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Search Results: 1 - 10 of 192377 matches for " Inga D. Neumann "
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Oxytocin and Major Depressive Disorder: Experimental and Clinical Evidence for Links to Aetiology and Possible Treatment
David A. Slattery,Inga D. Neumann
Pharmaceuticals , 2010, DOI: 10.3390/ph3030702
Abstract: Affective disorders represent the most common psychiatric diseases, with substantial co-morbidity existing between major depressive disorders (MDD) and anxiety disorders. The lack of truly novel acting compounds has led to non-monoaminergic based research and hypotheses in recent years. The large number of brain neuropeptides, characterized by discrete synthesis sites and multiple receptors, represent likely research candidates for novel therapeutic targets. The present review summarises the available preclinical and human evidence regarding the neuropeptide, oxytocin, and its implications in the aetiology and treatment of MDD. While the evidence is not conclusive at present additional studies are warranted to determine whether OXT may be of therapeutic benefit in subsets of MDD patients such as those with comorbid anxiety symptoms and low levels of social attachment.
Yes, I Am Ready Now: Differential Effects of Paced versus Unpaced Mating on Anxiety and Central Oxytocin Release in Female Rats
Kewir D. Nyuyki, Martin Waldherr, Sandra Baeuml, Inga D. Neumann
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0023599
Abstract: Sexual activity and partner intimacy results in several positive consequences in the context of stress-coping, both in males and females, such as reduced state anxiety in male rats after successful mating. However, in female rats, mating is a rewarding experience only when the estrous female is able to control sexual interactions, i.e., under paced-mating conditions. Here, we demonstrate that sex-steroid priming required for female mating is anxiolytic; subsequent sexual activity under paced mating conditions did not disrupt this anxiolytic priming effect, whereas mating under unpaced conditions increased anxiety-related behavior. In primed females, the release of the neuropeptide oxytocin (OT) within the hypothalamic paraventricular nucleus was found to be elevated and to further increase during paced, but not unpaced mating. Central administration of an OT receptor antagonist partly prevented priming/mating-induced anxiolysis indicating the involvement of brain OT in the anxiolysis triggered by priming and/or sexual activity. These findings reveal that the positive consequences of mating in females are dependent on her ability to control sexual interactions, and that brain OT release is at least in part the underlying neurobiological correlate.
Measuring Virgin Female Aggression in the Female Intruder Test (FIT): Effects of Oxytocin, Estrous Cycle, and Anxiety
Trynke R. de Jong, Daniela I. Beiderbeck, Inga D. Neumann
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0091701
Abstract: The costs of violence and aggression in our society have stimulated the scientific search for the predictors and causes of aggression. The majority of studies have focused on males, which are considered to be more aggressive than females in most species. However, rates of offensive behavior in girls and young women are considerable and are currently rising in Western society. The extrapolation of scientific results from males to young, non-maternal females is a priori limited, based on the profound sex differences in brain areas and functioning of neurotransmitters involved in aggression. Therefore, we established a paradigm to assess aggressive behavior in young virgin female rats, i.e. the female intruder test (FIT). We found that approximately 40% of un-manipulated adult (10–11 weeks old) female Wistar rats attack an intruder female during the FIT, independent of their estrous phase or that of their intruder. In addition, adolescent (7–8 weeks old) female rats selected for high anxiety behavior (HABs) displayed significantly more aggression than non-selected (NAB) or low-anxiety (LAB) rats. Intracerebroventricular infusion of oxytocin (OXT, 0.1 μg/5 μl) inhibited aggressive behavior in adult NAB and LAB, but not HAB females. Adolescent NAB rats that had been aggressive towards their intruder showed increased pERK immunoreactivity (IR) in the hypothalamic attack area and reduced pERK-IR in OXT neurons in the paraventricular hypothalamic nucleus compared to non-aggressive NAB rats. Taken together, aggressive behavior in young virgin female rats is partly dependent on trait anxiety, and appears to be under considerable OXT control.
Anti-aggressive effects of neuropeptide S independent of anxiolysis in male rats
Daniela I. Beiderbeck,Michael Lukas,Inga D. Neumann
Frontiers in Behavioral Neuroscience , 2014, DOI: 10.3389/fnbeh.2014.00185
Abstract: Neuropeptide S (NPS) exerts robust anxiolytic and memory enhancing effects, but only in a non-social context. In order to study whether NPS affects aggressive behavior we used Wistar rats bred for low (LAB) and high (HAB) levels of innate anxiety-related behavior, respectively, which were both described to display increased levels of aggression compared with Wistar rats not selectively bred for anxiety (NAB). Male LAB, HAB, and NAB rats were tested for aggressive behavior toward a male intruder rat within their home cage (10 min, resident-intruder [RI] test). Intracerebroventricular (icv) infusion of NPS (1 nmol) significantly reduced inter-male aggression in LAB rats, and tended to reduce aggression in HAB and NAB males. However, local infusion of NPS (0.2 or 0.1 nmol NPS) into either the nucleus accumbens or the lateral hypothalamus did not influence aggressive behavior. Social investigation in the RI test and general social motivation assessed in the social preference paradigm were not altered by icv NPS (1 nmol). The anti-aggressive effect of NPS is most likely not causally linked to its anxiolytic properties, as intraperitoneal administration of the anxiogenic drug pentylenetetrazole decreased aggression in LAB rats whereas the anxiolytic drug diazepam did not affect aggression in HAB rats. Thus, although NPS has so far only been shown to exert effects on non-social behaviors, our results are the first demonstration of anti-aggressive effects of NPS in male rats.
