umu.sePublications
Change search
Refine search result
1 - 22 of 22
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Allard, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Marcusson, J O
    Ross, S B
    [3H]WIN 35,428 binding in the human brain.1996In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 706, no 2, p. 347-50Article in journal (Refereed)
    Abstract [en]

    The binding of [3H]WIN 35,428 was studied in post-mortem human brain, including extrastriatal regions. In the putamen, dopamine almost completely inhibited the [3H]WIN 35,428 binding. Paroxetine inhibited the binding with similar affinity as cocaine, in the range 200-300 nM. In the frontal cortex, [3H]WIN 35,428 labelled cocaine- and alaproclate sensitive binding sites, of which a major fraction was of protein nature. The elucidation of the cocaine sensitive sites in the frontal cortex should be the subject of further research.

  • 2.
    Allard, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Rinne, J
    Marcusson, J O
    Dopamine uptake sites in Parkinson's disease and in dementia of the Alzheimer type.1994In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 637, no 1-2, p. 262-6Article in journal (Refereed)
    Abstract [en]

    The binding of [3H]GBR-12935 to dopamine (DA) uptake sites was studied in post-mortem putamen from a control group and from patients with Parkinson's disease (PD) or dementia of the Alzheimer type (DAT). The specific binding (Bmax) was almost completely abolished in the PD group and reduced by 65% in the DAT group. There were no significant differences in apparent binding affinity (Kd) between the DAT group and controls. The decreases in [3H]GBR-12935 binding to DA uptake sites in this study indicate a marked degeneration of DA neurites in the putamen in PD and also in DAT.

  • 3. Bergenheim, M
    et al.
    Johansson, H
    Pedersen, J
    Öhberg, Fredrik
    Umeå University, Faculty of Medicine, Radiation Sciences.
    Sjölander, P
    Ensamble coding of muscle stretches in afferent populations containing different types of muscle afferents1996In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 734, no 1-2, p. 157-166Article in journal (Refereed)
    Abstract [en]

    Ensemble coding of simple mechanical stimuli (small sinusoidal stretches) was studied in simultaneously recorded mixed ensembles of primary- and secondary muscle spindle afferents (MSAs), and Golgi tendon organ (GTO) afferents recorded from L7-S1 dorsal root filaments. The experiments were made on 48 recorded afferents (29 primary MSAs, 6 secondary MSAs and 13 GTO afferents) in chloralose anaesthetised cats. For the analyses, we used a combination of principal component analysis and algorithms for quantification of stimulus discrimination. Mixed ensembles of primary- and secondary MSAs, and GTO afferents, discriminated significantly better between different muscle stretches than ensembles of only one or two types of these afferents. All kinds of ensembles showed a successive increase in discriminative ability with increased ensemble size, and this ability seemed to level at larger populations. However, the increase in discriminative ability was significantly greater for the mixed ensembles. It is hypothesised that the main reason for the greater discriminative ability achieved by mixed ensembles, might be that the variation in response profiles (sensitivity tuning) among the individual afferents of the mixed ensemble will be larger than that for ensembles of only one type of afferent. Finally, the results in the present study give experimental support to some of the teleological arguments in favour of the ensemble coding theory.

  • 4.
    Eriksson, I S
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences. Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Allard, P
    Umeå University, Faculty of Medicine, Department of Clinical Sciences. Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Marcusson, J
    [3H]tiagabine binding to GABA uptake sites in human brain.1999In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 851, no 1-2, p. 183-8Article in journal (Refereed)
    Abstract [en]

