Kadowaki, Erina; Ozawa, Aisa; Yamamoto, Masako

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is a principal factor for neurogenesis, neurodevelopment and neural survival through a BDNF receptor, tropomyosin-related kinase (Trk) B, while BDNF can also cause a decrease in the intracellular glutathione (GSH) level. We investigated the exacerbation of methylmercury-induced death of rat cerebellar granular neurons (CGNs) by BDNF in vitro. Since methylmercury can decrease intracellular GSH levels, we hypothesized that a further decrease of the intracellular GSH level is involved in the process of the exacerbation of neuronal cell death. In the present study, we established that in CGN culture, a decrease of the intracellular GSH level was further potentiated with BDNF in the process of the methylmercury-induced neuronal death and also in GSH reducer-induced neuronal death. BDNF treatment promoted the decrease in GSH levels induced by methylmercury and also by L-buthionine sulfoximine (BSO) and diethyl maleate (DEM). The promoting effect of BDNF was observed in a TrkB-vector transformant of the rat neuroblastoma B35 cell line but not in the mock-vector transformant. These results indicate that the exacerbating effect of BDNF on methylmercury-induced neuronal death in cultures of CGNs includes a further decrease of intracellular GSH levels, for which TrkB is essential.

  8. Interaction between serum BDNF and aerobic fitness predicts recognition memory in healthy young adults.

    Science.gov (United States)

    Whiteman, Andrew S; Young, Daniel E; He, Xuemei; Chen, Tai C; Wagenaar, Robert C; Stern, Chantal E; Schon, Karin

    2014-02-01

    Convergent evidence from human and non-human animal studies suggests aerobic exercise and increased aerobic capacity may be beneficial for brain health and cognition. It is thought growth factors may mediate this putative relationship, particularly by augmenting plasticity mechanisms in the hippocampus, a brain region critical for learning and memory. Among these factors, glucocorticoids, brain derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF), hormones that have considerable and diverse physiological importance, are thought to effect normal and exercise-induced hippocampal plasticity. Despite these predictions, relatively few published human studies have tested hypotheses that relate exercise and fitness to the hippocampus, and none have considered the potential links to all of these hormonal components. Here we present cross-sectional data from a study of recognition memory; serum BDNF, cortisol, IGF-1, and VEGF levels; and aerobic capacity in healthy young adults. We measured circulating levels of these hormones together with performance on a recognition memory task, and a standard graded treadmill test of aerobic fitness. Regression analyses demonstrated BDNF and aerobic fitness predict recognition memory in an interactive manner. In addition, IGF-1 was positively associated with aerobic fitness, but not with recognition memory. Our results may suggest an exercise adaptation-related change in the BDNF dose-response curve that relates to hippocampal memory.

  9. BDNF pro-peptide regulates dendritic spines via caspase-3.

    Science.gov (United States)

    Guo, J; Ji, Y; Ding, Y; Jiang, W; Sun, Y; Lu, B; Nagappan, G

    2016-06-16

    The precursor of brain-derived neurotrophic factor (BDNF) (proBDNF) is enzymatically cleaved, by either intracellular (furin/PC1) or extracellular proteases (tPA/plasmin/MMP), to generate mature BDNF (mBDNF) and its pro-peptide (BDNF pro-peptide). Little is known about the function of BDNF pro-peptide. We have developed an antibody that specifically detects cleaved BDNF pro-peptide, but not proBDNF or mBDNF. Neuronal depolarization elicited a marked increase in extracellular BDNF pro-peptide, suggesting activity-dependent regulation of its extracellular levels. Exposure of BDNF pro-peptide to mature hippocampal neurons in culture dramatically reduced dendritic spine density. This effect was mediated by caspase-3, as revealed by studies with pharmacological inhibitors and genetic knockdown. BDNF pro-peptide also increased the number of 'elongated' mitochondria and cytosolic cytochrome c, suggesting the involvement of mitochondrial-caspase-3 pathway. These results, along with BDNF pro-peptide effects recently reported on growth cones and long-term depression (LTD), suggest that BDNF pro-peptide is a negative regulator of neuronal structure and function.

  10. Multiple functions of precursor BDNF to CNS neurons: negative regulation of neurite growth, spine formation and cell survival

    OpenAIRE

    Koshimizu Hisatsugu; Kiyosue Kazuyuki; Hara Tomoko; Hazama Shunsuke; Suzuki Shingo; Uegaki Koichi; Nagappan Guhan; Zaitsev Eugene; Hirokawa Takatsugu; Tatsu Yoshiro; Ogura Akihiko; Lu Bai; Kojima Masami

    2009-01-01

    Abstract Background Proneurotrophins and mature neurotrophins elicit opposite effects via the p75 neurotrophin receptor (p75NTR) and Trk tyrosine kinase receptors, respectively; however the molecular roles of proneurotrophins in the CNS are not fully understood. Results Based on two rare single nucleotide polymorphisms (SNPs) of the human brain-derived neurotrophic factor (BDNF) gene, we generated R125M-, R127L- and R125M/R127L-BDNF, which have amino acid substitution(s) near the cleavage sit...

  11. Blocking GSK3β-mediated dynamin1 phosphorylation enhances BDNF-dependent TrkB endocytosis and the protective effects of BDNF in neuronal and mouse models of Alzheimer's disease.

    Science.gov (United States)

    Liu, Xiang-Hua; Geng, Zhao; Yan, Jing; Li, Ting; Chen, Qun; Zhang, Qun-Ye; Chen, Zhe-Yu

    2015-02-01

    Endocytosis of tropomyosin related kinase B (TrkB) receptors has critical roles in brain-derived neurotrophic factor (BDNF) mediated signal transduction and biological function, however the mechanism that is governing TrkB endocytosis is still not completely understood. In this study, we showed that GSK3β, a key kinase in neuronal development and survival, could regulate TrkB endocytosis through phosphorylating dynamin1 (Dyn1) but not dynamin2 (Dyn2). Moreover, we found that beta-amyloid (Aβ) oligomer exposure could impair BDNF-dependent TrkB endocytosis and Akt activation through enhancing GSK3β activity in cultured hippocampal neurons, which suggested that BDNF-induced TrkB endocytosis and the subsequent signaling were impaired in neuronal model of Alzheimer's disease (AD). Notably, we found that inhibiting GSK3β phosphorylating Dyn1 by using TAT-Dyn1SpS could rescue the impaired TrkB endocytosis and Akt activation upon BDNF stimuli under Aβ exposure. Finally, TAT-Dyn1SpS could facilitate BDNF-mediated neuronal survival and cognitive enhancement in mouse models of AD. These results clarified a role of GSK3β in BDNF-dependent TrkB endocytosis and the subsequent signaling, and provided a potential new strategy by inhibiting GSK3β-induced Dyn1 phosphorylation for AD treatment.

  12. BDNF up-regulates TrkB protein and prevents the death of CA1 neurons following transient forebrain ischemia.

    Science.gov (United States)

    Ferrer, I; Ballabriga, J; Martí, E; Pérez, E; Alberch, J; Arenas, E

    1998-04-01

    The neurotrophin family of growth factors, which includes Nerve Growth Factor (NGF), Brain-Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT3) and Neurotrophin-4/5 (NT4/5) bind and activate specific tyrosine kinase (Trk) receptors to promote cell survival and growth of different cell populations. For these reasons, growing attention has been paid to the use of neurotrophins as therapeutic agents in neurodegeneration, and to the regulation of the expression of their specific receptors by the ligands. BDNF expression, as revealed by immunohistochemistry, is found in the pre-subiculum, CA1, CA3, and dentate gyrus of the hippocampus. Strong TrkB immunoreactivity is present in most CA3 neurons but only in scattered neurons of the CA1 area. Weak TrkB immunoreactivity is found in the granule cell layer of the dentate gyrus. Unilateral grafting of BDNF-transfected fibroblasts into the hippocampus resulted in a marked increase in the intensity of the immunoreaction and in the number of TrkB-immunoreactive neurons in the granule cell layer of the dentate gyrus, pre-subiculum and CA1 area in the vicinity of the graft. No similar effects were produced after the injection of control mock-transfected fibroblasts. Delayed cell death in the CA1 area was produced following 5 min of forebrain ischemia in the gerbil. The majority of living cells in the CA1 area at the fourth day were BDNF/TrkB immunoreactive. Unilateral grafting of control mock-transfected or BDNF fibroblasts two days before ischemia resulted in a moderate non-specific protection of TrkB-negative, but not TrkB-positive cells, in the CA1 area of the grafted side. This finding is in line with a vascular and glial reaction, as revealed, by immunohistochemistry using astroglial and microglial cell markers. This astroglial response was higher in the grafted side than in the contralateral side in ischemic gerbils, but no differences were seen between BDNF-producing and non-BDNF-producing grafts. However, grafting of

  13. The Impact of Bdnf Gene Deficiency to the Memory Impairment and Brain Pathology of APPswe/PS1dE9 Mouse Model of Alzheimer’s Disease

    Science.gov (United States)

    Rantamäki, Tomi; Kemppainen, Susanna; Autio, Henri; Stavén, Saara; Koivisto, Hennariikka; Kojima, Masami; Antila, Hanna; Miettinen, Pasi O.; Kärkkäinen, Elisa; Karpova, Nina; Vesa, Liisa; Lindemann, Lothar; Hoener, Marius C.; Tanila, Heikki; Castrén, Eero

    2013-01-01

    Brain-derived neurotrophic factor (BDNF) importantly regulates learning and memory and supports the survival of injured neurons. Reduced BDNF levels have been detected in the brains of Alzheimer’s disease (AD) patients but the exact role of BDNF in the pathophysiology of the disorder remains obscure. We have recently shown that reduced signaling of BDNF receptor TrkB aggravates memory impairment in APPswe/PS1dE9 (APdE9) mice, a model of AD. The present study examined the influence of Bdnf gene deficiency (heterozygous knockout) on spatial learning, spontaneous exploratory activity and motor coordination/balance in middle-aged male and female APdE9 mice. We also studied brain BDNF protein levels in APdE9 mice in different ages showing progressive amyloid pathology. Both APdE9 and Bdnf mutations impaired spatial learning in males and showed a similar trend in females. Importantly, the effect was additive, so that double mutant mice performed the worst. However, APdE9 and Bdnf mutations influenced spontaneous locomotion in contrasting ways, such that locomotor hyperactivity observed in APdE9 mice was normalized by Bdnf deficiency. Obesity associated with Bdnf deficiency did not account for the reduced hyperactivity in double mutant mice. Bdnf deficiency did not alter amyloid plaque formation in APdE9 mice. Before plaque formation (3 months), BDNF protein levels where either reduced (female) or unaltered (male) in the APdE9 mouse cortex. Unexpectedly, this was followed by an age-dependent increase in mature BDNF protein. Bdnf mRNA and phospho-TrkB levels remained unaltered in the cortical tissue samples of middle-aged APdE9 mice. Immunohistological studies revealed increased BDNF immunoreactivity around amyloid plaques indicating that the plaques may sequester BDNF protein and prevent it from activating TrkB. If similar BDNF accumulation happens in human AD brains, it would suggest that functional BDNF levels in the AD brains are even lower than reported, which could

  14. NCAM-deficient mice show prominent abnormalities in serotonergic and BDNF systems in brain - Restoration by chronic amitriptyline.

    Science.gov (United States)

    Aonurm-Helm, Anu; Anier, Kaili; Zharkovsky, Tamara; Castrén, Eero; Rantamäki, Tomi; Stepanov, Vladimir; Järv, Jaak; Zharkovsky, Alexander

    2015-12-01

    Mood disorders are associated with alterations in serotonergic system, deficient BDNF (brain-derived neurotrophic factor) signaling and abnormal synaptic plasticity. Increased degradation and reduced functions of NCAM (neural cell adhesion molecule) have recently been associated with depression and NCAM deficient mice show depression-related behavior and impaired learning. The aim of the present study was to investigate potential changes in serotonergic and BDNF systems in NCAM knock-out mice. Serotonergic nerve fiber density and SERT (serotonin transporter) protein levels were robustly reduced in the hippocampus, prefrontal cortex and basolateral amygdala of adult NCAM(-)(/-) mice. This SERT reduction was already evident during early postnatal development. [(3)H]MADAM binding experiments further demonstrated reduced availability of SERT in cell membranes of NCAM(-)(/-) mice. Moreover, the levels of serotonin and its major metabolite 5-HIAA were down regulated in the brains of NCAM(-)(/-) mice. NCAM(-)(/-) mice also showed a dramatic reduction in the BDNF protein levels in the hippocampus and prefrontal cortex. This BDNF deficiency was associated with reduced phosphorylation of its receptor TrkB. Importantly, chronic administration of antidepressant amitriptyline partially or completely restored these changes in serotonergic and BDNF systems, respectively. In conclusion, NCAM deficiency lead to prominent and persistent abnormalities in brain serotonergic and BDNF systems, which likely contributes to the behavioral and neurobiological phenotype of NCAM(-/-) mice.

  15. Structural plasticity in mesencephalic dopaminergic neurons produced by drugs of abuse: critical role of BDNF and dopamine.

    Directory of Open Access Journals (Sweden)

    Ginetta eCollo

    2014-11-01

    Full Text Available Mesencephalic dopaminergic neurons were suggested to be a critical physiopathology substrate for addiction disorders. Among neuroadaptive processes to addictive drugs, structural plasticity has attracted attention. While structural plasticity occurs at both pre- and post-synaptic levels in the mesolimbic dopaminergic system, the present review focuses only on dopaminergic neurons. Exposures to addictive drugs determine two opposite structural responses, hypothrophic plasticity produced by opioids and cannabinoids (in particular during the early withdrawal phase and hypertrophic plasticity, mostly driven by psychostimulants and nicotine. In vitro and in vivo studies indentified BDNF and extracellular dopamine as two critical factors in determining structural plasticity, the two molecules sharing similar intracellular pathways involved in cell soma and dendrite growth, the MEK-ERK1/2 and the PI3K-Akt-mTOR, via preferential activation of TrkB and dopamine D3 receptors, respectively. At present information regarding specific structural changes associated to the various stages of the addiction cycle is incomplete. Encouraging neuroimaging data in humans indirectly support the preclinical evidence of hypotrophic and hypertrophic effects, suggesting a possible differential engagement of dopamine neurons in parallel and partially converging circuits controlling motivation, stress and emotions.

  16. RACK1 affects morphine reward via BDNF.

    Science.gov (United States)

    Wan, Lihong; Xie, Yizhou; Su, Lan; Liu, Yanyou; Wang, Yuhui; Wang, Zhengrong

    2011-10-06

    Chronic morphine addiction may trigger functional changes in the mesolimbic dopamine system, which is believed to be the neurobiological substrate of opiate addiction. Brain derived neurotrophic factor (BDNF) has been implicated in addiction-related pathology in animal studies. Our previous studies have shown that RACK1 is involved in morphine reward in mice. The recent research indicates nuclear RACK1 by localizing at the promoter IV region of the BDNF gene and the subsequent chromatin modifications leads to the activation of the promoter and transcription of BDNF. The present study was designed to investigate if shRACK1 (a short hairpin RNA of RACK1) could reverse the mice's behavioral responses to morphine and BDNF expression in hippocampus and prefrontal cortex. No significant changes were observed in vehicle-infused mice which received no morphine treatment (CONC) and shRACK1-infused mice which received no morphine treatment (CONR), whereas vehicle-infused mice preceded the morphine injection (MIC) showed increased BDNF expression in hippocampus and prefrontal cortex, as compared to vehicle-infused mice which received no morphine treatment (CONC). Intracerebroventricular shRACK1 treatment reversed these, and in fact, ShRACK1-infused mice preceded the morphine injection (MIR) showed reduced BDNF expression in hippocampus and prefrontal cortex, as compared to MIC. In the conditioned place preference (CPP) test, inactivating RACK1 markedly reduces morphine-induced conditioned place preference. Non-specific changes in CPP could not account for these effects since general CPP of shRACK1- and vehicle-infused animals was not different. Combined behavioral and molecular approaches have support the possibility that the RACK1-BDNF system plays an important role in the response to morphine-induced reward.

  17. EPO protects Müller cell under high glucose state through BDNF/TrkB pathway.

    Science.gov (United States)

    Wang, Ping; Xia, Fei

    2015-01-01

    Neurotrophic factor decreased in the early stage of diabetic retinal nerve cells. Neurons damage brain derived neurotrophic factor (BDNF) and receptor TrkB expression reduced. Erythropoietin (EPO) plays an important role in protecting early diabetic retinopathy. The rats were euthanized at 24 h after EPO vitreous injection and the retina was separated. HE staining was applied to observe the pathological tissue morphology. Immunohistochemistry, immunofluorescence, and Western blot were used to detect BDNF, TrkB, extracellular signal-regulated kinase (ERK), and glial fibrillary acidic portein (GFAP) expression. Retinal structure was clear in group C, while the retinal thickness and RGCs number decreased in group B at 24 w. Retinal thickness in group E was greater than in group B but lower than in group C. GFAP and ERK expression increased in both group B and E, whereas the latter was significantly lower than the former. TrkB protein level was in group E > B > C at 4 w, while it was in group C > group E > group B at 24 w. BDNF expression in group B was higher than in group C at 4 w, whereas it was opposite at 24 w. BDNF expression increased in group E at 4 w, and it was similar in group E compared with group C at 24 w. EPO vitreous injection can increase BDNF and TrkB expression, while reduce GFAP and ERK expression in diabetes rat retina. It could protect Müller cells through BDNF/TrkB pathway to play a role of nerve nutrition.

  18. Regulation of BDNF and trkB mRNA in rat brain by chronic electroconvulsive seizure and antidepressant drug treatments.

    Science.gov (United States)

    Nibuya, M; Morinobu, S; Duman, R S

    1995-11-01

    The influence of chronic electroconvulsive seizure (ECS) or antidepressant drug treatments on expression of brain-derived neurotrophic factor (BDNF) and its receptor, trkB, was examined by in situ hybridization and Northern blot. In frontal cortex, acute ECS increased BDNF mRNA approximately twofold, an effect significantly augmented by a prior course of chronic ECS treatment (10 d). In the hippocampus, the influence of chronic ECS varied between the major subfields. In the dentate gyrus granule cell layer, chronic ECS decreased the acute induction of BDNF and trkB mRNA by approximately 50%, but prolonged their expression: levels remained elevated two- to threefold 18 hr later after the last chronic ECS treatment, but returned to control 18 hr after acute ECS. In CA3 and CA1 pyramidal cell layers, chronic ECS significantly elevated the acute induction of BDNF, and tended to prolong the expression of BDNF and trkB mRNA. A similar effect was observed in layer 2 of the piriform cortex, where chronic ECS significantly increased the acute induction and prolonged the expression of BDNF and trkB mRNA. Chronic (21 d), but not acute (1 d), administration of several different antidepressant drugs, including tranylcypromine, sertraline, desipramine, or mianserin, significantly increased BDNF mRNA and all but mianserin increased trkB mRNA in hippocampus. In contrast, chronic administration of nonantidepressant psychotropic drugs, including morphine, cocaine, or haloperidol, did not increase levels of BDNF mRNA. Furthermore, chronic administration of ECS or antidepressant drugs completely blocked the down-regulation of BDNF mRNA in the hippocampus in response to restraint stress. The enhanced induction and prolonged expression of BDNF in response to chronic ECS and antidepressant drug treatments could promote neuronal survival, and protect neurons from the damaging effects of stress.

  19. BDNF regulates spontaneous correlated activity at early developmental stages by increasing synaptogenesis and expression of the K+/Cl- co-transporter KCC2.

    Science.gov (United States)

    Aguado, Fernando; Carmona, Maria A; Pozas, Esther; Aguiló, Agustín; Martínez-Guijarro, Francisco J; Alcantara, Soledad; Borrell, Victor; Yuste, Rafael; Ibañez, Carlos F; Soriano, Eduardo

    2003-04-01

    Spontaneous neural activity is a basic property of the developing brain, which regulates key developmental processes, including migration, neural differentiation and formation and refinement of connections. The mechanisms regulating spontaneous activity are not known. By using transgenic embryos that overexpress BDNF under the control of the nestin promoter, we show here that BDNF controls the emergence and robustness of spontaneous activity in embryonic hippocampal slices. Further, BDNF dramatically increases spontaneous co-active network activity, which is believed to synchronize gene expression and synaptogenesis in vast numbers of neurons. In fact, BDNF raises the spontaneous activity of E18 hippocampal neurons to levels that are typical of postnatal slices. We also show that BDNF overexpression increases the number of synapses at much earlier stages (E18) than those reported previously. Most of these synapses were GABAergic, and GABAergic interneurons showed hypertrophy and a 3-fold increase in GAD expression. Interestingly, whereas BDNF does not alter the expression of GABA and glutamate ionotropic receptors, it does raise the expression of the recently cloned K(+)/Cl(-) KCC2 co-transporter, which is responsible for the conversion of GABA responses from depolarizing to inhibitory, through the control of the Cl(-) potential. Together, results indicate that both the presynaptic and postsynaptic machineries of GABAergic circuits may be essential targets of BDNF actions to control spontaneous activity. The data indicate that BDNF is a potent regulator of spontaneous activity and co-active networks, which is a new level of regulation of neurotrophins. Given that BDNF itself is regulated by neuronal activity, we suggest that BDNF acts as a homeostatic factor controlling the emergence, complexity and networking properties of spontaneous networks.

  20. BDNF mediated TrkB activation contributes to the EMT progression and the poor prognosis in human salivary adenoid cystic carcinoma.

    Science.gov (United States)

    Jia, Sen; Wang, Weixi; Hu, Zhiqiang; Shan, Chun; Wang, Lei; Wu, Baolei; Yang, Zihui; Yang, Xinjie; Lei, Delin

    2015-01-01

    The aim of the present study was to investigate whether the expression of Brain-Derived Neurotrophic Factor (BDNF) and its receptor Tropomyosin-related kinase B (TrkB) is correlated with the clinical progression of salivary adenoid cystic carcinoma (SACC) and whether the BDNF/TrkB axis is associated with the induction of epithelial-mesenchymal transition (EMT) in SACC cells. The expression of BDNF, TrkB, and E-cadherin (an EMT biomarker) in 76 primary SACC specimens and 20 normal salivary gland tissues was analyzed by immunohistochemistry. Additionally, the expression of BDNF, TrkB, and E-cadherin in SACC cell lines (SACC-83 and SACC-LM) was analyzed by RT-PCR and Western blotting. The biological role of the BDNF/TrkB axis in the EMT progression of SACC was evaluated after treatment with increased levels of BDNF and by inhibiting TrkB activity in SACC-83 cell line. The progression of SACC cells through EMT was assessed by RT-PCR, Western blotting, photography, migration and invasion assays. Elevated expression of TrkB (92.1%) and BDNF (89.5%), and downregulated expression of E-cadherin (47.4%) was found in SACC specimens, which was significantly correlated with the invasion and metastasis in SACC (PEMT in SACC cells. While obstruction of TrkB by its inhibitor, k252a (100 nM), significantly inhibited the EMT progression of SACC cells. These results suggest that BDNF-mediated TrkB activation contributes to the EMT progression and the poor prognosis in SACC. The present study demonstrated that the BDNF/TrkB axis promotes the migration and invasion of SACC cells via EMT in vitro. Targeting the inactivation of the BDNF/TrkB axis may be a potential strategy for the treatment of SACC. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Modulation of BDNF and TrkB expression in rat hippocampus in response to acute neurotoxicity by diethyldithiocarbamate.

    Science.gov (United States)

    Micheli, M R; Bova, R; Laurenzi, M A; Bazzucchi, M; Grassi Zucconi, G

    2006-12-13

    In this study, we examined the expression profile of brain-derived neurotrophic factor (BDNF) and its receptor TrkB in adult rat hippocampus following acute administration of diethyldithiocarbamate (DDTC), a neurotoxic compound which was previously shown to induce microglia activation and cell death. Semiquantitative RT-PCR analysis detected significant variations of BDNF mRNA levels in whole hippocampus homogenates, with a peak at 24h after DDTC injection. Increased BDNF protein expression was demonstrated by immunohistochemistry in various hippocampal subfields. The most relevant increase was observed in the hilus of the dentate gyrus where BDNF levels at 120h were found to be almost four times those of basal levels. Full-length TrkB (TrkB.FL) encoding mRNA was also shown to undergo an earlier increase in the hippocampus of DDTC-treated rats. TrkB immunostaining with an antibody binding both full-length and truncated (TrkB.T) isoforms was found to increase at 120h in the hippocampal CA2 and CA3 regions. These results demonstrate that DDTC modulates the expression of BDNF and its receptor in the adult rat hippocampus and suggest a possible involvement of this neurotrophin in the protective response to DDTC-induced neuronal damage.

  2. The BDNF Val66Met polymorphism and smoking

    NARCIS (Netherlands)

    Montag, C.; Basten, U.; Stelzel, C.; Fiebach, C.J.; Reuter, M.

    2008-01-01

    Although the brain derived neurotrophic factor (BDNF) has been mainly investigated in the context of depression and anxiety disorders, several studies also suggest an association between BDNF and smoking. BDNF represents a protein which crucially influences several processes in the cell ranging from

  3. BDNF control of adult SVZ neurogenesis.

    Science.gov (United States)

    Bath, Kevin G; Akins, Michael R; Lee, Francis S

    2012-09-01

    The sensory processing of odorants is a dynamic process that requires plasticity at multiple levels. In the olfactory bulb (OB), inhibitory interneurons undergo lifelong replacement through a process known as adult neurogenesis. These newly born cells are incorporated in a learning-dependent fashion, a process which has led some to suggest this as a primary mechanism through which the OB retains a high degree of plasticity throughout life. A continued focus of researchers in this field has been to understand the molecular mechanisms controlling adult subventricular zone (SVZ) neurogenesis and the innate functional role of these cells. Brain-derived neurotrophic factor (BDNF) has been identified as a strong candidate molecule regulating adult OB neurogenesis. We review what is known regarding the functional role of newly born cells, highlight the role of BDNF in this process, and describe preliminary findings from our lab implicating BDNF in the process of selecting of newly born cells for survival.

  4. Acute stress alters transcript expression pattern and reduces processing of proBDNF to mature BDNF in Dicentrarchus labrax

    Directory of Open Access Journals (Sweden)

    Saroglia Marco

    2010-01-01

    Full Text Available Abstract Background Stress involves alterations of brain functioning that may precipitate to mood disorders. The neurotrophin Brain Derived Neurotrophic Factor (BDNF has recently been involved in stress-induced adaptation. BDNF is a key regulator of neuronal plasticity and adaptive processes. Regulation of BDNF is complex and may reflect not only stress-specific mechanisms but also hormonal and emotional responses. For this reason we used, as an animal model of stress, a fish whose brain organization is very similar to that of higher vertebrates, but is generally considered free of emotional reactions. Results We provide a comprehensive characterization of BDNF gene in the Dicentrarchus labrax and its transcriptional, translational and post-translational regulation following acute stress. While total BDNF mRNA levels are unchanged, BDNF transcripts 1c and 1d resulted down regulated after acute stress. Acute stress induces also a significant increase in proBDNF levels and reduction in mature BDNF suggesting altered regulation of proBDNF proteolytic processing. Notably, we provide here the first evidence that fishes possess a simplified proteolytic regulation of BDNF since the pro28Kda form, generated by the SKI-1 protease in mammals, is absent in fishes because the cleavage site has first emerged in reptilians. Finally, we show that the proBDNF/totBDNF ratio is a highly predictive novel quantitative biomarker to detect stress in fishes with sensitivity = 100%, specificity = 87%, and Negative Predictive Value = 100%. Conclusion The high predictivity of proBDNF/totBDNF ratio for stress in lower vertebrates indicates that processing of BDNF is a central mechanism in adaptation to stress and predicts that a similar regulation of pro/mature BDNF has likely been conserved throughout evolution of vertebrates from fish to man.

  5. Advances in the research of BDNF with cerebral ischemia%脑源性神经营养因子与脑缺血的研究进展

    Institute of Scientific and Technical Information of China (English)

    付美红; 李海涛

    2012-01-01

    脑源性神经营养因子(brain derived neurotrophic factor,BDNF)是在脑内形成的一类神经营养因子.BDNF通过作用于其特异性受体TrkB、P75促进神经元的生长发育同时修复受损的神经元.BDNF对缺血性脑损伤的保护机制是通过下调钙离子浓度,减小Bax/Bcl-2比值,对抗NO毒性等途径实现的.该文介绍了BDNF的基本作用及其与脑缺血的相关作用研究,综述了BDNF的应用方法研究.%Brain derived neurotrophic factor ( BDNF ) is a class of neurotrophic factor formed within the brain. BDNF promotes the growth and development of the neurons and repair the damaged neurons acting on its specific receptors TrkB and P75. BDNF plays a key role in ischemic damage protection mainly by eliminating oxygen-derived free radicals, reducing Bax/Bcl-2 ratio, regulating the low levels of ca2 + and against NO toxicity as well. This paper introduces the basic function of BDNF and the related research of BDNF on ischemic damage. The article reviews the research of the application methods of BDNF.

  6. CREB-Dependent Regulation of GAD65 Transcription by BDNF/TrkB in Cortical Interneurons.

    Science.gov (United States)

    Sánchez-Huertas, Carlos; Rico, Beatriz

    2011-04-01

    In the cerebral cortex, the functional output of projection neurons is fine-tuned by inhibitory neurons present in the network, which use γ-aminobutyric acid (GABA) as their main neurotransmitter. Previous studies have suggested that the expression levels of the rate-limiting GABA synthetic enzyme, GAD65, depend on brain derived neurotrophic factor (BDNF)/TrkB activation. However, the molecular mechanisms by which this neurotrophic factor and its receptor controls GABA synthesis are still unknown. Here, we show a direct regulation of the GAD65 gene by BDNF-TrkB signaling via CREB in cortical interneurons. Conditional ablation of TrkB in cortical interneurons causes a cell-autonomous decrease in the synaptically enriched GAD65 protein and its transcripts levels, suggesting that transcriptional regulation of the GAD65 gene is altered. Dissection of the intracellular pathway that underlies this process revealed that BDNF/TrkB signaling controls the transcription of GAD65 in a Ras-ERK-CREB-dependent manner. Our study reveals a novel molecular mechanism through which BDNF/TrkB signaling may modulate the maturation and function of cortical inhibitory circuits.

  7. High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling.

    Directory of Open Access Journals (Sweden)

    Yang Yang

    Full Text Available Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose, 60 ppm Zn (high dose or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit.

  8. High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling.

    Science.gov (United States)

    Yang, Yang; Jing, Xiao-Peng; Zhang, Shou-Peng; Gu, Run-Xia; Tang, Fang-Xu; Wang, Xiu-Lian; Xiong, Yan; Qiu, Mei; Sun, Xu-Ying; Ke, Dan; Wang, Jian-Zhi; Liu, Rong

    2013-01-01

    Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose), 60 ppm Zn (high dose) or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit.

  9. 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.

  10. Activity-dependent BDNF release and TRPC signaling is impaired in hippocampal neurons of Mecp2 mutant mice.

    Science.gov (United States)

    Li, Wei; Calfa, Gaston; Larimore, Jennifer; Pozzo-Miller, Lucas

    2012-10-16

    Dysfunction of the neurotrophin brain-derived neurotrophic factor (BDNF) is implicated in Rett syndrome (RTT), but the state of its releasable pool and downstream signaling in mice lacking methyl-CpG-binding protein-2 (Mecp2) is unknown. Here, we show that membrane currents and dendritic Ca(2+) signals evoked by recombinant BDNF or an activator of diacylglycerol (DAG)-sensitive transient receptor potential canonical (TRPC) channels are impaired in CA3 pyramidal neurons of symptomatic Mecp2 mutant mice. TRPC3 and TRPC6 mRNA and protein levels are lower in Mecp2 mutant hippocampus, and chromatin immunoprecipitation (ChIP) identified Trpc3 as a target of MeCP2 transcriptional regulation. BDNF mRNA and protein levels are also lower in Mecp2 mutant hippocampus and dentate gyrus granule cells, which is reflected in impaired activity-dependent release of endogenous BDNF estimated from TRPC currents and dendritic Ca(2+) signals in CA3 pyramidal neurons. These results identify the gene encoding TRPC3 channels as a MeCP2 target and suggest a potential therapeutic strategy to boost impaired BDNF signaling in RTT.

  11. Brain-derived neurotrophic factor (BDNF) enhances GABA transport by modulating the trafficking of GABA transporter-1 (GAT-1) from the plasma membrane of rat cortical astrocytes.

    Science.gov (United States)

    Vaz, Sandra H; Jørgensen, Trine N; Cristóvão-Ferreira, Sofia; Duflot, Sylvie; Ribeiro, Joaquim A; Gether, Ulrik; Sebastião, Ana M

    2011-11-25

    The γ-aminobutyric acid (GABA) transporters (GATs) are located in the plasma membrane of neurons and astrocytes and are responsible for termination of GABAergic transmission. It has previously been shown that brain derived neurotrophic factor (BDNF) modulates GAT-1-mediated GABA transport in nerve terminals and neuronal cultures. We now report that BDNF enhances GAT-1-mediated GABA transport in cultured astrocytes, an effect mostly due to an increase in the V(max) kinetic constant. This action involves the truncated form of the TrkB receptor (TrkB-t) coupled to a non-classic PLC-γ/PKC-δ and ERK/MAPK pathway and requires active adenosine A(2A) receptors. Transport through GAT-3 is not affected by BDNF. To elucidate if BDNF affects trafficking of GAT-1 in astrocytes, we generated and infected astrocytes with a functional mutant of the rat GAT-1 (rGAT-1) in which the hemagglutinin (HA) epitope was incorporated into the second extracellular loop. An increase in plasma membrane of HA-rGAT-1 as well as of rGAT-1 was observed when both HA-GAT-1-transduced astrocytes and rGAT-1-overexpressing astrocytes were treated with BDNF. The effect of BDNF results from inhibition of dynamin/clathrin-dependent constitutive internalization of GAT-1 rather than from facilitation of the monensin-sensitive recycling of GAT-1 molecules back to the plasma membrane. We therefore conclude that BDNF enhances the time span of GAT-1 molecules at the plasma membrane of astrocytes. BDNF may thus play an active role in the clearance of GABA from synaptic and extrasynaptic sites and in this way influence neuronal excitability.

  12. Brain-derived neurotrophic factor signaling rewrites the glucocorticoid transcriptome via glucocorticoid receptor phosphorylation.

    Science.gov (United States)

    Lambert, W Marcus; Xu, Chong-Feng; Neubert, Thomas A; Chao, Moses V; Garabedian, Michael J; Jeanneteau, Freddy D

    2013-09-01

    Abnormal glucocorticoid and neurotrophin signaling has been implicated in numerous psychiatric disorders. However, the impact of neurotrophic signaling on glucocorticoid receptor (GR)-dependent gene expression is not understood. We therefore examined the impact of brain-derived neurotrophic factor (BDNF) signaling on GR transcriptional regulatory function by gene expression profiling in primary rat cortical neurons stimulated with the selective GR agonist dexamethasone (Dex) and BDNF, alone or in combination. Simultaneous treatment with BDNF and Dex elicited a unique set of GR-responsive genes associated with neuronal growth and differentiation and also enhanced the induction of a large number of Dex-sensitive genes. BDNF via its receptor TrkB enhanced the transcriptional activity of a synthetic GR reporter, suggesting a direct effect of BDNF signaling on GR function. Indeed, BDNF treatment induces the phosphorylation of GR at serine 155 (S155) and serine 287 (S287). Expression of a nonphosphorylatable mutant (GR S155A/S287A) impaired the induction of a subset of BDNF- and Dex-regulated genes. Mechanistically, BDNF-induced GR phosphorylation increased GR occupancy and cofactor recruitment at the promoter of a BDNF-enhanced gene. GR phosphorylation in vivo is sensitive to changes in the levels of BDNF and TrkB as well as stress. Therefore, BDNF signaling specifies and amplifies the GR transcriptome through a coordinated GR phosphorylation-dependent detection mechanism.

  13. Osthole Upregulates BDNF to Enhance Adult Hippocampal Neurogenesis in APP/PS1 Transgenic Mice.

    Science.gov (United States)

    Liu, Hong; Xue, Xinhong; Shi, Huijian; Qi, Lifeng; Gong, Dianrong

    2015-01-01

    Adult hippocampal neurogenesis occurs in the dentate gyrus (DG) of the mouse hippocampus, and plays roles in learning and memory progresses. In amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic mice, a rodent model of Alzheimer's disease (AD), severe impairment of neurogenesis in the dentate subgranular zone (SGZ) of the DG has been reported. Osthole, an active constituent of Cnidium monnieri (L.) CUSSON, has been reported to exert neuroprotective effects and may promote neural stem cell proliferation. However, whether osthole ameliorates spatial memory deficits and improves hippocampal neurogenesis in APP/PS1 mice remains unknown. In this study we found that osthole (30 mg/kg intraperitoneally (i.p.) once daily) treatment dramatically ameliorated the cognitive impairments by Morris Water Maze test and passive avoidance test, and augmented neurogenesis in the DG of hippocampus in APP/PS1 mice. Furthermore, osthole treatment upregulated expression of brain-derived neurotrophic factor (BDNF) and enhanced activation of the BDNF receptor tyrosine receptor kinase B (TrkB) following increased phosphorylation of cyclic AMP response element-binding protein (CREB), indicating that osthole improves neurogenesis via stimulating BDNF/TrkB/CREB signaling in APP/PS1 transgenic mice.

  14. FTY720/Fingolimod Reduces Synucleinopathy and Improves Gut Motility in A53T Mice: CONTRIBUTIONS OF PRO-BRAIN-DERIVED NEUROTROPHIC FACTOR (PRO-BDNF) AND MATURE BDNF.

    Science.gov (United States)

    Vidal-Martínez, Guadalupe; Vargas-Medrano, Javier; Gil-Tommee, Carolina; Medina, David; Garza, Nathan T; Yang, Barbara; Segura-Ulate, Ismael; Dominguez, Samantha J; Perez, Ruth G

    2016-09-23

    Patients with Parkinson's disease (PD) often have aggregated α-synuclein (aSyn) in enteric nervous system (ENS) neurons, which may be associated with the development of constipation. This occurs well before the onset of classic PD motor symptoms. We previously found that aging A53T transgenic (Tg) mice closely model PD-like ENS aSyn pathology, making them appropriate for testing potential PD therapies. Here we show that Tg mice overexpressing mutant human aSyn develop ENS pathology by 4 months. We then evaluated the responses of Tg mice and their WT littermates to the Food and Drug Administration-approved drug FTY720 (fingolimod, Gilenya) or vehicle control solution from 5 months of age. Long term oral FTY720 in Tg mice reduced ENS aSyn aggregation and constipation, enhanced gut motility, and increased levels of brain-derived neurotrophic factor (BDNF) but produced no significant change in WT littermates. A role for BDNF was directly assessed in a cohort of young A53T mice given vehicle, FTY720, the Trk-B receptor inhibitor ANA-12, or FTY720 + ANA-12 from 1 to 4 months of age. ANA-12-treated Tg mice developed more gut aSyn aggregation as well as constipation, whereas FTY720-treated Tg mice had reduced aSyn aggregation and less constipation, occurring in part by increasing both pro-BDNF and mature BDNF levels. The data from young and old Tg mice revealed FTY720-associated neuroprotection and reduced aSyn pathology, suggesting that FTY720 may also benefit PD patients and others with synucleinopathy. Another finding was a loss of tyrosine hydroxylase immunoreactivity in gut neurons with aggregated aSyn, comparable with our prior findings in the CNS.

