TY - JOUR A1 - Wiebking, Christine A1 - Lin, Chiao-I A1 - Wippert, Pia-Maria T1 - Training intervention effects on cognitive performance and neuronal plasticity — A pilot study JF - Frontiers in Neurology, section Neurorehabilitation N2 - Studies suggest that people suffering from chronic pain may have altered brain plasticity, along with altered functional connectivity between pain-processing brain regions. These may be related to decreased mood and cognitive performance. There is some debate as to whether physical activity combined with behavioral therapy (e.g. cognitive distraction, body scan) may counteract these changes. However, underlying neuronal mechanisms are unclear. The aim of the current pilot study with a 3-armed randomized controlled trial design was to examine the effects of sensorimotor training for nonspecific chronic low back pain on (1) cognitive performance; (2) fMRI activity co-fluctuations (functional connectivity) between pain-related brain regions; and (3) the relationship between functional connectivity and subjective variables (pain and depression). Six hundred and sixty two volunteers with non-specific chronic low back pain were randomly allocated to a unimodal (sensorimotor training), multidisciplinary (sensorimotor training and behavioral therapy) intervention, or to a control group within a multicenter study. A subsample of patients (n = 21) from one study center participated in the pilot study presented here. Measurements were at baseline, during (3 weeks, M2) and after intervention (12 weeks, M4 and 24 weeks, M5). Cognitive performance was measured by the Trail Making Test and functional connectivity by MRI. Pain perception and depression were assessed by the Von Korff questionnaire and the Hospital and Anxiety. Group differences were calculated by univariate and repeated ANOVA measures and Bayesian statistics; correlations by Pearson's r. Change and correlation of functional connection were analyzed within a pooled intervention group (uni-, multidisciplinary group). Results revealed that participants with increased pain intensity at baseline showed higher functional connectivity between pain-related brain areas used as ROIs in this study. Though small sample sizes limit generalization, cognitive performance increased in the multimodal group. Increased functional connectivity was observed in participants with increased pain ratings. Pain ratings and connectivity in pain-related brain regions decreased after the intervention. The results provide preliminary indication that intervention effects can potentially be achieved on the cognitive and neuronal level. The intervention may be suitable for therapy and prevention of non-specific chronic low back pain. KW - chronic back pain KW - sensorimotor training intervention KW - multimodal intervention KW - MRI KW - neuroplasticity Y1 - 2022 U6 - https://doi.org/10.3389/fneur.2022.773813 SN - 1664-2295 VL - 13 PB - Frontiers CY - Lausanne, Schweiz ER - TY - GEN A1 - Wiebking, Christine A1 - Lin, Chiao-I A1 - Wippert, Pia-Maria T1 - Training intervention effects on cognitive performance and neuronal plasticity — A pilot study T2 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe N2 - Studies suggest that people suffering from chronic pain may have altered brain plasticity, along with altered functional connectivity between pain-processing brain regions. These may be related to decreased mood and cognitive performance. There is some debate as to whether physical activity combined with behavioral therapy (e.g. cognitive distraction, body scan) may counteract these changes. However, underlying neuronal mechanisms are unclear. The aim of the current pilot study with a 3-armed randomized controlled trial design was to examine the effects of sensorimotor training for nonspecific chronic low back pain on (1) cognitive performance; (2) fMRI activity co-fluctuations (functional connectivity) between pain-related brain regions; and (3) the relationship between functional connectivity and subjective variables (pain and depression). Six hundred and sixty two volunteers with non-specific chronic low back pain were randomly allocated to a unimodal (sensorimotor training), multidisciplinary (sensorimotor training and behavioral therapy) intervention, or to a control group within a multicenter study. A subsample of patients (n = 21) from one study center participated in the pilot study presented here. Measurements were at baseline, during (3 weeks, M2) and after intervention (12 weeks, M4 and 24 weeks, M5). Cognitive performance was measured by the Trail Making Test and functional connectivity by MRI. Pain perception and depression were assessed by the Von Korff questionnaire and the Hospital and Anxiety. Group differences were calculated by univariate and repeated ANOVA measures and Bayesian statistics; correlations by Pearson's r. Change and correlation of functional connection were analyzed within a pooled intervention group (uni-, multidisciplinary group). Results revealed