    The binding of [3H]tiagabine ((RS-1-(4,4-(3-methyl-2-thienyl)-3-butenyl)-3-piperidine carboxylic acid) to homogenates of frozen post-mortem human brain has been characterized. Inhibition experiments with gamma-aminobutyric acid (GABA), GABA uptake inhibitors, ligands active at postsynaptic GABA receptors and receptors for other neurotransmitters, suggest that [3H]tiagabine binds with high affinity to GABA uptake sites. Inhibition and kinetic experiments suggests that 70%-80% of the binding is to a high affinity site. Saturation experiments showed that the binding was saturable. Bmax was 3.4 pmol/mg protein and Kd 16 nM in frontal cortex. The dissociation constants (Kd) measured in kinetic and equilibrium experiments were in the same range (16-56 nM). The regional distribution was studied in nine brain regions and the binding was heterogenous, with the highest binding in frontal cortex and parietal cortex and the lowest binding in nucleus caudatus and putamen. This is, to our knowledge, the first study on [3H]tiagabine binding in human tissue. It is concluded that [3H]tiagabine binding can be used as a specific marker for the GABA transporter GAT-1 in homogenates of human brain.

  • 5.
    Haage, David
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Druzin, Michael
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Laboratory of Ionic Channels of Cell Membranes, Institute of Cytology, Russian Academy of Sciences, Russia.
    Johansson, Staffan
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Allopregnanolone modulates spontaneous GABA release via presynaptic Cl- permeability in rat preoptic nerve terminals2002In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 958, no 2, p. 405-413Article in journal (Refereed)
    Abstract [en]

    The endogenous neurosteroid 3alpha-hydroxy-5alpha-pregnane-20-one (allopregnanolone) affects presynaptic nerve terminals and thereby increases the frequency of spontaneous GABA release. The present study aimed at clarifying the mechanisms underlying this presynaptic neurosteroid action, by recording the frequency of spontaneous GABA-mediated inhibitory postsynaptic currents (sIPSCs) in neurons from the medial preoptic nucleus (MPN) of rat. Acutely dissociated neurons with functional adhering nerve terminals were studied by perforated-patch recording under voltage-clamp conditions. It was shown that the sIPSC frequency increased with the external K(+) concentration ([K(+)](o)). Further, the effect of allopregnanolone on the sIPSC frequency was strongly dependent on [K(+)](o). In a [K(+)](o) of 5 mM, 2.0 microM allopregnanolone caused a clear increase in sIPSC frequency. However, the effect declined rapidly with increased [K(+)](o) and at high [K(+)](o) allopregnanolone reduced the sIPSC frequency. The effect of allopregnanolone was also strongly dependent on the external Cl(-) concentration ([Cl(-)](o)). In a reduced [Cl(-)](o) (40 mM, but with a standard [K(+)](o) of 5 mM), the effect on sIPSC frequency was larger than that in the standard [Cl(-)](o) of 146 mM. The dependence of the effect of allopregnanolone on [K(+)](o) and on estimated presynaptic membrane potential was also altered by the reduction in [Cl(-)](o). As in standard [Cl(-)](o), the effect in low [Cl(-)](o) declined when [K(+)](o) was raised, but reversed at a higher [K(+)](o). The GABA(A) receptor agonist muscimol also potentiated the sIPSC frequency. Altogether, the results suggest that allopregnanolone exerts its presynaptic effect by increasing the presynaptic Cl(-) permeability, most likely via GABA(A) receptors.

  • 6. Hascup, Erin R
    et al.
    af Bjerkén, Sara
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Hascup, Kevin N
    Pomerleau, Francois
    Huettl, Peter
    Strömberg, Ingrid
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Gerhardt, Greg A
    Histological studies of the effects of chronic implantation of ceramic-based microelectrode arrays and microdialysis probes in rat prefrontal cortex.2009In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1291, p. 12-20Article in journal (Refereed)
    Abstract [en]