Different Patterns of Respiration in Rat Lines Selectively Bred for High or Low Anxiety
Luca Carnevali, Andrea Sgoifo, Mimosa Trombini, Rainer Landgraf, Inga D. Neumann, Eugene Nalivaiko
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0064519
Abstract: In humans, there is unequivocal evidence of an association between anxiety states and altered respiratory function. Despite this, the link between anxiety and respiration has been poorly evaluated in experimental animals. The primary objective of the present study was to investigate the hypothesis that genetic lines of rats that differ largely in their anxiety level would display matching alterations in respiration. To reach this goal, respiration was recorded in high-anxiety behavior (HAB, n = 10) and low-anxiety behavior (LAB, n = 10) male rats using whole-body plethysmography. In resting state, respiratory rate was higher in HABs (85±2 cycles per minute, cpm) than LABs (67±2 cpm, p<0.05). During initial testing into the plethysmograph and during a restraint test, HAB rats spent less time at high-frequency sniffing compared to LAB rats. In addition, HAB rats did not habituate in terms of respiratory response to repetitive acoustic stressful stimuli. Finally, HAB rats exhibited a larger incidence of sighs during free exploration of the plethysmograph and under stress conditions. We conclude that: i) HAB rats showed respiratory changes (elevated resting respiratory rate, reduced sniffing in novel environment, increased incidence of sighs, and no habituation of the respiratory response to repetitive stimuli) that resemble those observed in anxious and panic patients, and ii) respiratory patterns may represent a promising way for assessing anxiety states in preclinical studies.
Differential Contribution of Hypothalamic MAPK Activity to Anxiety-Like Behaviour in Virgin and Lactating Rats
Benjamin Jurek, David A. Slattery, Rodrigue Maloumby, Katharina Hillerer, Sophie Koszinowski, Inga D. Neumann, Erwin H. van den Burg
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0037060
Abstract: The c-Raf – MEK1/2 – ERK1/2 mitogen-activated protein kinase (MAPK) intracellular signalling cascade in neurons plays important roles in the control of a variety of behaviours, including social behaviours and anxiety. These roles partially overlap with those described for oxytocin (OXT), and it has been shown that OXT activates the MAPK pathway in the hypothalamus (of male), and hippocampus (of female) rats. Here, by combining behavioural (light/dark box) and biochemical analyses (western blotting), we tested two hypotheses: (i) that OXT is anxiolytic within the hypothalamus of females, and (ii) that this effect, as well as that of lactation-associated anxiolysis, depends on the recruitment of the MAPK pathway. We found that, when injected bilaterally into the hypothalamic paraventricular nucleus (PVN), OXT decreased anxiety-like behaviour in virgins, and that this effect depended on phosphorylation of MEK1/2. MAPK pathway activation in lactation was evident by high phosphorylated (p) MEK1/2 levels, and nuclear translocation of ERK1. The high pMEK1/2 levels were necessary for the anxiolytic phenotype typically observed during lactation. Interestingly, exogenous OXT in lactating rats reduced pMEK1/2 levels without a concomitant effect on anxiety, indicating that OXT receptor activation can lead to recruitment of additional intracellular pathways to modulate MEK activity. Still other pathways could include MEK, but without subsequent activation of ERK, as we did not observe any increase in OXT-induced ERK phosphorylation. Together the results demonstrate that the MAPK pathway, especially MEK1/2, is critically involved in the regulation of anxiety-like behaviour in female rats.
The elliptic genus of Calabi-Yau 3- and 4-folds, product formulae and generalized Kac-Moody algebras
C. D. D. Neumann
Physics , 1996, DOI: 10.1016/S0393-0440(98)00015-1
Abstract: In this paper the elliptic genus for a general Calabi-Yau fourfold is derived. The recent work of Kawai calculating N=2 heterotic string one-loop threshold corrections with a Wilson line turned on is extended to a similar computation where K3 is replaced by a general Calabi-Yau 3- or 4-fold. In all cases there seems to be a generalized Kac-Moody algebra involved, whose denominator formula appears in the result.
