Increased brain-derived neurotrophic factor (BDNF) protein concentrations in mice lacking brain serotonin

The interplay between BDNF signaling and the serotonergic system remains incompletely understood. Using a highly sensitive enzyme-linked immunosorbent assay, we studied BDNF concentrations in hippocampus and cortex of two mouse models of altered serotonin signaling: tryptophan hydroxylase (Tph)2-deficient (Tph2 (-/-)) mice lacking brain serotonin and serotonin transporter (SERT)-deficient (SERT(-/-)) mice lacking serotonin re-uptake. Surprisingly, hippocampal BDNF was significantly elevated in Tph2 (-/-) mice, whereas no significant changes were observed in SERT(-/-) mice. Furthermore, BDNF levels were increased in the prefrontal cortex of Tph2 (-/-) but not of SERT(-/-) mice. Our results emphasize the interaction between serotonin signaling and BDNF. Complete lack of brain serotonin induces BDNF expression

Brain serotonin critically contributes to the biological effects of electroconvulsive seizures

Compounds targeting serotonin (5-HT) are widely used as antidepressants. However, the role of 5-HT in mediating the effects of electroconvulsive seizure (ECS) therapy remains undefined. Using Tph2(-/-) mice depleted of brain 5-HT, we studied the effects of ECS on behavior and neurobiology. ECS significantly prolonged the start latency in the elevated O-Maze test, an effect that was abolished in Tph2(-/-) mice. Furthermore, in the absence of 5-HT, the ECS-induced increase in adult neurogenesis and in brain-derived neurotrophic factor signaling in the hippocampus were significantly reduced. Our results indicate that brain 5-HT critically contributes to the neurobiological responses to ECS

Validation of biological recognition elements for signal transduction as first step in the development of whole cell biosensors

Choosing the proper combination of receptor element, cell type and measurable signal requires major consideration for developing cell-based biosensors. In order to use physiologically relevant cellular responses towards (geno)toxic conditions, information on the mechanism of action and of the expected outcome of exposure needs to be considered

Streamlining scenario analysis and optimization of key choices in value chains using a modular LCA approach

Industrial Ecolog

Performance of Several Low‐Cost Accelerometers

Several groups are implementing low-cost host-operated systems of strong-motion accelerographs to support the somewhat divergent needs of seismologists and earthquake engineers. The Advanced National Seismic System Technical Implementation Committee (ANSS TIC, 2002), managed by the U.S. Geological Survey (USGS) in cooperation with other network operators, is exploring the efficacy of such systems if used in ANSS networks. To this end, ANSS convened a working group to explore available Class C strong-motion accelerometers (defined later), and to consider operational and quality control issues, and the means of annotating, storing, and using such data in ANSS networks. The working group members are largely coincident with our author list, and this report informs instrument-performance matters in the working group’s report to ANSS. Present examples of operational networks of such devices are the Community Seismic Network (CSN; csn.caltech.edu), operated by the California Institute of Technology, and Quake-Catcher Network (QCN; Cochran et al., 2009; qcn.stanford.edu; November 2013), jointly operated by Stanford University and the USGS. Several similar efforts are in development at other institutions. The overarching goals of such efforts are to add spatial density to existing Class-A and Class-B (see next paragraph) networks at low cost, and to include many additional people so they become invested in the issues of earthquakes, their measurement, and the damage they cause

Coherence length of an elongated condensate: a study by matter-wave interferometry

We measure the spatial correlation function of Bose-Einstein condensates in the cross-over region between phase-coherent and strongly phase-fluctuating condensates. We observe the continuous path from a gaussian-like shape to an exponential-like shape characteristic of one-dimensional phase-fluctuations. The width of the spatial correlation function as a function of the temperature shows that the condensate coherence length undergoes no sharp transition between these two regimes.Comment: 8 pages, 6 figure, submitted to EPJ

Spatially explicit LCA analysis of biodiversity losses due to different bioenergy policies in the European Union