    Chronic implantation of neurotransmitter measuring devices is essential for awake, behavioral studies occurring over multiple days. Little is known regarding the effects of long term implantation on surrounding brain parenchyma and the resulting alterations in the functional properties of this tissue. We examined the extent of tissue damage produced by chronic implantation of either ceramic microelectrode arrays (MEAs) or microdialysis probes. Histological studies were carried out on fixed tissues using stains for neurons (cresyl violet), astrocytes (GFAP), microglia (Iba1), glutamatergic nerve fibers (VGLUT1), and the blood-brain barrier (SMI-71). Nissl staining showed pronounced tissue body loss with microdialysis implants compared to MEAs. The MEAs produced mild gliosis extending 50-100 microm from the tracks, with a significant change in the affected areas starting at 3 days. By contrast, the microdialysis probes produced gliosis extending 200-300 microm from the track, which was significant at 3 and 7 days. Markers for microglia and glutamatergic fibers supported that the MEAs produce minimal damage with significant changes occurring only at 3 and 7 days that return to control levels by 1 month. SMI-71 staining supported the integrity of the blood-brain barrier out to 1 week for both the microdialysis probes and the MEAs. This data support that the ceramic MEA's small size and biocompatibility are necessary to accurately measure neurotransmitter levels in the intact brain. The minimal invasiveness of the MEAs reduce tissue loss, allowing for long term (>6 month) electrochemical and electrophysiological monitoring of brain activity.

  • 7.
    Hashemian, Sanaz
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Marschinke, Franziska
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    af Bjerkén, Sara
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Strömberg, Ingrid
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Degradation of proteoglycans affects astrocytes and neurite formation in organotypic tissue cultures2014In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1564, p. 22-32Article in journal (Refereed)
    Abstract [en]

    Chondroitin sulfate proteoglycans (CSPGs) promote nerve growth during development, and inhibit axonal growth in the adult CNS after injury. Chondroitinase ABC (ChABC) and methyl-umbelliferyl-β-d-xyloside (β-xyloside), two enzymes that degrade CSPGs, promote regeneration after injury, however, they demonstrate opposing results in tissue culture. To elucidate the effect of the two enzymes, organotypic tissue cultures, treated with ChABC or β-xyloside, were employed to monitor nerve fiber outgrowth and astrocytic migration. Rat ventral mesencephalon (VM) and spinal cord (SC) from embryonic day (E) 14 and E18 were treated early, from the plating day for 14 days in vitro, or late where treatment was initiated after being cultured for 14 days. In the early treatment of E14 VM and SC cultures, astrocytic migration and nerve fiber outgrowth were hampered using both enzymes. Early treatment of E18 cultures reduced the astrocytic migration, while nerve growth was promoted by β-xyloside, but not by ChABC. In the late treated cultures of both E14 and E18 cultures, no differences in distances that astrocytes migrated or nerve fiber growth were observed. However, in β-xyloside-treated cultures, the confluency of astrocytic monolayer was disrupted. In E18 cultures both early and late treatments, neuronal migration was present in control cultures, which was preserved using ChABC but not β-xyloside. In conclusion, ChABC and β-xyloside had similar effects and hampered nerve fiber growth and astrocytic migration in E14 cultures. In E18 cultures nerve fiber growth was stimulated and neuronal migration was hampered after β-xyloside treatment while ChABC treatment did not exert these effects.

  • 8.
    Hu, XiaoLei
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Brännström, Thomas
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Gu, Weigang
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wester, Per
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    A photothrombotic ring stroke model in rats with or without late spontaneous reperfusion in the region at risk1999In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 849, no 1-2, p. 175-186Article in journal (Refereed)
    Abstract [en]

    This study aimed at developing a dual setup of the photothrombotic ring stroke model with or without late spontaneous reperfusion in the region at risk and to explore the morphological consequences. The exposed crania of adult male Wistar rats were subjected to a ring-shaped laser-irradiation beam (o.d. 5.0 mm, 0.35 mm thick) for 2 min simultaneously with intravenous erythrosin B (17 mg/kg) infusion. Transcardial carbon-black perfusion revealed that a laser intensity of 0.90 W/cm(2) resulted in late, that is, starting at 72 h, spontaneous reperfusion, whereas the lowest laser intensity that produced lack of reperfusion at 7 days post-irradiation was 1.84 W/cm(2). Laser-Doppler flowmetry showed prompt cortical cerebral blood flow (cCBF) reduction both in the ring lesion and region at risk (12% and 25% of control values) after high-intensity irradiation; these reduced flow values were more rapid and pronounced than in the low-intensity irradiation setup as previously shown. The high- compared with low-intensity irradiation setup produced more frequent occurrence of thrombi in the ring-lesion region and a larger ischemic cortical lesion with a more rapid pace of ischemic cellular changes in the ring-lesion region and the region at risk. The region at risk transformed into pannecrosis in the high-intensity, but recovered morphologically in the low-intensity irradiation setup. This dual photothrombotic setup with or without spontaneous reperfusion enables the study of events related to ischemic cell survival or death in an anatomically predefined region at risk.