  15. Contribution of BDNF/TrkB pathway to development of neuropathic pain by activation of astrocytes in rats%BDNF/TrkB通路活化星形胶质细胞对大鼠神经病理性痛的影响

    Institute of Scientific and Technical Information of China (English)

    汪静; 张昕; 江伟; 杜冬萍

    2012-01-01

    目的 观察外源性脑源性神经营养因子(BDNF)对大鼠机械痛阈和星形胶质细胞的影响,探讨BDNF参与疼痛调控的可能机制.方法 将30只鞘内置管成功的大鼠随机分为空白对照组、安慰剂组、BDNF组、BDNF+星形胶质细胞抑制剂组(BDNF+氟代柠檬酸组)及BDNF+酪氨酸激酶受体B(TrkB)抑制剂组(BDNF+ K252a组),每组6只.予鞘内注入药物,1次/d×7 d.每次注药前1h测定50%机械缩爪阈值(50% PWT);末次给药后1h取脊髓腰膨大,Western blotting法测定胶质细胞纤丝酸性蛋白(GFAP)及磷酸化TrkB的蛋白表达.结果 BDNF组大鼠后肢50% PWT较空白对照组显著下降(P<0.05);给药后第7天,BDNF组大鼠脊髓腰膨大GFAP和磷酸化TrkB的蛋白表达较空白对照组显著升高(P<0.01).BDNF+氟代柠檬酸组和BDNF+K252a组50% PWT和GFAP蛋白表达水平与空白对照组比较,差异无统计学意义(P>0.05).BDNF+ K252a组磷酸化TrkB的蛋白表达与空白对照组比较,差异无统计学意义(P>0.05).结论 BDNF可能通过磷酸化TrkB受体使脊髓星形胶质细胞活化,进而参与神经病理性痛的发生和发展过程.%Objective To investigate the effects of exogenous brain-derived neurotrophic factor ( BDNF) on mechanical pain threshold and astrocytes, and explore the potential mechanism of BDNF-induced pain. Methods Thirty rats with successful intrathecal catheterization were randomly divided into blank control group, placebo group, BDNF group, BDNF + astrocyte inhibitor group ( BDNF + fluorocitrate group) and BDNF + tyrosine kinase receptor B( TrkB) inhibitor group ( BDNF + K252a group), with 6 rats in each group. Intrathecal administration was performed once daily for 7 d. Fifty percent paw withdrawal threshold (50% PWT) was measured 1 h before each injection. Spinal enlargement parts were obtained 1 h after the last administration, and the expression of glial fibrillary acidic protein ( GFAP) and phosphorylated TrkB protein was

  16. Strong path convergence from Loewner driving convergence

    CERN Document Server

    Sheffield, Scott

    2010-01-01

    We show that, under mild assumptions on the limiting curve, a sequence of simple chordal planar curves converges uniformly whenever certain Loewner driving functions converge. We extend this result to random curves. The random version applies in particular to random lattice paths that have chordal SLE as a scaling limit, with kappa less than 8 (non-space-filling). Existing SLE convergence proofs often begin by showing that the Loewner driving functions of these paths (viewed from infinity) converge to Brownian motion. Unfortunately, this is not sufficient, and additional arguments are required to complete the proofs. We show that driving function convergence is sufficient if it can be established for both parametrization directions and a generic target.

  17. Persistent neural activity in the prefrontal cortex: a mechanism by which BDNF regulates working memory?

    Science.gov (United States)

    Galloway, Evan M; Woo, Newton H; Lu, Bai

    2008-01-01

    Working memory is the ability to maintain representations of task-relevant information for short periods of time to guide subsequent actions or make decisions. Neurons of the prefrontal cortex exhibit persistent firing during the delay period of working memory tasks. Despite extensive studies, the mechanisms underlying this persistent neural activity remain largely obscure. The neurotransmitter systems of dopamine, NMDA, and GABA have been implicated, but further investigations are necessary to establish their precise roles and relationships. Recent research has suggested a new component: brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, TrkB. We review the research on persistent activity and suggest that BDNF/TrkB signaling in a distinct class of interneurons plays an important role in organizing persistent neural activity at the single-neuron and network levels.

  18. Brain-derived neurotrophic factor (BDNF) and type 2 diabetes

    DEFF Research Database (Denmark)

    Krabbe, K. S.; Nielsen, A. R.; Krogh-Madsen, R.;

    2006-01-01

    Aims/hypothesis  Decreased levels of brain-derived neurotrophic factor (BDNF) have been implicated in the pathogenesis of Alzheimer's disease and depression. These disorders are associated with type 2 diabetes, and animal models suggest that BDNF plays a role in insulin resistance. We therefore...... explored whether BDNF plays a role in human glucose metabolism. Subjects and methods  We included (Study 1) 233 humans divided into four groups depending on presence or absence of type 2 diabetes and presence or absence of obesity; and (Study 2) seven healthy volunteers who underwent both a hyperglycaemic...... and a hyperinsulinaemic-euglycaemic clamp. Results  Plasma levels of BDNF in Study 1 were decreased in humans with type 2 diabetes independently of obesity. Plasma BDNF was inversely associated with fasting plasma glucose, but not with insulin. No association was found between the BDNF G196A (Val66Met) polymorphism...

  19. A simple role for BDNF in learning and memory?

    Science.gov (United States)

    Cunha, Carla; Brambilla, Riccardo; Thomas, Kerrie L

    2010-01-01

    Since its discovery almost three decades ago, the secreted neurotrophin brain-derived neurotrophic factor (BDNF) has been firmly implicated in the differentiation and survival of neurons of the CNS. More recently, BDNF has also emerged as an important regulator of synaptogenesis and synaptic plasticity mechanisms underlying learning and memory in the adult CNS. In this review we will discuss our knowledge about the multiple intracellular signalling pathways activated by BDNF, and the role of this neurotrophin in long-term synaptic plasticity and memory formation as well as in synaptogenesis. We will show that maturation of BDNF, its cellular localization and its ability to regulate both excitatory and inhibitory synapses in the CNS may result in conflicting alterations in synaptic plasticity and memory formation. Lack of a precise knowledge about the mechanisms by which BDNF influences higher cognitive functions and complex behaviours may constitute a severe limitation in the possibility to devise BDNF-based therapeutics for human disorders of the CNS.

  20. Spontaneous sleep-wake cycle and sleep deprivation differently induce Bdnf1, Bdnf4 and Bdnf9a DNA methylation and transcripts levels in the basal forebrain and frontal cortex in rats.

    Science.gov (United States)

    Ventskovska, Olena; Porkka-Heiskanen, Tarja; Karpova, Nina N

    2015-04-01

    Brain-derived neurotrophic factor (Bdnf) regulates neuronal plasticity, slow wave activity and sleep homeostasis. Environmental stimuli control Bdnf expression through epigenetic mechanisms, but there are no data on epigenetic regulation of Bdnf by sleep or sleep deprivation. Here we investigated whether 5-methylcytosine (5mC) DNA modification at Bdnf promoters p1, p4 and p9 influences Bdnf1, Bdnf4 and Bdnf9a expression during the normal inactive phase or after sleep deprivation (SD) (3, 6 and 12 h, end-times being ZT3, ZT6 and ZT12) in rats in two brain areas involved in sleep regulation, the basal forebrain and cortex. We found a daytime variation in cortical Bdnf expression: Bdnf1 expression was highest at ZT6 and Bdnf4 lowest at ZT12. Such variation was not observed in the basal forebrain. Also Bdnf p1 and p9 methylation levels differed only in the cortex, while Bdnf p4 methylation did not vary in either area. Factorial analysis revealed that sleep deprivation significantly induced Bdnf1 and Bdnf4 with the similar pattern for Bdnf9a in both basal forebrain and cortex; 12 h of sleep deprivation decreased 5mC levels at the cortical Bdnf p4 and p9. Regression analysis between the 5mC promoter levels and the corresponding Bdnf transcript expression revealed significant negative correlations for the basal forebrain Bdnf1 and cortical Bdnf9a transcripts in only non-deprived rats, while these correlations were lost after sleep deprivation. Our results suggest that Bdnf transcription during the light phase of undisturbed sleep-wake cycle but not after SD is regulated at least partially by brain site-specific DNA methylation. © 2014 European Sleep Research Society.

  1. The interplay of stress and sleep impacts BDNF level.

    Directory of Open Access Journals (Sweden)

    Maria Giese

    Full Text Available BACKGROUND: Sleep plays a pivotal role in normal biological functions. Sleep loss results in higher stress vulnerability and is often found in mental disorders. There is evidence that brain-derived neurotrophic factor (BDNF could be a central player in this relationship. Recently, we could demonstrate that subjects suffering from current symptoms of insomnia exhibited significantly decreased serum BDNF levels compared with sleep-healthy controls. In accordance with the paradigm indicating a link between sleep and BDNF, we aimed to investigate if the stress system influences the association between sleep and BDNF. METHODOLOGY/PRINCIPAL FINDINGS: Participants with current symptoms of insomnia plus a former diagnosis of Restless Legs Syndrome (RLS and/or Periodic Limb Movement (PLM and sleep healthy controls were included in the study. They completed questionnaires on sleep (ISI, Insomnia Severity Index and stress (PSS, Perceived Stress Scale and provided a blood sample for determination of serum BDNF. We found a significant interaction between stress and insomnia with an impact on serum BDNF levels. Moreover, insomnia severity groups and score on the PSS each revealed a significant main effect on serum BDNF levels. Insomnia severity was associated with increased stress experience affecting serum BDNF levels. Of note, the association between stress and BDNF was only observed in subjects without insomnia. Using a mediation model, sleep was revealed as a mediator of the association between stress experience and serum BDNF levels. CONCLUSIONS: This is the first study to show that the interplay between stress and sleep impacts BDNF levels, suggesting an important role of this relationship in the pathogenesis of stress-associated mental disorders. Hence, we suggest sleep as a key mediator at the connection between stress and BDNF. Whether sleep is maintained or disturbed might explain why some individuals are able to handle a certain stress load while

  2. The responsiveness of TrkB to BDNF and antidepressant drugs is differentially regulated during mouse development.

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    Antonio Di Lieto

    Full Text Available BACKGROUND: Previous studies suggest that the responsiveness of TrkB receptor to BDNF is developmentally regulated in rats. Antidepressant drugs (AD have been shown to increase TrkB signalling in the adult rodent brain, and recent findings implicate a BDNF-independent mechanism behind this phenomenon. When administered during early postnatal life, ADs produce long-lasting biochemical and behavioural alterations that are observed in adult animals. METHODOLOGY: We have here examined the responsiveness of brain TrkB receptors to BDNF and ADs during early postnatal life of mouse, measured as autophosphorylation of TrkB (pTrkB. PRINCIPAL FINDINGS: We found that ADs fail to induce TrkB signalling before postnatal day 12 (P12 after which an adult response of TrkB to ADs was observed. Interestingly, there was a temporally inverse correlation between the appearance of the responsiveness of TrkB to systemic ADs and the marked developmental reduction of BDNF-induced TrkB in brain microslices ex vivo. Basal p-TrkB status in the brain of BDNF deficient mice was significantly reduced only during early postnatal period. Enhancing cAMP (cyclic adenosine monophosphate signalling failed to facilitate TrkB responsiveness to BDNF. Reduced responsiveness of TrkB to BDNF was not produced by the developmental increase in the expression of dominant-negative truncated TrkB.T1 because this reduction was similarly observed in the brain microslices of trkB.T1(-/- mice. Moreover, postnatal AD administration produced long-lasting behavioural alterations observable in adult mice, but the responses were different when mice were treated during the time when ADs did not (P4-9 or did (P16-21 activate TrkB. CONCLUSIONS: We have found that ADs induce the activation of TrkB only in mice older than 2 weeks and that responsiveness of brain microslices to BDNF is reduced during the same time period. Exposure to ADs before and after the age when ADs activate TrkB produces differential

  3. Control of extracellular cleavage of ProBDNF by high frequency neuronal activity

    OpenAIRE

    Nagappan, Guhan; Zaitsev, Eugene; Senatorov, Vladimir V.; Yang, Jianmin; Hempstead, Barbara L.; Lu, Bai

    2009-01-01

    Pro- and mature neurotrophins often elicit opposing biological effects. For example, mature brain-derived neurotrophic factor (mBDNF) is critical for long-term potentiation induced by high-frequency stimulation, whereas proBDNF facilitate long-term depression induced by low-frequency stimulation. Because mBDNF is derived from proBDNF by endoproteolytic cleavage, mechanisms regulating the cleavage of proBDNF may control the direction of BDNF regulation. Using methods that selectively detect pr...

  4. Time-dependent contribution of non neuronal cells to BDNF production after ischemic stroke in rats.

    OpenAIRE

    Béjot, Yannick; Tessier, Anne; Cachia, Claire; Giroud, Maurice; Mossiat, Claude; Bertrand, Nathalie; Garnier, Philippe; Marie, Christine

    2011-01-01

    International audience; Although brain-derived neurotrophic factor (BDNF) plays a central role in recovery after cerebral ischemia, little is known about cells involved in BDNF production after stroke. The present study testes the hypothesis that neurons are not the unique source of neosynthesized BDNF after stroke and that non neuronal-BDNF producing cells differ according to the delay after stroke induction. For this purpose, cellular localization of BDNF and BDNF content of each hemisphere...

  5. New insights in the biology of BDNF synthesis and release: implications in CNS function

    OpenAIRE

    Greenberg, Michael E.; Xu, Baoji; Lu, Bai; Hempstead, Barbara L.

    2009-01-01

    BDNF has pleiotrophic effects on neuronal development and synaptic plasticity that underlie circuit formation and cognitive function. Recent breakthroughs reveal that neuronal activity regulates BDNF cell biology, including Bdnf transcription, dendritic targeting and trafficking of BDNF mRNA and protein, and secretion and extracellular conversion of proBDNF to mature BDNF. Defects in these mechanisms contribute differentially to cognitive dysfunction and anxiety–like behaviors. Here we review...

  6. Hydrogen Sulfide Protects against Chronic Unpredictable Mild Stress-Induced Oxidative Stress in Hippocampus by Upregulation of BDNF-TrkB Pathway

    Directory of Open Access Journals (Sweden)

    Min Hu

    2016-01-01

    Full Text Available Chronic unpredictable mild stress (CUMS induces hippocampal oxidative stress. H2S functions as a neuroprotectant against oxidative stress in brain. We have previously shown the upregulatory effect of H2S on BDNF protein expression in the hippocampus of rats. Therefore, we hypothesized that H2S prevents CUMS-generated oxidative stress by upregulation of BDNF-TrkB pathway. We showed that NaHS (0.03 or 0.1 mmol/kg/day ameliorates the level of hippocampal oxidative stress, including reduced levels of malondialdehyde (MDA and 4-hydroxy-2-trans-nonenal (4-HNE, as well as increased level of glutathione (GSH and activity of superoxide dismutase (SOD in the hippocampus of CUMS-treated rats. We also found that H2S upregulated the level of BDNF and p-TrkB protein in the hippocampus of CUMS rats. Furthermore, inhibition of BDNF signaling by K252a, an inhibitor of the BDNF receptor TrkB, blocked the antioxidant effects of H2S on CUMS-induced hippocampal oxidative stress. These results reveal the inhibitory role of H2S in CUMS-induced hippocampal oxidative stress, which is through upregulation of BDNF/TrkB pathway.

  7. Morphological differences in adipose tissue and changes in BDNF/Trkb expression in brain and gut of a diet induced obese zebrafish model.

    Science.gov (United States)

    Montalbano, Giuseppe; Mania, Manuela; Guerrera, Maria Cristina; Abbate, Francesco; Laurà, Rosaria; Navarra, Michele; Vega, Jose A; Ciriaco, Emilia; Germanà, Antonino

    2016-03-01

    Obesity is a multifactorial disease generated by an alteration in balance between energy intake and expenditure, also dependent on genetic and non-genetic factors. Moreover, various nuclei of the hypothalamus receive and process peripheral stimuli from the gastrointestinal tract, controlling food intake and therefore energy balance. Among anorexigenic molecules, brain-derived neurotrophic factor (BDNF) acts through the tyrosine-kinase receptor TrkB. Numerous data demonstrate that the BDNF/TrkB system has a fundamental role in the control of food intake and body weight. Quantitative PCR and immunohistochemistry for both BDNF and TrkB were used to determine changes in levels in the brain and gastro-intestinal tract of an experimental zebrafish model of diet-induced obesity. Overfed animals showed increased weight and body mass index as well as accumulation of adipose tissue in the visceral, subcutaneous and hepatic areas. These changes were concomitant with decreased levels of BDNF mRNA in the gastro-intestinal tract and increased expression of TrkB mRNA in the brain. Overfeeding did not change the density of cells displaying immunoreactivity for BDNF or TrkB in the brain although both were significantly diminished in the gastro-intestinal tract. These results suggest an involvement of the BDNF/TrkB system in the regulation of food intake and energy balance in zebrafish, as in mammals.

  8. Highest trkB mRNA expression in the entorhinal cortex among hippocampal subregions in the adult rat: contrasting pattern with BDNF mRNA expression.

    Science.gov (United States)

    Tokuyama, W; Hashimoto, T; Li, Y X; Okuno, H; Miyashita, Y

    1998-11-20

    Brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, regulate synaptic functions in the hippocampus of the adult rodent. In previous studies, in situ hybridization methods have been used to evaluate regional differences in BDNF and trkB mRNA expression levels in hippocampal subregions. However, these studies have failed to reach consensus regarding the regional differences in the mRNA expression levels. In the present study, we quantitated mRNA expression levels using two different methods, ribonuclease protection assays and a quantitative reverse-transcription polymerase chain reaction technique, in four hippocampal subregions: the entorhinal cortex, dentate gyrus (DG), CA3 and CA1. These two methods yielded the same results. We found that BDNF and trkB mRNA expression levels did not covary in the four subregions. BDNF and full length trkB (trkB FL) mRNA in the entorhinal cortex and the DG show contrasting expression patterns. The expression level of BDNF mRNA was highest in the DG among the hippocampal subregions and low in the entorhinal cortex and the CA1, whereas the trkB FL mRNA expression level was highest in the entorhinal cortex, low in the DG and lowest in the CA3. These results suggest regional differences in BDNF/TrkB signaling for maintenance and modifiability of neuronal connections in the hippocampal formation.

  9. BDNF/ TrkB interaction regulates migration of SVZ precursor cells via PI3-K and MAP-K signalling pathways.

    Science.gov (United States)

    Chiaramello, S; Dalmasso, G; Bezin, L; Marcel, D; Jourdan, F; Peretto, P; Fasolo, A; De Marchis, S

    2007-10-01

    Neuroblasts born in the subventricular zone (SVZ) migrate along the rostral migratory stream, reaching the olfactory bulb (OB) where they differentiate into local interneurons. Several extracellular factors have been suggested to control specific steps of this process. The brain-derived neurotrophic factor (BDNF) has been demonstrated to promote morphological differentiation and survival of OB interneurons. Here we show that BDNF and its receptor TrkB are expressed in vivo throughout the migratory pathway, implying that BDNF might also mediate migratory signals. By using in vitro models we demonstrate that BDNF promotes migration of SVZ neuroblasts, acting both as inducer and attractant through TrkB activation. We show that BDNF induces cAMP response element-binding protein (CREB) activation in migrating neuroblasts via phosphatidylinositol 3-kinase (PI3-K) and mitogen-activated protein kinase (MAP-K) signalling. Pharmacological blockade of these pathways on SVZ explants significantly reduces CREB activation and impairs neuronal migration. This study identifies a function of BDNF in the SVZ system, which involves multiple protein kinase pathways leading to neuroblast migration.

  10. Baclofen prevents the elevated plus maze behavior and BDNF expression during naloxone precipitated morphine withdrawal in male and female mice.

    Science.gov (United States)

    Pedrón, Valeria T; Varani, André P; Balerio, Graciela N

    2016-05-01

    In previous studies we have shown that baclofen, a selective GABAB receptor agonist, prevents the somatic expression and reestablishes the dopamine and μ-opioid receptors levels, modified during naloxone-precipitated morphine withdrawal syndrome in male and female mice. There are no previous reports regarding sex differences in the elevated plus maze (EPM) and the expression of BDNF in morphine-withdrawn mice. The present study analyses the behavioral and biochemical variations during morphine withdrawal in mice of both sexes, and whether these variations are prevented with baclofen. Swiss-Webster albino prepubertal mice received morphine (2 mg/kg, i.p.) twice daily, for 9 consecutive days. On the 10th day, one group of morphine-treated mice received naloxone (opioid receptor antagonist; 6 mg/kg, i.p.) 1 h after the last dose of morphine to precipitate withdrawal. A second group received baclofen (2 mg/kg, i.p.) before naloxone administration. The EPM behavior was measured during 15 min after naloxone injection. The expression of BDNF-positive cells was determined by immunohistochemistry. Withdrawn male mice showed a higher percentage of time spent and number of entries to the open arms compared to withdrawn female mice. Baclofen prevented this behavior in both sexes. BDNF expression decreased in the AcbC, BNST, CeC, and CA3 of the hippocampus while increased in the BLA of morphine withdrawn male. Baclofen pretreatment prevented the BDNF expression observed in morphine withdrawn male mice in all the brain areas studied except in the CeC. Baclofen prevention of the EPM behavior associated to morphine withdrawal could be partially related to changes in BDNF expression.

  11. There is poverty convergence

    OpenAIRE

    Crespo Cuaresma, Jesus; Klasen, Stephan; Wacker, Konstantin M.

    2016-01-01

    Martin Ravallion ("Why Don't We See Poverty Convergence?" American Economic Review, 102(1): 504-23; 2012) presents evidence against the existence of convergence in global poverty rates despite convergence in household mean income levels and the close linkage between income growth and poverty reduction. We show that this finding is driven by a specification that demands more than simple convergence in poverty headcount rates and assumes a growth elasticity of poverty reduction, which is well-k...

  12. Convergence S-compactifications

    Directory of Open Access Journals (Sweden)

    Bernd Losert

    2014-07-01

    Full Text Available Properties of continuous actions on convergence spaces are investigated. The primary focus is the characterization as to when a continuous action on a convergence space can be continuously extended to an action on a compactification of the convergence space. The largest and smallest such compactifications are studied.

  13. TrkB/BDNF-dependent striatal plasticity and behavior in a genetic model of epilepsy: modulation by valproic acid.

    Science.gov (United States)

    Ghiglieri, Veronica; Sgobio, Carmelo; Patassini, Stefano; Bagetta, Vincenza; Fejtova, Anna; Giampà, Carmela; Marinucci, Silvia; Heyden, Alexandra; Gundelfinger, Eckart D; Fusco, Francesca R; Calabresi, Paolo; Picconi, Barbara

    2010-06-01

    In mice lacking the central domain of the presynaptic scaffold Bassoon the occurrence of repeated cortical seizures induces cell-type-specific plasticity changes resulting in a general enhancement of the feedforward inhibition within the striatal microcircuit. Early antiepileptic treatment with valproic acid (VPA) reduces epileptic attacks, inhibits the emergence of pathological form of plasticity in fast-spiking (FS) interneurons and restores physiological striatal synaptic plasticity in medium spiny (MS) neurons. Brain-derived neurotrophic factor (BDNF) is a key factor for the induction and maintenance of synaptic plasticity and it is also implicated in the mechanisms underlying epilepsy-induced adaptive changes. In this study, we explore the possibility that the TrkB/BDNF system is involved in the striatal modifications associated with the Bassoon gene (Bsn) mutation. In epileptic mice abnormal striatum-dependent learning was paralleled by higher TrkB levels and an altered distribution of BDNF. Accordingly, subchronic intrastriatal administration of k252a, an inhibitor of TrkB receptor tyrosine kinase activity, reversed behavioral alterations in Bsn mutant mice. In addition, in vitro manipulations of the TrkB/BDNF complex by k252a, prevented the emergence of pathological plasticity in FS interneurons. Chronic treatment with VPA, by reducing seizures, was able to rebalance TrkB to control levels favoring a physiological redistribution of BDNF between MS neurons and FS interneurons with a concomitant recovery of striatal plasticity. Our results provide the first indication that BDNF is involved in determining the striatal alterations occurring in the early-onset epileptic syndrome associated with the absence of presynaptic protein Bassoon.

  14. H2S protects PC12 cells against toxicity of corticosterone by modulation of BDNF-TrkB pathway.

    Science.gov (United States)

    Gao, Shenglan; Li, Wenting; Zou, Wei; Zhang, Ping; Tian, Ying; Xiao, Fan; Gu, Hongfeng; Tang, Xiaoqing

    2015-11-01

    Corticosterone, one of the glucocorticoids, is toxic to neurons and plays an important role in depressive-like behavior and depression. We previously showed that hydrogen sulfide (H2S), a novel physiological mediator, plays an inhibitory role in depression. However, the mechanism underlying H2S-triggered antidepressant-like role is not clearly known. Brain-derived neurotrophic factor (BDNF), a neurotrophic factor, plays a neuroprotective role that is mediated by its high-affinity tropomysin-related kinase B (TrkB) receptor. In this study, to investigate the underlying mechanism of H2S-induced antidepressant-like role, we explored whether H2S could protect neurons against corticosterone-mediated cyctotoxicity and whether this protective role of H2S was involved in the regulation of BDNF-TrkB pathway. Our data demonstrated that sodium hydrosulfide (NaHS), the donor of H2S, could prevent corticosterone-induced cytotoxicity, apoptosis, accumulation of intracellular reactive oxygen species (ROS) and loss of mitochondrial membrane potential (MMP) in PC12 cells. NaHS not only induced the up-regulation of BDNF but also prevented the down-regulation of BDNF by corticosterone. It was also found that blocking BDNF-TrkB pathway by K252a, an inhibitor of TrkB, abolished the protection of H2S against corticosterone-induced cytotoxicity, apoptosis, accumulation of ROS, and loss of MMP. These results suggest that H2S protects against the neurotoxicity of corticosterone by modulation of the BDNF-TrkB pathway. © The Author 2015. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

  15. Early enriched environment induces an increased conversion of proBDNF to BDNF in the adult rat's hippocampus.

    Science.gov (United States)

    Cao, Wenyu; Duan, Juan; Wang, Xueqin; Zhong, Xiaolin; Hu, Zhaolan; Huang, Fulian; Wang, Hongtao; Zhang, Juan; Li, Fang; Zhang, Jianyi; Luo, Xuegang; Li, Chang-Qi

    2014-05-15

    An enriched environment has been shown to influence brain plasticity and function by involving the action of brain-derived neurotrophic factor (BDNF). BDNF, which is synthesized as a precursor molecule (proBDNF) that undergoes proteolytic cleavage, plays an important role in synaptic plasticity and contributes to several brain functions such as memory, learning, and behavior. The neurotrophins and proneurotrophins often play opposite roles in the brain, suggesting that proteolytic cleavage of proneurotrophins controls the action of neurotrophins. However, few studies have focused on the expression and cleavage of proBDNF after exposure to an enriched environment. Our study aimed to explore the effects of an early-enriched environment on the conversion of proBDNF to BDNF in the adult rats' hippocampus. We found that there was no difference in the expression of proBDNF in the hippocampus between the SE (standard environment) and EE (enriched environment) rats, but a significantly increased BDNF protein level was found in the EE rats. Thus, a remarkably enhanced ratio of BDNF to proBDNF (BDNF/proBDNF) was observed in the EE rats. In addition, the EE resulted in a remarkably up-regulated matrix metalloproteinase-9 (MMP-9) in the hippocampus, which played a key role in converting proBDNF to BDNF in the extracellular space. Furthermore, the expression of synapse-related proteins (NR1 and NR2A) was analyzed, and the results indicated that EE could significantly increase the expression of NR1 and NR2A in the hippocampus. In addition, the behavioral results showed that EE reduced anxiety-like behavior in the elevated-plus maze test and reduced immobility time in the forced swimming test. Moreover, the EE resulted in an increased preference for sucrose compared to the SE. These results suggested that the EE up-regulated MMP-9 levels within the hippocampus, which might facilitate the conversion of proBDNF to BDNF, thereby contributing to the long lasting alterations of

  16. Abeta(1-42) injection causes memory impairment, lowered cortical and serum BDNF levels, and decreased hippocampal 5-HT(2A) levels

    DEFF Research Database (Denmark)

    Christensen, R; Marcussen, Anders Bue; Wörtwein, Gitta;

    2008-01-01

    Aggregation of the beta-amyloid protein (Abeta) is a hallmark of Alzheimer's disease (AD) and is believed to be causally involved in a neurodegenerative cascade. In patients with AD, reduced levels of serum Brain Derived Neurotrophic Factor (BDNF) and cortical 5-HT(2A) receptor binding has recently...... been reported but it is unknown how these changes are related to beta-amyloid accumulation. In this study we examined in rats the effect of intrahippocampal injections of aggregated Abeta(1-42) (1 microg/microl) on serum and brain BDNF or 5-HT(2A) receptor levels. A social recognition test paradigm...... was used to monitor Abeta(1-42) induced memory impairment. Memory impairment was seen 22 days after injection of Abeta(1-42) in the experimental group and until termination of the experiments. In the Abeta(1-42) injected animals we saw an abolished increase in serum BDNF levels that was accompanied...

  17. Diverse neurotoxicants converge on gene expression for neuropeptides and their receptors in an in vitro model of neurodifferentiation: effects of chlorpyrifos, diazinon, dieldrin and divalent nickel in PC12 cells.

    Science.gov (United States)

    Slotkin, Theodore A; Seidler, Frederic J

    2010-09-24

    Unrelated developmental neurotoxicants can produce similar neurobehavioral outcomes. We examined whether disparate agents affect neuromodulators that control numerous neurotransmitters and circuits, employing PC12 cells to explore the targeting of neuroactive peptides by organophosphates (chlorpyrifos, diazinon), an organochlorine (dieldrin) and a metal (Ni(2+)); we utilized microarrays to profile gene expression for the peptides and their receptors. Chlorpyrifos evoked robust upregulation of cholecystokinin, corticotropin releasing hormone, galanin, neuropeptide Y, neurotensin, preproenkephalin and tachykinin 1; this involved a critical period at the commencement of neurodifferentiation, since the effects were much less notable in undifferentiated PC12 cells. Diazinon targeted a similar but smaller repertoire of neuropeptide genes and the magnitude of the effects was also generally less. Surprisingly, dieldrin shared many of the same neuropeptide targets as the organophosphates and concordance analysis showed significant overlap among all three pesticides. However, dieldrin had more notable effects on neuropeptide receptors, and overlap between diazinon and dieldrin for the receptors led to a stronger resemblance of these two agents than of chlorpyrifos and dieldrin. Ni(2+) was unique, evoking upregulation of only one of the peptides affected by the other agents, while causing downregulation of several others. Nevertheless, there was still significant concordance between Ni(2+) and either diazinon or dieldrin, reflecting similarities toward the receptors. Our results show that neuropeptides are likely to be a prominent target for the developmental neurotoxicity of organophosphates and other neurotoxicants, and further, that the convergence of disparate agents on the same genes and pathways may contribute to similar neurobehavioral outcomes. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Dysregulation of TrkB phosphorylation and proBDNF protein in adenylyl cyclase 1 and 8 knockout mice in a model of fetal alcohol spectrum disorder.

    Science.gov (United States)

    Susick, Laura L; Chrumka, Alexandria C; Hool, Steven M; Conti, Alana C

    2016-03-01

    Brain-derived neurotrophic factor (BDNF) mediates neuron growth and is regulated by adenylyl cyclases (ACs). Mice lacking AC1/8 (DKO) have a basal reduction in the dendritic complexity of medium spiny neurons in the caudate putamen and demonstrate increased neurotoxicity in the striatum following acute neonatal ethanol exposure compared to wild type (WT) controls, suggesting a compromise in BDNF regulation under varying conditions. Although neonatal ethanol exposure can negatively impact BDNF expression, little is known about the effect on BDNF receptor activation and its downstream signaling, including Akt activation, an established neuroprotective pathway. Therefore, here we determined the effects of AC1/8 deletion and neonatal ethanol administration on BDNF and proBDNF protein expression, and activation of tropomyosin-related kinase B (TrkB), Akt, ERK1/2, and PLCγ. WT and DKO mice were treated with a single dose of 2.5 g/kg ethanol or saline at postnatal days 5-7 to model late-gestational alcohol exposure. Striatal and cortical tissues were analyzed using a BDNF enzyme-linked immunosorbent assay or immunoblotting for proBDNF, phosphorylated and total TrkB, Akt, ERK1/2, and PLCɣ1. Neither postnatal ethanol exposure nor AC1/8 deletion affected total BDNF protein expression at any time point in either region examined. Neonatal ethanol increased the expression of proBDNF protein in the striatum of WT mice 6, 24, and 48 h after exposure, with DKO mice demonstrating a reduction in proBDNF expression 6 h after exposure. Six and 24 h after ethanol administration, phosphorylation of full-length TrkB in the striatum was significantly reduced in WT mice, but was significantly increased in DKO mice only at 24 h. Interestingly, 48 h after ethanol, both WT and DKO mice demonstrated a reduction in phosphorylated full-length TrkB. In addition, Akt and PLCɣ1 phosphorylation was also decreased in ethanol-treated DKO mice 48 h after injection. These data demonstrate

  19. A Novel Multisensory Integration Task Reveals Robust Deficits in Rodent Models of Schizophrenia: Converging Evidence for Remediation via Nicotinic Receptor Stimulation of Inhibitory Transmission in the Prefrontal Cortex.

    Science.gov (United States)

    Cloke, Jacob M; Nguyen, Robin; Chung, Beryl Y T; Wasserman, David I; De Lisio, Stephanie; Kim, Jun Chul; Bailey, Craig D C; Winters, Boyer D

    2016-12-14

    Atypical multisensory integration is an understudied cognitive symptom in schizophrenia. Procedures to evaluate multisensory integration in rodent models are lacking. We developed a novel multisensory object oddity (MSO) task to assess multisensory integration in ketamine-treated rats, a well established model of schizophrenia. Ketamine-treated rats displayed a selective MSO task impairment with tactile-visual and olfactory-visual sensory combinations, whereas basic unisensory perception was unaffected. Orbitofrontal cortex (OFC) administration of nicotine or ABT-418, an α4β2 nicotinic acetylcholine receptor (nAChR) agonist, normalized MSO task performance in ketamine-treated rats and this effect was blocked by GABAA receptor antagonism. GABAergic currents were also decreased in OFC of ketamine-treated rats and were normalized by activation of α4β2 nAChRs. Furthermore, parvalbumin (PV) immunoreactivity was decreased in the OFC of ketamine-treated rats. Accordingly, silencing of PV interneurons in OFC of PV-Cre mice using DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) selectively impaired MSO task performance and this was reversed by ABT-418. Likewise, clozapine-N-oxide-induced inhibition of PV interneurons in brain slices was reversed by activation of α4β2 nAChRs. These findings strongly imply a role for prefrontal GABAergic transmission in the integration of multisensory object features, a cognitive process with relevance to schizophrenia. Accordingly, nAChR agonism, which improves various facets of cognition in schizophrenia, reversed the severe MSO task impairment in this study and appears to do so via a GABAergic mechanism. Interactions between GABAergic and nAChR receptor systems warrant further investigation for potential therapeutic applications. The novel behavioral procedure introduced in the current study is acutely sensitive to schizophrenia-relevant cognitive impairment and should prove highly valuable for such research.

  20. Peripheral nerve regeneration and NGF-dependent neurite outgrowth of adult sensory neurons converge on STAT3 phosphorylation downstream of neuropoietic cytokine receptor gp130.

    Science.gov (United States)

    Quarta, Serena; Baeumer, Bastian E; Scherbakov, Nadja; Andratsch, Manfred; Rose-John, Stefan; Dechant, Georg; Bandtlow, Christine E; Kress, Michaela

    2014-09-24

    After nerve injury, adult sensory neurons can regenerate peripheral axons and reconnect with their target tissue. Initiation of outgrowth, as well as elongation of neurites over long distances, depends on the signaling of receptors for neurotrophic growth factors. Here, we investigated the importance of gp130, the signaling subunit of neuropoietic cytokine receptors in peripheral nerve regeneration. After sciatic nerve crush, functional recovery in vivo was retarded in SNS-gp130(-/-) mice, which specifically lack gp130 in sensory neurons. Correspondingly, a significantly reduced number of free nerve endings was detected in glabrous skin from SNS-gp130(-/-) compared with control mice after nerve crush. Neurite outgrowth and STAT3 activation in vitro were severely reduced in cultures in gp130-deficient cultured neurons. Surprisingly, in neurons obtained from SNS-gp130(-/-) mice the increase in neurite length was reduced not only in response to neuropoietic cytokine ligands of gp130 but also to nerve growth factor (NGF), which does not bind to gp130-containing receptors. Neurite outgrowth in the absence of neurotrophic factors was partially rescued in gp130-deficient neurons by leptin, which activates STAT3 downstream of leptic receptor and independent of gp130. The neurite outgrowth response of gp130-deficient neurons to NGF was fully restored in the presence of leptin. Based on these findings, gp130 signaling via STAT3 activation is suggested not only to be an important regulator of peripheral nerve regeneration in vitro and in vivo, but as determining factor for the growth promoting action of NGF in adult sensory neurons. Copyright © 2014 the authors 0270-6474/14/3413222-12$15.00/0.

  1. BDNF activates mTOR to regulate GluR1 expression required for memory formation.

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    Leandro Slipczuk

    Full Text Available BACKGROUND: The mammalian target of Rapamycin (mTOR kinase plays a key role in translational control of a subset of mRNAs through regulation of its initiation step. In neurons, mTOR is present at the synaptic region, where it modulates the activity-dependent expression of locally-translated proteins independently of mRNA synthesis. Indeed, mTOR is necessary for different forms of synaptic plasticity and long-term memory (LTM formation. However, little is known about the time course of mTOR activation and the extracellular signals governing this process or the identity of the proteins whose translation is regulated by this kinase, during mnemonic processing. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that consolidation of inhibitory avoidance (IA LTM entails mTOR activation in the dorsal hippocampus at the moment of and 3 h after training and is associated with a rapid and rapamycin-sensitive increase in AMPA receptor GluR1 subunit expression, which was also blocked by intra-hippocampal delivery of GluR1 antisense oligonucleotides (ASO. In addition, we found that pre- or post-training administration of function-blocking anti-BDNF antibodies into dorsal CA1 hampered IA LTM retention, abolished the learning-induced biphasic activation of mTOR and its readout, p70S6K and blocked GluR1 expression, indicating that BDNF is an upstream factor controlling mTOR signaling during fear-memory consolidation. Interestingly, BDNF ASO hindered LTM retention only when given into dorsal CA1 1 h after but not 2 h before training, suggesting that BDNF controls the biphasic requirement of mTOR during LTM consolidation through different mechanisms: an early one involving BDNF already available at the moment of training, and a late one, happening around 3 h post-training that needs de novo synthesis of this neurotrophin. CONCLUSIONS/SIGNIFICANCE: IN CONCLUSION, OUR FINDINGS DEMONSTRATE THAT: 1 mTOR-mediated mRNA translation is required for memory consolidation during

  2. Early Life Stress Effects on Glucocorticoid-BDNF Interplay in the Hippocampus.

    Science.gov (United States)

    Daskalakis, Nikolaos P; De Kloet, Edo Ronald; Yehuda, Rachel; Malaspina, Dolores; Kranz, Thorsten M

    2015-01-01

    Early life stress (ELS) is implicated in the etiology of multiple psychiatric disorders. Important biological effects of ELS are manifested in stress-susceptible regions of the hippocampus and are partially mediated by long-term effects on glucocorticoid (GC) and/or neurotrophin signaling pathways. GC-signaling mediates the regulation of stress response to maintain homeostasis, while neurotrophin signaling plays a key role in neuronal outgrowth and is crucial for axonal guidance and synaptic integrity. The neurotrophin and GC-signaling pathways co-exist throughout the central nervous system (CNS), particularly in the hippocampus, which has high expression levels of glucocorticoid-receptors (GR) and mineralocorticoid-receptors (MR) as well as brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase receptor B (TrkB). This review addresses the effects of ELS paradigms on GC- and BDNF-dependent mechanisms and their crosstalk in the hippocampus, including potential implications for the pathogenesis of common stress-related disorders.

