Time filter

Source Type

Kempermann G.,Deutsches Zentrum fur Neurodegenerative Erkrankungen DZNE | Kempermann G.,TU Dresden
Deutsche Zeitschrift fur Sportmedizin | Year: 2015

Neurodegenerative diseases, including Alzheimer’s disease, are complex multifactorial disorders. They are usually characterized by a chronic course of the disease and very long, clinically silent latency phase. This prolonged latency, during which the disease has not yet manifested itself, opens up the opportunity for targeted or general prevention. While there are to date hardly any lasting and causal therapeutic options for the most important neurodegenerative diseases, in the case of Alzheimer’s disease, for example, an estimated one third of the risk factors is potentially modifiable. Among these physical activity has a prominent position. Its relevance is very well documented, but many details, for example with respect to type and extent of sporting activity, remain unclear. The underlying mechanisms are poorly understood to date. Distinction between effects of actual sports and physical activity in daily living are difficult. The development of specific mechanistic hypotheses permits, however, to pursue more concrete and optimized lifestyle interventions. These hypotheses currently transform from the perception that the consequences of sports on the brain are simply positive side effects to the idea that here specific primary feedback mechanisms become visible, because nervous systems in the first place evolved to permit motility. In order to be successful with prevention, an early integration of sports and motility into the routines of daily life is required. From the perspective of sports medicine this opens important fields of activity, which are not fundamentally new but in the past have been little acknowledged. © 2015, WWF Verlagsgesellschaft mbH. All rights reserved. Source

Society paints an inconsistent picture of people with dementia: on the one hand they are people who can basically think and act (even) self-determinate. But on the other hand they need support and help from outside in daily routine. Self-help groups are a possible form of support. There are actually no research results to decide if this form of intervention is appropriate to people with dementia or not. The question must be answered in which way people in the early stage of dementia perceive their illness and what kind of influence the intervention of a support group has on their self-concept. In the first survey period five focus groups and eight narrative biographically oriented interviews are performed. The following results are noted: People with dementia are exposed to processes of incapacitation. It is well intentioned (in order to help them), but in reality they are forced to do something they probably don't like. They must bear unwanted interventions. In contrast, the self-help groups promote recognition processes. Finding internal security and being able to accept the illness are some of the most important functions. Independent living with dementia is supported. Two conclusions can be drawn: Forms of incapacitation from outside must be reduced. Self-help groups in a support role should accordingly supply the existing care services for people with dementia. The support of selfhelp groups should be the provision/ improvement of the existing care services for people with dementia. © 2013 Verlag Hans Huber, Hogrefe AG, Bern. Source

Henneberger C.,University of Bonn | Henneberger C.,University College London | Petzold G.C.,Deutsches Zentrum fur Neurodegenerative Erkrankungen DZNE
Neuroforum | Year: 2015

Fast signal exchange between neurons and astrocytes at the synaptic level has attracted considerable attention. Astrocytesoften respond with Ca2+ transients to widely different neuronal synaptic activity. At the same time, astrocyte Ca2+ elevations trigger profound and diverse changes of both excitatory and inhibitory synaptic transmission. Here, we briefly review examples of the heterogeneity of Ca2+-dependent astrocyte-neuron communication in the rodent hippocampus and discuss mechanisms that could maintain specificity of synaptic astrocyte-neuron signalling in the face of its diversity. © Springer-Verlag Berlin Heidelberg 2015. Source

Bano D.,Deutsches Zentrum fur Neurodegenerative Erkrankungen DZNE
Nucleus (Austin, Tex.) | Year: 2010

In eukaryotic cells, the exchange of molecules between the genetic material within the nucleus and the cytosol occurs through the Nuclear Pore Complex (NPC), which is a large membrane-embedded assembly composed by multiple proteins named nucleoporins arranged around an aqueous channel. The bi-directional passive diffusion and the active transport of factors across the nuclear envelope are responsible for a variety of biological processes and they are controlled respectively by the size of the pore and the interaction between nucleoporins and karyopherins. Thus, it is not surprising that most of the degenerative programs induce cellular stress by altering the NPC composition or the binding between nucleoporins and docking factors. This facilitates the access of nuclear DNA to pro-death factors, amplify the detrimental cascade and finally play a role in the disassembly of the nuclear structure. Recently, we have shown that during calcium-mediated neuronal degeneration NPC components can be degraded with consequent increase of NPC channel permeability. Moreover, we proved that these changes occurred much earlier than the final disassembly of the nuclear envelope and they are mediated by calcium overload. Is the increase of NPC leakiness the executioner of the excitotoxic process or simply a final event of a cell condemned to death? Here we speculate the consequence of the nucleoporin loss, the alteration of nucleocytoplasmic transport and their contribution to neuronal demise. Source

Functional magnetic resonance imaging and electrophysiology were combined to monitor blood oxygen level dependent (BOLD) signals in the entire rat brain and neuronal activities in the dentate gyrus during electrical stimulation of the right perforant pathway. In naïve, medetomidine sedated animals, stimulation of the fiber bundle with 15 trains (i.e. 8 bursts of 20 pulses given with 10 ms intervals, one burst per second, pulse width 0.2 ms) generated significant BOLD responses in the right hippocampal formation and the left entorhinal cortex. The stimulation condition also caused changes in the synaptic efficacy of perforant pathway granular cell synapses that lasted for at least one day. Rerun of the same experiment one day later resulted in a significantly increased electrophysiological response in the dentate gyrus and an increase of the BOLD response in the entire hippocampal formation. Consequently, long-lasting changes in synaptic efficacy go along with changes in the generated BOLD response. Additional electrical stimulations of the perforant pathway in the awake animal between the two fMRI experiments caused in the second fMRI measurement an increased BOLD response in the hippocampal formation and an appearance of significant BOLD responses in target regions of the hippocampus, such as the septum, nucleus accumbens (NAcc), and anterior cingulate cortex/medial prefrontal cortex/motor cortex (ACC/mPFC/MC) regions. Consequently, the efficacy of signal processing in and propagation through the hippocampus can be monitored by variations of the BOLD response in target regions of the hippocampus. Using the electrical perforant pathway stimulations as conditioned stimulus for an active avoidance task (shuttle box) caused a further spreading of the BOLD response in the hippocampus formation, septum and ACC/mPFC/MC but not in the NAcc. In addition, the magnitude of the BOLD response in the trained animals was further increased in the right and left hippocampus and the ACC/mPFC/MC region but not in the septum. These results demonstrate that in addition to general stimulus parameter the behavioral relevance of the stimulus controls the quality of the generated BOLD response. Copyright © 2013 Elsevier Inc. All rights reserved. Source

Discover hidden collaborations