  • 9.
    Johansson, I-M
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Birzniece, Vita
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lindblad, Charlotte
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Olsson, T
    Bäckström, T
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Allopregnanolone inhibits learning in the Morris water maze2002In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 934, no 2, p. 125-131Article in journal (Refereed)
    Abstract [en]

    The progesterone metabolite allopregnanolone (3alpha-OH-5alpha-pregnane-20-one) inhibits neural functions, enhancing the GABA induced GABA(A) receptor activation. This effect is benzodiazepine like and benzodiazepines are known to impair memory. Acute effects of allopregnanolone on the hippocampus dependent spatial learning in the Morris water maze have not been studied. Adult male Wistar rats where injected (i.v.) with allopregnanolone (2 mg/kg), or vehicle, daily for 11 days. At 8 or 20 min after each injection, studies of place navigation were performed in the Morris water maze. Allopregnanolone concentrations in plasma and in nine different brain areas where analyzed by radioimmunoassay. The latency to find the platform was increased 8 min after the allopregnanolone injection, while normal learning was seen after 20 min. Swim speed did not differ between groups. A higher number of rats were swimming close to the pool wall (thigmotaxis) in the 8 min allopregnanolone group compared to the other groups. Allopregnanolone concentrations in the brain tissue at 8 min were 1.5 to 2.5 times higher then at 20 min after the allopregnanolone injections. After vehicle injections the brain concentrations of allopregnanolone were at control levels. Plasma concentrations of allopregnanolone followed the same pattern as in the brain, with the exception of an increase 8 min after vehicle injections. The natural progesterone metabolite allopregnanolone can inhibit learning in the Morris water maze, an effect not caused by motor impairment. The learning impairment might be due to a combination of changed swimming behavior and difficulties in navigation.

  • 10.
    Karlsson, Urban
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Haage, David
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Staffan
    Currents evoked by GABA and glycine in acutely dissociated neurons from the rat medial preoptic nucleus1997In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 770, no 1-2, p. 256-260Article in journal (Refereed)
  • 11.
    Karlsson, Urban
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Sundgren, Anna
    Näsström, Jacques
    Johansson, Staffan
    Glutamate-evoked currents in acutely dissociated neurons from the rat medial preoptic nucleus1997In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 759, no 2, p. 270-276Article in journal (Refereed)
  • 12.
    Karlsson, Urban
    et al.
    Umeå University, Faculty of Medicine, Integrative Medical Biology.
    Sundgren-Andersson, Anna K
    Johansson, Staffan
    Umeå University, Faculty of Medicine, Integrative Medical Biology, Physiology. Fysiologi.
    Krupp, Johannes J
    Capsaicin augments synaptic transmission in the rat medial preoptic nucleus.2005In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1043, no 1-2, p. 1-11Article in journal (Refereed)
    Abstract [en]

    medial preoptic nucleus (MPN) is the major nucleus of the preoptic area (POA), a hypothalamic area involved in the regulation of body-temperature. Injection of capsaicin into this area causes hypothermia in vivo. Capsaicin also causes glutamate release from hypothalamic slices. However, no data are available on the effect of capsaicin on synaptic transmission within the MPN. Here, we have studied the effect of exogenously applied capsaicin on spontaneous synaptic activity in hypothalamic slices of the rat. Whole-cell patch-clamp recordings were made from visually identified neurons located in the MPN. In a subset of the studied neurons, capsaicin enhanced the frequency of spontaneous glutamatergic EPSCs. Remarkably, capsaicin also increased the frequency of GABAergic IPSCs, an effect that was sensitive to removal of extracellular calcium, but insensitive to tetrodotoxin. This suggests an action of capsaicin at presynaptic GABAergic terminals. In contrast to capsaicin, the TRPV4 agonist 4alpha-PDD did not affect GABAergic IPSCs. Our results show that capsaicin directly affects synaptic transmission in the MPN, likely through actions at presynaptic terminals as well as on projecting neurons. Our data add to the growing evidence that capsaicin receptors are not only expressed in primary afferent neurons, but also contribute to synaptic processing in some CNS regions.