  3. BDNF 和TrkB 在肝细胞癌中的表达及其功能研究%Expression and Functions of BDNF and TrkB in Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    郭大伟; 侯学忠; 张弘彬; 孙文郁; 朱磊; 姜晓峰; 梁健

    2012-01-01

    Objective: To investigate the expression of brain-derived neurotrophic factor ( BDNF ) and its primary receptor, tropo-mysin-related kinase B ( TrkB ) in hepatocellular carcinoma ( HCC ) tissues, and to evaluate the functions of these proteins in the onco-genesis and progression of HCC. Methods: The expression of BDNF and TrkB in 65 HCC cases was evaluated via immunohistochemi-cal staining. In the human HCC HepG2 cell lines, the secretory BDNF in the supernatant liquid was measured using enzyme-linked im-munosorbent assay ( ELISA ). The effects of BDNF-neutralizing antibody and the Trk tyrosine kinase inhibitor K252a on apoptosis and invasion were examined using flow cytometry and a Transwell assay, respectively. Results: Higher BDNF expression ( 63.1% ) or positive TrkB expression ( 55.4% ) was found in the HCC specimens. More cases of intrahepatic multiple tumors were found in HCCs with higher BDNF expression (P< 0.01 ). Similarly, HCCs with negative for TrkB tended to be solitary tumors (P< 0.05 ). In addition, patients with higher levels of BDNF expression or positive TrkB expression had more advanced stages of HCC ( P < 0.05 ). The level of BDNF secretion in HepG2 cells was 88.56 pg/ml ± 7.45 pg/ml. Both anti-BDNF and K252a antibodies effectively induced apoptosis and suppressed the invasion of the HepG2 cells. Conclusion: BDNF and TrkB are essential for the survival and invasion of the HCC cells. BDNF/TrkB signaling may be an effective target for promoting HCC advancement.%目的:研究BDNF及其受体TrkB在人肝细胞癌(HCC)中的表达,并探讨二者在HCC发生、发展中的作用.方法:采用免疫组织化学方法检测BDNF和TrkB在65例HCC组织中的表达.在人HCC细胞系HepG2中,采用ELISA方法检测BDNF在培养上清中的分泌水平,分别采用流式细胞术和Transwell细胞侵袭方法测定BDNF中和抗体或TrkB激酶活性抑制剂K252a处理对细胞凋亡和侵袭的影响.结果:65例HCC组织标本中,41例(63.1%)

  4. Aging Triggers a Repressive Chromatin State at Bdnf Promoters in Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Ernest Palomer

    2016-09-01

    Full Text Available Cognitive capacities decline with age, an event accompanied by the altered transcription of synaptic plasticity genes. Here, we show that the transcriptional induction of Bdnf by a mnemonic stimulus is impaired in aged hippocampal neurons. Mechanistically, this defect is due to reduced NMDA receptor (NMDAR-mediated activation of CaMKII. Decreased NMDAR signaling prevents changes associated with activation at specific Bdnf promoters, including displacement of histone deacetylase 4, recruitment of the histone acetyltransferase CBP, increased H3K27 acetylation, and reduced H3K27 trimethylation. The decrease in NMDA-CaMKII signaling arises from constitutive reduction of synaptic cholesterol that occurs with normal aging. Increasing the levels of neuronal cholesterol in aged neurons in vitro, ex vivo, and in vivo restored NMDA-induced Bdnf expression and chromatin remodeling. Furthermore, pharmacological prevention of age-associated cholesterol reduction rescued signaling and cognitive deficits of aged mice. Thus, reducing hippocampal cholesterol loss may represent a therapeutic approach to reverse cognitive decline during aging.

  5. NGF, BDNF, leptin, and mast cells in human coronary atherosclerosis and metabolic syndrome.

    Science.gov (United States)

    Chaldakov, G N; Fiore, M; Stankulov, I S; Hristova, M; Antonelli, A; Manni, L; Ghenev, P I; Angelucci, F; Aloe, L

    2001-10-01

    While multiple growth factor, cytokines, and immune cells are identified in atherosclerotic lesions, as well as an essential nonneuronal function of neurotrophins implicated in cardiovascular tissue development and in lipid and glucose metabolism, the role of the neurotrophins NGF and BDNF and also the adipokine leptin in human coronary atherosclerosis and related disorders, such as metabolic syndrome, remains unclear. Here we report that (i) both the amount and the immunoreactivity of NGF was reduced and the expression of p75NGF receptor and the number of mast cell increased in human atherosclerotic coronary arteries (n = 12) compared with control specimens (n = 9) obtained from autopsy cases, and (ii) NGF and BDNF plasma levels were reduced in patients with metabolic syndrome (n = 23) compared with control subjects (n = 10). Also, in metabolic syndrome patients, a positive correlation between the plasma leptin levels and the number of adipose tissue mast cells was found, suggesting that leptin may be a novel adipoimmune mediator. Altogether, the results provide the first correlative evidence for the potential involvement of NGF, BDNF, leptin, and mast cells in human coronary atherosclerosis and metabolic syndrome, implying neuroimmune and adipoimmune pathways in the pathobiology of these cardiovascular disorders.

  6. Plasma BDNF levels following weight recovery in anorexia nervosa.

    Science.gov (United States)

    Phillips, Kathryn E; Jimerson, David C; Pillai, Anilkumar; Wolfe, Barbara E

    2016-10-15

    Preclinical studies have implicated brain-derived neurotrophic factor (BDNF) in the regulation of eating behavior and body weight. As reviewed in this report, prior studies of BDNF levels in anorexia nervosa have yielded variable results, perhaps reflecting effects of malnutrition and psychiatric comorbidity. The goal of the current report was to assess plasma BDNF as a biomarker in weight-recovered individuals with a history of anorexia nervosa (ANWR). Study groups included women meeting criteria for ANWR and healthy female controls. Participants were in a normal weight range, free of current major psychiatric disorder, and free of medication. Self-ratings included eating disorder symptoms, depression and anxiety. Plasma BDNF levels were measured by enzyme linked immunoassay. Plasma BDNF levels were not significantly different for ANWR and control groups. Plasma BDNF levels were inversely correlated with anxiety ratings in controls (p<0.02) but not in the ANWR group. This report provides new evidence that circulating BDNF concentrations do not differ in healthy controls and ANWR free of psychiatric comorbidity. Additionally, the data provide new information on the relationship between plasma BDNF and anxiety in these two study groups. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. The expression and putative role of brain-derived neurotrophic factor and its receptor in bovine sperm.

    Science.gov (United States)

    Li, C; Li, C; Zhu, X; Wang, C; Liu, Zhuo; Li, W; Lu, Chen; Zhou, Xu

    2012-02-01

    The neurotrophin family of proteins promote the survival and differentiation of nerve cells and are thought to play an important role in development of reproductive tissues. The objective of the present study was to detect the presence of Brain-derived neurotrophic factor (BDNF) and its receptor TrkB in bovine sperm, and explore the potential role of BDNF in sperm function. We demonstrated that both the neorotrophin BDNF and the tyrosine kinase receptor protein TrkB were expressed in ejaculated bovine sperm. Furthermore, BDNF per se was secreted by sperm. Insulin and leptin secretion by bovine sperm were increased (P BDNF, whereas insulin was decreased by K252a. Therefore, we inferred that BDNF could be a regulator of sperm secretion of insulin and leptin through the TrkB receptor. Sperm viability and mitochondrial activity were both decreased (P BDNF/TrkB signaling pathway was blocked with K252a. Furthermore, BDNF promoted apoptosis of bovine sperm through TrkB binding (P BDNF secreted by bovine sperm was important in regulation of insulin and leptin secretion in ejaculated bovine sperm. Furthermore, BDNF may affect sperm mitochondrial activity and apoptosis, as well as their viability.

  8. Expression and localisation of BDNF, NT4 and TrkB in proliferative vitreoretinopathy.

    Science.gov (United States)

    Ghazi-Nouri, Seyed M S; Ellis, James S; Moss, Stephen; Limb, G Astrid; Charteris, David G

    2008-05-01

    Exogenous brain derived neurotrophic factor (BDNF) is known to rescue ganglion cell death after optic nerve injury. Its mechanism of action is believed to be indirect via glial cells in the retina. In this study we investigated the changes in expression and localisation of BDNF, neurotrophin-4 (NT4) and their common receptor (TrkB) in retinectomy sections of patients with proliferative vitreoretinopathy (PVR). Nine full-thickness retinectomy specimens obtained at retinal reattachment surgery for PVR were fixed in 4% paraformaldehyde immediately after excision and compared to similarly processed normal donor retinas (4 eyes). Agarose-embedded sections (100 microm thick) were double labelled for immunohistochemistry by confocal microscopy, with antibodies against BDNF, NT4, TrkB, rod opsin, glial fibrillary acidic protein (GFAP), cellular retinaldehyde binding protein (CRALBP) and Brn3. This study demonstrates expression of NT4 by ganglion cells and shows expression of BDNF and NT4 in the outer photoreceptor segments is downregulated during PVR, whilst NT4 is markedly upregulated throughout the retina during this condition. The findings here suggest that NT4 may play a neural protective role during the development of PVR. It also shows that upregulation of NT4 in PVR is localised to Müller glial cells, indicating either over-expression of this factor by Müller cells or that Müller cells internalise NT4 for trafficking across the retina. TrkB expression was not observed in PVR retina. The observations that Müller glia demonstrate upregulation of NT4 suggests that retinal injury may lead to activation of this neurotrophin by Müller cells as part of their neuroprotective functions.

  9. VGF and Its C-Terminal Peptide TLQP-62 Regulate Memory Formation in Hippocampus via a BDNF-TrkB-Dependent Mechanism.

    Science.gov (United States)

    Lin, Wei-Jye; Jiang, Cheng; Sadahiro, Masato; Bozdagi, Ozlem; Vulchanova, Lucy; Alberini, Cristina M; Salton, Stephen R

    2015-07-15

    Regulated expression and secretion of BDNF, which activates TrkB receptor signaling, is known to play a critical role in cognition. Identification of additional modulators of cognitive behavior that regulate activity-dependent BDNF secretion and/or potentiate TrkB receptor signaling would therefore be of considerable interest. In this study, we show in the adult mouse hippocampus that expression of the granin family gene Vgf and secretion of its C-terminal VGF-derived peptide TLQP-62 are required for fear memory formation. We found that hippocampal VGF expression and TLQP-62 levels were transiently induced after fear memory training and that sequestering secreted TLQP-62 peptide in the hippocampus immediately after training impaired memory formation. Reduced VGF expression was found to impair learning-evoked Rac1 induction and phosphorylation of the synaptic plasticity markers cofilin and synapsin in the adult mouse hippocampus. Moreover, TLQP-62 induced acute, transient activation of the TrkB receptor and subsequent CREB phosphorylation in hippocampal slice preparations and its administration immediately after training enhanced long-term memory formation. A critical role of BDNF-TrkB signaling as a downstream effector in VGF/TLQP-62-mediated memory consolidation was further revealed by posttraining activation of BDNF-TrkB signaling, which rescued impaired fear memory resulting from hippocampal administration of anti-VGF antibodies or germline VGF ablation in mice. We propose that VGF is a critical component of a positive BDNF-TrkB regulatory loop and, upon its induced expression by memory training, the TLQP-62 peptide rapidly reinforces BDNF-TrkB signaling, regulating hippocampal memory consolidation. Identification of the cellular and molecular mechanisms that regulate long-term memory formation and storage may provide alternative treatment modalities for degenerative and neuropsychiatric memory disorders. The neurotrophin BDNF plays a prominent role in cognitive

  10. BDNF-TrkB pathway mediates neuroprotection of hydrogen sulfide against formaldehyde-induced toxicity to PC12 cells.

    Directory of Open Access Journals (Sweden)

    Jia-Mei Jiang

    Full Text Available Formaldehyde (FA is a common environmental contaminant that has toxic effects on the central nervous system (CNS. Our previous data demonstrated that hydrogen sulfide (H2S, the third endogenous gaseous mediator, has protective effects against FA-induced neurotoxicity. As is known to all, Brain-derived neurotropic factor (BDNF, a member of the neurotrophin gene family, mediates its neuroprotective properties via various intracellular signaling pathways triggered by activating the tyrosine kinase receptor B (TrkB. Intriguingly, our previous data have illustrated the upregulatory role of H2S on BDNF protein expression in the hippocampus of rats. Therefore, in this study, we hypothesized that H2S provides neuroprotection against FA toxicity by regulating BDNF-TrkB pathway. In the present study, we found that NaHS, a donor of H2S, upregulated the level of BDNF protein in PC12 cells, and significantly rescued FA-induced downregulation of BDNF levels. Furthermore, we found that pretreatment of PC12 cells with K252a, an inhibitor of the BDNF receptor TrkB, markedly reversed the inhibition of NaHS on FA-induced cytotoxicity and ablated the protective effects of NaHS on FA-induced oxidative stress, including the accumulation of intracellular reactive oxygen species (ROS, 4-hydroxy-2-trans-nonenal (4-HNE, and malondialdehyde (MDA. We also showed that K252a abolished the inhibition of NaHS on FA-induced apoptosis, as well as the activation of caspase-3 in PC12 cells. In addition, K252a reversed the protection of H2S against FA-induced downregulation of Bcl-2 protein expression and upregulation of Bax protein expression in PC12 cells. These data indicate that the BDNF-TrkB pathway mediates the neuroprotection of H2S against FA-induced cytotoxicity, oxidative stress and apoptosis in PC12 cells. These findings provide a novel mechanism underlying the protection of H2S against FA-induced neurotoxicity.

  11. Social interaction rescues memory deficit in an animal model of Alzheimer's disease by increasing BDNF-dependent hippocampal neurogenesis.

    Science.gov (United States)

    Hsiao, Ya-Hsin; Hung, Hui-Chi; Chen, Shun-Hua; Gean, Po-Wu

    2014-12-03

    It has been recognized that the risk of cognitive decline during aging can be reduced if one maintains strong social connections, yet the neural events underlying this beneficial effect have not been rigorously studied. Here, we show that amyloid precursor protein (APP) and presenilin 1 (PS1) double-transgenic (APP/PS1) mice demonstrate improvement in memory after they are cohoused with wild-type mice. The improvement was associated with increased protein and mRNA levels of BDNF in the hippocampus. Concomitantly, the number of BrdU(+)/NeuN(+) cells in the hippocampal dentate gyrus was significantly elevated after cohousing. Methylazoxymethanol acetate, a cell proliferation blocker, markedly reduced BrdU(+) and BrdU/NeuN(+) cells and abolished the effect of social interaction. Selective ablation of mitotic neurons using diphtheria toxin (DT) and a retrovirus vector encoding DT receptor abolished the beneficial effect of cohousing. Knockdown of BDNF by shRNA transfection blocked, whereas overexpression of BDNF mimicked the memory-improving effect. A tropomyosin-related kinase B agonist, 7,8-dihydroxyflavone, occluded the effect of social interaction. These results demonstrate that increased BDNF expression and neurogenesis in the hippocampus after cohousing underlie the reversal of memory deficit in APP/PS1 mice. Copyright © 2014 the authors 0270-6474/14/3416207-13$15.00/0.

  12. CART attenuates endoplasmic reticulum stress response induced by cerebral ischemia and reperfusion through upregulating BDNF synthesis and secretion.

    Science.gov (United States)

    Qiu, Bin; Hu, Shengdi; Liu, Libing; Chen, Man; Wang, Lai; Zeng, Xianwei; Zhu, Shigong

    2013-07-12

    Cocaine and amphetamine regulated transcript (CART), a neuropeptide, has shown strong neuroprotective effects against cerebral ischemia and reperfusion (I/R) injury in vivo and in vitro. Here, we report a new effect of CART on ER stress which is induced by cerebral I/R in a rat model of middle cerebral artery occlusion (MCAO) or by oxygen and glucose deprivation (OGD) in cultured cortical neurons, as well as a new functionality of BDNF in the neuroprotection by CART against the ER stress in cerebral I/R. The results showed that CART was effective in reducing the neuronal apoptosis and expression of ER stress markers (GRP78, CHOP and cleaved caspase12), and increasing the BDNF expression in I/R injury rat cortex both in vivo and in vitro. In addition, the effects of CART on ischemia-induced neuronal apoptosis and ER stress were suppressed by tyrosine receptor kinase B (TrkB) IgG, whereas the effects of CART on BDNF transcription, synthesis and secretion were abolished by CREB siRNA. This work suggests that CART is functional in inhibiting the cerebral I/R-induced ER stress and neuronal apoptosis by facilitating the transcription, synthesis and secretion of BDNF in a CREB-dependent way.

  13. Converged Registries Solution (CRS)

    Data.gov (United States)

    Department of Veterans Affairs — The Converged Registries platform is a hardware and software architecture designed to host individual patient registries and eliminate duplicative development effort...

  14. Working Memory Deficits, Increased Anxiety-Like Traits, and Seizure Susceptibility in BDNF Overexpressing Mice

    Science.gov (United States)

    Papaleo, Francesco; Silverman, Jill L.; Aney, Jordan; Tian, Qingjun; Barkan, Charlotte L.; Chadman, Kathryn K.; Crawley, Jacqueline N.

    2011-01-01

    BDNF regulates components of cognitive processes and has been implicated in psychiatric disorders. Here we report that genetic overexpression of the BDNF mature isoform (BDNF-tg) in female mice impaired working memory functions while sparing components of fear conditioning. BDNF-tg mice also displayed reduced breeding efficiency, higher…

  15. BDNF serum levels, but not BDNF Val66Met genotype, are correlated with personality traits in healthy subjects.

    Science.gov (United States)

    Minelli, Alessandra; Zanardini, Roberta; Bonvicini, Cristian; Sartori, Riccardo; Pedrini, Laura; Gennarelli, Massimo; Bocchio-Chiavetto, Luisella

    2011-08-01

    Consisting evidence in animal models has suggested that alterations in brain-derived neurotrophic factor (BDNF) brain expression and release are involved in the pathogenesis of mental illnesses, such as, mood, anxiety, and eating disorders. This hypothesis is supported by data emerging from biochemical studies on serum BDNF levels and genetic studies on the functional polymorphism Val66Met in the BDNF gene in patients and control subjects. Anxiety-related personality traits are associated with several mental disorders. However, they are also measurable in non-affected subjects and, so, may represent a useful "endophenotype" to study the biological correlation of the vulnerability factors in the general population. In this study, we analyzed putative correlations in subjects unaffected by mental disorders between personality traits, serum BDNF levels (N = 107), and the BDNF Val66Met genotype (N = 217). Furthermore, we tested the possible interactions between these variables. A significant correlation has been observed between high scores of harm avoidance (HA) measured by the temperament and character inventory (TCI), and low BDNF serum concentration (r = -0.253, P = 0.009). In addition, an association has been evidenced between low BDNF levels in serum and the BDNF Val/Val genotype (P = 0.021). By analyzing putative concomitant effects of different variables on HA scores in a regression model, we observed a significant correlation only with BDNF serum concentrations (P = 0.022). The study results suggest that a decrease in serum BDNF concentrations may represent a biochemical marker associated with anxiety personality traits also retrievable in the general population.

  16. Downregulated GABA and BDNF-TrkB pathway in chronic cyclothiazide seizure model.

    Science.gov (United States)

    Kong, Shuzhen; Cheng, Zhihua; Liu, Jianhui; Wang, Yun

    2014-01-01

    Cyclothiazide (CTZ) has been reported to simultaneously enhance glutamate receptor excitation and inhibit GABAA receptor inhibition, and in turn it evokes epileptiform activities in hippocampal neurons. It has also been shown to acutely induce epileptic seizure behavior in freely moving rats. However, whether CTZ induced seizure rats could develop to have recurrent seizure still remains unknown. In the current study, we demonstrated that 46% of the CTZ induced seizure rats developed to have recurrent seizure behavior as well as epileptic EEG with a starting latency between 2 weeks and several months. In those chronic seizure rats 6 months after the seizure induction by the CTZ, our immunohistochemistry results showed that both GAD and GAT-1 were significantly decreased across CA1, CA3, and dentate gyrus area of the hippocampus studied. In addition, both BDNF and its receptor TrkB were also decreased in hippocampus of the chronic CTZ seizure rats. Our results indicate that CTZ induced seizure is capable of developing to have recurrent seizure, and the decreased GABA synthesis and transport as well as the impaired BDNF-TrkB signaling pathway may contribute to the development of the recurrent seizure. Thus, CTZ seizure rats may provide a novel animal model for epilepsy study and anticonvulsant drug testing in the future.

  17. Downregulated GABA and BDNF-TrkB Pathway in Chronic Cyclothiazide Seizure Model

    Directory of Open Access Journals (Sweden)

    Shuzhen Kong

    2014-01-01

    Full Text Available Cyclothiazide (CTZ has been reported to simultaneously enhance glutamate receptor excitation and inhibit GABAA receptor inhibition, and in turn it evokes epileptiform activities in hippocampal neurons. It has also been shown to acutely induce epileptic seizure behavior in freely moving rats. However, whether CTZ induced seizure rats could develop to have recurrent seizure still remains unknown. In the current study, we demonstrated that 46% of the CTZ induced seizure rats developed to have recurrent seizure behavior as well as epileptic EEG with a starting latency between 2 weeks and several months. In those chronic seizure rats 6 months after the seizure induction by the CTZ, our immunohistochemistry results showed that both GAD and GAT-1 were significantly decreased across CA1, CA3, and dentate gyrus area of the hippocampus studied. In addition, both BDNF and its receptor TrkB were also decreased in hippocampus of the chronic CTZ seizure rats. Our results indicate that CTZ induced seizure is capable of developing to have recurrent seizure, and the decreased GABA synthesis and transport as well as the impaired BDNF-TrkB signaling pathway may contribute to the development of the recurrent seizure. Thus, CTZ seizure rats may provide a novel animal model for epilepsy study and anticonvulsant drug testing in the future.

  18. Early Life Stress Effects on the Glucocorticoid - BDNF interplay in the Hippocampus

    Directory of Open Access Journals (Sweden)

    Nikolaos P Daskalakis

    2015-11-01

    Full Text Available Early life stress (ELS is implicated in the etiology of multiple psychiatric disorders. Important biological effects of ELS are manifested in stress-susceptible regions of the hippocampus and are partially mediated by long-term effects on glucocorticoid and/or neurotrophin signaling pathways. Glucocorticoid (GC signaling mediates the regulation of the stress response to maintain homeostasis, while neurotrophin signaling plays a key role in neuronal outgrowth and is crucial for axonal guidance and synaptic integrity. The neurotrophin and glucocorticoid signaling pathways co-exist throughout the central nervous system (CNS, particularly in the hippocampus, which has high expression of glucocorticoid and mineralocorticoid receptors (GR and MR as well as brain-derived neurotrophic factor (BDNF and its receptor, tropomyosin-related kinase receptor B (TrkB. This review addresses the effects of ELS paradigms on GC- and BDNF- dependent mechanisms and their crosstalk in the hippocampus, including potential implications for the pathogenesis of common stress-related disorders.

  19. New insights in the biology of BDNF synthesis and release: implications in CNS function.

    Science.gov (United States)

    Greenberg, Michael E; Xu, Baoji; Lu, Bai; Hempstead, Barbara L

    2009-10-14

    BDNF has pleiotropic effects on neuronal development and synaptic plasticity that underlie circuit formation and cognitive function. Recent breakthroughs reveal that neuronal activity regulates BDNF cell biology, including Bdnf transcription, dendritic targeting and trafficking of BDNF mRNA and protein, and secretion and extracellular conversion of proBDNF to mature BDNF. Defects in these mechanisms contribute differentially to cognitive dysfunction and anxiety-like behaviors. Here we review recent studies, presented at a symposium at Neuroscience 2009, that describe regulatory mechanisms that permit rapid and dynamic refinement of BDNF actions in neurons.

  20. BDNF, produced by a TPO-stimulated megakaryocytic cell line, regulates autocrine proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Shogo [Graduate School of Health Sciences, Hokkaido University, Sapporo (Japan); Research Fellow of the Japan Society for the Promotion of Science, Tokyo (Japan); Nagasawa, Ayumi; Masuda, Yuya; Tsunematsu, Tetsuya [Graduate School of Health Sciences, Hokkaido University, Sapporo (Japan); Hayasaka, Koji; Matsuno, Kazuhiko; Shimizu, Chikara [Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo (Japan); Ozaki, Yukio [Department of Clinical and Laboratory Medicine, Faculty of Medicine, University of Yamanashi (Japan); Moriyama, Takanori, E-mail: moriyama@hs.hokuda.ac.jp [Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Sapporo (Japan)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer It has been thought that BDNF is not produced in the megakaryocytic lineage. Black-Right-Pointing-Pointer MEG-01 produces BDNF upon TPO stimulation and regulates its proliferation. Black-Right-Pointing-Pointer BDNF accelerates proliferation of MEG-01 in an autocrine manner. Black-Right-Pointing-Pointer BDNF may be an autocrine MEG-CSF, which regulates megakaryopoiesis. -- Abstract: While human platelets release endogenous brain-derived neurotrophic factor (BDNF) upon activation, a previous report on MEG-01, a megakaryocytic cell line, found no trace of BDNF production, and the pathophysiological function of platelet BDNF has remained elusive. In the present study, we demonstrate that MEG-01 produces BDNF in the presence of TPO and that this serves to potentiate cell proliferation. Our in vitro findings suggest that BDNF regulates MEG-01 proliferation in an autocrine manner, and we suggest that BDNF may be a physiological autocrine regulator of megakaryocyte progenitors.

  1. BDNF Meditated trkB and Synapsin I Changes within the Hippocampus after Mild Traumatic Brain Injury in Rat:Reflections of Injury-induced Neuroplasticity

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionTraumatic brain injury (TBI) can produce chronic cognitive learning/memory deficits that are thought to be mediated, in part, by impaired hippocampal function. Brain-derived neurotrophic factor (BDNF), its signal transduction receptor trkB and its downstream effector synapsin I are involved in this period. BDNF, trkB and the slope of field excitatory post-synaptic potential(fEPSP) were measured in the hippocampus of rat after fluid percussion brain injury (FPI). Isofluorane anaesthe- tizeed 50...

  2. Increased BDNF levels in long-term bipolar disorder patients

    Directory of Open Access Journals (Sweden)

    Izabela Guimarães Barbosa

    2013-03-01

    Full Text Available INTRODUCTION: Bipolar disorder (BD is a prevalent, chronic and progressive illness. There is a growing body of evidence indicating that brain-derived neurotrophic factor (BDNF plays an important role in the pathophysiology of BD. OBJECTIVE: The aim of this study was to evaluate BDNF plasma levels in BD patients with long term illness in comparison with controls. METHODS: 87 BD type I patients and 58 controls matched by age, gender and education level were enrolled in this study. All subjects were assessed by the Mini-International Neuropsychiatric Interview and the patients by the Young Mania Rating Scale and the Hamilton Depression Rating Scale. The plasma levels of BDNF were measured by ELISA. RESULTS: On average, patients had suffered from BD for 23.4 years. In comparison with controls, BD patients with mania presented a 1.90-fold increase in BDNF plasma levels (p = .001, while BD patients in remission presented a 1.64-fold increase in BDNF plasma levels (p = .03. BDNF plasma levels were not influenced by age, length of illness or current medications. CONCLUSIONS: The present study suggests that long-term BD patients exhibit increased circulating levels of BDNF.

  3. Role of BDNF epigenetics in activity-dependent neuronal plasticity.

    Science.gov (United States)

    Karpova, Nina N

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) is a key mediator of the activity-dependent processes in the brain that have a major impact on neuronal development and plasticity. Impaired control of neuronal activity-induced BDNF expression mediates the pathogenesis of various neurological and psychiatric disorders. Different environmental stimuli, such as the use of pharmacological compounds, physical and learning exercises or stress exposure, lead to activation of specific neuronal networks. These processes entail tight temporal and spatial transcriptional control of numerous BDNF splice variants through epigenetic mechanisms. The present review highlights recent findings on the dynamic and long-term epigenetic programming of BDNF gene expression by the DNA methylation, histone-modifying and microRNA machineries. The review also summarizes the current knowledge on the activity-dependent BDNF mRNA trafficking critical for rapid local regulation of BDNF levels and synaptic plasticity. Current data open novel directions for discovery of new promising therapeutic targets for treatment of neuropsychiatric disorders. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. A novel role for BDNF-TrkB in the regulation of chemotherapy resistance in head and neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Junegoo Lee

    Full Text Available Mechanisms of resistance for HNSCC to cisplatin (CDDP, the foundational chemotherapeutic agent in the treatment of this disease, remain poorly understood. We previously demonstrated that cisplatin resistance (CR can be overcome by targeting Trk receptor. In the current study, we explored the potential mechanistic role of the BDNF-TrkB signaling system in the development of CDDP resistance in HNSCC. Utilizing an in vitro system of acquired CR, we confirmed a substantial up-regulation of both BDNF and TrkB at the protein and mRNA levels in CR cells, suggesting an autocrine pathway dysregulation in this system. Exogenous BDNF stimulation led to an enhanced expression of the drug-resistance and anti-apoptotic proteins MDR1 and XiAP, respectively, in a dose-dependently manner, demonstrating a key role for BDNF-TrkB signaling in modulating the response to cytotoxic agents. In addition, modulation of TrkB expression induced an enhanced sensitivity of cells to CDDP in HNSCC. Moreover, genetic suppression of TrkB resulted in changes in expression of Bim, XiAP, and MDR1 contributing to HNSCC survival. To elucidate intracellular signaling pathways responsible for mechanisms underlying BDNF/TrkB induced CDDP-resistance, we analyzed expression levels of these molecules following inhibition of Akt. Inhibition of Akt eliminated BDNF effect on MDR1 and Bim expression in OSC-19P cells as well as modulated expressions of MDR1, Bim, and XiAP in OSC-19CR cells. These results suggest BDNF/TrkB system plays critical roles in CDDP-resistance development by utilizing Akt-dependent signaling pathways.

  5. Convergence of DFP algorithm

    Institute of Scientific and Technical Information of China (English)

    袁亚湘

    1995-01-01

    The DFP method is one of the most famous numerical algorithms for unconstrained optimization. For uniformly convex objective functions convergence properties of the DFP method are studied. Several conditions that can ensure the global convergence of the DFP method are given.

  6. Inhibition of BDNF-AS Provides Neuroprotection for Retinal Ganglion Cells against Ischemic Injury

    OpenAIRE

    Xu, Lifang; Zhang, Ziyin; Xie, Tianhua; Zhang, Xiaoyang; Dai, Tu

    2016-01-01

    Background: Brain-derived neurotrophic factor (BDNF) protects retinal ganglion cells against ischemia in ocular degenerative diseases. We aimed to determine the effect of BDNF-AS on the ischemic injury of retinal ganglion cells. Methods: The levels of BDNF and BDNF-AS were measured in retinal ganglion cells subjected to oxygen and glucose deprivation. The lentiviral vectors were constructed to either overexpress or knock out BDNF-AS. The luciferase reporter gene assay was used to determine wh...

  7. Expression of BDNF and TrkB Phosphorylation in the Rat Frontal Cortex During Morphine Withdrawal are NO Dependent.

    Science.gov (United States)

    Peregud, Danil I; Yakovlev, Alexander A; Stepanichev, Mikhail Yu; Onufriev, Mikhail V; Panchenko, Leonid F; Gulyaeva, Natalia V

    2016-08-01

    Nitric oxide (NO) mediates pharmacological effects of opiates including dependence and abstinence. Modulation of NO synthesis during the induction phase of morphine dependence affects manifestations of morphine withdrawal syndrome, though little is known about mechanisms underlying this phenomenon. Neurotrophic and growth factors are involved in neuronal adaptation during opiate dependence. NO-dependent modulation of morphine dependence may be mediated by changes in expression and activity of neurotrophic and/or growth factors in the brain. Here, we studied the effects of NO synthesis inhibition during the induction phase of morphine dependence on the expression of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), nerve growth factor (NGF), and insulin-like growth factor 1 (IGF1) as well as their receptors in rat brain regions after spontaneous morphine withdrawal in dependent animals. Morphine dependence in rats was induced within 6 days by 12 injections of morphine in increasing doses (10-100 mg/kg), and NO synthase inhibitor L-N(G)-nitroarginine methyl ester (L-NAME) (10 mg/kg) was given 1 h before each morphine injection. The expression of the BDNF, GDNF, NGF, IGF1, and their receptors in the frontal cortex, striatum, hippocampus, and midbrain was assessed 40 h after morphine withdrawal. L-NAME treatment during morphine intoxication resulted in an aggravation of the spontaneous morphine withdrawal severity. Morphine withdrawal was accompanied by upregulation of BDNF, IGF1, and their receptors TrkB and IGF1R, respectively, on the mRNA level in the frontal cortex, and only BDNF in hippocampus and midbrain. L-NAME administration during morphine intoxication decreased abstinence-induced upregulation of these mRNAs in the frontal cortex, hippocampus and midbrain. L-NAME prevented from abstinence-induced elevation of mature but not pro-form of BDNF polypeptide in the frontal cortex. While morphine abstinence did not affect Trk

  8. HuD interacts with Bdnf mRNA and is essential for activity-induced BDNF synthesis in dendrites.

    Directory of Open Access Journals (Sweden)

    Filip Vanevski

    Full Text Available Highly specific activity-dependent neuronal responses are necessary for modulating synapses to facilitate learning and memory. We present evidence linking a number of important processes involved in regulating synaptic plasticity, suggesting a mechanistic pathway whereby activity-dependent signaling, likely through protein kinase C (PKC-mediated phosphorylation of HuD, can relieve basal repression of Bdnf mRNA translation in dendrites, allowing for increased TrkB signaling and synaptic remodeling. We demonstrate that the neuronal ELAV family of RNA binding proteins associates in vivo with several Bdnf mRNA isoforms present in the adult brain in an activity-dependent manner, and that one member, HuD, interacts directly with sequences in the long Bdnf 3' untranslated region (3'UTR and co-localizes with Bdnf mRNA in dendrites of hippocampal neurons. Activation of PKC leads to increased dendritic translation of mRNAs containing the long Bdnf 3'UTR, a process that is dependent on the presence of HuD and its phosphorylation at threonine residues 149 and/or 165. Thus, we found a direct effect of HuD on regulating translation of dendritic Bdnf mRNAs to mediate local and activity-dependent increases in dendritic BDNF synthesis.

  9. Effects of chronic ethanol administration on expression of BDNF and trkB mRNAs in rat hippocampus after experimental brain injury.

    Science.gov (United States)

    Zhang, L; Dhillon, H S; Barron, S; Hicks1, R R; Prasad, R M; Seroogy, K B

    2000-06-23

    Previous evidence indicates that both chronic alcohol treatment and traumatic brain injury modulate expression of certain neurotrophins and neurotrophin receptors in cortical tissue. However, the combined effects of chronic alcohol and brain trauma on expression of neurotrophins and their receptors have not been investigated. In the present study, we examined the effects of 6 weeks of chronic ethanol administration on lateral fluid percussion (FP) brain injury-induced alterations in expression of mRNAs for the neurotrophin brain-derived neurotrophic factor (BDNF) and its high affinity receptor, trkB, in rat hippocampus. In both the control- (pair-fed isocaloric sucrose) diet and the chronic ethanol-diet groups, unilateral FP brain injury induced a bilateral increase in levels of both BDNF and trkB mRNAs in the dentate gyrus granule cell layer, and of BDNF mRNA in hippocampal region CA3. However, no significant differences in expression were found between the control-diet and ethanol-diet groups, in either the sham-injured or FP-injured animals. These findings suggest that 6 weeks of chronic ethanol administration does not alter the plasticity of hippocampal BDNF/trkB expression in response to experimental brain injury.

  10. Convergence of Fuzzy Set Sequences

    Institute of Scientific and Technical Information of China (English)

    FENG Yu-hu

    2002-01-01

    There are more than one mode of convergence with respect to the fuzzy set sequences. In this paper,common six modes of convergence and their relationships are discussed. These six modes are convergence in uniform metric D, convergence in separable metric Dp or D*p, 1 ≤ p <∞, convergence in level set, strong convergence in level set and weak convergence. Suitable counterexamples are given. The necessary and sufficient conditions of convergence in uniform metric D are described. Some comme nts on the convergence of LRfuzzy number sequences are represented.

  11. Activated mGluR5 protects BV2 cells against OGD/R induced cytotoxicity by modulating BDNF-TrkB pathway.

    Science.gov (United States)

    Ye, Xinchun; Yu, Lu; Zuo, Dandan; Zhang, Liang; Zu, Jie; Hu, Jinxia; Tang, Jiao; Bao, Lei; Cui, Chengcheng; Zhang, Ruixue; Jin, Guoliang; Zan, Kun; Zhang, Zuohui; Yang, Xinxin; Shi, Hongjuan; Zhang, Zunsheng; Xiao, Qihua; Liu, Yonghai; Xiang, Jie; Zhang, Xueling; Cui, Guiyun

    2017-07-27

    Activated Metabotropic glutamate receptors 5(mGluR5) exhibits protective effects against ischemic brain damage, but the underlying mechanisms are not clearly known. Brain-derived neurotrophic factor (BDNF), as a valuable member of neurotrophic factor family, exerts its protection by combining with its high-affinity receptor tyrosine protein kinase B (TrkB). To investigate the role of activated mGluR5 against oxygen-glucose deprivation (OGD)/reoxygenation (R)-mediated cytotoxicity, the cell viability, apoptosis, the release of inflammatory cytokines and accumulation of reactive oxygen species (ROS) were evaluated in BV2 cells (Microglia cell line) with or without OGD/R exposure. Our data show that CHPG (the selective mGluR5 agonist) pretreatment, as an mGluR5 agonist, protected BV2 cells against OGD/R-induced cytotoxicity, apoptosis, the release of inflammatory cytokines, and the accumulation of ROS. However, these effects were significantly reversed by the mGluR5 antagonist MPEP pretreatment. Our data also show that the expressions of BDNF and TrkB were significantly decreased in BV2 cells with OGD/R exposure. CHPG pretreatment significantly enhanced the expressions of BDNF and TrkB in BV2 cells with OGD/R exposure. However, the increased expressions were significantly abrogated by MPEP pretreatment. In addition, inhibition of BDNF/TrKB pathway by K252a also attenuated the protective effects of activated mGluR5 against OGD/R-induced cytotoxicity, apoptosis and the release of inflammatory cytokines. Morever, pretreatment with exogenous BDNF protected BV2 cells against OGD/R induced apoptosis and release of inflammatory cytokines. These data suggested that BDNF/TrKB pathway may be involved in regulating activated mGluR5' protective effects against OGD/R induced cytotoxicity in BV2 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Brain-derived neurotrophic factor (BDNF) and TrkB in the piglet brainstem after post-natal nicotine and intermittent hypercapnic hypoxia.