that participants with increased pain intensity at baseline showed higher functional connectivity between pain-related brain areas used as ROIs in this study. Though small sample sizes limit generalization, cognitive performance increased in the multimodal group. Increased functional connectivity was observed in participants with increased pain ratings. Pain ratings and connectivity in pain-related brain regions decreased after the intervention. The results provide preliminary indication that intervention effects can potentially be achieved on the cognitive and neuronal level. The intervention may be suitable for therapy and prevention of non-specific chronic low back pain. T3 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe - 4 KW - chronic back pain KW - sensorimotor training intervention KW - multimodal intervention KW - MRI KW - neuroplasticity Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-580284 IS - 4 ER - TY - JOUR A1 - Frodl, Thomas A1 - Janowitz, Deborah A1 - Schmaal, Lianne A1 - Tozzi, Leonardo A1 - Dobrowolny, Henrik A1 - Stein, Dan J. A1 - Veltman, Dick J. A1 - Wittfeld, Katharina A1 - van Erp, Theo G. M. A1 - Jahanshad, Neda A1 - Block, Andrea A1 - Hegenscheid, Katrin A1 - Voelzke, Henry A1 - Lagopoulos, Jim A1 - Hatton, Sean N. A1 - Hickie, Ian B. A1 - Frey, Eva Maria A1 - Carballedo, Angela A1 - Brooks, Samantha J. A1 - Vuletic, Daniella A1 - Uhlmann, Anne A1 - Veer, Ilya M. A1 - Walter, Henrik A1 - Schnell, Knut A1 - Grotegerd, Dominik A1 - Arolt, Volker A1 - Kugel, Harald A1 - Schramm, Elisabeth A1 - Konrad, Carsten A1 - Zurowski, Bartosz A1 - Baune, Bernhard T. A1 - van der Wee, Nic J. A. A1 - van Tol, Marie-Jose A1 - Penninx, Brenda W. J. H. A1 - Thompson, Paul M. A1 - Hibar, Derrek P. A1 - Dannlowski, Udo A1 - Grabe, Hans J. T1 - Childhood adversity impacts on brain subcortical structures relevant to depression JF - Journal of psychiatric research N2 - Childhood adversity plays an important role for development of major depressive disorder (MDD). There are differences in subcortical brain structures between patients with MDD and healthy controls, but the specific impact of childhood adversity on such structures in MDD remains unclear. Thus, aim of the present study was to investigate whether childhood adversity is associated with subcortical volumes and how it interacts with a diagnosis of MDD and sex. Within the ENIGMA-MDD network, nine university partner sites, which assessed childhood adversity and magnetic resonance imaging in patients with MDD and controls, took part in the current joint mega-analysis. In this largest effort world-wide to identify subcortical brain structure differences related to childhood adversity, 3036 participants were analyzed for subcortical brain volumes using FreeSurfer. A significant interaction was evident between childhood adversity, MDD diagnosis, sex, and region. Increased exposure to childhood adversity was associated with smaller caudate volumes in females independent of MDD. All subcategories of childhood adversity were negatively associated with caudate volumes in females - in particular emotional neglect and physical neglect (independently from age, ICV, imaging site and MDD diagnosis). There was no interaction effect between childhood adversity and MDD diagnosis on subcortical brain volumes. Childhood adversity is one of the contributors to brain structural abnormalities. It is associated with subcortical brain abnormalities that are relevant to psychiatric disorders such as depression. (C) 2016 Published by Elsevier Ltd. KW - Depression KW - Childhood adversity KW - MRI KW - Caudate KW - Hippocampus KW - ENIGMA Y1 - 2016 U6 - https://doi.org/10.1016/j.jpsychires.2016.11.010 SN - 0022-3956 SN - 1879-1379 VL - 86 SP - 58 EP - 65 PB - Elsevier CY - Oxford ER - TY - THES A1 - Dziourkevitch, Natalia T1 - Interstellar turbulence driven by magneto-rotational instability T1 - Interstellare Turbulenzen hervorgerufen durch magnetische Rotationsinstabilitäten N2 - Origin and symmetry of the observed global magnetic fields in galaxies are not fully understood. We intend to clarify the question of the magnetic field origin and investigate the global action of the magneto-rotational instability (MRI) in galactic disks with the help of 3D global magneto-hydrodynamical (MHD) simulations. The calculations were done with the time-stepping ZEUS 3D code using massive parallelization. The alpha-Omega dynamo is known to be one of the most efficient mechanisms to reproduce the observed global galactic fields. The presence of strong turbulence is a pre-requisite for the alpha-Omega dynamo generation of the regular magnetic fields. The observed magnitude and spatial distribution of turbulence in galaxies present unsolved problems to theoreticians. The MRI is known to be a fast and powerful mechanism to generate MHD turbulence and to amplify magnetic fields. We find that the critical wavelength increases with the increasing of magnetic fields during the simulation, transporting the