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Strobach T.,Medical School Hamburg | Schubert T.,Martin Luther University of Halle Wittenberg
Psychology and Aging | Year: 2017

The present study investigated the ability of older adults in contrast to younger adults to automatize new choice tasks as a result of simultaneous dual-task practice. Importantly, the study was carried out in conditions optimal for dual-task performance and task automatization. Despite this, the results of detailed analyses were not consistent with the assumption that either older or younger adults are able to automatize new choice tasks; neither group showed evidence of automatization. Even in analyses focusing on high dual-task performers (i.e., individuals who performed equally well in single and dual tasks) the results were not consistent with this assumption. Instead, it seems to be the case that both older and younger adults continue to use capacity-limited processes to process choice tasks after dual-task practice. These conclusions are consistent with findings from studies using single-task practice and tests of task automatization in dual tasks (Maquestiaux, Laguë-Beauvais, Ruthruff, Hartley, & Bherer, 2010; Maquestiaux, Didierjean, Ruthruff, Chauvel, & Hartley, 2013). © 2017 American Psychological Association.

Becker M.,University of Hamburg | Schubert T.,Humboldt University of Berlin | Strobach T.,Medical School Hamburg | Gallinat J.,University of Hamburg | And 2 more authors.
NeuroImage | Year: 2016

There is a vast amount of literature indicating that multiple language expertise leads to positive transfer effects onto other non-language cognitive domains possibly due to enhanced cognitive control. However, there is hardly any evidence about underlying mechanisms on how complex behavior like simultaneous interpreting benefits cognitive functioning in other non-language domains. Therefore, we investigated whether simultaneous interpreters (SIs) exhibit cognitive benefits in tasks measuring aspects of cognitive control compared to a professional multilingual control group. We furthermore investigated in how far potential cognitive benefits are related to brain structure (using voxel-based morphometry) and function (using regions-of-interest-based functional connectivity and graph-analytical measures on low-frequency BOLD signals in resting-state brain data). Concerning cognitive control, the results reveal that SIs exhibit less mixing costs in a task switching paradigm and a dual-task advantage compared to professional multilingual controls. In addition, SIs show more gray matter volume in the left frontal pole (BA 10) compared to controls. Graph theoretical analyses revealed that this region exhibits higher network values for global efficiency and degree and is functionally more strongly connected to the left inferior frontal gyrus and middle temporal gyrus in SIs compared to controls. Thus, the data provide evidence that SIs possess cognitive benefits in tasks measuring cognitive control. It is discussed in how far the central role of the left frontal pole and its stronger functional connectivity to the left inferior frontal gyrus represents a correlate of the neural mechanisms for the observed behavioral effects. © 2016.

Janke C.,Institut Universitaire de France | Janke C.,French National Center for Scientific Research | Janke C.,French Institute of Health and Medical Research | Kneussel M.,Medical School Hamburg
Trends in Neurosciences | Year: 2010

In the past decades, a range of post-translational modifications has been discovered on tubulins, the major constituents of microtubules. Pioneering studies have described the occurrence and dynamics of these modifications and provided first insights into their potential functions in regulating the microtubule cytoskeleton. By contrast, several tubulin-modifying enzymes were only discovered in the last few years, and studies on molecular mechanisms and cellular functions of tubulin modifications are just beginning to emerge. This review highlights the roles of tubulin modifications in neurons. Recent studies are also discussed in relation to how the combinatorial use of tubulin modifications could generate a dynamic microtubule code, and how such a code might regulate basic as well as higher-order neuronal functions. © 2010 Elsevier Ltd.

