Time filter

Source Type

Zürich, Switzerland

Groch S.,University of Tubingen | Groch S.,University of Lubeck | Wilhelm I.,University of Zuerich | Lange T.,University of Lubeck | And 2 more authors.

Corticosteroids are known to modulate the consolidation of memories during sleep, specifically in the hippocampus-dependent declarative memory system. However, effects of the major human corticosteroid cortisol are conveyed via two different receptors, i.e., mineralocorticoid (MRs) and glucocorticoid receptors (GRs) whose specific contributions to memory consolidation are unclear. Whereas a shift in the balance between MR and GR activation toward predominant GR activation has been found to impair sleep-dependent consolidation of declarative memories, the effect of predominant MR activation is not well characterized. Here, we examined differential corticosteroid receptor contributions to memory consolidation during post-learning sleep in two placebo-controlled double-blind studies in humans, by comparing the effects of the selective MR agonist fludrocortisone (0.2. mg, orally, Study 1) and of hydrocortisone (22. mg, intravenously, Study 2) with strong binding affinity to both MR and GR. We hypothesized increased activation of MRs during sleep to enhance declarative memory consolidation, but the joint MR/GR activation to impair it. Participants (16 men in each study) learned a declarative (word pair associates) and a procedural task (mirror tracing) before a 7-h period of nocturnal retention sleep, with the substances administered before sleep (Study 1) and during sleep (Study 2), respectively. As hypothesized, retention of word pairs, but not of mirror tracing skill, was selectively enhanced by the MR agonist fludrocortisone. An impairing effect of hydrocortisone on word pair retention remained non-significant possibly reflecting that hydrocortisone administration failed to establish robust predominance of GR activation. Our results show that predominant MR activation benefits declarative memory consolidation presumably by enhancing the sleep-dependent reactivation of hippocampal memories and resultant synaptic plastic processes. The effect is counteracted by additional GR activation. Insufficient MR activation, like GR overactivation, might be a factor contributing to memory impairment in pathological conditions. © 2013 Elsevier Ltd. Source

Gabriel B.,University of Georgia | Beach S.R.H.,University of Georgia | Bodenmann G.,University of Zuerich
Behavior Therapy

The correlation between depression and dysfunctional marital interaction is well documented, but only a few studies have examined gender-related differences in marital interaction patterns of couples with a depressed partner. In this paper we examined differences in observed marital communication in a sample of 62 Swiss couples presenting for treatment of depression. There were 16 maritally distressed couples with a depressed wife, 21 maritally nondistressed couples with a depressed wife, 18 maritally distressed couples with a depressed husband, and 7 maritally nondistressed couples with a depressed husband. Marital interaction behavior was found to depend on gender, depression, marital distress, as well as gender of the depressed partner. Our results suggest the need for a gender-sensitive model of the link between marital interaction and depression. © 2008. Source

Li C.,European Bioinformatics Institute | Liakata M.,European Bioinformatics Institute | Liakata M.,University of Warwick | Rebholz-Schuhmann D.,European Bioinformatics Institute | Rebholz-Schuhmann D.,University of Zuerich
Briefings in Bioinformatics

Networks of molecular interactions explain complex biological processes, and all known information on molecular events is contained in a number of public repositories including the scientific literature. Metabolic and signalling pathways are often viewed separately, even though both types are composed of interactions involving proteins and other chemical entities. It is necessary to be able to combine data from all available resources to judge the functionality, complexity and completeness of any given network overall, but especially the full integration of relevant information from the scientific literature is still an ongoing and complex task. Currently, the text-mining research community is steadily moving towards processing the full body of the scientific literature by making use of rich linguistic features such as full text parsing, to extract biological interactions. The next step will be to combine these with information from scientific databases to support hypothesis generation for the discovery of new knowledge and the extension of biological networks. The generation of comprehensive networks requires technologies such as entity grounding, coordination resolution and co-reference resolution, which are not fully solved and are required to further improve the quality of results. Here, we analyse the state of the art for the extraction of network information from the scientific literature and the evaluation of extraction methods against reference corpora, discuss challenges involved and identify directions for future research. © The Author 2013. Source

Ziegler G.,Friedrich - Schiller University of Jena | Dahnke R.,Friedrich - Schiller University of Jena | Jancke L.,University of Zuerich | Yotter R.A.,Friedrich - Schiller University of Jena | And 2 more authors.
Human Brain Mapping

The aim of this large-sample cross-sectional voxel-based morphometry (VBM) study of anatomical brain data was to investigate linear and nonlinear age-related trajectories of grey matter volume in the human brain during the adult lifespan. To date, there are only a few structural brain studies investigating local nonlinear aspects at the voxel level, i.e., without using anatomical ROIs as a priori hypothesis. Therefore, we analyzed 547 T1-weighted MR images of healthy adult brains with an age range of 19 to 86 years, including 161 scans of subjects with ages 60 and older. We found that the gray matter volume in some regions did not linearly decrease over time, but rather exhibited a delayed decline. Nonlinear age trajectories were observed in the medial temporal lobe regions, the basal ganglia, and parts of the cerebellum. Their trajectories indicated a preservation of grey matter volume during the early adult lifespan. Interestingly, we found nonlinear grey matter structural dynamics specifically in parts of the brain that have been extensively discussed in the context of learning and memory. We propose a hypothesis in relation to the functional role of these brain regions that may explain these results. © 2011 Wiley Periodicals, Inc. Source

Langguth B.,University of Regensburg | Landgrebe M.,University of Regensburg | Kleinjung T.,University of Regensburg | Kleinjung T.,University of Zuerich | And 2 more authors.
World Journal of Biological Psychiatry

Objectives. Depressive symptoms are common in individuals with tinnitus and may substantially aggravate their distress. The mechanisms, however, by which depression and tinnitus mutually interact are still not fully understood. Methods. Here we review neurobiological knowledge relevant for the interplay between depression and tinnitus. Results. Neuroimaging studies confirm the existence of neural circuits that are activated both in depression and tinnitus. Studies of neuroendocrine function demonstrate alterations of the HPA-axis in depression and, more recently, in tinnitus. Studies addressing neurotransmission suggest that the dorsal cochlear nucleus that is typically hyperactive in tinnitus, is also involved in the control of attention and emotional responses via projections to the locus coeruleus, the reticular formation and the raphe nuclei. Impaired hippocampal neurogenesis has been documented in animals with tinnitus after noise trauma, as in animal models of depression. Finally, from investigations of human candidate genes, there is some evidence to suggest that variant BDNF may act as a common susceptibility factor in both disorders. Conclusions. These parallels in the pathophysiology of tinnitus and depression argue against comorbidity by chance and against depression as pure reaction on tinnitus. Instead, they stand for a complex interplay between tinnitus and depression. Implications for tinnitus treatment are discussed. © 2011 Informa Healthcare. Source

Discover hidden collaborations