    Science.gov (United States)

    Tang, Samantha; Machaalani, Rita; Waters, Karen A

    2008-09-26

    Brain-derived neurotrophic factor (BDNF) and its receptor TrkB play a significant role in the regulation of cell growth, survival and death during central nervous system development. The expression of BDNF and TrkB is affected by noxious insults. Two insults during the early post-natal period that are of interest to our laboratory are exposure to nicotine and to intermittent hypercapnic hypoxia (IHH). Piglet models were used to mimic the conditions associated with the risk factors for the sudden infant death syndrome (SIDS) including post-natal cigarette smoke exposure (nicotine model) and prone sleeping where the infant is subjected to re-breathing of expired gases (IHH model). We aimed to determine the effects of nicotine and IHH, alone or in combination, on pro- and rhBDNF and TrkB expression in the developing piglet brainstem. Four piglet groups were studied, with equal gender ratios in each: control (n=14), nicotine (n=14), IHH (n=10) and nic+IHH (n=14). Applying immunohistochemistry, and studying six nuclei of the caudal medulla, we found that compared to controls, TrkB was the only protein significantly decreased after nicotine and nic+IHH exposure regardless of gender. For pro-BDNF and rhBDNF however, observed changes were more evident in males than females exposed to nicotine and nic+IHH. The implications of these findings are that a prior nicotine exposure makes the developing brainstem susceptible to greater changes in the neurotrophic effects of BDNF and its receptor TrkB in the face of a hypoxic insult, and that the effects are greater in males than females.

  13. Physical Exercise and Antidepressants Enhance BDNF Targeting in Hippocampal CA3 Dendrites: Further Evidence of a Spatial Code for BDNF Splice Variants

    OpenAIRE

    Baj, Gabriele; D'Alessandro, Valentina; Musazzi, Laura; Mallei, Alessandra; Sartori, Cesar R; Sciancalepore, Marina; Tardito, Daniela; Langone, Francesco; Popoli, Maurizio; Tongiorgi, Enrico

    2012-01-01

    Brain-derived neurotrophic factor (BDNF) is encoded by multiple BDNF transcripts, whose function is unclear. We recently showed that a subset of BDNF transcripts can traffic into distal dendrites in response to electrical activity, while others are segregated into the somatoproximal domains. Physical exercise and antidepressant treatments exert their beneficial effects through upregulation of BDNF, which is required to support survival and differentiation of newborn dentate gyrus (DG) neurons...

  14. Expression and Dendritic Trafficking of BDNF-6 Splice Variant are Impaired in Knock-In Mice Carrying Human BDNF Val66Met Polymorphism

    OpenAIRE

    Mallei, A.; Baj, G.; Ieraci, A.; Corna, S.; Musazzi, L.; Lee, F S; Tongiorgi, E.; Popoli, M.

    2015-01-01

    Background: The human Val66Met polymorphism in brain-derived neurotrophic factor (BDNF), a key factor in neuroplasticity, synaptic function, and cognition, has been implicated in the pathophysiology of neuropsychiatric and neurodegenerative disorders. BDNF is encoded by multiple transcripts with distinct regulation and localization, but the impact of the Val66Met polymorphism on BDNF regulation remains unclear. Methods: In BDNF Val66Met knock-in mice, which recapitulate the phenotypic hallmar...

  15. Effect of Electroacupuncture at Different Acupoints on Expression of Cervico-spinal GDNF and BDNF and Their Receptor Genes in Neck-incision Pain Rats%电针刺激不同穴位对颈部切口痛大鼠镇痛效应及对颈髓神经营养因子及其受体mRNA表达的影响

    Institute of Scientific and Technical Information of China (English)

    王少军; 谭连红; 刘俊岭

    2012-01-01

    Objective To observe the effect of electroacupuncture (EA) of "Futu" (LI 18), etc. on the expression of genes of glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and their receptors in the cervico-spinal cord in neck-incision pain rats, so as to study its mechanism underlying incision-pain relief. Methods A total of 50 Sprague Dawley male rats were randomly divided into normal, model (incision pain) , EA-Futu (LI 18) , EA- Hegu (LI 4) -Neiguan (PC 6, LI 4-PC 6) and EA-Zusanli (ST 36)-Yanglingquan(GB 34, ST 36-GB 34) groups (n = 10/group). A 1. 5 cm long longitudinal incision was made along the midline of the neck under anesthesia to duplicate neck-incision pain model. Thermal pain threshold (PT) was measured before and after modeling and after the treatment, respectively. EA (1 -2 mA, 2 Hz/100 Hz) was applied to bilateral LI 18, PC 6-LI 4 and ST 36-GB 34 for 30 min. The expression of genes of GDNF and its receptor GFRα-1, and BDNF and its receptors TrkA, TrkB in the spinal cord (C1 -C4) tissue was detected by quantitative real-time-PCR. Results In comparison with pre-modeling in the same one group, the thermal PT levels were decreased obviously in the model, LI 18, LI 4-PC 6 and ST 36-GB 34 groups after neck incision (P0. 05). In comparison with the model group, the expression levels of spinal GDNF mRNA and GFRa-1 mRNA were up-regulated considerably (P0. 05) in the LI 18, LI 4-PC 6 and ST 36-GB 34 groups after EA treatment. Conclusion EA stimulation can significantly suppress pain reaction of neck incision, which is closely associated with its effects in up-regulating the expression of GDNF and its receptor GFRa-1 genes in the cervical spinal cord(C1- C4).%目的:观察电针“扶突”穴区等对颈部切口病痛反应及颈髓胶质细胞源性神经营养因子(GDNF)等神经营养因子及其受体基因表达的影响,探讨针刺缓解颈部切口痛的机制.方法:SD雄性大鼠随机分为正常组、模型

  16. Brain-derived Neurotrophic Factor (BDNF)-TrkB Signaling in Inflammation-related Depression and Potential Therapeutic Targets.

    Science.gov (United States)

    Zhang, Ji-Chun; Yao, Wei; Hashimoto, Kenji

    2016-01-01

    Depression is the most prevalent and among the most debilitating of psychiatric disorders. The precise neurobiology of this illness is unknown. Several lines of evidence suggest that peripheral and central inflammation plays a role in depressive symptoms, and that anti-inflammatory drugs can improve depressive symptoms in patients with inflammation-related depression. Signaling via brain-derived neurotrophic factor (BDNF) and its receptor, tropomycin receptor kinase B (TrkB) plays a key role in the pathophysiology of depression and in the therapeutic mechanisms of antidepressants. A recent paper showed that lipopolysaccharide (LPS)-induced inflammation gave rise to depression-like phenotype by altering BDNF-TrkB signaling in the prefrontal cortex, hippocampus, and nucleus accumbens, areas thought to be involved in the antidepressant effects of TrkB agonist, 7,8-dihydroxyflavone (7,8-DHF) and TrkB antagonist, ANA-12. Here we provide an overview of the tryptophan-kynurenine pathway and BDNF-TrkB signaling in the pathophysiology of inflammation-induced depression, and propose mechanistic actions for potential therapeutic agents. Additionally, the authors discuss the putative role of TrkB agonists and antagonists as novel therapeutic drugs for inflammation-related depression.

  17. BDNF and trkB mRNA expression in the rat hippocampus following entorhinal cortex lesions.

    Science.gov (United States)

    Lapchak, P A; Araujo, D M; Hefti, F

    1993-02-01

    Quantitative in situ hybridization was used to determine whether the prevalence or topographical distribution of brain-derived neurotrophic factor (BDNF) or tyrosine receptor kinase (trk) B mRNA is altered in the hippocampal formation following lesions of excitatory afferents from the entorhinal cortex which provides an external source of innervation for the hippocampal formation. BDNF mRNA levels were not altered in the hippocampal formation up to 10 days following entorhinal cortex lesions (ECLs). The levels of mRNA coding for all known forms of trkB receptors also remained unchanged. The prevalence of the synaptic plasticity marker SNAP-25 mRNA was increased in the CA2 and CA3 pyramidal cell layers and the dentate gyrus by 6 days following ECLs and remained elevated at 10 days following ECLs. Our findings indicate that hippocampal neuron sprouting which occurs in response to ECLs is not the result of changes in the expression of the BDNF or trkB mRNA.

  18. Nonaccommodative convergence excess.

    Science.gov (United States)

    von Noorden, G K; Avilla, C W

    1986-01-15

    Nonaccommodative convergence excess is a condition in which a patient has orthotropia or a small-angle esophoria or esotropia at distance and a large-angle esotropia at near, not significantly reduced by the addition of spherical plus lenses. The AC/A ratio, determined with the gradient method, is normal or subnormal. Tonic convergence is suspected of causing the convergence excess in these patients. Nonaccommodative convergence excess must be distinguished from esotropia with a high AC/A ratio and from hypoaccommodative esotropia. In 24 patients treated with recession of both medial recti muscles with and without posterior fixation or by posterior fixation alone, the mean correction of esotropia was 7.4 prism diopters at distance and 17 prism diopters at near.

  19. Convergent Aeronautics Solutions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Convergent Aeronautics Solutions (CAS) Project uses short-duration activities to establish early-stage concept and technology feasibility for high-potential...

  20. Brain derived neurotrophic factor (BDNF contributes to the pain hypersensitivity following surgical incision in the rats

    Directory of Open Access Journals (Sweden)

    Zhang Jian-Yi

    2008-07-01

    Full Text Available Abstract Background The pathogenic role of brain derived neurotrophic factor (BDNF in the incisional pain is poorly understood. The present study explores the role of the BDNF in the incision-induced pain hypersensitivity. Methods A longitudinal incision was made in one plantar hind paw of isoflurane-anesthetized rats. Dorsal root ganglias (DRG and spinal cords were removed at various postoperative times (1–72 h. Expression pattern of BDNF was determined by immunohistochemistry and double-labeling immunofluorescence. Lidocaine-induced blockade of sciatic nerve function was used to determine the importance of afferent nerve activity on BDNF expression in the DRG and spinal cord after incision. BDNF antibody was administered intrathecally (IT or intraperitoneal (IP to modulate the spinal BDNF or peripheral BDNF after incision. Results After hind-paw incision, the BDNF was upregulated in the ipsilateral lumbar DRG and spinal cord whereas thoracic BDNF remained unchanged in response to incision. The upregulated BDNF was mainly expressed in the large-sized neurons in DRG and the neurons and the primary nerve terminals in the spinal cord. Sciatic nerve blockade prevented the increase of BDNF in the DRG and spinal cord. IT injection of BDNF antibody greatly inhibited the mechanical allodynia induced by incision whereas IP administration had only marginal effect. Conclusion The present study showed that incision induced the segmental upregulation of BDNF in the DRG and spinal cord through somatic afferent nerve transmission, and the upregulated BDNF contributed to the pain hypersensitivity induced by surgical incision.

  1. Fixed mobile convergence handbook

    CERN Document Server

    Ahson, Syed A

    2010-01-01

    From basic concepts to future directions, this handbook provides technical information on all aspects of fixed-mobile convergence (FMC). The book examines such topics as integrated management architecture, business trends and strategic implications for service providers, personal area networks, mobile controlled handover methods, SIP-based session mobility, and supervisory and notification aggregator service. Case studies are used to illustrate technical and systematic implementation of unified and rationalized internet access by fixed-mobile network convergence. The text examines the technolo

  2. Subsequential Convergence Conditions

    Directory of Open Access Journals (Sweden)

    Dik Mehmet

    2007-01-01

    Full Text Available Let be a sequence of real numbers and let be any regular limitable method. We prove that, under some assumptions, if a sequence or its generator sequence generated regularly by a sequence in a class of sequences is a subsequential convergence condition for , then for any integer , the repeated arithmetic means of , , generated regularly by a sequence in the class , is also a subsequential convergence condition for .

  3. A simple role for BDNF in learning and memory?

    Directory of Open Access Journals (Sweden)

    Carla Cunha

    2010-02-01

    Full Text Available Since its discovery almost three decades ago, the secreted neurotrophin brain-derived neurotrophic factor (BDNF has been firmly implicated in the differentiation and survival of neurons of the CNS. More recently, BDNF has also emerged as an important regulator of synaptogenesis and synaptic plasticity mechanisms underlying learning and memory in the adult CNS. In this review we will discuss our knowledge about the multiple intracellular signalling pathways activated by BDNF, and the role of this neurotrophin in long-term synaptic plasticity and memory formation as well as in synaptogenesis. We will show that maturation of BDNF, its cellular localisation and its ability to regulate both excitatory and inhibitory synapses in the CNS may result in conflicting alterations in synaptic plasticity and memory formation. Lack of a precise knowledge about the mechanisms by which BDNF influences higher cognitive functions and complex behaviours may constitute a severe limitation in the possibility to devise BDNF-based therapeutics for human disorders of the CNS.

  4. IT-BT convergence technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    This book explains IT-BT convergence technology as the future technology, which includes a prolog, easy IT-BT convergence technology that has infinite potentials for new value, policy of IT-BT convergence technology showing the potential of smart Korea, IT-BT convergence opening happy future, for the new future of IT powerful nation Korea with IT-BT convergence technology and an epilogue. This book reveals the conception, policy, performance and future of IT-BT convergence technology.

  5. Intracerebroventricular 4-methylcatechol (4-MC) ameliorates chronic pain associated with depression-like behavior via induction of brain-derived neurotrophic factor (BDNF).

    Science.gov (United States)

    Fukuhara, Kayoko; Ishikawa, Kozo; Yasuda, Seiko; Kishishita, Yusuke; Kim, Hae-Kyu; Kakeda, Takahiro; Yamamoto, Misa; Norii, Takafumi; Ishikawa, Toshizo

    2012-08-01

    Neuropathic pain concurrent with mood disorder from peripheral nerve injury is a serious clinical problem that significantly affects quality of life. Recent studies have suggested that a lack of brain-derived neurotrophic factor (BDNF) in the limbic system may cause this pain-emotion. BDNF is induced in cultured neurons by 4-methylcatechol (4-MC), but the role of 4-MC-induced BDNF in pain-emotion is poorly understood. Thus, we assessed the possible involvement of BDNF in brain in depression-like behavior during chronic pain following peripheral nerve injury. In addition, we examined whether intracerebroventricular (i.c.v.) 4-MC prevents chronic pain in rats and produces an antidepressant effect. Sprague-Dawley rats implanted intracerebroventricularly with a PE-10 tube were subjected to chronic constriction injury (CCI). Pain was assessed by a reduction in paw withdrawal latency (PWL) to heat stimuli after CCI. We also used a forced swimming testing (FST; time of immobility, in seconds) from day 14 to day 21 after CCI. Modulation of pain and emotional behavior was performed by injection of PD0325901 (a MEK1/2 inhibitor). 4-MC (100 nM) was continuously administered i.c.v. for 3 days during the period from day 14 to day 21 after CCI. To block analgesic and antidepressant effects, anti-BDNF antibody or K252a (a TrkB receptor inhibitor) was injected in combination with 4-MC. Naloxone was also coadministered to confirm the analgesic effect of 4-MC. During the chronic stage after CCI, the rats showed a sustained decrease in PWL (thermal hyperalgesia) associated with extension of the time of immobility (depression-like behavior). PD0325901 significantly reduced the decrease in PWL and the increased time of immobility after CCI. The decreased PWL and increased time of immobility were also reduced by 4-MC and by treatment with an ERK1/2 inhibitor. These effects of 4-MC i.c.v. were reversed by anti-BDNF and K252a. The analgesic effect of 4-MC i.c.v. was also antagonized by

  6. Therapeutic potential of brain-derived neurotrophic factor (BDNF) and a small molecular mimics of BDNF for traumatic brain injury

    Science.gov (United States)

    Wurzelmann, Mary; Romeika, Jennifer; Sun, Dong

    2017-01-01

    Traumatic brain injury (TBI) is a major health problem worldwide. Following primary mechanical insults, a cascade of secondary injuries often leads to further neural tissue loss. Thus far there is no cure to rescue the damaged neural tissue. Current therapeutic strategies primarily target the secondary injuries focusing on neuroprotection and neuroregeneration. The neurotrophin brain-derived neurotrophic factor (BDNF) has significant effect in both aspects, promoting neuronal survival, synaptic plasticity and neurogenesis. Recently, the flavonoid 7,8-dihydroxyflavone (7,8-DHF), a small TrkB agonist that mimics BDNF function, has shown similar effects as BDNF in promoting neuronal survival and regeneration following TBI. Compared to BDNF, 7,8-DHF has a longer half-life and much smaller molecular size, capable of penetrating the blood-brain barrier, which makes it possible for non-invasive clinical application. In this review, we summarize functions of the BDNF/TrkB signaling pathway and studies examining the potential of BDNF and 7,8-DHF as a therapy for TBI.

  7. Therapeutic potential of brain-derived neurotrophic factor (BDNF) and a small molecular mimics of BDNF for traumatic brain injury.

    Science.gov (United States)

    Wurzelmann, Mary; Romeika, Jennifer; Sun, Dong

    2017-01-01

    Traumatic brain injury (TBI) is a major health problem worldwide. Following primary mechanical insults, a cascade of secondary injuries often leads to further neural tissue loss. Thus far there is no cure to rescue the damaged neural tissue. Current therapeutic strategies primarily target the secondary injuries focusing on neuroprotection and neuroregeneration. The neurotrophin brain-derived neurotrophic factor (BDNF) has significant effect in both aspects, promoting neuronal survival, synaptic plasticity and neurogenesis. Recently, the flavonoid 7,8-dihydroxyflavone (7,8-DHF), a small TrkB agonist that mimics BDNF function, has shown similar effects as BDNF in promoting neuronal survival and regeneration following TBI. Compared to BDNF, 7,8-DHF has a longer half-life and much smaller molecular size, capable of penetrating the blood-brain barrier, which makes it possible for non-invasive clinical application. In this review, we summarize functions of the BDNF/TrkB signaling pathway and studies examining the potential of BDNF and 7,8-DHF as a therapy for TBI.

  8. Risperidone reverses the spatial object recognition impairment and hippocampal BDNF-TrkB signalling system alterations induced by acute MK-801 treatment.

    Science.gov (United States)

    Chen, Guangdong; Lin, Xiaodong; Li, Gongying; Jiang, Diego; Lib, Zhiruo; Jiang, Ronghuan; Zhuo, Chuanjun

    2017-03-01

    The aim of the present study was to investigate the effects of a commonly-used atypical antipsychotic, risperidone, on alterations in spatial learning and in the hippocampal brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signalling system caused by acute dizocilpine maleate (MK-801) treatment. In experiment 1, adult male Sprague-Dawley rats subjected to acute treatment of either low-dose MK801 (0.1 mg/kg) or normal saline (vehicle) were tested for spatial object recognition and hippocampal expression levels of BDNF, TrkB and the phophorylation of TrkB (p-TrkB). We found that compared to the vehicle, MK-801 treatment impaired spatial object recognition of animals and downregulated the expression levels of p-TrkB. In experiment 2, MK-801- or vehicle-treated animals were further injected with risperidone (0.1 mg/kg) or vehicle before behavioural testing and sacrifice. Of note, we found that risperidone successfully reversed the deleterious effects of MK-801 on spatial object recognition and upregulated the hippocampal BDNF-TrkB signalling system. Collectively, the findings suggest that cognitive deficits from acute N-methyl-D-aspartate receptor blockade may be associated with the hypofunction of hippocampal BDNF-TrkB signalling system and that risperidone was able to reverse these alterations.

  9. Exposure to music in the perinatal period enhances learning performance and alters BDNF/TrkB signaling in mice as adults.

    Science.gov (United States)

    Chikahisa, Sachiko; Sei, Hiroyoshi; Morishima, Masaki; Sano, Atsuko; Kitaoka, Kazuyoshi; Nakaya, Yutaka; Morita, Yusuke

    2006-05-15

    Music has been suggested to have a beneficial effect on various types of performance in humans. However, the physiological and molecular mechanism of this effect remains unclear. We examined the effect of music exposure during the perinatal period on learning behavior in adult mice, and measured the levels of brain-derived neurotrophic factor (BDNF) and its receptor, tyrosine kinase receptor B (TrkB), which play critical roles in synaptic plasticity. In addition, we measured the levels of 3-phosphoinositide-dependent protein kinase-1 (PDK1) and mitogen-activated protein kinase (MAPK), downstream targets of two main pathways in BDNF/TrkB signaling. Music-exposed mice completed a maze learning task with fewer errors than the white noise-exposed mice and had lower levels of BDNF and higher levels of TrkB and PDK1 in the cortex. MAPK levels were unchanged. Furthermore, TrkB and PDK1 protein levels in the cortex showed a significant negative correlation with the number of errors on the maze. These results suggest that perinatal exposure of mice to music has an influence on BDNF/TrkB signaling and its intracellular signaling pathway targets, including PDK1, and thus may induce improved learning and memory functions.

  10. Critical role of promoter IV-driven BDNF transcription in GABAergic transmission and synaptic plasticity in the prefrontal cortex

    OpenAIRE

    Sakata, Kazuko; Woo, Newton H.; Martinowich, Keri; Greene, Joshua S.; Schloesser, Robert J.; Shen, Liya; Lu, Bai

    2009-01-01

    Transcription of Bdnf is controlled by multiple promoters, which drive expression of multiple transcripts encoding for the same protein. Promoter IV contributes significantly to activity-dependent brain-derived neurotrophic factor (BDNF) transcription. We have generated promoter IV mutant mice (BDNF-KIV) by inserting a GFP-STOP cassette within the Bdnf exon IV locus. This genetic manipulation results in disruption of promoter IV-mediated Bdnf expression. BDNF-KIV animals exhibited significant...

  11. Maternal Voluntary Exercise during Pregnancy Enhances the Spatial Learning Acquisition but not the Retention of Memory in Rat Pups via a TrkB-mediated Mechanism: The Role of Hippocampal BDNF Expression

    Directory of Open Access Journals (Sweden)

    Maziar M Akhavan

    2013-09-01

    Full Text Available   Objective(s: The effect of maternal voluntary exercise on hippocampal BDNF level in rat offspring was studied. In addition, the possible role of hippocampal BDNF receptors in maternal exercise induced enhancement of learning in the rat pups was investigated.   Materials and Methods: Pregnant rats have been randomly assigned to sedentary control or voluntary exercise groups. Each of the exercising pregnant rats was given access to a cage that was equipped with a running wheel until the end of their pregnancy. On post natal day (PND 36, two groups consisted of 7 male rat pups in each group from sedentary or exercised mothers were sacrificed and the hippocampus was dissected for BDNF proteins level determination. Also, bilateral injection of K252a to the hippocampus was used to block the hippocampal BDNF action on PND59 in the rat pups. Results: Voluntary exercise during pregnancy significantly increased the level of BDNF protein in the hippocampus of the rat pups on PND36 compared to the control group (P=0.048. Inhibiting BDNF action abolished the exercise-induced improvement of learning acquisition in offspring in training trials (P=0.0001. No difference was observed in the platform location latency and the time spent in the target in the probe test between two groups. Conclusion : This study demonstrates that voluntary exercise during pregnancy via a TrkB-mediated mechanism enhances the spatial learning acquisition, however, not the retention of memory in the rat pups.

  12. HuD promotes BDNF expression in brain neurons via selective stabilization of the BDNF long 3'UTR mRNA.

    Directory of Open Access Journals (Sweden)

    Megan Allen

    Full Text Available Complex regulation of brain-derived neurotrophic factor (BDNF governs its intricate functions in brain development and neuronal plasticity. Besides tight transcriptional control from multiple distinct promoters, alternative 3'end processing of the BDNF transcripts generates either a long or a short 3'untranslated region (3'UTR. Previous reports indicate that distinct RNA sequence in the BDNF 3'UTRs differentially regulates BDNF production in the brain to accommodate neuronal activity changes, conceivably through differential interactions with undefined trans-acting factors that regulate stability and translation of these BDNF mRNA isoforms. In this study, we report that the neuronal RNA-binding protein (RBP HuD interacts with a highly conserved AU-rich element (ARE specifically located in the BDNF long 3'UTR. Such interaction is necessary and sufficient for selective stabilization of mRNAs that contain the BDNF long 3'UTR in vitro and in vivo. Moreover, in a HuD transgenic mouse model, the BDNF long 3'UTR mRNA is increased in the hippocampal dentate granule cells (DGCs, leading to elevated expression of BDNF protein that is transported and stored in the mossy fiber (MF terminals. Our results identify HuD as the first trans-acting factor that enhances BDNF expression specifically through the long 3'UTR and a novel mechanism that regulates BDNF protein production in selected neuronal populations by HuD abundance.

  13. An Experimental Study of the Regulation of BDNF/TrkB Signal Pathway by Different Isoforms of TrkB in Epileptic Hippocampal Neurons%TrkB不同亚型对癫海马神经元BDNF/TrkB信号通路调控的研究

    Institute of Scientific and Technical Information of China (English)

    吴秋静; 常伟; 潘立平; 宋毅军; 赵文

    2014-01-01

    Objective To investigate the mechanism of brain derived neurotrophic factor (BDNF) regulated by differ-ent isoforms of tyrosine kinase receptor B (TrkB) in epileptic hippocampal neurons. Methods Primary hippocampal neu-rons were cultured in vitro for 7 days, and divided into two groups, ALLN (calcineurin inhibitor) group and Anisomycin (trans-lation inhibitor) group. ALLN group included control group, control+BDNF group, epilepsy group, epilepsy+BDNF group, control+ALLN group, epilepsy+ALLN group and epilepsy+ALLN+BDNF group. Anisomycin group was sub-divided into con-trol group, control+BDNF group, epilepsy group, epilepsy+BDNF group, control+Anisomycin group, epilepsy+Anisomycin group and epilepsy+Anisomycin+BDNF group. The immunofluorescent technique was used to identificate the hippocampal neurons. Epileptiform discharges were detected by electrophysiological techniques. Western blot assay was used to deter-mine the protein expression of TrkB and phosphorylated TrkB (p-TrkB) in all cell groups. Results (1) In ALLN group, the gray value of p-TrkB/TrkB was higher in control+BDNF group compared with that of control group, the value was higher in epilepsy+BDNF group than that of epilepsy group but was lower than that of control+BDNF group. The gray value of p-TrkB/TrkB was lower in epilepsy+ALLN+BDNF group than that of epilepsy+BDNF group, but no significant difference compared with that of epilepsy+ALLN group. (2) In Anisomycin group:the gray value of p-TrkB/TrkB was higher in control+BDNF group than that of control group. The gray value of p-TrkB/TrkB was higher in epilepsy+BDNF group than that of epilepsy group, but which was lower than that of control+BDNF group. The gray value of p-TrkB/TrkB was higher in epilepsy+Aniso-mycin+BDNF group than that of epilepsy+BDNF group and epilepsy+Anisomycin group. Conclusion The decreased ex-pression of TrkB.T can improve the inhibition of BDNF/TrkB signaling, and BDNF can activate BDNF/TrkB signal pathway in epileptic

  14. Are variations in whole blood BDNF level associated with the BDNF Val66Met polymorphism in patients with first episode depression?

    DEFF Research Database (Denmark)

    Vinberg, Maj; Bukh, Jens Otto Drachmann; Bennike, Bente;

    2013-01-01

    Brain derived neurotrophic factor (BDNF) seems to play an important role in the pathophysiology of affective disorders. The current study investigated whether blood level BDNF is correlated with the severity of depressive symptoms and recent (six months prior to onset of depression) experience......). Symptomatology was rated using Hamilton Rating Scale for Depression (HAMD-17) and Becks Depression Inventory (BDI 21). No differences in whole blood BDNF was seen in relation to the BDNF Val66Met polymorphism and no significant correlations between whole blood BDNF and HAMD-17 or BDI 21 scores were found....... No significant associations between the experiences of SLE before onset of depression and BDNF level were observed. Finally, peripheral BDNF differentiated between patients and healthy control persons. In the current sample of first episode depressed patients, the Val66Met polymorphism was not associated...

  15. Pro-brain-derived neurotrophic factor inhibits GABAergic neurotransmission by activating endocytosis and repression of GABAA receptors.

    Science.gov (United States)

    Riffault, Baptiste; Medina, Igor; Dumon, Camille; Thalman, Carine; Ferrand, Nadine; Friedel, Perrine; Gaiarsa, Jean-Luc; Porcher, Christophe

    2014-10-01

    GABA is the canonical inhibitory neurotransmitter in the CNS. This inhibitory action is largely mediated by GABA type A receptors (GABAARs). Among the many factors controlling GABAergic transmission, brain-derived neurotrophic factor (BDNF) appears to play a major role in regulating synaptic inhibition. Recent findings have demonstrated that BDNF can be released as a precursor (proBDNF). Although the role of mature BDNF on GABAergic synaptogenesis and maintenance has been well studied, an important question still unanswered is whether secreted proBDNF might affect GABAergic neurotransmission. Here, we have used 14 d in vitro primary culture of hippocampal neurons and ex vivo preparations from rats to study the function of proBDNF in regulation of GABAAR trafficking and activity. We demonstrate that proBDNF impairs GABAergic transmission by the activation of two distinct pathways: (1) a RhoA-Rock-PTEN pathway that decreases the phosphorylation levels of GABAAR, thus affecting receptor function and triggering endocytosis and degradation of internalized receptors, and (2) a JAK-STAT-ICER pathway leading to the repression of GABAARs synthesis. These effects lead to the diminution of GABAergic synapses and are correlated with a decrease in GABAergic synaptic currents. These results revealed new functions for proBDNF-p75 neurotrophin receptor signaling pathway in the control of the efficacy of GABAergic synaptic activity by regulating the trafficking and synthesis of GABAARs at inhibitory synapses.

  16. Hydroxysafflor yellow A increases BDNF and NMDARs in the hippocampus in a vascular dementia rat model.

    Science.gov (United States)

    Xing, Mengya; Sun, Qingna; Wang, Yiyi; Cheng, Yan; Zhang, Nan

    2016-07-01

    Hydroxysafflor yellow A (HSYA) is a drug that exerts angiogenesis regulatory and neuroprotective effects and has become an effective therapy for brain and heart ischemic disorders. There is no definite evidence supporting a therapeutic effect of HSYA in vascular dementia (VaD). We used HSYA in a rat model of chronic cerebral ischemia to determine its potential therapeutic effects in VaD. The Morris water maze (MWM) was used to evaluate spatial cognitive function, and long-term potentiation (LTP) was tested as a marker of synaptic plasticity. The expression levels of brain-derived neurotrophic factor (BDNF) and two subunits of N-methyl-d-aspartate receptor (NMDAR; GluN2A and GluN2B) in the hippocampus were measured via western blotting. The MWM results showed that the experimental VaD group had longer escape latencies than the sham group, whereas the HSYA group had a decreased escape latency compared with the VaD group (PCA3-CA1 synapses in the hippocampus was also enhanced in the HSYA compared with the VaD group (P<0.05). The western blotting results revealed lower hippocampal BDNF and GluN2B expression in the VaD group compared with the sham group and significantly higher hippocampal expression in the HSYA group compared with the VaD group. No significant change in GluN2A expression was detected. The results indicate that HSYA may enhance the endogenous expression of BDNF and GluN2B, which are associated with the synaptic plasticity of the hippocampus, and may improve spatial learning and memory abilities in a rat model of VaD.

  17. Variant brain-derived neurotrophic factor (BDNF) (Met66) alters the intracellular trafficking and activity-dependent secretion of wild-type BDNF in neurosecretory cells and cortical neurons.

    Science.gov (United States)

    Chen, Zhe-Yu; Patel, Paresh D; Sant, Gayatree; Meng, Chui-Xiang; Teng, Kenneth K; Hempstead, Barbara L; Lee, Francis S

    2004-05-05

    Brain-derived neurotrophic factor (BDNF) plays a critical role in nervous system and cardiovascular development and function. Recently, a common single nucleotide polymorphism in the bdnf gene, resulting in a valine to methionine substitution in the prodomain (BDNF(Met)), has been shown to lead to memory impairment and susceptibility to neuropsychiatric disorders in humans heterozygous for the variant BDNF. When expressed by itself in hippocampal neurons, less BDNF(Met) is secreted in an activity-dependent manner. The nature of the cellular defect when both BDNF(Met) and wild-type BDNF (BDNF(Val)) are present in the same cell is not known. Given that this is the predominant expression profile in humans, we examined the effect of coexpressed BDNF(Met) on BDNF(Val) intracellular trafficking and processing. Our data indicate that abnormal trafficking of BDNF(Met) occurred only in neuronal and neurosecretory cells and that BDNF(Met) could alter the intracellular distribution and activity-dependent secretion of BDNF(Val). We determined that, when coexpressed in the same cell, approximately 70% of the variant BDNF forms BDNF(Val).BDNF(Met) heterodimers, which are inefficiently sorted into secretory granules resulting in a quantitative decreased secretion. Finally, we determined the form of BDNF secreted in an activity-dependent manner and observed no differences in the forms of BDNF(Met) or the BDNF(Val).BDNF(Met) heterodimer compared with BDNF(Val). Together, these findings indicate that components of the regulated secretory machinery interacts specifically with a signal in the BDNF prodomain and that perturbations in BDNF trafficking may lead to selective impairment in CNS function.

  18. Depression, 5HTTLPR and BDNF Val66Met polymorphisms, and plasma BDNF levels in hemodialysis patients with chronic renal failure

    Directory of Open Access Journals (Sweden)

    Wang LJ

    2014-07-01

    Full Text Available Liang-Jen Wang,1,* Chih-Ken Chen,2,3,* Heng-Jung Hsu,3,4 I-Wen Wu,3,4 Chiao-Yin Sun,3,4 Chin-Chan Lee3,41Department of Child and Adolescent Psychiatry, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; 2Department of Psychiatry, Chang Gung Memorial Hospital, Keelung, Taiwan; 3Chang Gung University School of Medicine, Taoyuan, Taiwan; 4Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan *LJW and CKC are joint first authors and contributed equally to this manuscriptObjective: Depression is the most prevalent comorbid psychiatric disease among hemodialysis patients with end-stage renal disease. This cross-sectional study investigated whether depression in hemodialysis patients is associated with the polymorphism of the 5' flanking transcriptional region (5-HTTLPR of the serotonin transporter gene, the valine (Val-to-methionine (Met substitution at codon 66 (Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF gene, or plasma BDNF levels.Methods: A total of 188 participants (mean age: 58.5±14.0 years; 89 men and 99 women receiving hemodialysis at the Chang Gung Memorial Hospital were recruited. The diagnosis of major depressive disorder (MDD was confirmed using the Chinese version of the Mini International Neuropsychiatric Interview. The genotypes of 5-HTTLPR and BDNF Val66Met were conducted using polymerase chain reactions plus restriction fragment length polymorphism analysis. The plasma BDNF levels were measured using an enzyme-linked immunosorbent assay kit.Results: Forty-five (23.9% patients fulfilled the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV-TR criteria for a MDD. There were no significant effects of the 5-HTTLPR or BDNF Val66Met gene polymorphism on MDD among the hemodialysis patients. The plasma BDNF levels correlated significantly with age (P=0.003 and sex (P=0.047 but not with depression, the genotypes of 5

  19. Converging towards the future

    Energy Technology Data Exchange (ETDEWEB)

    Gale, R. W.

    1997-05-01

    The likelihood of convergence in the electric power industry in Canada and the United Sates was examined, and the impact of such a development with respect to electricity and natural gas was explored. Based on developments to date, convergence between gas and electric utilities was considered an inevitable step towards the ultimate consolidation of the energy industry as a whole. Characteristics shared by gas and electric utilities were described, and likely developments leading to convergence of the two industries were reviewed. According to this author the competition between the opposing utilities will lead to price wars, loss leaders and other marketing strategies. Prices will be set by supply and demand principles. While users will be able to select customized, money-saving energy solutions, for suppliers, the new utility market will be a Darwinian battle royale, where only the most viable will survive. The end result will be a larger market dominated by a few super players.

  20. On the Fuzzy Convergence

    Directory of Open Access Journals (Sweden)

    Abdul Hameed Q. A. Al-Tai

    2011-01-01

    Full Text Available The aim of this paper is to introduce and study the fuzzy neighborhood, the limit fuzzy number, the convergent fuzzy sequence, the bounded fuzzy sequence, and the Cauchy fuzzy sequence on the base which is adopted by Abdul Hameed (every real number r is replaced by a fuzzy number r¯ (either triangular fuzzy number or singleton fuzzy set (fuzzy point. And then, we will consider that some results respect effect of the upper sequence on the convergent fuzzy sequence, the bounded fuzzy sequence, and the Cauchy fuzzy sequence.

  1. Convergence of Networks

    DEFF Research Database (Denmark)

    Prasad, Ramjee; Ruggieri, Marina

    2008-01-01

    The paper focuses on the revolutionary changes that could characterise the future of networks. Those changes involve many aspects in the conceivement and exploitation of networks: architecture, services, technologies and modeling. The convergence of wired and wireless technologies along...... with the integration of system componennts and the convergence of services (e.g. communications and navigation) are only some of the elements that shape the perpsected mosaic. Authors delineate this vision, highlighting the presence of the space and stratospheric components and the related services as building block...

  2. Alterations of BDNF and trkB mRNA expression in the 6-hydroxydopamine-induced model of preclinical stages of Parkinson's disease: an influence of chronic pramipexole in rats.

    Directory of Open Access Journals (Sweden)

    Klemencja Berghauzen-Maciejewska

    Full Text Available Our recent study has indicated that a moderate lesion of the mesostriatal and mesolimbic pathways in rats, modelling preclinical stages of Parkinson's disease, induces a depressive-like behaviour which is reversed by chronic treatment with pramipexole. The purpose of the present study was to examine the role of brain derived neurotrophic factor (BDNF signalling in the aforementioned model of depression. Therefore, we investigated the influence of 6-hydoxydopamine (6-OHDA administration into the ventral region of the caudate-putamen on mRNA levels of BDNF and tropomyosin-related kinase B (trkB receptor. The BDNF and trkB mRNA levels were determined in the nigrostriatal and limbic structures by in situ hybridization 2 weeks after the operation. Pramipexole (1 mg/kg sc twice a day and imipramine (10 mg/kg ip once a day were injected for 2 weeks. The lesion lowered the BDNF and trkB mRNA levels in the hippocampus [CA1, CA3 and dentate gyrus (DG] and amygdala (basolateral/lateral as well as the BDNF mRNA content in the habenula (medial/lateral. The lesion did not influence BDNF and trkB expression in the caudate-putamen, substantia nigra, nucleus accumbens (shell and core and ventral tegmental area (VTA. Chronic imipramine reversed the lesion-induced decreases in BDNF mRNA in the DG. Chronic pramipexole increased BDNF mRNA, but decreased trkB mRNA in the VTA in lesioned rats. Furthermore, it reduced BDNF and trkB mRNA expression in the shell and core of the nucleus accumbens, BDNF mRNA in the amygdala and trkB mRNA in the caudate-putamen in these animals. The present study indicates that both the 6-OHDA-induced dopaminergic lesion and chronic pramipexole influence BDNF signalling in limbic structures, which may be related to their pro-depressive and antidepressant activity in rats, respectively.

  3. Alterations of BDNF and trkB mRNA expression in the 6-hydroxydopamine-induced model of preclinical stages of Parkinson's disease: an influence of chronic pramipexole in rats.

    Science.gov (United States)

    Berghauzen-Maciejewska, Klemencja; Wardas, Jadwiga; Kosmowska, Barbara; Głowacka, Urszula; Kuter, Katarzyna; Ossowska, Krystyna

    2015-01-01

    Our recent study has indicated that a moderate lesion of the mesostriatal and mesolimbic pathways in rats, modelling preclinical stages of Parkinson's disease, induces a depressive-like behaviour which is reversed by chronic treatment with pramipexole. The purpose of the present study was to examine the role of brain derived neurotrophic factor (BDNF) signalling in the aforementioned model of depression. Therefore, we investigated the influence of 6-hydoxydopamine (6-OHDA) administration into the ventral region of the caudate-putamen on mRNA levels of BDNF and tropomyosin-related kinase B (trkB) receptor. The BDNF and trkB mRNA levels were determined in the nigrostriatal and limbic structures by in situ hybridization 2 weeks after the operation. Pramipexole (1 mg/kg sc twice a day) and imipramine (10 mg/kg ip once a day) were injected for 2 weeks. The lesion lowered the BDNF and trkB mRNA levels in the hippocampus [CA1, CA3 and dentate gyrus (DG)] and amygdala (basolateral/lateral) as well as the BDNF mRNA content in the habenula (medial/lateral). The lesion did not influence BDNF and trkB expression in the caudate-putamen, substantia nigra, nucleus accumbens (shell and core) and ventral tegmental area (VTA). Chronic imipramine reversed the lesion-induced decreases in BDNF mRNA in the DG. Chronic pramipexole increased BDNF mRNA, but decreased trkB mRNA in the VTA in lesioned rats. Furthermore, it reduced BDNF and trkB mRNA expression in the shell and core of the nucleus accumbens, BDNF mRNA in the amygdala and trkB mRNA in the caudate-putamen in these animals. The present study indicates that both the 6-OHDA-induced dopaminergic lesion and chronic pramipexole influence BDNF signalling in limbic structures, which may be related to their pro-depressive and antidepressant activity in rats, respectively.