In this study, the potential global loss of species directly associated with land use in the EU and due to trade with other regions is computed over time, in order to reveal differences in impacts between the considered alternatives of plausible bioenergy policies development in the EU. The spatially explicit study combines a life cycle analysis (LCA) for biodiversity impact assessment with a global high resolution economic land use model. Both impacts of domestic land use and impacts through imports were included for estimating the biodiversity footprint of the member states of the (EU28). The analyzed scenarios assumed similar biomass demand until 2020 but differed thereafter, from keeping the growth of demand for bioenergy constant (CONST), to a strong increase of bioenergy in line with the EU target of decreasing greenhouse gas (GHG) emissions by 80% by 2050 (EMIRED) and with the baseline (BASE) scenario falling between the other two. As a general trend, the increasing demand for biomass was found to have substantial impact on biodiversity in all scenarios, while the differences between the scenarios were found to be modest. The share caused by imports was 15% of the overall biodiversity impacts detected in this study in the year 2000, and progressively increased to 24% to 26% in 2050, depending on the scenario. The most prominent future change in domestic land use in all scenarios was the expansion of perennial cultivations for energy. In the EMIRED scenario, there is a larger expansion of perennial cultivations and a smaller expansion of cropland in the EU than in the other two scenarios. As the biodiversity damage is smaller for land used for perennial cultivations than for cropland, this development decreases the internal biodiversity damage per unit of land. At the same time, however, the EMIRED scenario also features the largest outsourcing of damage, due to increased import of cropland products from outside the EU for satisfying the EU food demand. These two opposite effects even out each other, resulting in the total biodiversity damage for the EMIRED scenario being only slightly higher than the other two scenarios. The results of this study indicate that increasing cultivation of perennials for bioenergy and the consequent decrease in the availability of cropland for food production in the EU may lead to outsourcing of agricultural products supply to other regions. This development is associated with a leakage of biodiversity damages to species-rich and vulnerable regions outside the EU. In the case of a future increase in bioenergy demand, the combination of biomass supply from sustainable forest management in the EU, combined with imported wood pellets and cultivation of perennial energy crops, appears to be less detrimental to biodiversity than expansion of energy crops in the EU

Probing structural relaxation in complex fluids by critical fluctuations

Complex fluids, such as polymer solutions and blends, colloids and gels, are of growing interest in fundamental and applied soft-condensed-matter science. A common feature of all such systems is the presence of a mesoscopic structural length scale intermediate between atomic and macroscopic scales. This mesoscopic structure of complex fluids is often fragile and sensitive to external perturbations. Complex fluids are frequently viscoelastic (showing a combination of viscous and elastic behaviour) with their dynamic response depending on the time and length scales. Recently, non-invasive methods to infer the rheological response of complex fluids have gained popularity through the technique of microrheology, where the diffusion of probe spheres in a viscoelastic fluid is monitored with the aid of light scattering or microscopy. Here we propose an alternative to traditional microrheology that does not require doping of probe particles in the fluid (which can sometimes drastically alter the molecular environment). Instead, our proposed method makes use of the phenomenon of "avoided crossing" between modes associated with the structural relaxation and critical fluctuations that are spontaneously generated in the system.Comment: 4 pages, 4 figure

Mice with genetically altered glucocorticoid receptor expression show altered sensitivity for stress-induced depressive reactions

Altered glucocorticoid receptor (GR) signaling is a postulated mechanism for the pathogenesis of major depression. To mimic the human situation of altered GR function claimed for depression, we generated mouse strains that underexpress or overexpress GR, but maintain the regulatory genetic context controlling the GR gene. To achieve this goal, we used the following: (1) GR-heterozygous mutant mice (GR+/-) with a 50% GR gene dose reduction, and (2) mice overexpressing GR by a yeast artificial chromosome resulting in a twofold gene dose elevation. GR+/- mice exhibit normal baseline behaviors but demonstrate increased helplessness after stress exposure, a behavioral correlate of depression in mice. Similar to depressed patients, GR+/- mice have a disinhibited hypothalamic-pituitary-adrenal (HPA) system and a pathological dexamethasone/corticotropin-releasing hormone test. Thus, they represent a murine depression model with good face and construct validity. Overexpression of GR in mice evokes reduced helplessness after stress exposure, and an enhanced HPA system feedback regulation. Therefore, they may represent a model for a stress-resistant strain. These mouse models can now be used to study biological changes underlying the pathogenesis of depressive disorders. As a first potential molecular correlate for such changes, we identified a downregulation of BDNF protein content in the hippocampus of GR+/- mice, which is in agreement with the so-called neurotrophin hypothesis of depression