Meltzer S.,Howard Hughes Medical Institute | Yadav S.,Howard Hughes Medical Institute | Lee J.,University of Washington | Soba P.,Medical School Hamburg | And 6 more authors.
Neuron | Year: 2016

Precise patterning of dendritic arbors is critical for the wiring and function of neural circuits. Dendrite-extracellular matrix (ECM) adhesion ensures that the dendrites of Drosophila dendritic arborization (da) sensory neurons are properly restricted in a 2D space, and thereby facilitates contact-mediated dendritic self-avoidance and tiling. However, the mechanisms regulating dendrite-ECM adhesion in vivo are poorly understood. Here, we show that mutations in the semaphorin ligand sema-2b lead to a dramatic increase in self-crossing of dendrites due to defects in dendrite-ECM adhesion, resulting in a failure to confine dendrites to a 2D plane. Furthermore, we find that Sema-2b is secreted from the epidermis and signals through the Plexin B receptor in neighboring neurons. Importantly, we find that Sema-2b/PlexB genetically and physically interacts with TORC2 complex, Tricornered (Trc) kinase, and integrins. These results reveal a novel role for semaphorins in dendrite patterning and illustrate how epidermal-derived cues regulate neural circuit assembly. Meltzer et al. demonstrate that semaphorin ligand derived from epidermis is required to restrict dendrites into a 2D space, thereby facilitating self-avoidance. They further show that Trc/Fry and integrin signaling pathways are components of Sema-2b/PlexB signaling. © 2016 Elsevier Inc.

Wegner M.,University of Bern | Schuler J.,University of Bern | Budde H.,Medical School Hamburg | Budde H.,Reykjavik University
Psychoneuroendocrinology | Year: 2014

It has been previously shown that the implicit affiliation motive - the need to establish and maintain friendly relationships with others - leads to chronic health benefits. The underlying assumption for the present research was that the implicit affiliation motive also moderates the salivary cortisol response to acute psychological stress when some aspects of social evaluation and uncontrollability are involved. By contrast we did not expect similar effects in response to exercise as a physical stressor. Fifty-nine high school students aged M=14.8 years were randomly assigned to a psychosocial stress (publishing the results of an intelligence test performed), a physical stress (exercise intensity of 65-75% of HRmax), and a control condition (normal school lesson) each lasting 15min. Participants' affiliation motives were assessed using the Operant Motive Test and salivary cortisol samples were taken pre and post stressor. We found that the strength of the affiliation motive negatively predicted cortisol reactions to acute psychosocial but not to physical stress when compared to a control group. The results suggest that the affiliation motive buffers the effect of acute psychosocial stress on the HPA axis. © 2014 Elsevier Ltd.

Wegwarth O.,Max Planck Institute for Human Development | Kurzenhauser-Carstens S.,Medical School Hamburg | Gigerenzer G.,Max Planck Institute for Human Development
Vaccine | Year: 2014

Objective: Informed decision making requires transparent and evidence-based (=balanced) information on the potential benefit and harms of medical preventions. An analysis of German HPV vaccination leaflets revealed, however, that none met the standards of balanced risk communication. Methods: We surveyed a sample of 225 girl-parent pairs in a before-after design on the effects of balanced and unbalanced risk communication on participants' knowledge about cervical cancer and the HPV vaccination, their perceived risk, their intention to have the vaccine, and their actual vaccination decision. Results: The balanced leaflet increased the number of participants who were correctly informed about cervical cancer and the HPV vaccine by 33 to 66 absolute percentage points. In contrast, the unbalanced leaflet decreased the number of participants who were correctly informed about these facts by 0 to 18 absolute percentage points. Whereas the actual uptake of the HPV vaccination 14 months after the initial study did not differ between the two groups (22% balanced leaflet vs. 23% unbalanced leaflet; p=.93, r=.01), the originally stated intention to have the vaccine reliably predicted the actual vaccination decision for the balanced leaflet group only (concordance between intention and actual uptake: 97% in the balanced leaflet group, rs=.92, p=.00; 60% in the unbalanced leaflet group, rs=.37, p=.08). Conclusion: In contrast to a unbalanced leaflet, a balanced leaflet increased people's knowledge of the HPV vaccination, improved perceived risk judgments, and led to an actual vaccination uptake, which first was robustly predicted by people's intention and second did not differ from the uptake in the unbalanced leaflet group. These findings suggest that balanced reporting about HPV vaccination increases informed decisions about whether to be vaccinated and does not undermine actual uptake. © 2014 The Authors.