  4. Serum brain-derived neurotrophic factor (BDNF) levels in schizophrenia: A systematic review

    National Research Council Canada - National Science Library

    Cui, Huiru; Jin, Yi; Wang, Jijun; Weng, Xuchu; Li, Chunbo

    2012-01-01

    There is increasing interest in the role of brain-derived neurotrophic factor (BDNF) in the onset and course of schizophrenia, but there are conflicting reports about serum levels of BDNF in patients with schizophrenia...

  5. The convergence of chaotic integrals

    CERN Document Server

    Bauer, O; Bauer, Oliver; Mainieri, Ronnie

    1995-01-01

    We review the convergence of chaotic integrals computed by Monte Carlo simulation, the trace method, dynamical zeta function, and Fredholm determinant on a simple one-dimensional example: the parabola repeller. There is a dramatic difference in convergence between these approaches. The convergence of the Monte Carlo method follows an inverse power law, whereas the trace method and dynamical zeta function converge exponentially, and the Fredholm determinant converges faster than any exponential.

  6. Distribution of brain-derived neurotrophic factor and TrkB receptor proteins in the fetal and postnatal hippocampus and cerebellum of the guinea pig.

    Science.gov (United States)

    Dieni, Sandra; Rees, Sandra

    2002-12-16

    This study investigates the distribution of brain-derived neurotrophic factor protein (BDNF) and its receptor, TrkB, during the development of hippocampus and cerebellum in a long-gestation species, the guinea pig. In the granule cell populations of both structures, BDNF immunoreactivity (-IR) was exclusive to postmigratory, mature neurons. In dentate granule cells, TrkB-IR was coexpressed with BDNF-IR, suggesting that the ligand-receptor interaction could occur by means of an autocrine/paracrine mechanism. In cerebellar granule cells, TrkB-IR was detected in both pre- and postmigratory cells, indicating that immature neurons are also BDNF-responsive. With advancing gestational age an increase in the intensity of BDNF-IR in granule cells was accompanied by concomitant increases in the staining and areal growth of the associated mossy fiber layer in the hippocampus, and the molecular layer in the cerebellum. The developmental increase in BDNF- and TrkB-IR in the neuropil of both structures coincided with periods of significant growth in all strata, indicating a role for BDNF and TrkB in process outgrowth. In the hippocampus, CA2, CA3, and hilar, neurons demonstrated both BDNF- and TrkB-IR during development and maturation, whereas CA1 neurons showed TrkB-IR throughout this period but only transient BDNF-IR in early gestation. In the fetal cerebellum, Purkinje cell bodies coexpressed BDNF-IR and TrkB-IR. In the postnatal period, BDNF-IR was down-regulated but TrkB-IR persisted, indicating that mature Purkinje cells might retain their responsiveness to BDNF. Thus, we have demonstrated in both the hippocampus and cerebellum that the spatiotemporal distribution of BDNF-IR and TrkB-IR coincides with the maturation of granule cells prenatally and with significant periods of neuropil growth, both prenatally and in the immediate postnatal period.

  7. A novel form of synaptic plasticity in field CA3 of hippocampus requires GPER1 activation and BDNF release.

    Science.gov (United States)

    Briz, Victor; Liu, Yan; Zhu, Guoqi; Bi, Xiaoning; Baudry, Michel

    2015-09-28

    Estrogen is an important modulator of hippocampal synaptic plasticity and memory consolidation through its rapid action on membrane-associated receptors. Here, we found that both estradiol and the G-protein-coupled estrogen receptor 1 (GPER1) specific agonist G1 rapidly induce brain-derived neurotrophic factor (BDNF) release, leading to transient stimulation of activity-regulated cytoskeleton-associated (Arc) protein translation and GluA1-containing AMPA receptor internalization in field CA3 of hippocampus. We also show that type-I metabotropic glutamate receptor (mGluR) activation does not induce Arc translation nor long-term depression (LTD) at the mossy fiber pathway, as opposed to its effects in CA1, and it only triggers LTD after GPER1 stimulation. Furthermore, this form of mGluR-dependent LTD is associated with ubiquitination and proteasome-mediated degradation of GluA1, and is prevented by proteasome inhibition. Overall, our study identifies a novel mechanism by which estrogen and BDNF regulate hippocampal synaptic plasticity in the adult brain.

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

    OpenAIRE

    Bianca Seifert; Robert Eckenstaler; Raik Rönicke; Julia Leschik; Beat Lutz; Klaus Reymann; Volkmar Lessmann; Tanja Brigadski

    2016-01-01

    The neurotrophin brain derived neurotrophic factor (BDNF) is an important growth factor in the CNS. Deficits in transport of this secretory protein could underlie neurodegenerative diseases. Investigation of disease-related changes in BDNF transport might provide insights into the cellular mechanism underlying, for example, Alzheimer’s disease (AD). To analyze the role of BDNF transport in AD, live cell imaging of fluorescently labeled BDNF was performed in hippocampal neurons of different AD...

  9. The Convergence Years

    Science.gov (United States)

    Kolodzy, Janet; Grant, August E.; DeMars, Tony R.; Wilkinson, Jeffrey S.

    2014-01-01

    The emergence of the Internet, social media, and digital technologies in the twenty-first century accelerated an evolution in journalism and communication that fit under the broad term of convergence. That evolution changed the relationship between news producers and consumers. It broke down the geographical boundaries in defining our communities,…

  10. Convergent Filter Bases

    OpenAIRE

    Coghetto Roland

    2015-01-01

    We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres) and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections).

  11. Convergence of Networks

    DEFF Research Database (Denmark)

    Prasad, Ramjee; Ruggieri, Marina

    2008-01-01

    with the integration of system componennts and the convergence of services (e.g. communications and navigation) are only some of the elements that shape the perpsected mosaic. Authors delineate this vision, highlighting the presence of the space and stratospheric components and the related services as building block...

  12. Convergent Filter Bases

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-09-01

    Full Text Available We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections.

  13. Language Convergence Infrastructure

    NARCIS (Netherlands)

    V. Zaytsev (Vadim); J.M. Fernandes; R. Lämmel (Ralf); J.M.W. Visser (Joost); J. Saraiva

    2011-01-01

    htmlabstractThe process of grammar convergence involves grammar extraction and transformation for structural equivalence and contains a range of technical challenges. These need to be addressed in order for the method to deliver useful results. The paper describes a DSL and the infrastructure behind

  14. Convergence of Arnoldi method

    Energy Technology Data Exchange (ETDEWEB)

    Nevanlinna, O. [Helsinki Univ. of Technology, Espoo (Finland)

    1994-12-31

    This note summarizes some results on (a monitored version of) the Arnoldi method in Hilbert spaces. The interest in working in infinite dimensional spaces comes partly from the fact that only then can one have meaningful asymptotical statements (which hopefully give some light to the convergence of Arnoldi in large dimensional problems with iteration indices far less than the dimension).

  15. The Convergence Years

    Science.gov (United States)

    Kolodzy, Janet; Grant, August E.; DeMars, Tony R.; Wilkinson, Jeffrey S.

    2014-01-01

    The emergence of the Internet, social media, and digital technologies in the twenty-first century accelerated an evolution in journalism and communication that fit under the broad term of convergence. That evolution changed the relationship between news producers and consumers. It broke down the geographical boundaries in defining our communities,…

  16. 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.

  17. Exuberant neuronal convergence onto reduced taste bud targets with preservation of neural specificity in mice overexpressing neurotrophin in the tongue epithelium.

    Science.gov (United States)

    Zaidi, Faisal N; Krimm, Robin F; Whitehead, Mark C

    2007-12-12

    A mouse fungiform taste bud is innervated by only four to five geniculate ganglion neurons; their peripheral fibers do not branch to other buds. We examined whether the degree or specificity of this exclusive innervation pattern is influenced by brain-derived neurotrophic factor (BDNF), a prominent lingual neurotrophin implicated in taste receptoneural development. Labeled ganglion cells were counted after injecting single buds with different color markers in BDNF-lingual-overexpressing (OE) mice. To evaluate the end-organs, taste buds and a class of putative taste receptor cells were counted from progeny of BDNF-OE mice crossbred with green fluorescent protein (GFP) (gustducin) transgenic mice. Fungiform bud numbers in BDNF-OE mice are 35%, yet geniculate neuron numbers are 195%, of wild-type mice. Neurons labeled by single-bud injections in BDNF-OE animals were increased fourfold versus controls. Injecting three buds, each with different color markers, resulted in predominantly single-labeled ganglion cells, a discrete innervation pattern similar to controls. Thus, hyper-innervation of BDNF-OE buds involves many neurons innervating single buds, not increased fiber branching. Therefore, both wild-type and BDNF-OE mice exhibit, in fungiform buds, the same, "discrete" receptoneural pattern, this despite dramatic neurotrophin overexpression-related decreases in bud numbers and increases in innervation density. Hyperinnervation did not affect GFP positive cell numbers; proportions of GFP cells in BDNF-OE buds were the same as in wild-type mice. Total numbers of ganglion cells innervating buds in transgenic mice are similar to controls; the density of taste input to the brain appears maintained despite dramatically reduced receptor organs and increased ganglion cells.

  18. Effect of 8 weeks Resistance Training on BDNF and TrkB in the Hippocampus of Adult Male Rats

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    S Mojtahedi

    2014-08-01

    Full Text Available Background & aim: Exercise enhances the synaptic plasticity and neuroprotective effects in the adult brain. However, it remains unknown that how plasticity molecules change following types of training. The purpose of this study was to determine the effect of eight weeks resistance training on protein levels of Brain Derived Neurotrophic Factor(BDNF and receptor of TrkB, in the hippocampus of adult male rats. Methods: In this experimental study, twelve adult male rats, 8 weeks of age, with an average weight of 200 to 225 grams were randomly divided into two groups, control and exercise respectively. The exercise was to increase the weight on the ladder. 24 hours after their last training session. The animals were killed and the hippocampus was removed for further testing. ELISA determined changes in protein levels. Data were analyzed by independent t test. Results: There was a significant difference between train and control groups In protein level of variables statically (p≤0.05. In addition, protein levels of BDNF and TrkB in the hippocampus of rats increased. Conclusion: Resistance training is beneficial for promoting hippocampal plasticity associated with BDNF signaling and consequently functional and cognitive benefits.

  19. Serotonin transporter function, but not expression, is dependent on brain-derived neurotrophic factor (BDNF): in vivo studies in BDNF-deficient mice.

    Science.gov (United States)

    Daws, L C; Munn, J L; Valdez, M F; Frosto-Burke, T; Hensler, J G

    2007-05-01

    In the present study, we used high-speed chronoamperometry to examine serotonin (5-HT) transporter (5-HTT) function in vivo in 2-, 5-, and 10-month-old brain-derived neurotrophic factor (BDNF)+/- mice. The rate of clearance of exogenously applied 5-HT was measured in CA3 region of hippocampus. In 2-month-old mice, the rate of 5-HT clearance did not differ between BDNF+/+ and BDNF+/- mice. In BDNF+/+ mice, 5-HT clearance rate (Tc) increased markedly with age. In contrast, Tc remained relatively static in BDNF+/- mice across 2-, 5-, and 10-month age groups. At 5 months of age, female BDNF+/+ mice had a lower maximal velocity (Vmax) for 5-HT clearance than male BDNF+/+ mice. There was a similar trend in 5-month-old BDNF+/- mice, but this did not reach statistical significance. There was an age-dependent increase in KT value for 5-HT clearance (i.e., decreased in vivo affinity of 5-HTT), but no significant effect of genotype or gender. 5-HTT density, as measured by [3H]cyanoimipramine binding, was not different between BDNF+/+ and BDNF+/- mice, although there was a significant increase in 5-HTT binding with age. The selective 5-HT reuptake inhibitor fluvoxamine (50 and 100 pmol) significantly decreased 5-HT clearance in BDNF+/+ mice, but not in BDNF+/- mice. Our data suggest that the profoundly reduced ability of 5- and 10-month-old BDNF+/- mice to clear 5-HT is not because of a decrease in the total number of 5-HTTs, but may be due to functional deficits in the 5-HTT, e.g., in the machinery/signaling required for insertion of 5-HTTs into the plasma membrane and/or activation of the 5-HTT once it is positioned to take up 5-HT from extracellular fluid.

  20. Spinal Plasticity and Behavior: BDNF-Induced Neuromodulation in Uninjured and Injured Spinal Cord

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    Sandra M. Garraway

    2016-01-01

    Full Text Available Brain-derived neurotrophic factor (BDNF is a member of the neurotrophic factor family of signaling molecules. Since its discovery over three decades ago, BDNF has been identified as an important regulator of neuronal development, synaptic transmission, and cellular and synaptic plasticity and has been shown to function in the formation and maintenance of certain forms of memory. Neural plasticity that underlies learning and memory in the hippocampus shares distinct characteristics with spinal cord nociceptive plasticity. Research examining the role BDNF plays in spinal nociception and pain overwhelmingly suggests that BDNF promotes pronociceptive effects. BDNF induces synaptic facilitation and engages central sensitization-like mechanisms. Also, peripheral injury-induced neuropathic pain is often accompanied with increased spinal expression of BDNF. Research has extended to examine how spinal cord injury (SCI influences BDNF plasticity and the effects BDNF has on sensory and motor functions after SCI. Functional recovery and adaptive plasticity after SCI are typically associated with upregulation of BDNF. Although neuropathic pain is a common consequence of SCI, the relation between BDNF and pain after SCI remains elusive. This article reviews recent literature and discusses the diverse actions of BDNF. We also highlight similarities and differences in BDNF-induced nociceptive plasticity in naïve and SCI conditions.

  1. The human BDNF gene: peripheral gene expression and protein levels as biomarkers for psychiatric disorders

    Science.gov (United States)

    Cattaneo, A; Cattane, N; Begni, V; Pariante, C M; Riva, M A

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) regulates the survival and growth of neurons, and influences synaptic efficiency and plasticity. The human BDNF gene consists of 11 exons, and distinct BDNF transcripts are produced through the use of alternative promoters and splicing events. The majority of the BDNF transcripts can be detected not only in the brain but also in the blood cells, although no study has yet investigated the differential expression of BDNF transcripts at the peripheral level. This review provides a description of the human BDNF gene structure as well as a summary of clinical and preclinical evidence supporting the role of BDNF in the pathogenesis of psychiatric disorders. We will discuss several mechanisms as possibly underlying BDNF modulation, including epigenetic mechanisms. We will also discuss the potential use of peripheral BDNF as a biomarker for psychiatric disorders, focusing on the factors that can influence BDNF gene expression and protein levels. Within this context, we have also characterized, for we believe the first time, the expression of BDNF transcripts in the blood, with the aim to provide novel insights into the molecular mechanisms and signaling that may regulate peripheral BDNF gene expression levels. PMID:27874848

  2. BDNF Val66Met polymorphism interacts with sex to influence bimanual motor control in healthy humans

    NARCIS (Netherlands)

    Smolders, R.; Rijpkema, M.J.P.; Franke, B.; Fernandez, G.S.E.

    2012-01-01

    Brain-derived neurotrophic factor (BDNF) plays a critical role in brain development. A common single nucleotide polymorphism in the gene encoding BDNF (rs6265, Val66Met) affects BDNF release and has been associated with altered learning and memory performance, and with structural changes in brain mo

  3. BDNF Val66Met polymorphism interacts with sex to influence bimanual motor control in healthy humans

    NARCIS (Netherlands)

    Smolders, R.; Rijpkema, M.J.P.; Franke, B.; Fernandez, G.S.E.

    2012-01-01

    Brain-derived neurotrophic factor (BDNF) plays a critical role in brain development. A common single nucleotide polymorphism in the gene encoding BDNF (rs6265, Val66Met) affects BDNF release and has been associated with altered learning and memory performance, and with structural changes in brain

  4. Endurance training enhances BDNF release from the human brain

    DEFF Research Database (Denmark)

    Seifert, Thomas; Brassard, Patrice; Wissenberg, Mads

    2010-01-01

    the human brain as detected from arterial and internal jugular venous blood samples. In a randomized controlled study, 12 healthy sedentary males carried out 3 mo of endurance training (n = 7) or served as controls (n = 5). Before and after the intervention, blood samples were obtained at rest and during...... in the hippocampus (4.5 + or - 1.6 vs. 1.4 + or - 1.1 mRNA/ssDNA; P human brain following training suggest......The circulating level of brain-derived neurotrophic factor (BDNF) is reduced in patients with major depression and type-2 diabetes. Because acute exercise increases BDNF production in the hippocampus and cerebral cortex, we hypothesized that endurance training would enhance the release of BDNF from...

  5. BDNF in schizophrenia, depression and corresponding animal models.

    Science.gov (United States)

    Angelucci, F; Brenè, S; Mathé, A A

    2005-04-01

    Understanding the etiology and pathogenesis schizophrenia and depression is a major challenge facing psychiatry. One hypothesis is that these disorders are secondary to a malfunction of neurotrophic factors. Inappropriate neurotrophic support during brain development could lead to structural disorganisation in which neuronal networks are established in a nonoptimal manner. Inadequate neurotrophic support in adult individuals could ultimately be an underlying mechanism leading to decreased capacity of brain to adaptive changes and increased vulnerability to neurotoxic damage. Brain-derived neurotrophic factor (BDNF) is a mediator involved in neuronal survival and plasticity of dopaminergic, cholinergic, and serotonergic neurons in the central nervous system (CNS). In this review, we summarize findings regarding altered BDNF in schizophrenia and depression and animal models, as well as the effects of antipsychotic and antidepressive treatments on the expression of BDNF.

  6. Endothelial nitric oxide synthase regulates white matter changes via the BDNF/TrkB pathway after stroke in mice.

    Directory of Open Access Journals (Sweden)

    Xu Cui

    Full Text Available Stroke induced white matter (WM damage is associated with neurological functional deficits, but the underlying mechanisms are not well understood. In this study, we investigate whether endothelial nitric oxide synthase (eNOS affects WM-damage post-stroke. Adult male wild-type (WT and eNOS knockout (eNOS(-/- mice were subjected to middle cerebral artery occlusion. Functional evaluation, infarct volume measurement, immunostaining and primary cortical cell culture were performed. To obtain insight into the mechanisms underlying the effects of eNOS(-/- on WM-damage, measurement of eNOS, brain-derived neurotrophic factor (BDNF and its receptor TrkB in vivo and in vitro were also performed. No significant differences were detected in the infarction volume, myelin density in the ipsilateral striatal WM-bundles and myelin-based protein expression in the cerebral ischemic border between WT and eNOS(-/- mice. However, eNOS(-/- mice showed significantly: 1 decreased functional outcome, concurrent with decreases of total axon density and phosphorylated high-molecular weight neurofilament density in the ipsilateral striatal WM-bundles. Correlation analysis showed that axon density is significantly positive correlated with neurological functional outcome; 2 decreased numbers of oligodendrocytes / oligodendrocyte progenitor cells in the ipsilateral striatum; 3 decreased synaptophysin, BDNF and TrkB expression in the ischemic border compared with WT mice after stroke (n = 12/group, p<0.05. Primary cortical cell culture confirmed that the decrease of neuronal neurite outgrowth in the neurons derived from eNOS(-/- mice is mediated by the reduction of BDNF/TrkB (n = 6/group, p<0.05. Our data show that eNOS plays a critical role in WM-damage after stroke, and eNOS(-/--induced decreases in the BDNF/TrkB pathway may contribute to increased WM-damage, and thereby decrease functional outcome.

  7. Endothelial nitric oxide synthase regulates white matter changes via the BDNF/TrkB pathway after stroke in mice.

    Science.gov (United States)

    Cui, Xu; Chopp, Michael; Zacharek, Alex; Ning, Ruizhuo; Ding, Xiaoshuang; Roberts, Cynthia; Chen, Jieli

    2013-01-01

    Stroke induced white matter (WM) damage is associated with neurological functional deficits, but the underlying mechanisms are not well understood. In this study, we investigate whether endothelial nitric oxide synthase (eNOS) affects WM-damage post-stroke. Adult male wild-type (WT) and eNOS knockout (eNOS(-/-)) mice were subjected to middle cerebral artery occlusion. Functional evaluation, infarct volume measurement, immunostaining and primary cortical cell culture were performed. To obtain insight into the mechanisms underlying the effects of eNOS(-/-) on WM-damage, measurement of eNOS, brain-derived neurotrophic factor (BDNF) and its receptor TrkB in vivo and in vitro were also performed. No significant differences were detected in the infarction volume, myelin density in the ipsilateral striatal WM-bundles and myelin-based protein expression in the cerebral ischemic border between WT and eNOS(-/-) mice. However, eNOS(-/-) mice showed significantly: 1) decreased functional outcome, concurrent with decreases of total axon density and phosphorylated high-molecular weight neurofilament density in the ipsilateral striatal WM-bundles. Correlation analysis showed that axon density is significantly positive correlated with neurological functional outcome; 2) decreased numbers of oligodendrocytes / oligodendrocyte progenitor cells in the ipsilateral striatum; 3) decreased synaptophysin, BDNF and TrkB expression in the ischemic border compared with WT mice after stroke (n = 12/group, pBDNF/TrkB (n = 6/group, pstroke, and eNOS(-/-)-induced decreases in the BDNF/TrkB pathway may contribute to increased WM-damage, and thereby decrease functional outcome.

  8. Neurotrophin presence in human coronary atherosclerosis and metabolic syndrome: a role for NGF and BDNF in cardiovascular disease?

    Science.gov (United States)

    Chaldakov, George N; Fiore, Marco; Stankulov, Ivan S; Manni, Luigi; Hristova, Mariyana G; Antonelli, Alessia; Ghenev, Peter I; Aloe, Luigi

    2004-01-01

    The development of atherosclerotic cardiovascular disease is a common comorbidity in patients with the metabolic syndrome, a concurrence of cardiovascular risk factors in one individual. While multiple growth factors and adipokines are identified in atherosclerotic lesions, as well as neurotrophins implicated in both cardiac ischemia and lipid and glucose metabolism, the potential role of neurotrophins in human coronary atherosclerosis and in the metabolic syndrome still remains to be elucidated. Here we describe and discuss our results that represent a novel attempt to study the cardiovascular and metabolic biology of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and mast cells (MC). The local amount of NGF, the immunolocalization of p75 neurotrophin receptor (p75NTR) and the number of MC were correlatively examined in coronary vascular wall and in the surrounding subepicardial adipose tissue, obtained from autopsy cases in humans with advanced coronary atherosclerosis. We also analyzed the plasma levels of NGF, BDNF and leptin and the number of MC in biopsies from abdominal subcutaneous adipose tissue in patients with a severe form of the metabolic syndrome. The results demonstrate that NGF levels are decreased in atherosclerotic coronary vascular tissue but increased in the subepicardial adipose tissue, whereas both tissues express a greater number of MC and a stronger p75NTR immunoreactivity, compared to controls. Metabolic syndrome patients display a significant hyponeurotrophinemia and an increased number of adipose MC; the later correlates with elevated plasma leptin levels. In effect, we provide the first evidence for (i) an altered presence of NGF, p75NTR and MC in both coronary vascular and subepicardial adipose tissue in human coronary atherosclerosis, and (ii) a significant decrease in plasma NGF and BDNF levels and an elevated amount of plasma leptin and adipose MC in metabolic syndrome patients. Together our findings suggest that

  9. Expression of BDNF and its receptor TrkB in brain tissue resected from patients with intractable mesial temporal lobe epilepsy%难治性颞叶内侧型癫痫患者脑组织内BDNF及其受体TrkB的表达

    Institute of Scientific and Technical Information of China (English)

    李春梅; 侯晓华; 张黎明; 赵姝

    2009-01-01

    目的 研究难治性颞叶内侧型癫痫(MTLE)患者脑组织内脑源性神经营养因子(brain derived neuro-trophic factor,BDNF)及其受体TrkB的表达,探讨其在癫痫发病机制中的作用.方法 采集11例难治性MTLE患者手术中切除的颞叶和海马脑组织,用免疫组化、逆转录一聚合酶链反应(RT-PCR)法检测BDNF、TrkB的蛋白和mRNA表达,并与非癫痫患者对照.结果 与对照组相同部位比较,患者组颞叶和海马中的BDNF蛋白和TrkB蛋白的表达明显增加(P<0.01),BDNF mRNA和TrkB mRNA在患者组颢叶(P<0.01)和海马(P<0.05)的表达明显增加.结论 难治性MTLE患者颞叶和海马中BDNF和TrkB受体表达增高,可能在癫痫发生、发展中具有重要作用.

  10. Sigma-1 receptor chaperone and brain-derived neurotrophic factor: emerging links between cardiovascular disease and depression.

    Science.gov (United States)

    Hashimoto, Kenji

    2013-01-01

    Epidemiological studies have demonstrated a close relationship between depression and cardiovascular disease (CVD). Although it is known that the central nervous system (CNS) contributes to this relationship, the detailed mechanisms involved in this process remain unclear. Recent studies suggest that the endoplasmic reticulum (ER) molecular chaperone sigma-1 receptor and brain-derived neurotrophic factor (BDNF) play a role in the pathophysiology of CVD and depression. Several meta-analysis studies have showed that levels of BDNF in the blood of patients with major depressive disorder (MDD) are lower than normal controls, indicating that blood BDNF might be a biomarker for depression. Furthermore, blood levels of BDNF in patients with CVD are also lower than normal controls. A recent study using conditional BDNF knock-out mice in animal models of myocardial infarction highlighted the role of CNS-mediated mechanisms in the cardioprotective effects of BDNF. In addition, a recent study shows that decreased levels of sigma-1 receptor in the mouse brain contribute to the association between heart failure and depression. Moreover, sigma-1 receptor agonists, including the endogenous neurosteroid dehydroepiandosterone (DHEA) and the selective serotonin reuptake inhibitor (SSRI) fluvoxamine, show potent cardioprotective and antidepressive effects in rodents, via sigma-1 receptor stimulation. Interestingly, agonist activation of sigma-1 receptors increased the secretion of mature BDNF from its precursor proBDNF via chaperone activity in the ER. Given the role of ER stress in the pathophysiology of CVD and MDD, the author will discuss the potential link between sigma-1 receptors and BDNF-TrkB pathway in the pathophysiology of these two diseases. Finally, the author will make a case for potent sigma-1 receptor agonists and TrkB agonists as new potential therapeutic drugs for depressive patients with CVD.

  11. Summable series and convergence factors

    CERN Document Server

    Moore, Charles N

    1938-01-01

    Fairly early in the development of the theory of summability of divergent series, the concept of convergence factors was recognized as of fundamental importance in the subject. One of the pioneers in this field was C. N. Moore, the author of the book under review.... Moore classifies convergence factors into two types. In type I he places the factors which have only the property that they preserve convergence for a convergent series or produce convergence for a summable series. In type II he places the factors which not only maintain or produce convergence but have the additional property that

  12. A novel BDNF gene promoter directs expression to skeletal muscle

    Directory of Open Access Journals (Sweden)

    Heinrich Gerhard

    2003-06-01

    Full Text Available Abstract Background Cell-specific expression of the gene that encodes brain-derived neurotrophic factor (BDNF is required for the normal development of peripheral sensory neurons and efficient synaptic transmission in the mature central and peripheral nervous system. The control of BDNF gene expression involves multiple tissue and cell-specific promoters that are differentially regulated. The molecular mechanisms that are responsible for tissue and cell-specific expression of these promoters are still incompletely understood. Results The cloning and analysis of three additional zebrafish (Danio rerio BDNF gene exons and two associated promoters, is reported. Among them are two exons that generate a novel tripartite mature transcript. The exons were located on the transcription unit, whose overall organization was determined by cloning, Southern blot hybridization and sequence analysis, and compared with the pufferfish (Fugu rubripes and mammalian BDNF loci, revealing a conserved but more compact organization. Structural and functional analysis of the exons, their adjacent promoters and 5' flanks, showed that they are expressed cell-specifically. The promoter associated with the 5' exon of the tripartite transcript is GC-rich, TATA-less and the 5' flank adjacent to it contains multiple Sp1, Mef2, and AP1 elements. A fusion gene containing the promoter and 1.5 KB of 5' flank is directed exclusively to skeletal muscle of transiently transfected embryos. The second promoter, whose associated 5' exon contains a 25-nucleotide segment of identity with a mammalian BDNF gene exon, was transiently expressed in yolk of the early embryo. RT-PCR analysis of total RNA from whole juvenile fish and adult female skeletal muscle revealed tissue-specific expression of the 5' exons but the novel exon could not be detected even after two rounds of nested PCR. Conclusion The zebrafish BDNF gene is as complex as the mammalian gene yet much more compact. Its exons are

  13. High abundance of BDNF within glutamatergic presynapses of cultured hippocampal neurons

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    Thomas eAndreska

    2014-04-01

    Full Text Available In the mammalian brain, the neurotrophin brain-derived neurotrophic factor (BDNF has emerged as a key factor for synaptic refinement, plasticity and learning. Although BDNF-induced signaling cascades are well known, the spatial aspects of the synaptic BDNF localization remained unclear. Recent data provide strong evidence for an exclusive presynaptic location and anterograde secretion of endogenous BDNF at synapses of the hippocampal circuit. In contrast, various studies using BDNF overexpression in cultured hippocampal neurons support the idea that postsynaptic synapses and other dendritic structures are the preferential sites of BDNF localization and release. In this study we used rigorously tested anti-BDNF antibodies and achieved a dense labeling of endogenous BDNF close to synapses. Confocal microscopy showed natural BDNF close to many, but not all glutamatergic synapses, while neither GABAergic synapses nor postsynaptic structures carried a typical synaptic BDNF label. To visualize the BDNF distribution within the fine structure of synapses, we implemented super resolution fluorescence imaging by direct stochastic optical reconstruction microscopy (dSTORM. Two-color dSTORM images of neurites were acquired with a spatial resolution of ~20 nm. At this resolution, the synaptic scaffold proteins Bassoon and Homer exhibit hallmarks of mature synapses and form juxtaposed bars, separated by a synaptic cleft. BDNF imaging signals form granule-like clusters with a mean size of ~60 nm and are preferentially found within the fine structure of the glutamatergic presynapse. Individual glutamatergic presynapses carried up to 90% of the synaptic BDNF immunoreactivity, and only a minor fraction of BDNF molecules was found close to the postsynaptic bars. Our data proof that hippocampal neurons are able to enrich and store high amounts of BDNF in small granules within the mature glutamatergic presynapse, at a principle site of synaptic plasticity.

  14. Potentiation of Synaptic GluN2B NMDAR Currents by Fyn Kinase Is Gated through BDNF-Mediated Disinhibition in Spinal Pain Processing.

    Science.gov (United States)

    Hildebrand, Michael E; Xu, Jian; Dedek, Annemarie; Li, Yi; Sengar, Ameet S; Beggs, Simon; Lombroso, Paul J; Salter, Michael W

    2016-12-06

    In chronic pain states, the neurotrophin brain-derived neurotrophic factor (BDNF) transforms the output of lamina I spinal neurons by decreasing synaptic inhibition. Pain hypersensitivity also depends on N-methyl-D-aspartate receptors (NMDARs) and Src-family kinases, but the locus of NMDAR dysregulation remains unknown. Here, we show that NMDAR-mediated currents at lamina I synapses are potentiated in a peripheral nerve injury model of neuropathic pain. We find that BDNF mediates NMDAR potentiation through activation of TrkB and phosphorylation of the GluN2B subunit by the Src-family kinase Fyn. Surprisingly, we find that Cl(-)-dependent disinhibition is necessary and sufficient to prime potentiation of synaptic NMDARs by BDNF. Thus, we propose that spinal pain amplification is mediated by a feedforward mechanism whereby loss of inhibition gates the increase in synaptic excitation within individual lamina I neurons. Given that neither disinhibition alone nor BDNF-TrkB signaling is sufficient to potentiate NMDARs, we have discovered a form of molecular coincidence detection in lamina I neurons.

  15. NGF and BDNF long-term variations in the thyroid, testis and adrenal glands of a mouse model of fetal alcohol spectrum disorders

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    Mauro Ceccanti

    2013-12-01

    Full Text Available OBJECTIVES: Fetal Alcohol Spectrum Disorders (FASD due to prenatal ethanol consumption may induce long-lasting changes to the newborns affecting also the endocrine system and the nerve growth factor (NGF and brain derived neurotrophic factor (BDNF signaling. Thus the aim of this study was to investigate in the thyroid, testis and adrenal glands of a FASD mouse model the long-lasting effects of ethanol exposure during pregnancy and lactation on NGF and BDNF and their main receptors, TrkA and TrkB, including their phosphorylated patterns. METHODS: We used aged male CD-1 mice early exposed to ethanol solution or red wine at same ethanol concentration (11% vol. RESULTS We found elevations in NGF and BDNF in the thyroid of aged mice exposed to ethanol solution only but not in the red wine group. In the testis NGF resulted to be increased only in the ethanol solution group. In the adrenal glands data showed an elevation in NGF in both the ethanol solution group and red wine. No changes in TrkA, TrkB, phospho-TrkA and phospho-TrkB were revealed in all tissues examined. CONCLUSIONS Early administration of ethanol may induce long-lasting changes in the mouse thyroid, testis and adrenal glands at NGF and BDNF levels.

  16. Activity-Dependent Bidirectional Regulation of GAD Expression in a Homeostatic Fashion Is Mediated by BDNF-Dependent and Independent Pathways.

    Science.gov (United States)

    Hanno-Iijima, Yoko; Tanaka, Masami; Iijima, Takatoshi

    2015-01-01

    Homeostatic synaptic plasticity, or synaptic scaling, is a mechanism that tunes neuronal transmission to compensate for prolonged, excessive changes in neuronal activity. Both excitatory and inhibitory neurons undergo homeostatic changes based on synaptic transmission strength, which could effectively contribute to a fine-tuning of circuit activity. However, gene regulation that underlies homeostatic synaptic plasticity in GABAergic (GABA, gamma aminobutyric) neurons is still poorly understood. The present study demonstrated activity-dependent dynamic scaling in which NMDA-R (N-methyl-D-aspartic acid receptor) activity regulated the expression of GABA synthetic enzymes: glutamic acid decarboxylase 65 and 67 (GAD65 and GAD67). Results revealed that activity-regulated BDNF (brain-derived neurotrophic factor) release is necessary, but not sufficient, for activity-dependent up-scaling of these GAD isoforms. Bidirectional forms of activity-dependent GAD expression require both BDNF-dependent and BDNF-independent pathways, both triggered by NMDA-R activity. Additional results indicated that these two GAD genes differ in their responsiveness to chronic changes in neuronal activity, which could be partially caused by differential dependence on BDNF. In parallel to activity-dependent bidirectional scaling in GAD expression, the present study further observed that a chronic change in neuronal activity leads to an alteration in neurotransmitter release from GABAergic neurons in a homeostatic, bidirectional fashion. Therefore, the differential expression of GAD65 and 67 during prolonged changes in neuronal activity may be implicated in some aspects of bidirectional homeostatic plasticity within mature GABAergic presynapses.

  17. The influence of infant-caregiver experiences on amygdala Bdnf, OXTr, and NPY expression in developing and adult male and female rats.

    Science.gov (United States)

    Hill, Kathryn T; Warren, Megan; Roth, Tania L

    2014-10-01

    Previous work with various animal models has demonstrated that alterations in the caregiving environment produce long-term changes in anxiety-related and social behaviors, as well as amygdala gene expression. We previously introduced a rodent model in which the timing and duration of exposure to maltreatment or nurturing care outside the home cage can be controlled to assess neurobiological outcomes. Here we sought to determine whether our brief experimental conditions produce changes in gene expression within the developing and adult amygdala. Using a candidate gene approach, we examined fold mRNA changes for the Brain-derived neurotrophic factor (Bdnf), Oxytocin receptor (OXTr), and Neuropeptide Y (NPY) genes, which are all highly expressed in the amygdala and play important roles in anxiety-related and social behaviors. In adults, significant group differences were detected for only Bdnf, with higher levels of Bdnf mRNA for females that had been exposed to maltreatment and males exposed to nurturing care outside the home cage relative to littermate controls. For pups, significant group differences were detected for only OXTr, with lower levels of OXTr mRNA in females exposed to maltreatment. Finally, for adolescents, maltreated-females showed significant changes in Bdnf (decreased), OXTr (decreased), and NPY (increased) mRNA relative to controls. These data illustrate the ability of brief, but repeated exposure to different caregiving environments during the first postnatal week to have long-term effects on gene expression within the developing and adult amygdala, especially for females.

  18. Modulation of dendritic spine development and plasticity by BDNF and vesicular trafficking: fundamental roles in neurodevelopmental disorders associated with mental retardation and autism.

    Science.gov (United States)

    Chapleau, Christopher A; Larimore, Jennifer L; Theibert, Anne; Pozzo-Miller, Lucas

    2009-09-01

    The process of axonal and dendritic development establishes the synaptic circuitry of the central nervous system (CNS) and is the result of interactions between intrinsic molecular factors and the external environment. One growth factor that has a compelling function in neuronal development is the neurotrophin brain-derived neurotrophic factor (BDNF). BDNF participates in axonal and dendritic differentiation during embryonic stages of neuronal development, as well as in the formation and maturation of dendritic spines during postnatal development. Recent studies have also implicated vesicular trafficking of BDNF via secretory vesicles, and both secretory and endosomal trafficking of vesicles containing synaptic proteins, such as neurotransmitter and neurotrophin receptors, in the regulation of axonal and dendritic differentiation, and in dendritic spine morphogenesis. Several genes that are either mutated or deregulated in neurodevelopmental disorders associated with mental retardation have now been identified, and several mouse models of these disorders have been generated and characterized. Interestingly, abnormalities in dendritic and synaptic structure are consistently observed in human neurodevelopmental disorders associated with mental retardation, and in mouse models of these disorders as well. Abnormalities in dendritic and synaptic differentiation are thought to underlie altered synaptic function and network connectivity, thus contributing to the clinical outcome. Here, we review the roles of BDNF and vesicular trafficking in axonal and dendritic differentiation in the context of dendritic and axonal morphological impairments commonly observed in neurodevelopmental disorders associated with mental retardation.

  19. The Convergent Learning Space:

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher; Kjeldsen, Lars Peter; Asmussen, Jørgen Bering

    2013-01-01

    is described as well as the theoretical construct and hypotheses surrounding the emergence of the concept in technology-rich classrooms, where students bring their own devices and involve their personal learning spaces and networks. The need for new ways of approaching concepts like choice, learning resources......This paper describes the concept of “The Convergent Learning Space” as it is being explored in an ongoing action research project carried out at undergraduate level in select bachelor programs at a Danish University College. The background nature, design, and beginning of this work in progress......, trajectories of participation etc. calls for new action and new pedagogies by teachers in order to secure alignment between students’ worlds and expectations and aims and plans of the teacher. Action research methods are being used to define and test the constituents and variables of the convergent learning...