  • 13.
    Kompus, Kristiina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). University of Bergen.
    Kalpouzos, Gregoria
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Stockholm University.
    Westerhausen, Rene
    University of Bergen.
    The size of the anterior corpus callosum correlates with the strength of hemispheric encoding-retrieval asymmetry in the ventrolateral prefrontal cortex2011In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1419, p. 61-67Article in journal (Refereed)
    Abstract [en]

    Functional lateralization of episodic memory processes in the frontal lobe is an area of intense study in the field of cognitive neuroimaging. Yet, to date there is insufficient knowledge of what role the interhemispheric structural connectivity plays in this lateralized organization. We analyzed functional and structural magnetic resonance imaging data from healthy adult volunteers who performed an associative encoding and retrieval task. We examined the relationship between functional voxel-based relative asymmetry of encoding and retrieval in the frontal lobes and the size of the anterior corpus callosum (antCC; corrected for brain size). The size of the antCC was strongly associated to the relative encoding-retrieval asymmetry in the ventrolateral prefrontal cortex (BA 47). These findings show that the functional asymmetry of episodic memory processes in the frontal lobes is associated with the structural connectivity between the hemispheres. (C) 2011 Elsevier B.V. All rights reserved.

  • 14.
    Lundgren, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Strömberg, Jessica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Allopregnanolone-stimulated GABA-mediated chloride ion flux is inhibited by 3beta-hydroxy-5alpha-pregnane-20-one (isoallopregnanolone)2003In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 982, no 1, p. 45-53Article in journal (Refereed)
  • 15.
    Marschinke, Franziska
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    Strömberg, Ingrid
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    Dual effects of TNFalpha on nerve fiber formation from ventral mesencephalic organotypic tissue cultures2008In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1215, p. 30-39Article in journal (Refereed)
    Abstract [en]

    Tumor necrosis factor alpha (TNFalpha) is toxic to dopamine neurons and increased levels of TNFalpha are observed in Parkinson's disease. Dopamine nerve fiber outgrowth in organotypic cultures of fetal ventral mesencephalon occurs in two waves. The early appearing nerve fibers are formed in the absence of astroglia, while migrating astrocytes guide the late appearing dopamine nerve fibers. TNFalpha (40 ng/ml) was added to the medium of organotypic ventral mesencephalic tissue cultures between days 4-7 and 11-14. The cultures were evaluated at days 7 or 19 to study the effects of TNFalpha on both types of nerve fiber formation. Tyrosine hydroxylase (TH)-immunohistochemistry demonstrated that the number of cultures showing non-glial-guided TH-positive outgrowth was reduced compared to controls, when TNFalpha was added at day 4. By contrast, the glial-guided TH-positive nerve fiber outgrowth and the astrocytic migration reached significantly longer distances by early TNFalpha treatment. Ki67-immunohistochemistry revealed that TNFalpha did not affect proliferation of astrocytes. Treatment with TNFalpha and antibodies against TNFalpha receptor 1 between days 4 and 7 revealed that the non-glial-guided TH-positive outgrowth reappeared. TNFalpha treatment between days 11 and 14 triggered neither the TH-positive glial-guided outgrowth, nor promoted the astrocytic migration to reach longer distances. The number of microglia was significantly increased after the late but not early TNFalpha treatment. In conclusion, TNFalpha is toxic for the non-glial dopaminergic nerve fiber outgrowth but stimulates the glial-guided outgrowth and the migration of astrocytes at an early time point. TNFalpha increased the number of microglia in VM tissue cultures after late but not after early treatment.