Comorbid substance use disorders in schizophrenia are mostly associated with an unfavorable course of the disease and with difficulties in clinical management. Therefore, some therapists tend to react to these patients in a resigned manner. However, there is growing evidence for higher cognitive functioning and less severe deficits in brain morphology of these patients compared to patients without cannabis use. A common interpretation refers to relatively low vulnerability for psychosis in some of these patients, who mainly became schizophrenic because of the propsychotic properties of cannabis. Low vulnerability is reflected by a higher cognitive functioning; therefore, the pessimistic view of therapists seems unjustified for at least a subgroup of young patients. Provided that patients are treated in adequate therapeutic settings and that they stop using cannabis, a lower vulnerability may be associated with overall better socio-rehabilitative outcome parameters. © 2013, Springer-Verlag Berlin Heidelberg.

Dumoulin A.,Ecole Normale Superieure de Paris | Triller A.,Ecole Normale Superieure de Paris | Kneussel M.,Medical School Hamburg
Frontiers in Molecular Neuroscience | Year: 2010

Regulation of synaptic transmission is essential to tune individual-to-network neuronal activity. One way to modulate synaptic strength is to regulate neurotransmitter receptor numbers at postsynaptic sites. This can be achieved either through plasma membrane insertion of receptors derived from intracellular vesicle pools, a process depending on active cytoskeleton transport, or through surface membrane removal via endocytosis. In parallel, lateral diffusion events along the plasma membrane allow the exchange of receptor molecules between synaptic and extrasynaptic compartments, contributing to synaptic strength regulation. In recent years, results obtained from several groups studying glycine receptor (GlyR) trafficking and dynamics shed light on the regulation of synaptic GlyR density. Here, we review (i) proteins and mechanisms involved in GlyR cytoskeletal transport, (ii) the diffusion dynamics of GlyR and of its scaffolding protein gephyrin that control receptor numbers, and its relationship with synaptic plasticity, and (iii) adaptative changes in GlyR diffusion in response to global activity modifications, as a homeostatic mechanism. © 2010 Dumoulin, Triller and Kneussel.

Mansour W.Y.,Medical School Hamburg | Mansour W.Y.,Cairo University | Rhein T.,Medical School Hamburg | Dahm-Daphi J.,Medical School Hamburg
Nucleic Acids Research | Year: 2010

Non-homologous end-joining (NHEJ), the major repair pathway for DNA double-strand breaks (DSB) in mammalian cells, employs a repertoire of core proteins, the recruitment of which to DSB-ends is Ku-dependent. Lack of either of the core components invariably leads to a repair deficiency. There has been evidence that an alternative end-joining operates in the absence of the core components. We used chromosomal reporter substrates to specifically monitor NHEJ of single I-SceI-induced-DSB for detailed comparison of classical and alternative end-joining. We show that rapid repair of both compatible and non-compatible ends require Ku-protein. In the absence of Ku, cells use a slow but efficient repair mode which experiences increasing sequence-loss with time after DSB induction. Chemical inhibition and PARP1-depletion demonstrated that the alternative end-joining in vivo is completely dependent upon functional PARP1. Furthermore, we show that the requirement for PARP1 depends on the absence of Ku but not on DNA-dependent protein kinase (DNA-PKcs). Extensive sequencing of repair junctions revealed that the alternative rejoining does not require long microhomologies. Together, we show that mammalian cells need Ku for rapid and conservative NHEJ. PARP1-dependent alternative route may partially rescue the deficient repair phenotype presumably at the expense of an enhanced mutation rate. © The Author(s) 2010. Published by Oxford University Press.

Foeldvari I.,Medical School Hamburg
Current Rheumatology Reports | Year: 2015

Juvenile systemic sclerosis is an orphan disease of the macro- and microvasculature with an unknown etiology. Although pediatric and adult classification systems have been developed, neither has been validated yet. Recent publications have shown a shift in the subset pattern in juvenile-onset adult patients, with a better outcome in these patients as compared with young adult patients. As a first step in assessing activity, damage, and severity, a pediatric severity score—a modification of the adult Medsger scale—was proposed but has not been validated. An activity score also has been developed but has not yet been published. Currently, treatment approaches are based only on adult data, and problems exist in extrapolating these data to a pediatric population. © 2015, Springer Science+Business Media New York.

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