  20. Subsequential Convergence Conditions

    Directory of Open Access Journals (Sweden)

    İbrahim Çanak

    2007-10-01

    Full Text Available Let (un be a sequence of real numbers and let L be any (C,1 regular limitable method. We prove that, under some assumptions, if a sequence (un or its generator sequence (Vn(0(Δu generated regularly by a sequence in a class 𝒜 of sequences is a subsequential convergence condition for L, then for any integer m≥1, the mth repeated arithmetic means of (Vn(0(Δu, (Vn(m(Δu, generated regularly by a sequence in the class 𝒜(m, is also a subsequential convergence condition for L.

  1. Correlated network activity enhances synaptic efficacy via BDNF and the ERK pathway at immature CA3 CA1 connections in the hippocampus.

    Science.gov (United States)

    Mohajerani, Majid H; Sivakumaran, Sudhir; Zacchi, Paola; Aguilera, Pedro; Cherubini, Enrico

    2007-08-07

    At early developmental stages, correlated neuronal activity is thought to exert a critical control on functional and structural refinement of synaptic connections. In the hippocampus, between postnatal day 2 (P2) and P6, network-driven giant depolarizing potentials (GDPs) are generated by the synergistic action of glutamate and GABA, which is depolarizing and excitatory. Here the rising phase of GDPs was used to trigger Schaffer collateral stimulation in such a way that synchronized network activity was coincident with presynaptic activation of afferent input. This procedure produced a persistent increase in spontaneous and evoked alpha-amino-3-hydroxy-5-methyl-4-isoxadepropionic acid-mediated glutamatergic currents, an effect that required calcium influx through postsynaptic L-type calcium channels. No potentiation was observed when a delay of 3 sec was introduced between GDPs and afferent stimulation. Pairing-induced potentiation was prevented by scavengers of endogenous BDNF or tropomyosin-related kinase receptor B (TrkB) receptor antagonists. Blocking TrkB receptors in the postsynaptic cell did not prevent the effects of pairing, suggesting that BDNF, possibly secreted from the postsynaptic cell during GDPs, acts on TrkB receptors localized on presynaptic neurons. Application of exogenous BDNF mimicked the effects of pairing on synaptic transmission. In addition, pairing-induced synaptic potentiation was blocked by ERK inhibitors, suggesting that BDNF activates the MAPK/ERK cascade, which may lead to transcriptional regulation and new protein synthesis in the postsynaptic neuron. These results support the hypothesis that, during a critical period of postnatal development, GABAA-mediated GDPs are instrumental in tuning excitatory synaptic connections and provide insights into the molecular mechanisms involved in this process.

  2. Tissue-specific and neural activity-regulated expression of human BDNF gene in BAC transgenic mice

    Directory of Open Access Journals (Sweden)

    Palm Kaia

    2009-06-01

    Full Text Available Abstract Background Brain-derived neurotrophic factor (BDNF is a small secreted protein that has important roles in the developing and adult nervous system. Altered expression or changes in the regulation of the BDNF gene have been implicated in a variety of human nervous system disorders. Although regulation of the rodent BDNF gene has been extensively investigated, in vivo studies regarding the human BDNF gene are largely limited to postmortem analysis. Bacterial artificial chromosome (BAC transgenic mice harboring the human BDNF gene and its regulatory flanking sequences constitute a useful tool for studying human BDNF gene regulation and for identification of therapeutic compounds modulating BDNF expression. Results In this study we have generated and analyzed BAC transgenic mice carrying 168 kb of the human BDNF locus modified such that BDNF coding sequence was replaced with the sequence of a fusion protein consisting of N-terminal BDNF and the enhanced green fluorescent protein (EGFP. The human BDNF-BAC construct containing all BDNF 5' exons preceded by different promoters recapitulated the expression of endogenous BDNF mRNA in the brain and several non-neural tissues of transgenic mice. All different 5' exon-specific BDNF-EGFP alternative transcripts were expressed from the transgenic human BDNF-BAC construct, resembling the expression of endogenous BDNF. Furthermore, BDNF-EGFP mRNA was induced upon treatment with kainic acid in a promotor-specific manner, similarly to that of the endogenous mouse BDNF mRNA. Conclusion Genomic region covering 67 kb of human BDNF gene, 84 kb of upstream and 17 kb of downstream sequences is sufficient to drive tissue-specific and kainic acid-induced expression of the reporter gene in transgenic mice. The pattern of expression of the transgene is highly similar to BDNF gene expression in mouse and human. This is the first study to show that human BDNF gene is regulated by neural activity.

  3. Convergence Reflects Maturity

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Competition has been playing a dominant role among telecommunication equipment manufacturers. In 2006, however, merger overwhelmed competition. In the tide of converging, a large number of equipment manufacturers were involved in mergers. At the same time, telecommunication equipment manufacturers, the most innovative community in the world, drive 3G technology fast in line with its technical roadmap. In addition, Chinese equipment manufacturers cut a figure in world-class telecommunication markets, whic...

  4. 灯盏细辛对大鼠急性脑缺血BDNF及其受体trkB表达的影响%Effect of breviscapine with BDNF and TrkB in cerebral ischemic rat

    Institute of Scientific and Technical Information of China (English)

    周弋人; 何柳; 张仲; 曾仲; 高励; 沈富伟; 罗祖明

    2011-01-01

    Objective To observe the effect of breviscapine on exspression of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (trkB) of focal cerebral iscbemia in rats.Methods 45 SD rats were randomized into 3 groups including model group, treatment group and sham group.The expressions of BDNF and trkB neurons were observed with immunochemical method.Results The expressions of BDNF and trkB neurons of treatment group was different from that of model group and treatment group, P<0.05.Conclusion Breviscapine may be related with the upregulation expression of BDNF and trkB.%目的 观察灯盖细辛在急性脑缺血期对内源性脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)及酪氨酸激酶受体B(tyrosine kinase receptor B receptor,trkB)合成的影响.方法 采用改良的 Zealonga法建立大鼠大脑中动脉局灶缺血/再灌注梗死(Middle cerebral artery occlusion/reperfusion,MCAO)模型.45只SD大鼠随机分为MCA0模型组(A组),给药组2.7ml/kg×7天(B组)及对照组(C组).然后制作冰冻切片对BDNF,trkB免疫组化测量.结果 BDNF及trkB免疫组化检测结果均提示,给药组与模型组比较有显著性差异(P<0.05).结论 灯盏细辛可诱导脑梗死后BDNF及其高亲和性受体trkB表达上调.

  5. Local Administration of AAV-BDNF to Subventricular Zone Induces Functional Recovery in Stroke Rats

    OpenAIRE

    Seong-Jin Yu; Kuan-Yin Tseng; Hui Shen; Harvey, Brandon K.; Mikko Airavaara; Yun Wang

    2013-01-01

    Migration of new neuroprogenitor cells (NPCs) from the subventricular zone (SVZ) plays an important role in neurorepair after injury. Previous studies have shown that brain derived neurotrophic factor (BDNF) enhances the migration of NPCs from SVZ explants in neonatal mice in vitro. The purpose of this study was to identify the role of BDNF in SVZ cells using AAV-BDNF in an animal model of stroke. BDNF protein production after AAV-BDNF infection was verified in primary neuronal culture. AAV-B...

  6. Reduced brain-derived neurotrophic factor (BDNF) mRNA expression and presence of BDNF-immunoreactive granules in the spinocerebellar ataxia type 6 (SCA6) cerebellum.

    Science.gov (United States)

    Takahashi, Makoto; Ishikawa, Kinya; Sato, Nozomu; Obayashi, Masato; Niimi, Yusuke; Ishiguro, Taro; Yamada, Mitsunori; Toyoshima, Yasuko; Takahashi, Hitoshi; Kato, Takeo; Takao, Masaki; Murayama, Shigeo; Mori, Osamu; Eishi, Yoshinobu; Mizusawa, Hidehiro

    2012-12-01

    Spinocerebellar ataxia type 6 (SCA6) is an autosomal-dominant neurodegenerative disorder caused by a small expansion of tri-nucleotide (CAG) repeat encoding polyglutamine (polyQ) in the gene for α(1A) voltage-dependent calcium channel (Ca(v) 2.1). Thus, this disease is one of the nine neurodegenerative disorders called polyQ diseases. The Purkinje cell predominant neuronal loss is the characteristic neuropathology of SCA6, and a 75-kDa carboxy-terminal fragment (CTF) of Ca(v) 2.1 containing polyQ, which remains soluble in normal brains, becomes insoluble in the cytoplasm of SCA6 Purkinje cells. Because the suppression of the brain-derived neurotrophic factor (BDNF) expression is a potentially momentous phenomenon in many other polyQ diseases, we implemented BDNF expression analysis in SCA6 human cerebellum using quantitative RT-PCR for the BDNF mRNA, and by immunohistochemistry for the BDNF protein. We observed significantly reduced BDNF mRNA levels in SCA6 cerebellum (n = 3) compared to controls (n = 6) (Mann-Whitney U-test, P = 0.0201). On immunohistochemistry, BDNF protein was only weakly stained in control cerebellum. On the other hand, we found numerous BDNF-immunoreactive granules in dendrites of SCA6 Purkinje cells. We did not observe similar BDNF-immunoreactive granules in other polyQ diseases, such as Huntington's disease or SCA2. As we often observed that the 1C2-positive Ca(v) 2.1 aggregates existed more proximally than the BDNF-positive granules in the dendrites, we speculated that the BDNF protein trafficking in dendrites may be disturbed by Ca(v) 2.1 aggregates in SCA6 Purkinje cells. We conclude that the SCA6 pathogenic mechanism associates with the BDNF mRNA expression reduction and abnormal localization of BDNF protein.

  7. Physical exercise and antidepressants enhance BDNF targeting in hippocampal CA3 dendrites: further evidence of a spatial code for BDNF splice variants.

    Science.gov (United States)

    Baj, Gabriele; D'Alessandro, Valentina; Musazzi, Laura; Mallei, Alessandra; Sartori, Cesar R; Sciancalepore, Marina; Tardito, Daniela; Langone, Francesco; Popoli, Maurizio; Tongiorgi, Enrico

    2012-06-01

    Brain-derived neurotrophic factor (BDNF) is encoded by multiple BDNF transcripts, whose function is unclear. We recently showed that a subset of BDNF transcripts can traffic into distal dendrites in response to electrical activity, while others are segregated into the somatoproximal domains. Physical exercise and antidepressant treatments exert their beneficial effects through upregulation of BDNF, which is required to support survival and differentiation of newborn dentate gyrus (DG) neurons. While these DG processes are required for the antidepressant effect, a role for CA1 in antidepressant action has been excluded, and the effect on CA3 neurons remains unclear. Here, we show for the first time that physical exercise and antidepressants induce local increase of BDNF in CA3. Voluntary physical exercise for 28 consecutive days, or 2-week treatment with 10 mg/kg per day fluoxetine or reboxetine, produced a global increase of BDNF mRNA and protein in the neuronal somata of the whole hippocampus and a specific increase of BDNF in dendrites of CA3 neurons. This increase was accounted for by BDNF exon 6 variant. In cultured hippocampal neurons, application of serotonin or norepinephrine (10-50 μM) induced increase in synaptic transmission and targeting of BDNF mRNA in dendrites. The increased expression of BDNF in CA3 dendrites following antidepressants or exercise further supports the neurotrophin hypothesis of antidepressants action and confirms that the differential subcellular localization of BDNF mRNA splice variants provides a spatial code for a selective expression of BDNF in specific subcellular districts. This selective expression may be exploited to design more specific antidepressants.

  8. IT Convergence and Security 2012

    CERN Document Server

    Chung, Kyung-Yong

    2013-01-01

    The proceedings approaches the subject matter with problems in technical convergence and convergences of security technology. This approach is new because we look at new issues that arise from techniques converging. The general scope of the proceedings content is convergence security and the latest information technology. The intended readership are societies, enterprises, and research institutes, and intended content level is mid- to highly educated personals. The most important features and benefits of the proceedings are the introduction of the most recent information technology and its related ideas, applications and problems related to technology convergence, and its case studies and finally an introduction of converging existing security techniques through convergence security. Overall, through the proceedings, authors will be able to understand the most state of the art information strategies and technologies of convergence security.

  9. The BDNF Val66Met polymorphism: relation to familiar risk of affective disorder, BDNF levels and salivary cortisol

    DEFF Research Database (Denmark)

    Vinberg, Maj; Trajkovska, Viktorija; Bennike, Bente

    2009-01-01

    with a familiar risk of affective disorder and whether these genotypes affect whole blood BDNF level and salivary cortisol. METHOD: In a high-risk study, healthy monozygotic and dizygotic twins with and without a co-twin (high- and low-risk twins, respectively) history of affective disorder were identified...... familiar risk of affective disorder and the met allele was associated with a higher whole blood BDNF (p=0.02) and a higher evening cortisol level (p=0.01), but not with awakening cortisol. CONCLUSION: Individuals at high risk of affective disorders and who are carriers of the met allele of the Val66Met...

  10. Corticosterone regulates expression of BDNF and trkB but not NT-3 and trkC mRNA in the rat hippocampus.

    Science.gov (United States)

    Schaaf, M J; Hoetelmans, R W; de Kloet, E R; Vreugdenhil, E

    1997-05-15

    Corticosterone has profound effects on growth, differentiation, and synaptic transmission of hippocampal neurons by activation of mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs). In the present study we tested if neurotrophins can be implicated in these effects. For this purpose we injected 30, 300, and 1,000 microg corticosterone s.c. (per kg body weight) in adrenalectomized rats and measured the mRNA levels of brain-derived neurotrophic factor (BDNF), tyrosine receptor kinase (trk)B, neurotrophin (NT)-3, and trkC in hippocampal cell fields at 6 hr after steroid administration by in situ hybridization. NT-3 and trkC mRNA did not show significant changes in any hippocampal region after the various doses of corticosterone. BDNF mRNA decreased after corticosterone administration dose dependently, resulting in a maximal suppression of 35, 20, and 50% in dentate gyrus, CA3, and CA1, respectively. Interestingly, trkB responded to corticosterone in an inverted U-shaped fashion in CA3 and dentate gyrus: the low dose of corticosterone increased trkB mRNA expression in both regions by approximately 30%, while the effect of the two higher doses was not different from the vehicle injected controls. In conclusion, we found differential effects of low and high doses of corticosterone on BDNF and trkB expression in hippocampus, which suggests involvement of a coordinated MR- and GR-mediated action.

  11. Physical exercise and environment exploration affect synaptogenesis in adult-generated neurons in the rat dentate gyrus: possible role of BDNF.

    Science.gov (United States)

    Ambrogini, P; Lattanzi, D; Ciuffoli, S; Betti, M; Fanelli, M; Cuppini, R

    2013-10-09

    A brief training in a pool maze, with or without cognitive tasks, modifies the synaptogenesis and maturation of newborn neurons in adult rat dentate gyrus. These types of trainings have many aspects, including physical activity and exploration. Therefore, to evaluate whether physical exercise and environment exploration are able to affect synapse formation and the maturation of adult-generated neurons, GFP-retrovirus infusion was performed on rats which, on the fourth day after injection, were housed under running conditions or allowed to explore an enriched environment briefly in the absence of exercise for the following three days. Afterward, at the end of the trainings, electrophysiological and morphological studies were conducted. Considering that neurotrophic factors increase after exercise or environment exploration, hippocampal BDNF levels and TrkB receptor activation were evaluated. In this study, we show that both spontaneous physical activity and enriched environment exploration induced synaptogenesis and T-type voltage-dependent Ca(2+) currents in very immature neurons. Hippocampal BDNF levels and TrkB receptor activation were determined to be increasing following physical activity and exploration. A possible contribution of BDNF signaling in mediating the observed effects was supported by the use of 7-8-dihydroxyflavone, a selective TrkB agonist, and of ANA-12, an inhibitor of TrkB receptors.

  12. Local administration of AAV-BDNF to subventricular zone induces functional recovery in stroke rats.

    Directory of Open Access Journals (Sweden)

    Seong-Jin Yu

    Full Text Available Migration of new neuroprogenitor cells (NPCs from the subventricular zone (SVZ plays an important role in neurorepair after injury. Previous studies have shown that brain derived neurotrophic factor (BDNF enhances the migration of NPCs from SVZ explants in neonatal mice in vitro. The purpose of this study was to identify the role of BDNF in SVZ cells using AAV-BDNF in an animal model of stroke. BDNF protein production after AAV-BDNF infection was verified in primary neuronal culture. AAV-BDNF or AAV-RFP was injected into the left SVZ region of adult rats at 14 days prior to right middle cerebral artery occlusion (MCAo. SVZ tissues were collected from the brain and placed in Metrigel cultures 1 day after MCAo. Treatment with AAV-BDNF significantly increased the migration of SVZ cells in the stroke brain in vitro. In another set of animals, AAV-GFP was co-injected with AAV-BDNF or AAV-RFP to label cells in left SVZ prior to right MCAo. Local administration of AAV-BDNF significantly enhanced recovery of locomotor function and migration of GFP-positive cells from the SVZ toward the lesioned hemisphere in stroke rats. Our data suggest that focal administration of AAV-BDNF to the SVZ increases behavioral recovery post stroke, possibly through the enhancement of migration of cells from SVZ in stroke animals. Regional manipulation of BDNF expression through AAV may be a novel approach for neurorepair in stroke brains.

  13. Local administration of AAV-BDNF to subventricular zone induces functional recovery in stroke rats.

    Science.gov (United States)

    Yu, Seong-Jin; Tseng, Kuan-Yin; Shen, Hui; Harvey, Brandon K; Airavaara, Mikko; Wang, Yun

    2013-01-01

    Migration of new neuroprogenitor cells (NPCs) from the subventricular zone (SVZ) plays an important role in neurorepair after injury. Previous studies have shown that brain derived neurotrophic factor (BDNF) enhances the migration of NPCs from SVZ explants in neonatal mice in vitro. The purpose of this study was to identify the role of BDNF in SVZ cells using AAV-BDNF in an animal model of stroke. BDNF protein production after AAV-BDNF infection was verified in primary neuronal culture. AAV-BDNF or AAV-RFP was injected into the left SVZ region of adult rats at 14 days prior to right middle cerebral artery occlusion (MCAo). SVZ tissues were collected from the brain and placed in Metrigel cultures 1 day after MCAo. Treatment with AAV-BDNF significantly increased the migration of SVZ cells in the stroke brain in vitro. In another set of animals, AAV-GFP was co-injected with AAV-BDNF or AAV-RFP to label cells in left SVZ prior to right MCAo. Local administration of AAV-BDNF significantly enhanced recovery of locomotor function and migration of GFP-positive cells from the SVZ toward the lesioned hemisphere in stroke rats. Our data suggest that focal administration of AAV-BDNF to the SVZ increases behavioral recovery post stroke, possibly through the enhancement of migration of cells from SVZ in stroke animals. Regional manipulation of BDNF expression through AAV may be a novel approach for neurorepair in stroke brains.

  14. Regulation of Energy Balance via BDNF Expressed in Nonparaventricular Hypothalamic Neurons.

    Science.gov (United States)

    Yang, Haili; An, Juan Ji; Sun, Chao; Xu, Baoji

    2016-05-01

    Brain-derived neurotrophic factor (BDNF) expressed in the paraventricular hypothalamus (PVH) has been shown to play a key role in regulating energy intake and energy expenditure. BDNF is also expressed in other hypothalamic nuclei; however, the role in the control of energy balance for BDNF produced in these structures remains largely unknown. We found that deleting the Bdnf gene in the ventromedial hypothalamus (VMH) during embryogenesis using the Sf1-Cre transgene had no effect on body weight in mice. In contrast, deleting the Bdnf gene in the adult VMH using Cre-expressing virus led to significant hyperphagia and obesity. These observations indicate that the lack of a hyperphagia phenotype in the Sf1-Cre/Bdnf mutant mice is likely due to developmental compensation. To investigate the role of BDNF expressed in other hypothalamic areas, we employed the hypothalamus-specific Nkx2.1-Cre transgene to delete the Bdnf gene. We found that the Nkx2.1-Cre transgene could abolish BDNF expression in many hypothalamic nuclei, but not in the PVH, and that the resulting mutant mice developed modest obesity due to reduced energy expenditure. Thus, BDNF produced in the VMH plays a role in regulating energy intake. Furthermore, BDNF expressed in hypothalamic areas other than PVH and VMH is also involved in the control of energy expenditure.

  15. Time-dependent biphasic modulation of human BDNF by antidepressants in neuroblastoma cells

    Directory of Open Access Journals (Sweden)

    Musazzi Laura

    2008-07-01

    Full Text Available Abstract Background Recent rodent studies reported that antidepressant treatments affect the expression of brain-derived neurotrophic factor (BDNF mRNA in a way that is dependent on treatment duration, by selective modulation of different BDNF transcripts. However, no data are available for the human BDNF gene. We studied the effect of different antidepressants on BDNF mRNA expression in human neuroblastoma SH-SY5Y cells. Results Cultured cells were treated with the antidepressants fluoxetine, reboxetine and desipramine for different time lengths (6, 24, 48 hours. Expression of total BDNF mRNA was analyzed by reverse transcription PCR and levels of different BDNF transcripts were detected by hemi-nested PCR with specific primers. Short-term treatment (6 hours with reboxetine or desipramine reduced total BDNF, whereas long-term treatment (48 hours significantly increased total BDNF mRNA levels. These changes were accounted for by differential regulation of BDNF IV and VIa/b transcripts. Fluoxetine showed no significant effects. Conclusion This is the first study showing biphasic changes in the expression of total and specific BDNF transcripts in human cells following antidepressant treatments. These findings suggest that biphasic induction of BDNF by antidepressants could be a feature common to rodents and humans and encourage the use of SH-SY5Y cells as a tool for investigation of drug effects on human genes.

  16. Die Rolle des neurotrophen Faktors BDNF für läsionsinduzierte Plastizität im visuellen Kortex der BDNF (+/-) Maus

    OpenAIRE

    Breiter, Sarah

    2011-01-01

    Der neurotrophe Faktor BDNF steht im Verdacht, läsionsinduzierte Plastizität zu beeinflussen. Durch elektrophysiologische Versuche konnte in Wt Kontrolltieren eine 20%ige LTP beobachtet werden, während BDNF(+/-) Mäuse keine LTP ausbildeten. Nach Läsionen zeigten Wt Tiere eine erhöhte LTP von ca. 40%. Bei BDNF(+/-) Mäusen post-Läsion wurde ebenfalls eine stabile LTP von etwas mehr als 20% gemessen. Zudem zeigten BDNF(+/-) Tieren wie auch in Wt Tieren 24h nach Läsion eine signifikan...

  17. Circulating brain derived neurotrophic factor (BDNF) and frequency of BDNF positive T cells in peripheral blood in human ischemic stroke: Effect on outcome.

    Science.gov (United States)

    Chan, Adeline; Yan, Jun; Csurhes, Peter; Greer, Judith; McCombe, Pamela

    2015-09-15

    The aim of this study was to measure the levels of circulating BDNF and the frequency of BDNF-producing T cells after acute ischaemic stroke. Serum BDNF levels were measured by ELISA. Flow cytometry was used to enumerate peripheral blood leukocytes that were labelled with antibodies against markers of T cells, T regulatory cells (Tregs), and intracellular BDNF. There was a slight increase in serum BDNF levels after stroke. There was no overall difference between stroke patients and controls in the frequency of CD4(+) and CD8(+) BDNF(+) cells, although a subgroup of stroke patients showed high frequencies of these cells. However, there was an increase in the percentage of BDNF(+) Treg cells in the CD4(+) population in stroke patients compared to controls. Patients with high percentages of CD4(+) BDNF(+) Treg cells had a better outcome at 6months than those with lower levels. These groups did not differ in age, gender or initial stroke severity. Enhancement of BDNF production after stroke could be a useful means of improving neuroprotection and recovery after stroke.

  18. Epibranchial placode-derived neurons produce BDNF required for early sensory neuron development.

    Science.gov (United States)

    Harlow, Danielle E; Yang, Hui; Williams, Trevor; Barlow, Linda A

    2011-02-01

    In mice, BDNF provided by the developing taste epithelium is required for gustatory neuron survival following target innervation. However, we find that expression of BDNF, as detected by BDNF-driven β-galactosidase, begins in the cranial ganglia before its expression in the central (hindbrain) or peripheral (taste papillae) targets of these sensory neurons, and before gustatory ganglion cells innervate either target. To test early BDNF function, we examined the ganglia of bdnf null mice before target innervation, and found that while initial neuron survival is unaltered, early neuron development is disrupted. In addition, fate mapping analysis in mice demonstrates that murine cranial ganglia arise from two embryonic populations, i.e., epibranchial placodes and neural crest, as has been described for these ganglia in non-mammalian vertebrates. Only placodal neurons produce BDNF, however, which indicates that prior to innervation, early ganglionic BDNF produced by placode-derived cells promotes gustatory neuron development.

  19. Knowledge Convergence and Collaborative Learning

    Science.gov (United States)

    Jeong, Heisawn; Chi, Michelene T. H.

    2007-01-01

    This paper operationalized the notion of knowledge convergence and assessed quantitatively how much knowledge convergence occurred during collaborative learning. Knowledge convergence was defined as an increase in common knowledge where common knowledge referred to the knowledge that all collaborating partners had. Twenty pairs of college students…

  20. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  1. Comparative effect of treadmill exercise on mature BDNF production in control versus stroke rats.

    Directory of Open Access Journals (Sweden)

    Aurore Quirié

    Full Text Available Physical exercise constitutes an innovative strategy to treat deficits associated with stroke through the promotion of BDNF-dependent neuroplasticity. However, there is no consensus on the optimal intensity/duration of exercise. In addition, whether previous stroke changes the effect of exercise on the brain is not known. Therefore, the present study compared the effects of a clinically-relevant form of exercise on cerebral BDNF levels and localization in control versus stroke rats. For this purpose, treadmill exercise (0.3 m/s, 30 min/day, for 7 consecutive days was started in rats with a cortical ischemic stroke after complete maturation of the lesion or in control rats. Sedentary rats were run in parallel. Mature and proBDNF levels were measured on the day following the last boot of exercise using Western blotting analysis. Total BDNF levels were simultaneously measured using ELISA tests. As compared to the striatum and the hippocampus, the cortex was the most responsive region to exercise. In this region, exercise resulted in a comparable increase in the production of mature BDNF in intact and stroke rats but increased proBDNF levels only in intact rats. Importantly, levels of mature BDNF and synaptophysin were strongly correlated. These changes in BDNF metabolism coincided with the appearance of intense BDNF labeling in the endothelium of cortical vessels. Notably, ELISA tests failed to detect changes in BDNF forms. Our results suggest that control beings can be used to find conditions of exercise that will result in increased mBDNF levels in stroke beings. They also suggest cerebral endothelium as a potential source of BDNF after exercise and highlight the importance to specifically measure the mature form of BDNF to assess BDNF-dependent plasticity in relation with exercise.

  2. Differential regulation of BDNF, synaptic plasticity and sprouting in the hippocampal mossy fiber pathway of male and female rats

    OpenAIRE

    SCHARFMAN, HELEN E.; MacLusky, Neil J.

    2013-01-01

    Many studies have described potent effects of BDNF, 17β-estradiol or androgen on hippocampal synapses and their plasticity. Far less information is available about the interactions between 17β-estradiol and BDNF in hippocampus, or interactions between androgen and BDNF in hippocampus. Here we review the regulation of BDNF in the mossy fiber pathway, a critical part of hippocampal circuitry. We discuss the emerging view that 17β-estradiol upregulates mossy fiber BDNF synthesis in the adult fem...

  3. Convergence Patterns in Latin America

    DEFF Research Database (Denmark)

    Quiroga, Paola Andrea Barrientos

    Literature on convergence among Latin American countries is still scarce compared to other regions. Moreover, almost none of the research connects convergence to the economic history of Latin America and the usual finding is one speed of convergence. In this paper I analyze 32 countries and 108...... years, more observations than any other study. This long span of data allows me to use economic history to explain, analyze, validate, and understand the results of convergence patterns in the region. I find more than one speed of convergence (clubs) related to the known historical background, country...

  4. Medialogy - convergence and transdisciplinarity

    DEFF Research Database (Denmark)

    Nordahl, Rolf

    2007-01-01

    for changes in society, developments in taste etc.  However, it certainly seems fair to say, that available technology makes a great difference to the development of any art form or practice. With the up rise of new educations such as Medialogy, new aspects of convergence and different forms...... of interdisciplinarity and transdisciplinarity is a pre-requisite for both researchers and students. In this talk we will demonstrate our approach through concrete examples of student productions and projects. We will also display the pedagogical method (problem based learning), that enables students to bridge gaps...... between art and science....

  5. Cooperative roles of BDNF expression in neurons and Schwann cells are modulated by exercise to facilitate nerve regeneration.

    Science.gov (United States)

    Wilhelm, Jennifer C; Xu, Mei; Cucoranu, Delia; Chmielewski, Sarah; Holmes, Tiffany; Lau, Kelly Shukkwan; Bassell, Gary J; English, Arthur W

    2012-04-04

    After peripheral nerve injury, neurotrophins play a key role in the regeneration of damaged axons that can be augmented by exercise, although the distinct roles played by neurons and Schwann cells are unclear. In this study, we evaluated the requirement for the neurotrophin, brain-derived neurotrophic factor (BDNF), in neurons and Schwann cells for the regeneration of peripheral axons after injury. Common fibular or tibial nerves in thy-1-YFP-H mice were cut bilaterally and repaired using a graft of the same nerve from transgenic mice lacking BDNF in Schwann cells (BDNF(-/-)) or wild-type mice (WT). Two weeks postrepair, axonal regeneration into BDNF(-/-) grafts was markedly less than WT grafts, emphasizing the importance of Schwann cell BDNF. Nerve regeneration was enhanced by treadmill training posttransection, regardless of the BDNF content of the nerve graft. We further tested the hypothesis that training-induced increases in BDNF in neurons allow regenerating axons to overcome a lack of BDNF expression in cells in the pathway through which they regenerate. Nerves in mice lacking BDNF in YFP(+) neurons (SLICK) were cut and repaired with BDNF(-/-) and WT nerves. SLICK axons lacking BDNF did not regenerate into grafts lacking Schwann cell BDNF. Treadmill training could not rescue the regeneration into BDNF(-/-) grafts if the neurons also lacked BDNF. Both Schwann cell- and neuron-derived BDNF are thus important for axon regeneration in cut peripheral nerves.

  6. An evaluation of the effects of acute and chronic L-tyrosine administration on BDNF levels and BDNF mRNA expression in the rat brain.

    Science.gov (United States)

    Ferreira, Gabriela K; Scaini, Giselli; Jeremias, Isabela C; Carvalho-Silva, Milena; Gonçalves, Cinara L; Pereira, Talita C B; Oliveira, Giovanna M T; Kist, Luiza W; Bogo, Maurício R; Schuck, Patrícia F; Ferreira, Gustavo C; Streck, Emilio L

    2014-04-01

    Tyrosinemia type II, which is also known as Richner-Hanhart syndrome, is an inborn error of metabolism that is due to a block in the transamination reaction that converts tyrosine to p-hydroxyphenylpyruvate. Because the mechanisms of neurological dysfunction in hypertyrosinemic patients are poorly known and the symptoms of these patients are related to the central nervous system, the present study evaluated brain-derived neurotrophic factor (BDNF) levels and bdnf mRNA expression in young rats and during growth. In our acute protocol, Wistar rats (10 and 30 days old) were killed 1 h after a single intraperitoneal L-tyrosine injection (500 mg/kg) or saline. Chronic administration consisted of L-tyrosine (500 mg/kg) or saline injections 12 h apart for 24 days in Wistar rats (7 days old), and the rats were killed 12 h after the last injection. The brains were rapidly removed, and we evaluated the BDNF levels and bdnf mRNA expression. The present results showed that the acute administration of L-tyrosine decreased both BDNF and bdnf mRNA levels in the striatum of 10-day-old rats. In the 30-day-old rats, we observed decreased BDNF levels without modifications in bdnf transcript level in the hippocampus and striatum. Chronic administration of L-tyrosine increased the BDNF levels in the striatum of rats during their growth, whereas bdnf mRNA expression was not altered. We hypothesize that oxidative stress can interact with the BDNF system to modulate synaptic plasticity and cognitive function. The present results enhance our knowledge of the pathophysiology of hypertyrosinemia.

  7. Alterations in BDNF and synapsin I within the occipital cortex and hippocampus after mild traumatic brain injury in the developing rat: reflections of injury-induced neuroplasticity.

    Science.gov (United States)

    Griesbach, Grace Sophia; Hovda, David Allen; Molteni, Raffaella; Gomez-Pinilla, Fernando

    2002-07-01

    Brain-derived neurotrophic factor (BDNF), its signal transduction receptor trkB, and its downstream effector, synapsin I, were measured in the hippocampus and occipital cortex of young animals after fluid-percussion brain injury (FPI). Isofluorane anaesthetized postnatal day 19 rats were subjected to a mild lateral FPI or sham injury. Rats were sacrificed at 24 h, 7 days, or 14 days after injury in order to determine mRNA expression. Additional animals were sacrificed at 7 and 14 days after injury for protein analysis. Only FPI animals exhibited hemispheric differences in BDNF levels. These animals exhibited a contralateral increase, ranging from 40% to 75%, in BDNF mRNA within both the hippocampus and occipital cortex at 24 h and 7 days after injury. The increase in message within the occipital cortex was accompanied by an increase in BDNF protein at 7 and 14 days after injury. However, hippocampal BDNF protein increased in both hemispheres at postinjury day 7 and was restricted to the ipsilateral hippocampus at postinjury day 14. At postinjury day 7, both trkB and synapsin I mRNA expression increased ipsilaterally and decreased contralaterally in the occipital cortex. In addition, synapsin I phosphorylation was increased by 20% in the ipsilateral cortex and by 30% in the hippocampus on this day. These results indicate that the developing brain responds to a mild injury by modifying factors related to synaptic plasticity and suggest that regions remote from the site of injury express neurotrophic signals potentially needed for compensatory responses.

  8. The antidepressant-like effects of glutamatergic drugs ketamine and AMPA receptor potentiator LY 451646 are preserved in bdnf⁺/⁻ heterozygous null mice.

    Science.gov (United States)

    Lindholm, Jesse S O; Autio, Henri; Vesa, Liisa; Antila, Hanna; Lindemann, Lothar; Hoener, Marius C; Skolnick, Phil; Rantamäki, Tomi; Castrén, Eero

    2012-01-01

    Accumulating evidence suggests that biogenic amine-based antidepressants act, at least in part, via regulation of brain-derived neurotrophic factor (BDNF) signaling. Biogenic amine-based antidepressants increase BDNF synthesis and activate its signaling pathway through TrkB receptors. Moreover, the antidepressant-like effects of these molecules are abolished in BDNF deficient mice. Glutamate-based drugs, including the NMDA antagonist ketamine, and the AMPA receptor potentiator LY 451646, mimic the effects of antidepressants in preclinical tests with high predictive validity. In humans, a single intravenous dose of ketamine produces an antidepressant effect that is rapid, robust and persistent. In this study, we examined the role of BDNF in expression of the antidepressant-like effects of ketamine and an AMPA receptor potentiator (LY 451646) in the forced swim test (FST). Ketamine and LY 451646 produced antidepressant-like effects in the FST in mice at 45 min after a single injection, but no effects were observed one week after a single ketamine injection. As previously reported, the effects of imipramine in the forced swim test were blunted in heterozygous BDNF knockout (bdnf(+/-)) mice. However ketamine and LY 451646 produced similar antidepressant-like responses in wildtype and bdnf(+/-) mice. Neither ketamine nor LY 451646 significantly influenced the levels BDNF or TrkB phosphorylation in the hippocampus when assessed at 45 min or 7 days after the drug administration. These data demonstrate that under the conditions tested, neither ketamine nor the AMPA-potentiator LY 451656 activate BDNF signaling, but produce a characteristic antidepressant-like response in heterozygous bdnf(+/-) mice. These data indicate that unlike biogenic amine-based agents, BDNF signaling does not play a pivotal role in the antidepressant effects of glutamate-based compounds. This article is part of a Special Issue entitled 'Anxiety and Depression'.

  9. A BDNF loop-domain mimetic acutely reverses spontaneous apneas and respiratory abnormalities during behavioral arousal in a mouse model of Rett syndrome

    Directory of Open Access Journals (Sweden)

    Miriam Kron

    2014-09-01

    Full Text Available Reduced levels of brain-derived neurotrophic factor (BDNF are thought to contribute to the pathophysiology of Rett syndrome (RTT, a severe neurodevelopmental disorder caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2. In Mecp2 mutant mice, BDNF deficits have been associated with breathing abnormalities, a core feature of RTT, as well as with synaptic hyperexcitability within the brainstem respiratory network. Application of BDNF can reverse hyperexcitability in acute brainstem slices from Mecp2-null mice, suggesting that therapies targeting BDNF or its receptor, TrkB, could be effective at acute reversal of respiratory abnormalities in RTT. Therefore, we examined the ability of LM22A-4, a small-molecule BDNF loop-domain mimetic and TrkB partial agonist, to modulate synaptic excitability within respiratory cell groups in the brainstem nucleus tractus solitarius (nTS and to acutely reverse abnormalities in breathing at rest and during behavioral arousal in Mecp2 mutants. Patch-clamp recordings in Mecp2-null brainstem slices demonstrated that LM22A-4 decreases excitability at primary afferent synapses in the nTS by reducing the amplitude of evoked excitatory postsynaptic currents and the frequency of spontaneous and miniature excitatory postsynaptic currents. In vivo, acute treatment of Mecp2-null and -heterozygous mutants with LM22A-4 completely eliminated spontaneous apneas in resting animals, without sedation. Moreover, we demonstrate that respiratory dysregulation during behavioral arousal, a feature of human RTT, is also reversed in Mecp2 mutants by acute treatment with LM22A-4. Together, these data support the hypothesis that reduced BDNF signaling and respiratory dysfunction in RTT are linked, and establish the proof-of-concept that treatment with a small-molecule structural mimetic of a BDNF loop domain and a TrkB partial agonist can acutely reverse abnormal breathing at rest and in response to

  10. Antidepressive and BDNF effects of enriched environment treatment across ages in mice lacking BDNF expression through promoter IV

    Science.gov (United States)

    Jha, S; Dong, B E; Xue, Y; Delotterie, D F; Vail, M G; Sakata, K

    2016-01-01

    Reduced promoter IV-driven expression of brain-derived neurotrophic factor (BDNF) is implicated in stress and major depression. We previously reported that defective promoter IV (KIV) caused depression-like behavior in young adult mice, which was reversed more effectively by enriched environment treatment (EET) than antidepressants. The effects of promoter IV-BDNF deficiency and EET over the life stages remain unknown. Since early-life development (ED) involves dynamic epigenetic processes, we hypothesized that EET during ED would provide maximum antidepressive effects that would persist later in life due to enhanced, long-lasting BDNF induction. We tested this hypothesis by determining EET effects across three life stages: ED (0–2 months), young adult (2–4 months), and old adult (12–14 months). KIV mice at all life stages showed depression-like behavior in the open-field and tail-suspension tests compared with wild-type mice. Two months of EET reduced depression-like behavior in ED and young adult, but not old adult mice, with the largest effect in ED KIV mice. This effect lasted for 1 month after discontinuance of EET only in ED mice. BDNF protein induction by EET in the hippocampus and frontal cortex was also the largest in ED mice and persisted only in the hippocampus of ED KIV mice after discontinuance of EET. No gender-specific effects were observed. The results suggest that defective promoter IV causes depression-like behavior, regardless of age and gender, and that EET during ED is particularly beneficial to individuals with promoter IV-BDNF deficiency, while additional treatment may be needed for older adults. PMID:27648918

  11. An adaptive role for BDNF Val66Met polymorphism in motor recovery in chronic stroke.

    Science.gov (United States)

    Qin, Luye; Jing, Deqiang; Parauda, Sarah; Carmel, Jason; Ratan, Rajiv R; Lee, Francis S; Cho, Sunghee

    2014-02-12

    Little is known about the influence of genetic diversity on stroke recovery. One exception is the polymorphism in brain derived neurotrophic factor (BDNF), a critical neurotrophin for brain repair and plasticity. Humans have a high-frequency single nucleotide polymorphism (SNP) in the prodomain of the BDNF gene. Previous studies show that the BDNF Val66Met variant negatively affects motor learning and severity of acute stroke. To investigate the impact of this common BDNF SNP on stroke recovery, we used a mouse model that contains the human BDNF Val66Met variant in both alleles (BDNF(M/M)). Male BDNF(+/+) and BDNF(M/M) littermates received sham or transient middle cerebral artery occlusion. We assessed motor function regularly for 6 months after stroke and then performed anatomical analyses. Despite reported negative association of the SNP with motor learning and acute deficits, we unexpectedly found that BDNF(M/M) mice displayed significantly enhanced motor/kinematic performance in the chronic phase of motor recovery, especially in ipsilesional hindlimb. The enhanced recovery was associated with significant increases in striatum volume, dendritic arbor, and elevated excitatory synaptic markers in the contralesional striatum. Transient inactivation of the contralateral striatum during recovery transiently abolished the enhanced function. This study showed an unexpected benefit of the BDNFVal66Met carriers for functional recovery, involving structural and molecular plasticity in the nonstroked hemisphere. Clinically, this study suggests a role for BDNF genotype in predicting stroke recovery and identifies a novel systems-level mechanism for enhanced motor recovery.