  • 16.
    Nevalainen, Nina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Andersson, Micael
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Ögren, Mattias
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Lövdén, M
    Aging Research Center, Karolinska Institutet & Stockholm University, Stockholm.
    Lindenberger, U
    Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.
    Bäckman, L
    Aging Research Center, Karolinska Institutet & Stockholm University, Stockholm.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    COBRA: A prospective multimodal imaging study of dopamine, brain structure and function, and cognition.2015In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1612, p. 83-103Article in journal (Refereed)
    Abstract [en]

    Cognitive decline is a characteristic feature of normal human aging. Previous work has demonstrated marked interindividual variability in onset and rate of decline. Such variability has been linked to factors such as maintenance of functional and structural brain integrity, genetics, and lifestyle. Still, few, if any, studies have combined a longitudinal design with repeated multimodal imaging and a comprehensive assessment of cognition as well as genetic and lifestyle factors. The present paper introduces the Cognition, Brain, and Aging (COBRA) study, in which cognitive performance and brain structure and function are measured in a cohort of 181 older adults aged 64 to 68 years at baseline. Participants will be followed longitudinally over a 10-year period, resulting in a total of three equally spaced measurement occasions. The measurement protocol at each occasion comprises a comprehensive set of behavioral and imaging measures. Cognitive performance is evaluated via computerized testing of working memory, episodic memory, perceptual speed, motor speed, implicit sequence learning, and vocabulary. Brain imaging is performed using positron emission tomography with [(11)C]-raclopride to assess dopamine D2/D3 receptor availability. Structural magnetic resonance imaging (MRI) is used for assessment of white and gray-matter integrity and cerebrovascular perfusion, and functional MRI maps brain activation during rest and active task conditions. Lifestyle descriptives are collected, and blood samples are obtained and stored for future evaluation. Here, we present selected results from the baseline assessment along with a discussion of sample characteristics and methodological considerations that determined the design of the study.

  • 17.
    Norgren, Niklas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Rosengren, Lars
    Stigbrand, Torgny
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Elevated neurofilament levels in neurological diseases2003In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 987, no 1, p. 25-31Article in journal (Refereed)
    Abstract [en]

    Neurofilaments, a major cytoskeletal constituent of neuronal cells, can be released into the cerebrospinal fluid during several neurodegenerative diseases. By means of a new sensitive ELISA capable of measuring 60 ng/l of neurofilament light, significant elevations were observed for different neurological disorders. Cerebral infarction presented levels of 19800+/-9100 ng/l, amyothropic lateral sclerosis 3600+/-1200 ng/l, 'relapsing-remitting' MS 2500+/-1500 ng/l, extrapyramidal symptoms 1100+/-300 ng/l, late onset AD 300+/-100 ng/l and vascular dementia 1400+/-800 ng/l. In patients with no signs of neurological diseases the upper normal level and cut-off values was determined to be below 100 ng/l. NF-L determinations will be a valuable complement in identifying neuronal degradation and can be used clinically for diagnostic and monitoring purposes.

  • 18. Pilyavskii, Alexander I
    et al.
    Maisky, Vladimir A
    Kalezic, Ivana
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Ljubisavljevic, Milos
    Centre for Musculoskeletal Research, National Institute for Working Life - Umeå.
    Kostyukov, Alexander I
    Windhorst, Uwe
    Centre for Musculoskeletal Research, National Institute for Working Life - Umeå.
    Johansson, Håkan
    Centre for Musculoskeletal Research, National Institute for Working Life - Umeå.
    c-fos expression and NADPH-d reactivity in spinal neurons after fatiguing stimulation of hindlimb muscles in the rat2001In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 923, no 1-2, p. 91-102Article in journal (Refereed)
    Abstract [en]