energy from critical to larger scales. The final structure, if not disrupted by supernovae explosions, is the structure of `thin layers' of thickness of about 100 pcs. An important outcome of all simulations is the magnitude of the horizontal components of the Reynolds and Maxwell stresses. The result is that the MRI-driven turbulence is magnetic-dominated: its magnetic energy exceeds the kinetic energy by a factor of 4. The Reynolds stress is small and less than 1% of the Maxwell stress. The angular momentum transport is thus completely dominated by the magnetic field fluctuations. The volume-averaged pitch angle is always negative with a magnitude of about -30. The non-saturated MRI regime is lasting sufficiently long to fill the time between the galactic encounters, independently of strength and geometry of the initial field. Therefore, we may claim the observed pitch angles can be due to MRI action in the gaseous galactic disks. The MRI is also shown to be a very fast instability with e-folding time proportional to the time of one rotation. Steep rotation curves imply a stronger growth for the magnetic energy due to MRI. The global e-folding time is from 44 Myr to 100 Myr depending on the rotation profile. Therefore, MRI can explain the existence of rather large magnetic field in very young galaxies. We also have reproduced the observed rms values of velocities in the interstellar turbulence as it was observed in NGC 1058. We have shown with the simulations that the averaged velocity dispersion of about 5 km/s is a typical number for the MRI-driven turbulence in galaxies, which agrees with observations. The dispersion increases outside of the disk plane, whereas supernovae-driven turbulence is found to be concentrated within the disk. In our simulations the velocity dispersion increases a few times with the heights. An additional support to the dynamo alpha-effect in the galaxies is the ability of the MRI to produce a mix of quadrupole and dipole symmetries from the purely vertical seed fields, so it also solves the seed-fields problem of the galactic dynamo theory. The interaction of magneto-rotational instability and random supernovae explosions remains an open question. It would be desirable to run the simulation with the supernovae explosions included. They would disrupt the calm ring structure produced by global MRI, may be even to the level when we can no longer blame MRI to be responsible for the turbulence. N2 - Die Beobachtung polarisierter Synchrotronstrahlung mit modernen Radioteleskopen zeigen die Existenz von großskaligen Magnetfeldern in Galaxien. Mit den ständig verbesserten Beobachtungsinstrumenten findet man Magnetfelder in immer mehr Galaxien, so dass man annehmen kann, Magnetfelder treten mehr oder weniger in allen Galaxien auf. Selbst in sehr jungen Galaxien (damit weit entfernten) wurden schon Magnetfelder von einigen mikroG gefunden. Eine mögliche Erklärung für die Entstehung der Magnetfeldern ist die Wirkung eines turbulenten Dynamos. Neben Supernova-Explosionen können magnetische Instabilitäten eine Quelle für die Turbulenz im interstellaren Medium sein. So werden Galaxien bei Anwesenheit eines schwachen Magnetfeldes auf Grund der "Magneto-Rotations-Instabilität" (MRI) turbulent. Die globale Entwicklung des interstellaren Gases in Galaxien unter Wirkung der MRI ist in der vorliegenden Arbeit betrachtet worden. Mit drei-dimensionalen numerischen Simulationen auf großen Clusterrechnern wurde die zeitliche Entwicklung des Geschwindigkeitsfeldes und der Magnetfelder untersucht. Für die extrem rechenintensiven globalen Modelle wurde ein hochgradig parallelisierbares Rechenprogramm zur Lösung der MHD-Gleichungen an die Problemstellung angepasst, in der Rechenzeit optimiert und ausführlich getestet. Es konnte erstmalig die zeitliche Entwicklung des interstellaren Gases unter dem Einfluss eines schwachen Magnetfeldes über mehrere Milliarden Jahre verfolgt werden. In der galaktischen Scheibe entwickelt sich Turbulenz mit einer Geschwindigkeitsdispersion von einigen km/s und großskalige Magnetfelder von einigen mikroG, genau wie in realen Galaxien beobachtet. Damit konnte der Nachweis erbracht werden, dass das interstellare Gas durch Wirkung der MRI auch bei geringer Sternaktivität Turbulenz entwickelt, wie es in einigen ruhigen Galaxien auch beobachtet wird. Ein anderes wichtiges Resultat ist die Entstehung großskaliger Magnetfelder aus kleinskaligen Strukturen in der Art eines turbulenten Dynamos. Die Wachstumsrate der magnetischen Energie geht bei diesem Prozess mit der Umlaufzeit, schnell genug um auch Magnetfelder mit einigen mikroG in sehr jungen Galaxien zu erreichen. Die Entstehung von Magnetfeldern aus der MRI löst auch die bisher ungeklärte Frage nach der Geometrie der Saatfelder für turbulente Dynamos. KW - Magnetohydrodynamik KW - Instabilität KW - Turbulenz KW - Galaxie KW - Dynamo KW - MHD KW - MRI KW - spiral galaxies KW - dynamo KW - turbulence Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-5306 ER -