Perturbative BPS-algebras in superstring theory
C. D. D. Neumann
Physics , 1997, DOI: 10.1016/S0550-3213(97)00360-X
Abstract: This paper investigates the algebraic structure that exists on perturbative BPS-states in the superstring, compactified on the product of a circle and a Calabi-Yau fourfold. This structure was defined in a recent article by Harvey and Moore. It shown that for a toroidal compactification this algebra is related to a generalized Kac-Moody algebra. The BPS-algebra itself is not a Lie-algebra. However, it turns out to be possible to construct a Lie-algebra with the same graded dimensions, in terms of a half-twisted model. The dimensions of these algebras are related to the elliptic genus of the transverse part of the string algebra. Finally, the construction is applied to an orbifold compactification of the superstring.
Knieendoprothetik - Update
Dorn U,Neumann D
Journal für Mineralstoffwechsel , 2008,
Abstract: Weltweit hat in den letzten 10 Jahren die Zahl der Knieendoprothesen-Implantationen stark zugenommen. Nach relativ kurzer Zeit wird durch die Operation eine erhebliche Verbesserung bezogen auf Schmerzbelastung, Gelenksfunktion und Lebensqualit t erzielt. Minimal-invasive Zug nge in Kombination mit dazu neu entwickelten Instrumenten beeintr chtigen die Muskelfunktion weniger als der mediale parapatellare Standardzugang und verkürzen die frühe Rehabilitationsphase. Der Einsatz der Navigation erleichtert die pr zise Positionierung der Implantate. Sowohl für die minimal-invasive Implantationstechnik als auch für die navigationsunterstützte Technik fehlen noch Ergebnisse, die gegenüber konventioneller Technik bessere Funktion und l ngere Standzeit dokumentieren. Moderne Prothesen erm glichen eine Rotation des Unterschenkels entweder durch asymmetrische Formgebung der Femurkondylen oder durch die Rotation der Polyethylenplattform auf der Tibiakomponente bei Prothesen mit konformer Kondylengestaltung. Femur- und Tibiakomponenten mit rotierender Plattform sind aus CoCr-Stahl, Tibiakomponenten mit fest montiertem Polyethylenteil sind meist aus Titanlegierungen gefertigt. In den letzten Jahren werden bei Patienten mit bekannter Metallallergie (insbesondere Nickelallergie) spezielle Implantate aus oberfl chenbeschichtetem Titan oder Zirkonium eingesetzt. Cross-linked Polyethylen hat noch nicht die gleiche Verbreitung gefunden wie bei Hüftimplantaten. Prothesen mit erh hter Flexionsm glichkeit gewannen in letzter Zeit an Bedeutung. Der Einsatz von Halbschlitten-Prothesen ist durch minimal-invasive Zug nge und verbesserte Instrumente wieder popul rer geworden. Die Vielfalt modularer Endoprothesensysteme verschiedener Hersteller hat insbesondere Revisionsoperationen leichter gemacht. Dadurch sind auch nach Wechseloperationen hnliche Ergebnisse zu erzielen wie nach prim rer Implantation.
3C 295, a cluster and its cooling flow at z=0.46
D. M. Neumann
Physics , 1999, DOI: 10.1086/307424
Abstract: We present ROSAT HRI data of the distant and X-ray luminous (L_x(bol)=2.6^ {+0.4}_{-0.2} 10^{45}erg/sec) cluster of galaxies 3C 295. We fit both a one-dimensional and a two-dimensional isothermal beta-model to the data, the latter one taking into account the effects of the point spread function (PSF). For the error analysis of the parameters of the two-dimensional model we introduce a Monte-Carlo technique. Applying a substructure analysis, by subtracting a cluster model from the data, we find no evidence for a merger, but we see a decrement in emission South-East of the center of the cluster, which might be due to absorption. We confirm previous results by Henry & Henriksen(1986) that 3C 295 hosts a cooling flow. The equations for the simple and idealized cooling flow analysis presented here are solely based on the isothermal beta-model, which fits the data very well, including the center of the cluster. We determine a cooling flow radius of 60-120kpc and mass accretion rates of dot{M}=400-900 Msun/y, depending on the applied model and temperature profile. We also investigate the effects of the ROSAT PSF on our estimate of dot{M}, which tends to lead to a small overestimate of this quantity if not taken into account. This increase of dot{M} (10-25%) can be explained by a shallower gravitational potential inferred by the broader overall profile caused by the PSF, which diminishes the efficiency of mass accretion. We also determine the total mass of the cluster using the hydrostatic approach. At a radius of 2.1 Mpc, we estimate the total mass of the cluster (M{tot}) to be (9.2 +/- 2.7) 10^{14}Msun. For the gas to total mass ratio we get M{gas}/M{tot} =0.17-0.31, in very good agreement with the results for other clusters of galaxies, giving strong evidence for a low density universe.
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