  12. Combined cisplatin and aurora inhibitor treatment increase neuroblastoma cell death but surviving cells overproduce BDNF.

    Science.gov (United States)

    Polacchini, Alessio; Albani, Clara; Baj, Gabriele; Colliva, Andrea; Carpinelli, Patrizia; Tongiorgi, Enrico

    2016-07-15

    Drug-resistance to chemotherapics in aggressive neuroblastoma (NB) is characterized by enhanced cell survival mediated by TrkB and its ligand, brain-derived neurotrophic factor (BDNF); thus reduction in BDNF levels represent a promising strategy to overcome drug-resistance, but how chemotherapics regulate BDNF is unknown. Here, cisplatin treatment in SK-N-BE neuroblastoma upregulated multiple BDNF transcripts, except exons 5 and 8 variants. Cisplatin increased BDNF mRNA and protein, and enhanced translation of a firefly reporter gene flanked by BDNF 5'UTR exons 1, 2c, 4 or 6 and 3'UTR-long. To block BDNF translation we focused on aurora kinases inhibitors which are proposed as new chemotherapeutics. NB cell survival after 24 h treatment was 43% with cisplatin, and 22% by cisplatin+aurora kinase inhibitor PHA-680632, while the aurora kinases inhibitor alone was less effective; however the combined treatment induced a paradoxical increase of BDNF in surviving cells with strong translational activation of exon6-3'UTR-long transcript, while translation of BDNF transcripts 1, 2C and 4 was suppressed. In conclusion, combined cisplatin and aurora kinase inhibitor treatment increases cell death, but induces BDNF overproduction in surviving cells through an aurora kinase-independent mechanism.

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

    Directory of Open Access Journals (Sweden)

    Bianca Seifert

    2016-01-01

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

  14. Postnatal Administration of Allopregnanolone Modifies Glutamate Release but Not BDNF Content in Striatum Samples of Rats Prenatally Exposed to Ethanol

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    Roberto Yunes

    2015-01-01

    Full Text Available Ethanol consumption during pregnancy may induce profound changes in fetal CNS development. We postulate that some of the effects of ethanol on striatal glutamatergic transmission and neurotrophin expression could be modulated by allopregnanolone, a neurosteroid modulator of GABAA receptor activity. We describe the acute pharmacological effect of allopregnanolone (65 μg/kg, s.c. administered to juvenile male rats (day 21 of age on the corticostriatal glutamatergic pathway, in both control and prenatally ethanol-exposed rats (two ip injections of 2.9 g/kg in 24% v/v saline solution on gestational day 8. Prenatal ethanol administration decreased the K+-induced release of glutamate regarding the control group. Interestingly, this effect was reverted by allopregnanolone. Regarding BDNF, allopregnanolone decreases the content of this neurotrophic factor in the striatum of control groups. However, both ethanol alone and ethanol plus allopregnanolone treated animals did not show any change regarding control values. We suggest that prenatal ethanol exposure may produce an alteration of GABAA receptors which blocks the GABA agonist-like effect of allopregnanolone on rapid glutamate release, thus disturbing normal neural transmission. Furthermore, the reciprocal interactions found between GABAergic neurosteroids and BDNF could underlie mechanisms operating during the neuronal plasticity of fetal development.

  15. Convergence as Organization

    DEFF Research Database (Denmark)

    Harrison, Yannick Nehemiah Antonio; Risager, Bjarke Skærlund

    2016-01-01

    . The article is based on participant observation of the Blockupy event and interviews with a group of Danish activists who also participated. The article constructs sociospatial narrative that unfolds through three different scales of organization: the Blockupy coalition, the participating formal and informal...... organizations, and the activist subject. This narrative explicates the mode of organization as a ‘convergence space’ (cf. Routledge, 2003), with different ‘roots’ and ‘routes’ of organization (cf. Davies, 2012). Thus, through an analysis of the modes of organization constituting this mass protest event......, this article restates the relevance of the concept of organization, which have recently been ignored or understated in favour of master-narratives of networks or the dichotomy of horizontalism and verticality. It concludes by posing a set of questions for further discussion among both activists...

  16. Homology, convergence and parallelism.

    Science.gov (United States)

    Ghiselin, Michael T

    2016-01-05

    Homology is a relation of correspondence between parts of parts of larger wholes. It is used when tracking objects of interest through space and time and in the context of explanatory historical narratives. Homologues can be traced through a genealogical nexus back to a common ancestral precursor. Homology being a transitive relation, homologues remain homologous however much they may come to differ. Analogy is a relationship of correspondence between parts of members of classes having no relationship of common ancestry. Although homology is often treated as an alternative to convergence, the latter is not a kind of correspondence: rather, it is one of a class of processes that also includes divergence and parallelism. These often give rise to misleading appearances (homoplasies). Parallelism can be particularly hard to detect, especially when not accompanied by divergences in some parts of the body. © 2015 The Author(s).

  17. The EU's Convergence Dilemma

    Directory of Open Access Journals (Sweden)

    Notermans Ton

    2015-02-01

    Full Text Available As economic stagnation continues to mark the EU in the fifth year of the euro zone crisis, political support for integration is waning. The European Parliament elections of 2014 returned a hitherto unparalleled number of Eurosceptic MEPs, with EU-critical parties becoming the largest ones in several Member States. Much of this Euroscepticism is driven by economic polarisation between core and peripheral countries. While an increasing number of voters in the northwestern creditor countries resent having to foot the bill for what they consider economic mismanagement in the periphery, voters in peripheral countries increasingly rebel against what they deem to be an economically catastrophic Diktat from Germany and its allies. Continued political support for European integration will hinge on successful income convergence in the EU but the current dilemma is that such policies might not be politically feasible. Periods of rapid convergence would seem to suggest that success depends on two main policy strategies. First, a monetary policy that promotes credit for productive purposes, leaves inflation control to other instruments, and employs selective credit rationing to prevent asset booms. Second, a vertical industrial policy prioritising selected industrial sectors. The first policy conflicts with the present framework of euro zone monetary policy, but that framework was only installed in the first place because many peripheral countries were desperately in search of an external constraint on domestic distributional conflict. Industrial policies, in turn, require a sufficient degree of state autonomy from business elites in order to be effective, but it is highly questionable whether most states in the EU possess such autonomy. Though there are, as yet hesitant, signs of a reorientation of both monetary and cohesion policy in the EU, the question of the institutional and political preconditions for their successful implementation has been largely

  18. The Convergence in Spatial Tasks

    OpenAIRE

    Vladimir P. Kulagin; Victor Y. Tsvetkov; Maiya V. Maksimova

    2013-01-01

    The article reveals the problem of convergence of direct and inverse problems in Earth Sciences, describes the features and application of these problems, discloses analytical features of direct and inverse problems. The convergence criteria and conditions for convergence were presented. This work is supported by the Grant of the Government of the Russian Federation for support of scientific research, implemented under the supervision of leading scientists in Russian institutions of higher ed...

  19. Robust changes in expression of brain-derived neurotrophic factor (BDNF) mRNA and protein across the brain do not translate to detectable changes in BDNF levels in CSF or plasma.

    Science.gov (United States)

    Lanz, Thomas A; Bove, Susan E; Pilsmaker, Catherine D; Mariga, Abigail; Drummond, Elena M; Cadelina, Gregory W; Adamowicz, Wendy O; Swetter, Brentt J; Carmel, Sharon; Dumin, Jo Ann; Kleiman, Robin J

    2012-09-01

    Adult rats were treated acutely with peripheral kainic acid (KA), and changes in brain-derived neurotrophic factor (BDNF) mRNA and protein were tracked over time across multiple brain regions. Despite robust elevation in both mRNA and protein in multiple brain regions, plasma BDNF was unchanged and cerebrospinal fluid (CSF) BDNF levels remained undetectable. Primary neurons were then treated with KA. BDNF was similarly elevated within neurons, but was undetectable in neuronal media. Thus, while deficits in BDNF signaling have been implicated in a number of diseases, these data suggest that extracellular concentrations of BDNF may not be a facile biomarker for changes in neurons.

  20. Increased brain-derived neurotrophic factor (BDNF) protein concentrations in mice lacking brain serotonin.

    Science.gov (United States)

    Kronenberg, Golo; Mosienko, Valentina; Gertz, Karen; Alenina, Natalia; Hellweg, Rainer; Klempin, Friederike

    2016-04-01

    The interplay between BDNF signaling and the serotonergic system remains incompletely understood. Using a highly sensitive enzyme-linked immunosorbent assay, we studied BDNF concentrations in hippocampus and cortex of two mouse models of altered serotonin signaling: tryptophan hydroxylase (Tph)2-deficient (Tph2 (-/-)) mice lacking brain serotonin and serotonin transporter (SERT)-deficient (SERT(-/-)) mice lacking serotonin re-uptake. Surprisingly, hippocampal BDNF was significantly elevated in Tph2 (-/-) mice, whereas no significant changes were observed in SERT(-/-) mice. Furthermore, BDNF levels were increased in the prefrontal cortex of Tph2 (-/-) but not of SERT(-/-) mice. Our results emphasize the interaction between serotonin signaling and BDNF. Complete lack of brain serotonin induces BDNF expression.

  1. BDNF and its pro-peptide are stored in presynaptic dense core vesicles in brain neurons

    Science.gov (United States)

    Dieni, Sandra; Matsumoto, Tomoya; Dekkers, Martijn; Rauskolb, Stefanie; Ionescu, Mihai S.; Deogracias, Ruben; Gundelfinger, Eckart D.; Kojima, Masami; Nestel, Sigrun; Frotscher, Michael

    2012-01-01

    Although brain-derived neurotrophic factor (BDNF) regulates numerous and complex biological processes including memory retention, its extremely low levels in the mature central nervous system have greatly complicated attempts to reliably localize it. Using rigorous specificity controls, we found that antibodies reacting either with BDNF or its pro-peptide both stained large dense core vesicles in excitatory presynaptic terminals of the adult mouse hippocampus. Both moieties were ∼10-fold more abundant than pro-BDNF. The lack of postsynaptic localization was confirmed in Bassoon mutants, a seizure-prone mouse line exhibiting markedly elevated levels of BDNF. These findings challenge previous conclusions based on work with cultured neurons, which suggested activity-dependent dendritic synthesis and release of BDNF. They instead provide an ultrastructural basis for an anterograde mode of action of BDNF, contrasting with the long-established retrograde model derived from experiments with nerve growth factor in the peripheral nervous system. PMID:22412021

  2. [BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF): NEUROBIOLOGY AND MARKER VALUE IN NEUROPSYCHIATRY].

    Science.gov (United States)

    Levada, O A; Cherednichenko, N V

    2015-01-01

    In this review current publications about neurobiology and marker value of brain derived neurotrophic factor (BDNF) in neuropsychiatry are analyzed. It is shown that BDNF is an important member of the family of neurotrophins which widely represented in various structures of the CNS. In prenatal period BDNF is involved in all stages of neuronal networks formation, and in the postnatal period its main role is maintaining the normal brain architectonics, involvement in the processes of neurogenesis and realization of neuroprotective functions. BDNF plays an important role in learning and memory organization, food and motor behavior. BDNF brain expression decreases with age, as well as in degenerative and vascular dementias, affective, anxiety, and behavioral disorders. The reducing of BDNF serum, level reflects the decreasing of its cerebral expression and could be used as a neurobiological marker of these pathological processes but the rising of its concentration could indicate the therapy effectiveness.

  3. Comparison of serum BDNF levels in deficit and nondeficit chronic schizophrenia and healthy controls.

    Science.gov (United States)

    Valiente-Gómez, Alicia; Amann, Benedikt L; Mármol, Frederic; Oliveira, Cristina; Messeguer, Ana; Lafuente, Amalia; Pomarol-Clotet, Edith; Bernardo Arroyo, Miguel

    2014-12-15

    The aim of this study was to compare serum BDNF levels of chronic schizophrenic patients, with or without deficit syndrome, and healthy controls. A comparative study of serum BDNF levels, determined by ELISA, was performed in 47 chronic patients with schizophrenia matched with 47 healthy controls. A part of the chronic schizophrenic sample was further divided into patients with a deficit (n=14) and a nondeficit syndrome (n=20), according to the Proxy for the Deficit Syndrome Scale. A significant difference was observed in decreased serum BDNF levels between chronic schizophrenia and healthy controls. No statistical significant differences in BDNF levels between deficit and nondeficit chronic schizophrenic patients were found. Our study confirms differences of serum BDNF levels of chronic schizophrenia and healthy controls, which correspond to the clinical progression of the disease. Our results do not support a relation between deficit profile in chronic schizophrenia and lower serum BDNF levels.

  4. Glucocorticoids modulate BDNF mRNA expression in the rat hippocampus after traumatic brain injury.

    Science.gov (United States)

    Grundy, P L; Patel, N; Harbuz, M S; Lightman, S L; Sharples, P M

    2000-10-20

    Brain-derived neurotrophic factor (BDNF) expression in rat hippocampus is increased after experimental traumatic brain injury (TBI) and may be neuroprotective. Glucocorticoids are important regulators of brain neurotrophin levels and are often prescribed following TBI. The effect of adrenalectomy (ADX) on the expression of BDNF mRNA in the hippocampus after TBI has not been investigated to date. We used fluid percussion injury (FPI) and in situ hybridization to evaluate the expression of BDNF mRNA in the hippocampus 4 h after TBI in adrenal-intact or adrenalectomized rats (with or without corticosterone replacement). FPI and ADX independently increased expression of BDNF mRNA. In animals undergoing FPI, prior ADX caused further elevation of BDNF mRNA and this upregulation was prevented by corticosterone replacement in ADX rats. These findings suggest that glucocorticoids are involved in the modulation of the BDNF mRNA response to TBI.

  5. Depression, the Val66Met polymorphism, age, and gender influence the serum BDNF level

    DEFF Research Database (Denmark)

    Elfving, Betina; Buttenschøn, Henriette N; Foldager, Leslie

    2012-01-01

    Brain-derived neurotrophic factor (BDNF) has been suggested as a candidate gene for depression and numerous studies have investigated the possible association between genetic variants within BDNF and depression. Clinical studies have investigated the serum BDNF levels in individuals with depression....... However, few studies have combined genetic association studies with serum BDNF measurements. The purpose of the present study was therefore to perform an investigation of BDNF using 162 individuals with depression and 289 healthy individuals. All individuals returned a completed questionnaire......, and health indicators in a statistical model. In the present study the serum BDNF levels were increased in the depressive subjects compared to control individuals. Additionally, six SNPs were successfully analyzed, but did not associate with depression. Multiple linear regression models were applied and age...

  6. Involvement of BDNF/TrkB and ERK/CREB axes in nitroglycerin-induced rat migraine and effects of estrogen on these signals in the migraine

    Directory of Open Access Journals (Sweden)

    Jiu-Qing Guo

    2017-01-01

    Full Text Available Migraine is a highly prevalent headache disorder, especially in women. Brain-derived neurotrophic factor (BDNF and its receptor tropomyosin receptor kinases (TrkB, as well as extracellular signal-regulated kinase (ERK and its downstream target c-AMP-responsive element binding protein (CREB are strongly associated with the transmission of nociceptive information. However, the involvement of these substances in migraine has rarely been examined. In the present study, intraperitoneal injection of nitroglycerin (NTC successfully induced rat migraine attack, as evidenced by behavioral testing. The location and abundance of these substances in the migraine model were determined by immunohistochemistry, real-time polymerase chain reaction (RT-PCR, western blot and enzyme-linked immunosorbant assays (ELISA. Results showed that BDNF, TrkB, phosphor(p-ERK and p-CREB were up-regulated in the brain neurons of both male and female rats with NTG-induced migraine compared to non-migraine control, whereas their expression levels were decreased in headache-free intervals of the migraine compared to migraine attacks. Estrogen is an important contributor to migraine. Female ovariectomized rats showed significant reduction in the expression of BDNF, TrkB, p-CREB and p-ERK in both attacks and intervals of NTG-induced migraine, relative to rats that have their ovaries. But, intraperitoneal administration of exogenous estrogen recovered their expression in ovariectomized rats. Collectively, this study unveiled a positive correlation of BDNF/TrkB and ERK/CREB axes in NTG-induced migraine and promoting effects of estrogen on their signals in the migraine. These findings contribute to further understanding the pathogenesis of migraine in the molecular basis.

  7. HO-1 attenuates hippocampal neurons injury via the activation of BDNF-TrkB-PI3K/Akt signaling pathway in stroke.

    Science.gov (United States)

    Qi, Dashi; Ouyang, Changjie; Wang, Yulan; Zhang, Shichun; Ma, Xijuan; Song, YuanJian; Yu, HongLi; Tang, Jiali; Fu, Wei; Sheng, Lei; Yang, Lihua; Wang, Mei; Zhang, Weihao; Miao, Lei; Li, Tengteng; Huang, Xiaojing; Dong, Hongyan

    2014-08-19

    Although recent studies have found that HO-1 plays an important role in neuronal survival, little is known about the precise mechanisms occurring during cerebral ischemia/reperfusion (I/R). Therefore, the aim of this study was to investigate the neuroprotective mechanisms of HO-1 against ischemic brain injury induced by cerebral I/R and to explore whether the BDNF-TrkB-PI3K/Akt signaling pathway contributed to the protection provided by HO-1. Over-expressed HO-1 plasmids were employed to induce the overexpression of HO-1 through hippocampi CA1 injection 5 days before the cerebral I/R animal model was induced by four-vessel occlusion for 15 min transient ischemia and followed by reperfusion in Sprague-Dawley rats. Immunoblotting was carried out to examine the expression of the related proteins, and HE-staining was used to detect the percentage of living neurons in the hippocampal CA1 region. The results showed that over-expressed HO-1 could significantly protect neurons against cerebral I/R. Furthermore, the protein expression of BDNF, TrkB and p-Akt also increased in the rats treated with over-expressed HO-1 plasmids. However, treatment with tropomyosin receptor kinase B (TrkB) receptor antagonist (K252a) reversed the HO-1-induced increase in BDNF and p-Akt protein levels and decreased the level of cleaved caspase-3 protein in I/R rats. In summary, our results imply that HO-1 can decrease cell apoptosis in the I/R rat brain and that the mechanism may be related to the activation of the BDNF-TrkB-PI3K/Akt signaling pathway.

  8. BDNF Variants May Modulate Long-Term Visual Memory Performance in a Healthy Cohort

    Directory of Open Access Journals (Sweden)

    Nesli Avgan

    2017-03-01

    Full Text Available Brain-derived neurotrophic factor (BDNF is involved in numerous cognitive functions including learning and memory. BDNF plays an important role in synaptic plasticity in humans and rats with BDNF shown to be essential for the formation of long-term memories. We previously identified a significant association between the BDNF Val66Met polymorphism (rs6265 and long-term visual memory (p-value = 0.003 in a small cohort (n = 181 comprised of healthy individuals who had been phenotyped for various aspects of memory function. In this study, we have extended the cohort to 597 individuals and examined multiple genetic variants across both the BDNF and BDNF-AS genes for association with visual memory performance as assessed by the Wechsler Memory Scale—Fourth Edition subtests Visual Reproduction I and II (VR I and II. VR I assesses immediate visual memory, whereas VR II assesses long-term visual memory. Genetic association analyses were performed for 34 single nucleotide polymorphisms genotyped on Illumina OmniExpress BeadChip arrays with the immediate and long-term visual memory phenotypes. While none of the BDNF and BDNF-AS variants were shown to be significant for immediate visual memory, we found 10 variants (including the Val66Met polymorphism (p-value = 0.006 that were nominally associated, and three variants (two variants in BDNF and one variant in the BDNF-AS locus that were significantly associated with long-term visual memory. Our data therefore suggests a potential role for BDNF, and its anti-sense transcript BDNF-AS, in long-term visual memory performance.

  9. BDNF Variants May Modulate Long-Term Visual Memory Performance in a Healthy Cohort

    Science.gov (United States)

    Avgan, Nesli; Sutherland, Heidi G.; Spriggens, Lauren K.; Yu, Chieh; Ibrahim, Omar; Bellis, Claire; Haupt, Larisa M.; Shum, David H. K.; Griffiths, Lyn R.

    2017-01-01

    Brain-derived neurotrophic factor (BDNF) is involved in numerous cognitive functions including learning and memory. BDNF plays an important role in synaptic plasticity in humans and rats with BDNF shown to be essential for the formation of long-term memories. We previously identified a significant association between the BDNF Val66Met polymorphism (rs6265) and long-term visual memory (p-value = 0.003) in a small cohort (n = 181) comprised of healthy individuals who had been phenotyped for various aspects of memory function. In this study, we have extended the cohort to 597 individuals and examined multiple genetic variants across both the BDNF and BDNF-AS genes for association with visual memory performance as assessed by the Wechsler Memory Scale—Fourth Edition subtests Visual Reproduction I and II (VR I and II). VR I assesses immediate visual memory, whereas VR II assesses long-term visual memory. Genetic association analyses were performed for 34 single nucleotide polymorphisms genotyped on Illumina OmniExpress BeadChip arrays with the immediate and long-term visual memory phenotypes. While none of the BDNF and BDNF-AS variants were shown to be significant for immediate visual memory, we found 10 variants (including the Val66Met polymorphism (p-value = 0.006)) that were nominally associated, and three variants (two variants in BDNF and one variant in the BDNF-AS locus) that were significantly associated with long-term visual memory. Our data therefore suggests a potential role for BDNF, and its anti-sense transcript BDNF-AS, in long-term visual memory performance. PMID:28304362

  10. Whole blood BDNF levels in healthy twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Trajkovska, Viktorija; Vinberg, Maj; Aznar, Susana

    2008-01-01

    and protected against affective disorder. Whole blood assessed for BDNF concentrations and correlated to risk status, neuroticism, and number of stressful life events. RESULTS: Between the groups, we found no significant difference in whole blood BDNF levels. Women at high-risk for depression who had...... neuroticism scores and two or less recent stressful events were associated with decreased whole blood BDNF levels (n=50, p

  11. BDNF Variants May Modulate Long-Term Visual Memory Performance in a Healthy Cohort.

    Science.gov (United States)

    Avgan, Nesli; Sutherland, Heidi G; Spriggens, Lauren K; Yu, Chieh; Ibrahim, Omar; Bellis, Claire; Haupt, Larisa M; Shum, David H K; Griffiths, Lyn R

    2017-03-17

    Brain-derived neurotrophic factor (BDNF) is involved in numerous cognitive functions including learning and memory. BDNF plays an important role in synaptic plasticity in humans and rats with BDNF shown to be essential for the formation of long-term memories. We previously identified a significant association between the BDNF Val66Met polymorphism (rs6265) and long-term visual memory (p-value = 0.003) in a small cohort (n = 181) comprised of healthy individuals who had been phenotyped for various aspects of memory function. In this study, we have extended the cohort to 597 individuals and examined multiple genetic variants across both the BDNF and BDNF-AS genes for association with visual memory performance as assessed by the Wechsler Memory Scale-Fourth Edition subtests Visual Reproduction I and II (VR I and II). VR I assesses immediate visual memory, whereas VR II assesses long-term visual memory. Genetic association analyses were performed for 34 single nucleotide polymorphisms genotyped on Illumina OmniExpress BeadChip arrays with the immediate and long-term visual memory phenotypes. While none of the BDNF and BDNF-AS variants were shown to be significant for immediate visual memory, we found 10 variants (including the Val66Met polymorphism (p-value = 0.006)) that were nominally associated, and three variants (two variants in BDNF and one variant in the BDNF-AS locus) that were significantly associated with long-term visual memory. Our data therefore suggests a potential role for BDNF, and its anti-sense transcript BDNF-AS, in long-term visual memory performance.

  12. Synaptic secretion of BDNF after high-frequency stimulation of glutamatergic synapses

    OpenAIRE

    Hartmann, Matthias; Heumann, Rolf; Lessmann, Volkmar

    2001-01-01

    The protein brain-derived neurotrophic factor (BDNF) has been postulated to be a retrograde or paracrine synaptic messenger in long-term potentiation and other forms of activity-dependent synaptic plasticity. Although crucial for this concept, direct evidence for the activity-dependent synaptic release of BDNF is lacking. Here we investigate secretion of BDNF labelled with green fluorescent protein (BDNF–GFP) by monitoring the changes in fluorescence intensity of dendritic BDNF–GFP vesicles a...

  13. Expression of brain-derived neurotrophic factor (BDNF) is regulated by the Wnt signaling pathway

    OpenAIRE

    Yi, Hyun; Hu, Jianfei; Qian, Jiang; Hackam, Abigail S.

    2012-01-01

    BDNF is a well-characterized neurotrophin that mediates a wide variety of activities in the central nervous system (CNS), including neuronal differentiation, neuroprotection and synaptic plasticity. The canonical Wnt signaling pathway is a critical regulator of embryonic development and homeostasis in adult tissues. Our group and others recently demonstrated that Wnt signaling induces BDNF expression in neurons and glia. However, the precise relationship between BDNF and Wnt signaling pathway...

  14. Stress and CRF gate neural activation of BDNF in the mesolimbic reward pathway.

    Science.gov (United States)

    Walsh, Jessica J; Friedman, Allyson K; Sun, Haosheng; Heller, Elizabeth A; Ku, Stacy M; Juarez, Barbara; Burnham, Veronica L; Mazei-Robison, Michelle S; Ferguson, Deveroux; Golden, Sam A; Koo, Ja Wook; Chaudhury, Dipesh; Christoffel, Daniel J; Pomeranz, Lisa; Friedman, Jeffrey M; Russo, Scott J; Nestler, Eric J; Han, Ming-Hu

    2014-01-01

    Mechanisms controlling release of brain-derived neurotrophic factor (BDNF) in the mesolimbic dopamine reward pathway remain unknown. We report that phasic optogenetic activation of this pathway increases BDNF amounts in the nucleus accumbens (NAc) of socially stressed mice but not of stress-naive mice. This stress gating of BDNF signaling is mediated by corticotrophin-releasing factor (CRF) acting in the NAc. These results unravel a stress context-detecting function of the brain's mesolimbic circuit.

  15. BDNF及其受体TrkB在不同程度癫痫患者颞叶或海马中的差异性表达%The Expression of BDNF and Receptor TrkBin the Brains of Intractable Epilepsy

    Institute of Scientific and Technical Information of China (English)

    赵姝; 韩大勇; 王秀杰

    2011-01-01

    目的 检测不同发病程度的癫痫患者颞叶或海马中脑源性神经营养因子(BDNF)及其酪氨酸激酶B 受体(TrkB)差异性表达情况,探讨其在癫痫发病机制中的作用.方法 取82例癫痫患者颞叶或海马脑组织,用免疫组化方法检测BDNF及其受体TrkB的表达,分析不同病程和发作频率患者脑组织中BDNF及TrkB的表达差异.结果 癫痫患者与非癫痫患者比较,颞叶或海马中BDNF及其受体TrkB的含量明显增加.随着患者病程的延长和发作频率的增高,BDNF及其受体TrkB的含量逐渐增加.结论 癫痫患者脑组织中BDNF和Trkb表达增高,可能是促进癫痫反复发作的原因之一.

  16. Binding characteristics of brain-derived neurotrophic factor to its receptors on neurons from the chick embryo

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Tebar, A.; Barde, Y.A.

    1988-09-01

    Brain-derived neurotrophic factor (BDNF), a protein known to support the survival of embryonic sensory neurons and retinal ganglion cells, was derivatized with 125I-Bolton-Hunter reagent and obtained in a biologically active, radioactive form (125I-BDNF). Using dorsal root ganglion neurons from chick embryos at 9 d of development, the basic physicochemical parameters of the binding of 125I-BDNF with its receptors were established. Two different classes of receptors were found, with dissociation constants of 1.7 x 10(-11) M (high-affinity receptors) and 1.3 x 10(-9) M (low-affinity receptors). Unlabeled BDNF competed with 125I-BDNF for binding to the high-affinity receptors with an inhibition constant essentially identical to the dissociation constant of the labeled protein: 1.2 x 10(-11) M. The association and dissociation rates from both types of receptors were also determined, and the dissociation constants calculated from these kinetic experiments were found to correspond to the results obtained from steady-state binding. The number of high-affinity receptors (a few hundred per cell soma) was 15 times lower than that of low-affinity receptors. No high-affinity receptors were found on sympathetic neurons, known not to respond to BDNF, although specific binding of 125I-BDNF to these cells was detected at a high concentration of the radioligand. These results are discussed and compared with those obtained with nerve growth factor on the same neuronal populations.

  17. High-intensity interval training evokes larger serum BDNF levels compared with intense continuous exercise.

    Science.gov (United States)

    Saucedo Marquez, Cinthia Maria; Vanaudenaerde, Bart; Troosters, Thierry; Wenderoth, Nicole

    2015-12-15

    Exercise can have a positive effect on the brain by activating brain-derived neurotrophic factor (BDNF)-related processes. In healthy humans there appears to be a linear relationship between exercise intensity and the positive short-term effect of acute exercise on BDNF levels (i.e., the highest BDNF levels are reported after high-intensity exercise protocols). Here we performed two experiments to test the effectiveness of two high-intensity exercise protocols, both known to improve cardiovascular health, to determine whether they have a similar efficacy in affecting BDNF levels. Participants performed a continuous exercise (CON) protocol at 70% of maximal work rate and a high-intensity interval-training (HIT) protocol at 90% of maximal work rate for periods of 1 min alternating with 1 min of rest (both protocols lasted 20 min). We observed similar BDNF kinetics in both protocols, with maximal BDNF concentrations being reached toward the end of training (experiment 1). We then showed that both exercise protocols significantly increase BDNF levels compared with a rest condition (CON P = 0.04; HIT P exercise are slightly more effective than continuous high-intensity exercise for elevating serum BDNF. Additionally, 73% of the participants preferred the HIT protocol (P = 0.02). Therefore, we suggest that the HIT protocol might represent an effective and preferred intervention for elevating BDNF levels and potentially promoting brain health.

  18. BDNF-secreting capsule exerts neuroprotective effects on epilepsy model of rats.

    Science.gov (United States)

    Kuramoto, Satoshi; Yasuhara, Takao; Agari, Takashi; Kondo, Akihiko; Jing, Meng; Kikuchi, Yoichiro; Shinko, Aiko; Wakamori, Takaaki; Kameda, Masahiro; Wang, Feifei; Kin, Kyohei; Edahiro, Satoru; Miyoshi, Yasuyuki; Date, Isao

    2011-01-12

    Brain-derived neurotrophic factor (BDNF) is a well neurotrophic factor with neuroprotective potentials for various diseases in the central nervous system. However several previous studies demonstrated that BDNF might deteriorate symptoms for epilepsy model of animals by progression of abnormal neurogenesis. We hypothesized that continuous administration of BDNF at low dose might be more effective for epilepsy model of animals because high dose of BDNF was used in many studies. BDNF-secreting cells were genetically made and encapsulated for transplantation. Rats receiving BDNF capsule showed significant amelioration of seizure stage and reduction of the number of abnormal spikes at 7 days after kainic acid administration, compared to those of control group. The number of BrdU and BrdU/doublecortin positive cells in the hippocampus of BDNF group significantly increased, compared to that of control group. NeuN positive cells in the CA1 and CA3 of BDNF group were significantly preserved, compared to control group. In conclusion, low dose administration using encapsulated BDNF-secreting cells exerted neuroprotective effects with enhanced neurogenesis on epilepsy model of rats. These results might suggest the importance of the dose and administrative way of this neurotrophic factor to the epilepsy model of animals.

  19. Giant lobelias exemplify convergent evolution.

    Science.gov (United States)

    Givnish, Thomas J

    2010-01-14

    Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution.

  20. Giant lobelias exemplify convergent evolution

    Directory of Open Access Journals (Sweden)

    Givnish Thomas J

    2010-01-01

    Full Text Available Abstract Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution.

  1. Endogenous BDNF protein is increased in adult rat hippocampus after a kainic acid induced excitotoxic insult but exogenous BDNF is not neuroprotective.

    Science.gov (United States)

    Rudge, J S; Mather, P E; Pasnikowski, E M; Cai, N; Corcoran, T; Acheson, A; Anderson, K; Lindsay, R M; Wiegand, S J

    1998-02-01

    Systemic administration of the excitotoxin kainic acid to adult rats results in a well defined pattern of loss of the CA1 and CA3 pyramidal neurons of the hippocampus. Prior to this neuronal loss, brain-derived neurotrophic factor (BDNF) mRNA is substantially increased. We show here that BDNF protein is increased after excitotoxic insult in specific areas of the hippocampus, reaching maximal levels 24 h after the insult. BDNF protein levels in the hippocampus increase in direct relation to the severity of seizure. Up to 7 days after injection of kainic acid, levels of full-length TrkB protein were unchanged, whereas levels of truncated TrkB protein were significantly increased by 12 h. To determine whether elevations in BDNF protein levels are potentially beneficial to hippocampal neurons exposed to an excitotoxic stress, we infused exogenous BDNF prior to and during the period of neuronal death caused by kainic acid. We find that administration of high levels of exogenous BDNF does not affect severity of seizure, but does in fact, exacerbate the injury caused by kainic acid, specifically to CA3 pyramidal neurons. Although there was a trend toward sparing of CA1 pyramidal neurons on the side infused with BDNF, this was not significant. In the same paradigm, infusion of exogenous NT-3 had no effect.

  2. Notes on Some Convergences in Riesz Space

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-jie; AI Fu-ju

    2007-01-01

    An equivalent description of u-uniform convergence is presented first. Then the relations among the order convergence,u-uniform convergence and norm convergence of sequences are discussed in Riesz spaces. An equivalence of the three convergences is brought forward; namely, {fn} is a u-uniform Cauchy sequence. Finally the relations among the three convergences of sequences am also extended to the relations among the convergences of nets in Riesz spaces.

  3. Expression of brain-derived neurotrophic factor and TrkB receptor in the sudden infant death syndrome brainstem.

    Science.gov (United States)

    Tang, Samantha; Machaalani, Rita; Waters, Karen A

    2012-01-15

    This study compared the expression of BDNF (proBDNF and rhBDNF forms) and its receptor TrkB, in the medulla of sudden infant death syndrome (SIDS) infants and infants who died from known causes (non-SIDS). This study also evaluated these markers in association with SIDS clinical risk factors including, sleep position, cigarette smoke exposure and gender. Brainstem tissue was immunohistochemically stained and quantitative analyses were made for eight nuclei of the caudal and rostral medulla. Compared to non-SIDS, SIDS infants had lower rhBDNF in the caudal nucleus of the solitary tract and higher TrkB in the caudal dorsal motor nucleus of the vagus. Within the SIDS cohort, prone sleep position was associated with lower rhBDNF in the caudal arcuate nucleus, and cigarette smoke exposure was associated with lower rhBDNF and TrkB in the inferior olivary nucleus. Abnormal expression of BDNF and TrkB suggests that neuroprotective functions of the BDNF/TrkB system may be reduced in respiratory-related nuclei of SIDS infants.

  4. Estradiol induce neural proliferation and differetiation through regulating the expression of BDNF%雌二醇通过BDNF促进端脑神经细胞增殖与分化

    Institute of Scientific and Technical Information of China (English)

    陈琼; 林丽英; 唐晓华; 郭旭光; 夏勇

    2016-01-01

    目的:探讨雌二醇(E2)在神经组织中的作用机制,分析E2对神经细胞增殖及神经元分化的影响,以及其是否由脑源性神经营养因子(BDNF)介导。方法离体条件下培养动物端脑神经组织,设置各实验组,分别以 E2、E2受体抑制剂、BDNF、BDNF抗体或以上试剂联合处理,之后进行相关免疫组织化学染色分析不同处理条件下神经细胞的增殖、神经元分化情况;在此基础上通过实时荧光定量PCR检测E2能否调节BDNF基因的表达。结果 E2和BDNF均能促进新生神经细胞的产生,增加Hu+神经元数目,E2受体抑制剂及BDNF抗体则有相反作用;并且E2的作用效果能被BDNF抗体消减,而E2受体抑制剂不能影响BDNF正常发挥作用;实时荧光定量PCR实验结果显示,E2能显著上调BDNF mRNA的表达,而E2受体抑制剂能抑制BD‐NF mRNA表达。结论体外培养条件下,E2对神经组织内细胞增殖、神经元分化的促进作用可由BDNF介导。%Objective To address the influences of estradiol on the proliferation and neuronal differentiation in neural tis‐sues ,and then analyse whether BDNF involves in the pathway of this estradiol‐induced cell division and specification .Methods The forebrain tissues of experimental animals were cultured in vitro ,and treated respectively with estradiol ,estrogen receptor inhibitor , BDNF ,BDNF antibody ,or received a combined treatment .And the immunohistochemistry was performed to reveal the situation of cell proliferation ,neuronal differentiation in different experimental groups .Then real‐time PCR was carried out to detect whether the expression of BDNF was regulated by estradiol .Results Both estradiol and BDNF increased the newborn cells and Hu positive neurons in cultured tissues ,estrogen receptor inhibitor tamoxifen and BDNF antibody decreased the measurements conversely ;the effects of estradiol were diminished by anti‐BDNF ,while

  5. Changes in 5-HT2A-mediated behavior and 5-HT2A- and 5-HT1A receptor binding and expression in conditional brain-derived neurotrophic factor knock-out mice

    DEFF Research Database (Denmark)

    Klein, A B; Santini, M A; Aznar, S;

    2010-01-01

    Changes in brain-derived neurotrophic factor (BDNF) expression have been implicated in the etiology of psychiatric disorders. To investigate pathological mechanisms elicited by perturbed BDNF signaling, we examined mutant mice with central depletion of BDNF (BDNF(2L/2LCk-cre)). A severe impairment...... by BDNF depletion. 5-HT(2A) ([(3)H]-MDL100907) and 5-HT(1A) ([(3)H]-WAY100635) receptor autoradiography revealed site-specific alterations in BDNF mutant mice. They exhibited lower 5-HT(2A) receptor binding in frontal cortex but increased binding in hippocampus. Additionally, 5-HT(1A) receptor binding...... was decreased in hippocampus of BDNF mutants, but unchanged in frontal cortex. Molecular analysis indicated corresponding changes in 5-HT(2A) and 5-HT(1A) mRNA expression but normal 5-HT(2C) content in these brain regions in BDNF(2L/2LCk-cre) mice. We investigated whether the reduction in frontal 5-HT(2A...