    The distribution of Fos-immunoreactive (Fos-ir) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-reactive neurons in the rat lumbar spinal cord was examined following muscle fatigue caused by intermittent high-rate (100 s(-1)) electrical stimulation of the triceps surae muscle or the ventral root L5 (VRL5) for 30 min. Following both types of stimulation, the fatigue-related c-fos gene expression was more extensive in the L2-L5 segments on the stimulated side, and the majority of Fos-ir neurons were concentrated in the dorsal horn. After direct muscle stimulation, the highest number of Fos-ir neurons were detected in two regions: layer 5, and superficial layers (1 and 2(o)), although many labeled cells were also found in layers 3, 4, 6, and 7. In response to VRL5 stimulation, the maximal density of Fos-ir neurons was detected in the middle and lateral parts of layers 1 and 2(o), the zone of termination of high-threshold muscle afferents(.) Statistically significant prevalence of Fos-ir cell number was also found in layers 5 and 7 on the stimulated side. A few Fos-ir neurons were detected in the ventral horn (layer 8 and area 10) on both sides. The lamellar distribution of NADPH-d-reactive neurons was similar over all experimental groups of animals. In the L3-L6 segments, such reactive cells were arranged in two distinct regions: dorsal horn (layers 2(i), 3, and 5) and area 10; in the L1 and L2 segments, an additional cluster of NADPH-d positive cells was found in the intermediolateral cell column (IML). Double-labeled cells were not detected. We suggest that c-fos expression in response to muscle fatigue reveals activity of functionally different types of spinal neurons which could operate together with NOS-containing cells in pre-motoneuronal networks to modulate the motoneuron output.

  • 19.
    Reid, Adam J
    et al.
    Blond McIndoe Research Laboratories, Tissue Injury and Repair Group, University of Manchester, UK.
    Welin, Dag
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Hand Surgery.
    Wiberg, Mikael
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Hand Surgery.
    Terenghi, Giorgio
    Blond McIndoe Research Laboratories, Tissue Injury and Repair Group, University of Manchester, UK.
    Novikov, Lev N
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Peripherin and ATF3 genes are differentially regulated in regenerating and non-regenerating primary sensory neurons2010In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1310, p. 1-7Article in journal (Refereed)
    Abstract [en]

    Peripheral nerve injury leads to deficient recovery of sensation and a causative factor may be that only 50-60% of primary sensory neurons succeed in regenerating axons after primary nerve repair. In this study, an in vivo rat sciatic nerve injury and regeneration model was combined with laser microdissection and quantitative real-time polymerase chain reaction with the aim of examining the gene expression of regenerative molecules in cutaneous and muscular sensory neurons. Recent studies have identified peripherin and ATF-3 molecules as crucial for neurite outgrowth propagation; our novel findings demonstrate a subpopulation of non-regenerating sensory neurons characterized by a failure to upregulate transcription of these molecules and that a greater peripherin mRNA expression in injured cutaneous neurons may potentiate this subpopulation to regenerate more axons than muscle afferent neurons following injury. The gene expression of the structural neurofilament NF-H is found to be significantly downregulated following injury in both sensory subpopulations.

  • 20.
    Rojo, Maria Luisa
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Pharmacology.
    Söderström, Ingegerd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Fowler, Christopher J
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Pharmacology.
    Residual effects of focal brain ischaemia upon cannabinoid CB(1) receptor density and functionality in female rats2011In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1373, p. 195-201Article in journal (Refereed)
    Abstract [en]

    Ischaemic insult results in short-term changes in cannabinoid-1 (CB(1)) receptor expression in the brain, but it is not known whether long-term changes occur, which could potentially mean a change in the intrinsic ability of the brain to withstand new ischaemic episodes. In this study, we have investigated the expression and functionality of CB(1) receptors in coronal brain slices obtained from ovariectomised female rats 46days after middle cerebral artery occlusion (MCAO). The animals were treated with either 17ß-oestradiol or placebo pellets 6h after MCAO and thereafter housed either in isolated or enriched environments. [(3)H]CP55,940 autoradiography indicated no significant effect of 17ß-oestradiol treatment or housing environment upon CB(1) receptor densities. There was, however, a modest but significant decrease in the CB(1) receptor density on the ipsilateral side relative to the contralateral side in the frontal cortex, parietal cortex, CA1-CA3 regions of the hippocampus, thalamus and hypothalamus. CB(1) receptor functionality was assessed by measurement of basal and CP55,940-stimulated [(35)S]GTPγS autoradiography. In the frontal cortex, parietal cortex, CA1-CA3 regions of the hippocampus and dentate gyrus, a robust stimulation, blocked by the CB(1) receptor inverse agonist AM251, was seen. There were no significant changes in the response to CP55,940 with respect either to the 17ß-oestradiol treatment, housing environment or MCAO. Our results reveal that although there are modest long-term decreases in ipsilateral CB(1) receptor densities following MCAO in female rats, these decreases do not result in a functional CB(1) receptor deficit.