  6. Small molecules activating TrkB receptor for treating a variety of CNS disorders.

    Science.gov (United States)

    Zeng, Yan; Wang, Xiaonan; Wang, Qiang; Liu, Shumin; Hu, Xiamin; McClintock, Shawn M

    2013-11-01

    The brain-derived neurotrophic factor (BDNF) and its high affinity receptor tropomyosin-receptor-kinase B (TrkB) play a critical role in neuronal differentiation and survival, synapse plasticity, and memory. Indeed, both have been implicated in the pathophysiology of numerous diseases. Although the remarkable therapeutic potential of BDNF has generated much research over the past decade, the poor pharmacokinetics and adverse side effect profile have limited its clinical usefulness of BDNF. Small compounds that mimic BDNF's neurotrophic signaling and overcome the pharmacokinetic and side effect barriers may have greater therapeutic potential. The purpose of this review is to provide a survey of the various strategies taken towards the development of small molecule mimetics for BDNF and the selective TrkB agonist. A particular focus was placed on TrkB agonist 7, 8-dihydroxyflavone, which modulates multiple functions and has demonstrated remarkable therapeutic efficacy in a variety of central nervous system disease models. Two other small molecules included in this review are adenosine A2A receptor agonists that indirectly activate TrkB, and TrkB binding domains of BDNF, loop II-LM22A compounds that directly activate TrkB. These alternative molecules have shown promise in preclinical studies and may be included in prospective clinical investigations.

  7. Stochastic Engine Convergence Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, R

    2001-12-11

    ;'burn-in'' period. The MCMC process begins at a particular state, which is selected at random or by design, according to the wish of the user of the engine. After the burn-in period, the chain has essentially forgotten where it started. Moreover, the sample x{sup (t{sub 0})}, x{sup (T{sub 0}+1)},... can be used for most purposes as a random sample from f, even though the x{sup (T{sub 0}+t)}, because of Markovian dependency, are not independent. For example, averages involving x{sup (t{sub 0})}, x{sup (t{sub 0}+1)},... may have an approximate normal distribution. The purpose of this note is to discuss the monitoring techniques currently in place in the stochastic engine software that addresses the issues of burn-in, stationarity, and normality. They are loosely termed ''convergence diagnostics'', in reference to the underlying Markov chains, which converge asymptotically to the desired posterior distribution.

  8. The Convergence of Intelligences

    Science.gov (United States)

    Diederich, Joachim

    Minsky (1985) argued an extraterrestrial intelligence may be similar to ours despite very different origins. ``Problem- solving'' offers evolutionary advantages and individuals who are part of a technical civilisation should have this capacity. On earth, the principles of problem-solving are the same for humans, some primates and machines based on Artificial Intelligence (AI) techniques. Intelligent systems use ``goals'' and ``sub-goals'' for problem-solving, with memories and representations of ``objects'' and ``sub-objects'' as well as knowledge of relations such as ``cause'' or ``difference.'' Some of these objects are generic and cannot easily be divided into parts. We must, therefore, assume that these objects and relations are universal, and a general property of intelligence. Minsky's arguments from 1985 are extended here. The last decade has seen the development of a general learning theory (``computational learning theory'' (CLT) or ``statistical learning theory'') which equally applies to humans, animals and machines. It is argued that basic learning laws will also apply to an evolved alien intelligence, and this includes limitations of what can be learned efficiently. An example from CLT is that the general learning problem for neural networks is intractable, i.e. it cannot be solved efficiently for all instances (it is ``NP-complete''). It is the objective of this paper to show that evolved intelligences will be constrained by general learning laws and will use task-decomposition for problem-solving. Since learning and problem-solving are core features of intelligence, it can be said that intelligences converge despite very different origins.

  9. CONVERGENCE OF TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    R. Siriram

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Technology is a catalyst for competitive advantage. However, it is how technology is used that leads to a firm’s improved performance. In this article, an investigative framework is constructed to understand better what strategically drives new technology adoption. The strategic drivers include technology and business strategy alignment, better technology planning and selection of new technologies, the effects on a firm’s culture and climate, links to a firm’s organisational and environmental evolution, and benefits through convergence and collaboration. Using an investigative framework, it is shown how the strategic drivers link to improve a firm’s performance, producing competitive advantage. The investigative framework is tested using structural equation modelling. Various hypotheses are formed, and recommendations for further research are made.

    AFRIKAANSE OPSOMMING: Tegnologie is ‘n katalisator vir mededingende voordeel. Dit is egter hoe tegnologie aangewend word wat aanleiding gee tot ‘n onderneming se verbeterde prestasie. In hierdie artikel word ‘n ondersoekende raamwerk gekonstrueer om insig te kry in dit wat die aanvaarding van nuwe tegnologie strategies dryf. Die strategiese dryfvere sluit in die belyning van tegnologie en ondernemingstrategie, beter tegnologiebeplanning en seleksie van nuwe tegnologieë, die effek op ‘n onderneming se kultuur en klimaat, koppeling na ‘n onderneming se organisatoriese en omgewingsevolusie, en voordele verkry deur konvergensie en samewerking. Deur ‘n ondersoekende raamwerk te gebruik, word daar getoon dat die strategiese dryfvere koppel om ‘n onderneming se prestasie te verbeter en sodoende ‘n mededingende voordeel te skep. Die raamwerk word getoets en hipoteses geformuleer waarna aanbevelings oor verdere navorsing aan die hand gedoen word.

  10. Alterations of serum levels of BDNF-related miRNAs in patients with depression.

    Directory of Open Access Journals (Sweden)

    You-Jie Li

    Full Text Available Depression is a serious and potentially life-threatening mental disorder with unknown etiology. Emerging evidence shows that brain-derived neurotrophic factor (BDNF and microRNAs (miRNAs play critical roles in the etiology of depression. Here this study was aimed to identify and characterize the roles of BDNF and its putative regulatory miRNAs in depression. First, we identified that miR-182 may be a putative miRNA that regulates BDNF levels by bioinformatic studies, and characterized the effects of miR-182 on the BDNF levels using cell-based studies, side by side with miR-132 (a known miRNA that regulates BDNF expression. We showed that treatment of miR-132 and miR-182 respectively decreased the BDNF protein levels in a human neuronal cell model, supporting the regulatory roles of miR-132 and miR-182 on the BDNF expression. Furthermore, we explored the roles of miR-132 and miR-182 on the BDNF levels in depression using human subjects by assessing their serum levels. Compared with the healthy controls, patients with depression showed lower serum BDNF levels (via the enzyme-linked immunosorbent assays and higher serum miR-132 and miR-182 levels (via the real-time PCR. Finally, the Pearson's (or Spearman's correlation coefficient was calculated to study whether there was a relationship among the Self-Rating Depression Scale score, the serum BDNF levels, and serum BDNF-related miRNA levels. Our results revealed that there was a significant negative correlation between the SDS scores and the serum BDNF levels, and a positive correlation between the SDS scores and miR-132 levels. In addition, we found a reverse relationship between the serum BDNF levels and the miR-132/miR-182 levels in depression. Collectively, we provided evidence supporting that miR-182 is a putative BDNF-regulatory miRNA, and suggested that the serum BDNF and its related miRNAs may be utilized as important biomarkers in the diagnosis or as therapeutic targets of depression.

  11. The requirement of BDNF for hippocampal synaptic plasticity is experience‐dependent

    Science.gov (United States)

    Aarse, Janna; Herlitze, Stefan

    2016-01-01

    ABSTRACT Brain‐derived neurotrophic factor (BDNF) supports neuronal survival, growth, and differentiation and has been implicated in forms of hippocampus‐dependent learning. In vitro, a specific role in hippocampal synaptic plasticity has been described, although not all experience‐dependent forms of synaptic plasticity critically depend on BDNF. Synaptic plasticity is likely to enable long‐term synaptic information storage and memory, and the induction of persistent (>24 h) forms, such as long‐term potentiation (LTP) and long‐term depression (LTD) is tightly associated with learning specific aspects of a spatial representation. Whether BDNF is required for persistent (>24 h) forms of LTP and LTD, and how it contributes to synaptic plasticity in the freely behaving rodent has never been explored. We examined LTP, LTD, and related forms of learning in the CA1 region of freely dependent mice that have a partial knockdown of BDNF (BDNF+/−). We show that whereas early‐LTD (BDNF, short‐term depression (BDNF is required for LTP that is induced by mild, but not strong short afferent stimulation protocols. Object‐place learning triggers LTD in the CA1 region of mice. We observed that object‐place memory was impaired and the object‐place exploration failed to induce LTD in BDNF+/− mice. Furthermore, spatial reference memory, that is believed to be enabled by LTP, was also impaired. Taken together, these data indicate that BDNF is required for specific, but not all, forms of hippocampal‐dependent information storage and memory. Thus, very robust forms of synaptic plasticity may circumvent the need for BDNF, rather it may play a specific role in the optimization of weaker forms of plasticity. The finding that both learning‐facilitated LTD and spatial reference memory are both impaired in BDNF+/− mice, suggests moreover, that it is critically required for the physiological encoding of hippocampus‐dependent memory. © 2015 The Authors

  12. The BDNF Val66Met polymorphism regulates glucocorticoid-induced corticohippocampal remodeling and behavioral despair.

    Science.gov (United States)

    Notaras, M; Du, X; Gogos, J; van den Buuse, M; Hill, R A

    2017-09-19

    The BDNF Val66Met polymorphism has been associated with sensitivity to stress and affective disorders. We therefore sought to model the inter-causality of these relationships under controlled laboratory conditions. We subjected humanized BDNF Val66Met (hBDNF(Val66Met)) transgenic mice to a history of stress, modeled by chronic late-adolescent corticosterone (CORT) exposure, before evaluating affective-related behavior using the forced-swim test (FST) in adulthood. While hBDNF(Met/Met) mice had a depression-like phenotype in the FST irrespective of CORT, hBDNF(Val/Val) wildtype mice had a resilient phenotype but developed an equally robust depressive-like phenotype following CORT. A range of stress-sensitive molecules were studied across the corticohippocampal axis, and where genotype differences occurred following CORT they tended to inversely coincide with the behavior of the hBDNF(Val/Val) group. Notably, tyrosine hydroxylase was markedly down-regulated in the mPFC of hBDNF(Val/Val) mice as a result of CORT treatment, which mimicked expression levels of hBDNF(Met/Met) mice and the FST behavior of both groups. The expression of calretinin, PSD-95, and truncated TrkB were also concomitantly reduced in the mPFC of hBDNF(Val/Val) mice by CORT. This work establishes BDNF(Val66Met) genotype as a regulator of behavioral despair, and identifies new biological targets of BDNF genetic variation relevant to stress-inducible disorders such as depression.

  13. The Convergence in Spatial Tasks

    Directory of Open Access Journals (Sweden)

    Vladimir P. Kulagin

    2013-01-01

    Full Text Available The article reveals the problem of convergence of direct and inverse problems in Earth Sciences, describes the features and application of these problems, discloses analytical features of direct and inverse problems. The convergence criteria and conditions for convergence were presented. This work is supported by the Grant of the Government of the Russian Federation for support of scientific research, implemented under the supervision of leading scientists in Russian institutions of higher education in the field "Space Research and Technologies" in 2011–2013.

  14. Convergence of linkage, gene expression and association data demonstrates the influence of the RAR-related orphan receptor alpha (RORA) gene on neovascular AMD: A systems biology based approach

    Science.gov (United States)

    Silveira, Alexandra C.; Morrison, Margaux A.; Ji, Fei; Xu, Haiyan; Reinecke, James B.; Adams, Scott M.; Arneberg, Trevor M.; Janssian, Maria; Lee, Joo-Eun; Yuan, Yang; Schaumberg, Debra A.; Kotoula, Maria G.; Tsironi, Evangeline E.; Tsiloulis, Aristoteles N.; Chatzoulis, Dimitrios Z.; Miller, Joan W.; Kim, Ivana K.; Hageman, Gregory H.; Farrer, Lindsay A.; Haider, Neena B.; DeAngelis, Margaret M.

    2009-01-01

    To identify novel genes and pathways associated with AMD, we performed microarray gene expression and linkage analysis which implicated the candidate gene, retinoic acid receptor-related orphan receptor alpha (RORA, 15q). Subsequent genotyping of 159 RORA single nucleotide polymorphisms (SNPs) in a family-based cohort, followed by replication in an unrelated case-control cohort, demonstrated that SNPs and haplotypes located in intron 1 were significantly associated with neovascular AMD risk in both cohorts. This is the first report demonstrating a possible role for RORA, a receptor for cholesterol, in the pathophysiology of AMD. Moreover, we found a significant interaction between RORA and the ARMS2/HTRA1 locus suggesting a novel pathway underlying AMD pathophysiology. PMID:19786043

  15. Plasma levels of mature brain-derived neurotrophic factor (BDNF) and matrix metalloproteinase-9 (MMP-9) in treatment-resistant schizophrenia treated with clozapine.

    Science.gov (United States)

    Yamamori, Hidenaga; Hashimoto, Ryota; Ishima, Tamaki; Kishi, Fukuko; Yasuda, Yuka; Ohi, Kazutaka; Fujimoto, Michiko; Umeda-Yano, Satomi; Ito, Akira; Hashimoto, Kenji; Takeda, Masatoshi

    2013-11-27

    Brain-derived neurotrophic factor (BDNF) regulates the survival and growth of neurons, and influences synaptic efficiency and plasticity. Peripheral BDNF levels in patients with schizophrenia have been widely reported in the literature. However, it is still controversial whether peripheral levels of BDNF are altered in patients with schizophrenia. The peripheral BDNF levels previously reported in patients with schizophrenia were total BDNF (proBDNF and mature BDNF) as it was unable to specifically measure mature BDNF due to limited BDNF antibody specificity. In this study, we examined whether peripheral levels of mature BDNF were altered in patients with treatment-resistant schizophrenia. Matrix metalloproteinase-9 (MMP-9) levels were also measured, as MMP-9 plays a role in the conversion of proBDNF to mature BDNF. Twenty-two patients with treatment-resistant schizophrenia treated with clozapine and 22 age- and sex-matched healthy controls were enrolled. The plasma levels of mature BDNF and MMP-9 were measured using ELISA kits. No significant difference was observed for mature BDNF however, MMP-9 was significantly increased in patients with schizophrenia. The significant correlation was observed between mature BDNF and MMP-9 plasma levels. Neither mature BDNF nor MMP-9 plasma levels were associated clinical variables. Our results do not support the view that peripheral BDNF levels are associated with schizophrenia. MMP-9 may play a role in the pathophysiology of schizophrenia and serve as a biomarker for schizophrenia.

  16. Motor activity affects adult skeletal muscle re-innervation acting via tyrosine kinase receptors.

    Science.gov (United States)

    Sartini, Stefano; Bartolini, Fanny; Ambrogini, Patrizia; Betti, Michele; Ciuffoli, Stefano; Lattanzi, Davide; Di Palma, Michael; Cuppini, Riccardo

    2013-05-01

    Recently, muscle expression of brain-derived neurotrophic factor (BDNF) mRNA and protein under activity control has been reported. BDNF is a neurotrophin known to be involved in axon sprouting in the CNS. Hence, we set out to study the effect of chronic treadmill mid-intensity running on adult rat muscle re-innervation, and to explore the involvement of BDNF and tropomyosin-related kinase (Trk) receptors. After nerve crush, muscle re-innervation was evaluated using intracellular recordings, tension recordings, immunostaining and Western blot analyses. An enhanced muscle multiple innervation was found in running rats that was fully reversed to control values blocking Trk receptors or interrupting the running activity. An increase in muscle multiple innervation was also found in sedentary rats treated with a selective TrkB receptor agonist. The expression of TrkB receptors by intramuscular axons was demonstrated, and increased muscle expression of BDNF was found in running animals. The increase in muscle multiple innervation was consistent with the faster muscle re-innervation that we found in running animals. We conclude that, when regenerating axons contact muscle cells, muscle activity progressively increases modulating BDNF and possibly other growth factors, which in turn, acting via Trk receptors, induce axon sprouting to re-innervate skeletal muscle.

  17. Effect of dexmedetomidine on hippocampal neuron development and BDNF-TrkB signal expression in neonatal rats

    Science.gov (United States)

    Lv, Jie; Ou, Wei; Zou, Xiao-Hua; Yao, Yin; Wu, Jin-Li

    2016-01-01

    The study aimed to explore the effect of dexmedetomidine (DEX) on hippocampal neuron development process and on molecular expression of brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signaling pathway in neonatal rats. The hippocampal neuron cells were isolated from newborn neonatal rats and cultured in vitro. One control group and three treated groups with 1, 10, and 100 μmol/L DEX were used for the study. Cell activity and apoptosis were detected by the MTT and terminal deoxynucleotidyl transferase-mediated biotinylated uridine triphosphate (UTP) nick end labeling assays. The synaptophysin (SYN) and postsynaptic density 95 (PSD95) were detected by quantitative polymerase chain reaction. There was no difference in the viability of neuron cells among the different dose groups of DEX and the control group during days 2–10 (P>0.05). Compared to the control group, there was no significant difference (P>0.05) in the expressions of SYN and PSD95 in the groups treated with 1 and 10 μmol/L DEX, whereas significant difference in the expression was observed in the group treated with 100 μmol/L DEX (PBDNF was significantly upregulated (PTrkB expression among the four groups. The expression of p-N-methyl-D-aspartate receptor increased with an increase in the concentration of DEX; however, only the high dose revealed a significant upregulation compared with the control group. The neuroprotective effect of DEX may be achieved by upregulating the expression of BDNF and phosphorylation level of N-methyl-D-aspartate receptor. PMID:28003751

  18. Proteolysis of proBDNF is a key regulator in the formation of memory.

    Directory of Open Access Journals (Sweden)

    Philip Barnes

    Full Text Available It is essential to understand the molecular processes underlying long-term memory to provide therapeutic targets of aberrant memory that produce pathological behaviour in humans. Under conditions of recall, fully-consolidated memories can undergo reconsolidation or extinction. These retrieval-mediated memory processes may rely on distinct molecular processes. The cellular mechanisms initiating the signature molecular events are not known. Using infusions of protein synthesis inhibitors, antisense oligonucleotide targeting brain-derived neurotrophic factor (BDNF mRNA or tPA-STOP (an inhibitor of the proteolysis of BDNF protein into the hippocampus of the awake rat, we show that acquisition and extinction of contextual fear memory depended on the increased and decreased proteolysis of proBDNF (precursor BDNF in the hippocampus, respectively. Conditions of retrieval that are known to initiate the reconsolidation of contextual fear memory, a BDNF-independent memory process, were not correlated with altered proBDNF cleavage. Thus, the processing of BDNF was associated with the acquisition of new information and the updating of information about a salient stimulus. Furthermore, the differential requirement for the processing of proBDNF by tPA in distinct memory processes suggest that the molecular events actively engaged to support the storage and/or the successful retrieval of memory depends on the integration of ongoing experience with past learning.

  19. BDNF in late-life depression: effect of SSRI usage and interaction with childhood abuse

    NARCIS (Netherlands)

    Meij, A. van der; Comijs, H.C.; Dols, A.; Janzing, J.G.E.; Oude Voshaar, R.C.

    2014-01-01

    Brain-Derived Neurotrophic Factor (BDNF) serum levels are abnormally low in depressed patients as compared to healthy controls and normalize with SSRI treatment. The aim of this study is to examine serum BDNF levels in late-life depression, stratified for SSRI usage, and to explore the relation betw

  20. BDNF serum levels are not related to cognitive functioning in older depressed patients and controls

    NARCIS (Netherlands)

    Dols, A.; Thesing, C.S.; Bouckaert, F.; Oude Voshaar, R.C.; Comijs, H.C.; Stek, M.L.

    2015-01-01

    BACKGROUND: Depression and cognitive decline are highly prevalent in older persons and both are associated with low serum brain derived neurotrophic factor (BDNF). Mutual pathways of depression and cognitive decline in older persons may explain the overlap in symptoms and low serum BDNF. We hypothes

  1. Age-Dependent Deficits in Fear Learning in Heterozygous BDNF Knock-Out Mice

    Science.gov (United States)

    Endres, Thomas; Lessmann, Volkmar

    2012-01-01

    Beyond its trophic function, the neurotrophin BDNF (brain-derived neurotrophic factor) is well known to crucially mediate synaptic plasticity and memory formation. Whereas recent studies suggested that acute BDNF/TrkB signaling regulates amygdala-dependent fear learning, no impairments of cued fear learning were reported in heterozygous BDNF…

  2. Alternative Splicing Variants and DNA Methylation Status of BDNF in Inbred Chicken Lines

    Science.gov (United States)

    Brain derived neurotrophic factor (BDNF) plays essential roles in neuronal survival and differentiation, synaptic plasticity, central regulation of energy homeostasis, and neuronal development of the central and peripheral nerve system. Here, we report two new splicing variants of the chicken BDNF g...

  3. A meta-analysis of circulating BDNF concentrations in anorexia nervosa

    NARCIS (Netherlands)

    Brandys, Marek K; Kas, Martien J H; van Elburg, Annemarie A; Campbell, Iain C; Adan, Roger A H

    2011-01-01

    OBJECTIVES: Brain derived neurotrophic factor (BDNF) is involved in neuroplasticity, and in the homeostatic regulation of food intake and energy expenditure. It also has a role in stress responsivity and reward processing. On the basis of its involvement in these various processes, BDNF can be hypot

  4. BDNF in late-life depression : Effect of SSRI usage and interaction with childhood abuse

    NARCIS (Netherlands)

    van der Meij, Annemarie; Comijs, Hannie C.; Dols, Annemieke; Janzing, Joost G. E.; Oude Voshaar, Richard

    2014-01-01

    Brain-Derived Neurotrophic Factor (BDNF) serum levels are abnormally low in depressed patients as compared to healthy controls and normalize with SSRI treatment. The aim of this study is to examine serum BDNF levels in late-life depression, stratified for SSRI usage, and to explore the relation betw

  5. Association between BDNF-rs6265 and obesity in the Boston Puerto Rican Health Study

    Science.gov (United States)

    The objective of this study is to examine a functional variant (rs6265) in the BDNF gene interacting with dietary intake modulate obesity traits in the Boston Puerto Rican Health Study population. BDNF rs6265 was genotyped in 1147 Puerto Ricans (aged 45-75 years), and examined for association with o...

  6. A meta-analysis of circulating BDNF concentrations in anorexia nervosa

    NARCIS (Netherlands)

    Brandys, Marek K.; Kas, Martien J. H.; van Elburg, Annemarie A.; Campbell, Iain C.; Adan, Roger A. H.

    2011-01-01

    Objectives. Brain derived neurotrophic factor (BDNF) is involved in neuroplasticity, and in the homeostatic regulation of food intake and energy expenditure. It also has a role in stress responsivity and reward processing. On the basis of its involvement in these various processes, BDNF can be hypot

  7. BDNF serum levels are not related to cognitive functioning in older depressed patients and controls

    NARCIS (Netherlands)

    Dols, Annemiek; Thesing, Carisha S.; Bouckaert, Filip; Oude Voshaar, Richard; Comijs, Hannie C.; Stek, M. L.

    2015-01-01

    Background: Depression and cognitive decline are highly prevalent in older persons and both are associated with low serum brain derived neurotrophic factor (BDNF). Mutual pathways of depression and cognitive decline in older persons may explain the overlap in symptoms and low serum BDNF. We hypothes

  8. BDNF mediates improvements in executive function following a 1-year exercise intervention

    Directory of Open Access Journals (Sweden)

    Regina Lynn Leckie

    2014-12-01

    Full Text Available Executive function declines with age, but engaging in aerobic exercise may attenuate decline. One mechanism by which aerobic exercise may preserve executive function is through the up-regulation of brain-derived neurotropic factor (BDNF, which also declines with age. The present study examined BDNF as a mediator of the effects of a 1-year walking intervention on executive function in 90 older adults (mean age = 66.82. Participants were randomized to a stretching and toning control group or a moderate intensity walking intervention group. BDNF serum levels and performance on a task-switching paradigm were collected at baseline and follow-up. We found that age moderated the effect of intervention group on changes in BDNF levels, with those in the highest age quartile showing the greatest increase in BDNF after 1-year of moderate intensity walking exercise (p = .036. The mediation analyses revealed that BDNF mediated the effect of the intervention on task-switch accuracy, but did so as a function of age, such that exercise-induced changes in BDNF mediated the effect of exercise on task-switch performance only for individuals over the age of 71. These results demonstrate that both age and BDNF serum levels are important factors to consider when investigating the mechanisms by which exercise interventions influence cognitive outcomes, particularly in elderly populations.

  9. BDNF val66met genotype and schizotypal personality traits interact to influence probabilistic association learning.

    Science.gov (United States)

    Skilleter, Ashley Jayne; Weickert, Cynthia Shannon; Moustafa, Ahmed Abdelhalim; Gendy, Rasha; Chan, Mico; Arifin, Nur; Mitchell, Philip Bowden; Weickert, Thomas Wesley

    2014-11-01

    The brain derived neurotrophic factor (BDNF) val66met polymorphism rs6265 influences learning and may represent a risk factor for schizophrenia. Healthy people with high schizotypal personality traits display cognitive deficits that are similar to but not as severe as those observed in schizophrenia and they can be studied without confounds of antipsychotics or chronic illness. How genetic variation in BDNF may impact learning in individuals falling along the schizophrenia spectrum is unknown. We predicted that schizotypal personality traits would influence learning and that schizotypal personality-based differences in learning would vary depending on the BDNF val66met genotype. Eighty-nine healthy adults completed the Schizotypal Personality Questionnaire (SPQ) and a probabilistic association learning test. Blood samples were genotyped for the BDNF val66met polymorphism. An ANOVA was performed with BDNF genotype (val homozygotes and met-carriers) and SPQ score (high/low) as grouping variables and probabilistic association learning as the dependent variable. Participants with low SPQ scores (fewer schizotypal personality traits) showed significantly better learning than those with high SPQ scores. BDNF met-carriers displaying few schizotypal personality traits performed best, whereas BDNF met-carriers displaying high schizotypal personality traits performed worst. Thus, the BDNF val66met polymorphism appears to influence probabilistic association learning differently depending on the extent of schizotypal personality traits displayed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  10. Investigating the Role of Hippocampal BDNF in Anxiety Vulnerability Using Classical Eyeblink Conditioning.

    Science.gov (United States)

    Janke, Kellie L; Cominski, Tara P; Kuzhikandathil, Eldo V; Servatius, Richard J; Pang, Kevin C H

    2015-01-01

    Dysregulation of brain-derived neurotrophic factor (BDNF), behavioral inhibition temperament (BI), and small hippocampal volume have been linked to anxiety disorders. Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER) as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY) rat. The present study examined the role of hippocampal BDNF in the facilitated delay CCER of WKY rats. Consistent with earlier work, acquisition was facilitated in WKY rats compared to the Sprague Dawley (SD) rats. Facilitated acquisition was associated with increased BDNF, TrkB, and Arc mRNA in the dentate gyrus of SD rats, but learning-induced increases in BDNF and Arc mRNA were significantly smaller in WKY rats. To determine whether reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region 1 h prior to training. BDNF infusion did not alter the acquisition of SD rats, but significantly dampened the acquisition of CCER in the WKY rats, such that acquisition was similar to SD rats. Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI. Facilitated associative learning may represent a vulnerability factor in the development of anxiety disorders.

  11. proBDNF negatively regulates neuronal remodeling, synaptic transmission, and synaptic plasticity in hippocampus.

    Science.gov (United States)

    Yang, Jianmin; Harte-Hargrove, Lauren C; Siao, Chia-Jen; Marinic, Tina; Clarke, Roshelle; Ma, Qian; Jing, Deqiang; Lafrancois, John J; Bath, Kevin G; Mark, Willie; Ballon, Douglas; Lee, Francis S; Scharfman, Helen E; Hempstead, Barbara L

    2014-05-08

    Experience-dependent plasticity shapes postnatal development of neural circuits, but the mechanisms that refine dendritic arbors, remodel spines, and impair synaptic activity are poorly understood. Mature brain-derived neurotrophic factor (BDNF) modulates neuronal morphology and synaptic plasticity, including long-term potentiation (LTP) via TrkB activation. BDNF is initially translated as proBDNF, which binds p75(NTR). In vitro, recombinant proBDNF modulates neuronal structure and alters hippocampal long-term plasticity, but the actions of endogenously expressed proBDNF are unclear. Therefore, we generated a cleavage-resistant probdnf knockin mouse. Our results demonstrate that proBDNF negatively regulates hippocampal dendritic complexity and spine density through p75(NTR). Hippocampal slices from probdnf mice exhibit depressed synaptic transmission, impaired LTP, and enhanced long-term depression (LTD) in area CA1. These results suggest that proBDNF acts in vivo as a biologically active factor that regulates hippocampal structure, synaptic transmission, and plasticity, effects that are distinct from those of mature BDNF. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  12. A meta-analysis of circulating BDNF concentrations in anorexia nervosa

    NARCIS (Netherlands)

    Brandys, Marek K.; Kas, Martien J. H.; van Elburg, Annemarie A.; Campbell, Iain C.; Adan, Roger A. H.

    2011-01-01

    Objectives. Brain derived neurotrophic factor (BDNF) is involved in neuroplasticity, and in the homeostatic regulation of food intake and energy expenditure. It also has a role in stress responsivity and reward processing. On the basis of its involvement in these various processes, BDNF can be hypot

  13. A meta-analysis of circulating BDNF concentrations in anorexia nervosa

    NARCIS (Netherlands)

    Brandys, Marek K; Kas, Martien J H; van Elburg, Annemarie A; Campbell, Iain C; Adan, Roger A H

    2011-01-01

    OBJECTIVES: Brain derived neurotrophic factor (BDNF) is involved in neuroplasticity, and in the homeostatic regulation of food intake and energy expenditure. It also has a role in stress responsivity and reward processing. On the basis of its involvement in these various processes, BDNF can be hypot

  14. 3-Hydroxybutyrate regulates energy metabolism and induces BDNF expression in cerebral cortical neurons

    DEFF Research Database (Denmark)

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

    2016-01-01

    . The mechanism by which 3OHB induces Bdnf gene expression involves generation of reactive oxygen species, activation of the transcription factor NF-κB, and activity of the histone acetyltransferase p300/EP300. Because BDNF plays important roles in synaptic plasticity and neuronal stress resistance, our findings...

  15. Investigating the role of hippocampal BDNF in anxiety vulnerability using classical eyeblink conditioning

    Directory of Open Access Journals (Sweden)

    Kellie L Janke

    2015-07-01

    Full Text Available Dysregulation of brain-derived neurotrophic factor (BDNF, behavioral inhibition temperament (BI and small hippocampal volume have been linked to anxiety disorders. Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY rat. The present study examined the role of hippocampal BDNF in the facilitated delay CCER of WKY rats. Consistent with earlier work, acquisition was facilitated in WKY rats compared to the SD rats. Facilitated acquisition was associated with increased BDNF, TrkB, and Arc mRNA in the dentate gyrus of SD rats, but learning-induced increases in BDNF and Arc mRNA were significantly smaller in WKY rats. To determine if reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region one hour prior to training. BDNF infusion did not alter the acquisition of SD rats, but significantly dampened the acquisition of CCER in the WKY rats, such that acquisition was similar to SD rats. Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI. Facilitated associative learning may represent a vulnerability factor in the development of anxiety disorders.

  16. BDNF Val66Met polymorphism and protein levels in Amniotic Fluid

    Directory of Open Access Journals (Sweden)

    Calabrese Francesca

    2010-02-01

    Full Text Available Abstract Background Brain-Derived Neurotrophic Factor (BDNF is a neurotrophin which plays survival- and growth-promoting activity in neuronal cells and it is involved in cellular plasticity mechanisms as it controls activity dependent synaptic transmission. A functional polymorphism (Val66Met in the pro-region of BDNF, which affects the intracellular trafficking of proBDNF has been associated with memory and cognitive deficits as well as to an increased susceptibility for several psychiatric disorders especially those with a neurodevelopmental origin. To date, no study has evaluated the influence of the Val66Met polymorphism on BDNF levels in a peripheral system that may reflect fetal neurodevelopment. Therefore we investigated in amniotic fluids (AF obtained from 139 healthy women during 15-17 week of pregnancy, BDNF protein levels in correlation with the Val66Met polymorphism. Results Interestingly we found a significant BDNF protein levels reduction in 55 Met carriers (Val/Met and Met/Met (p = 0.002 as compared to 84 non carriers (Val/Val, and no effect of fetus gender, maternal age or gestation week on BDNF levels has been observed. Conclusion These results, although explorative, indicate that during fetal life the Val66Met genotype might influences BDNF protein levels in AF supporting the involvement of this polymorphism in behavioral and functional brain individual differences in the adulthood.

  17. Positive Feedback Loop of Autocrine BDNF from Microglia Causes Prolonged Microglia Activation

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2014-08-01

    Full Text Available Background/Aims: Microglia, which represent the immune cells of the central nervous system (CNS, have long been a subject of study in CNS disease research. Substantial evidence indicates that microglial activation functions as a strong neuro-inflammatory response in neuropathic pain, promoting the release of pro-inflammatory cytokines, such as tumor necrosis factor (TNF-α. In addition, activated microglia release brain-derived neurotrophic factor (BDNF, which acts as a powerful cytokine. In this study, we performed a series of in vitro experiments to examine whether a positive autocrine feedback loop existed between microglia-derived BDNF and subsequent microglial activation as well as the mechanisms underlying this positive feedback loop. Methods: Because ATP is a classic inducer of microglial activation, firstly, we examined ATP-activated microglia in the present study. Secondly, we used TrkB/Fc, the BDNF sequester, to eliminate the effects of endogenous BDNF. ATP-stimulated microglia without BDNF was examined. Finally, we used exogenous BDNF to further determine whether BDNF could directly activate BV2 microglia. In all experiments, to quantify BV2 microglia activation, the protein levels of CD11b, a microglial activation marker, were measured by western blot. A Transwell migration assay was used to examine microglial migration. To assess the synthesis and release of proinflammatory cytokines, western blot was used to measure BDNF synthesis, and ELISA was used to quantify TNF-α release. Results: In our present research, we have observed that ATP dramatically activates microglia, enhancing microglial migration, increasing the synthesis of BDNF and up-regulating the release of TNF-α. Microglial activation is inhibited following the sequestration of endogenous BDNF, resulting in impaired microglial migration and decreased TNF-α release. Furthermore, exogenous BDNF can also activate microglia to subsequently enhance migration and increase TNF

  18. WEAK CONVERGENCE OF SOME SERIES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper continues the study of [1] on weak functions.The weak convergence theory is investigated in complex analysis,Fourier transform and Mellin transform.A Mobius inverse formula of weak functions is obtained.

  19. Dynamical Convergence Trajectory in Networks

    Institute of Scientific and Technical Information of China (English)

    TAN Ning; ZHANG Yun-Jun; OUYANG Qi; GENG Zhi

    2005-01-01

    @@ It is well known that topology and dynamics are two major aspects to determine the function of a network. We study one of the dynamic properties of a network: trajectory convergence, i.e. how a system converges to its steady state. Using numerical and analytical methods, we show that in a logical-like dynamical model, the occurrence of convergent trajectory in a network depends mainly on the type of the fixed point and the ratio between activation and inhibition links. We analytically proof that this property is induced by the competition between two types of state transition structures in phase space: tree-like transition structure and star-like transition structure. We show that the biological networks, such as the cell cycle network in budding yeast, prefers the tree-like transition structures and suggest that this type of convergence trajectories may be universal.

  20. Spaces of Ideal Convergent Sequences

    Directory of Open Access Journals (Sweden)

    M. Mursaleen

    2014-01-01

    Full Text Available In the present paper, we introduce some sequence spaces using ideal convergence and Musielak-Orlicz function ℳ=Mk. We also examine some topological properties of the resulting sequence spaces.

  1. Weak entropy inequalities and entropic convergence

    Institute of Scientific and Technical Information of China (English)

    GAO FuQing; LI LiNa

    2008-01-01

    A criterion for algebraic convergence of the entropy is presented and an algebraic convergence result for the entropy of an exclusion process is improved.A weak entropy inequality is considered and its relationship to entropic convergence is discussed.

  2. Weak entropy inequalities and entropic convergence

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A criterion for algebraic convergence of the entropy is presented and an algebraic convergence result for the entropy of an exclusion process is improved. A weak entropy inequality is considered and its relationship to entropic convergence is discussed.

  3. Noncell- and cell-autonomous G-protein-signaling converges with Ca2+/mitogen-activated protein kinase signaling to regulate str-2 receptor gene expression in Caenorhabditis elegans.

    NARCIS (Netherlands)

    H. Lans (Hannes); G. Jansen (Gert)

    2006-01-01

    textabstractIn the sensory system of C. elegans, the candidate odorant receptor gene str-2 is strongly expressed in one of the two AWC neurons and weakly in both ASI neurons. Asymmetric AWC expression results from suppression of str-2 expression by a Ca2+/MAPK signaling pathway in one of the AWC neu

  4. Reduced serum concentrations of brain-derived neurotrophic factor (BDNF) in transsexual Brazilian men.

    Science.gov (United States)

    Fontanari, Anna Martha Vaitses; Costa, Angelo Brandelli; Aguiar, Bianca; Tusset, Cíntia; Andreazza, Tahiana; Schneider, Maiko; da Rosa, Eduarda Dias; Soll, Bianca Machado Borba; Schwarz, Karine; da Silva, Dhiordan Cardoso; Borba, André Oliveira; Mueller, Andressa; Massuda, Raffael; Lobato, Maria Inês Rodrigues

    2016-09-06

    Serum BDNF levels are significantly decreased in transsexual Brazilian women when compared to cis-sexual men. Since transsexual men are also exposed to chronic social stress and have a high prevalence of associated psychopathologies, it is plausible to inquire if BDNF serum levels are altered in transsexual men as well. Therefore, our objective was to evaluate differences in BDNF serum level of transsexual men when compared to cis-sexual men and women. Our sample comprises 27 transsexual men, 31 cis-sexual women and 30 cis-sexual men recruited between 2011 and 2015. We observed that BDNF serum concentration is decreased in transsexual men comparing to cis-sexual men and women. Cross-sex hormone treatment, chronic social stress or long-term gender dysphoria (GD) could explain the variation found in BDNF serum levels.

  5. Transcranial magnetic stimulation and BDNF plasma levels in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Angelucci, Francesco; Oliviero, Antonio; Pilato, Fabio; Saturno, Eleonora; Dileone, Michele; Versace, Viviana; Musumeci, Gabriella; Batocchi, Anna P; Tonali, Pietro A; Di Lazzaro, Vincenzo

    2004-03-22

    Low- and high-frequency repetitive transcranial magnetic stimulation (rTMS) of the motor cortex results in lasting changes of excitatory neurotransmission. We investigated the effects of suprathreshold 1 Hz rTMS on brain derived neurotrophic factor (BDNF) plasma levels in 10 healthy subjects and effects of either 1 Hz or 20 Hz rTMS in four amyotrophic lateral sclerosis (ALS) patients. BDNF levels were progressively decreased by 1 Hz rTMS in healthy subjects; there was no effect of 1 Hz rTMS on BDNF plasma levels in ALS patients, an effect probably due to the loss of motor cortex pyramidal cells. High frequency rTMS determined a transitory decrease in BDNF plasma levels. Cumulatively these findings suggest that rTMS might influence the BDNF production by interfering with neuronal activity.

  6. Brain-derived neurotrophic factor (BDNF) overexpression in the forebrain results in learning and memory impairments.

    Science.gov (United States)

    Cunha, Carla; Angelucci, Andrea; D'Antoni, Angela; Dobrossy, Mate D; Dunnett, Stephen B; Berardi, Nicoletta; Brambilla, Riccardo

    2009-0