  • 21.
    Vedin, Viktoria
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Eriksson, Björn
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Berghard, Anna
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Organization of the chemosensory neuroepithelium of the vomeronasal organ of the Scandinavian moose Alces alces2010In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1306, p. 53-61Article in journal (Refereed)
    Abstract [en]

    A functional vomeronasal organ is present in most land-living vertebrates, but not in all. Studies in a limited number of mammals have shown that stimulation of the vomeronasal neurons by odorous cues from conspecifics can lead to changes in innate behaviors in association to e.g. mating and aggression. Given the role of the organ in detecting odorous molecules important for species-specific communication, investigations of the structure of the vomeronasal organ within the mammalian group are warranted. Wild Scandinavian moose (Alces alces) is an even-toed ungulate (order: Artiodactyla) and the largest representative of the deer family Cervidae. This is the first study of the vomeronasal organ of a deer species that includes immunohistochemistry. The gross anatomy of the tubular vomeronasal. organ of moose was investigated including a nasopalatine duct that may allow for entrance of odorous substances from the oral and nasal cavities. The histology of the neuroepithelial part, in moose of both sexes, appeared overall similar to that of representatives of other Artiodactyla families. Basement membrane, structural epithelial cells, glia and sensory neurons were analyzed by expression of specific markers. The results suggest that the vomeronasal neuroepithelium of even-toed ungulates is more similar in organization to that of carnivores than e.g. rodents with regard to the relative number of sensory neurons and presence of functionally distinct populations of neurons. (C) 2009 Elsevier B.V. All rights reserved.

  • 22.
    Welin, Dag
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Hand Surgery.
    Novikova, Liudmila N
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Wiberg, Mikael
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Hand Surgery.
    Kellerth, Jan-Olof
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Novikov, Lev N
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Effects of N-acetyl-cysteine on the survival and regeneration of sural sensory neurons in adult rats2009In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1287, no 1, p. 58-66Article in journal (Refereed)
    Abstract [en]

    Microsurgical reconstruction of injured peripheral nerves often results in limited functional recovery. One contributing factor is the retrograde neuronal degeneration of sensory neurons in the dorsal root ganglia (DRG) and of motor neurons in the spinal cord. The present study investigates the neuroprotective and growth-promoting effects of N-acetyl-cysteine (NAC) on sensory DRG neurons and spinal motoneurons after sciatic axotomy and nerve grafting in adult rats. Sciatic axotomy and nerve grafting were performed at 1 week after sural DRG neurons and motoneurons were retrogradely labeled with the fluorescent tracer Fast Blue. To assess the efficacy of axonal regeneration, a second fluorescent dye Fluoro-Ruby was applied distal to the graft at 12 weeks after nerve repair. At 8-13 weeks after axotomy, only 52-56% of the sural sensory neurons remained in the lumbar DRG, while the majority of motoneurons survived the sciatic nerve injury. Nerve grafting alone or continuous intrathecal NAC treatment (2.4 mg/day) improved survival of sural DRG neurons. Combined treatment with nerve graft and NAC had significant additive effect on neuronal survival and also increased the number of sensory neurons regenerating across the graft. However, NAC treatment neither affected the number of regenerating motoneurons nor the number of myelinated axons in the nerve graft or in the distal nerve stump. The present results demonstrate that NAC provides a highly significant effect of neuroprotection in an animal nerve injury model and that combination with nerve grafting further attenuates retrograde cell death and promotes regeneration of sensory neurons.

1 - 22 of 22
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf