Observation of own exploration movements impairs haptic spatial perception

The present study was designed to assess whether the visibility of ones’ own exploratory movements impairs or enhances perceptual speed and precision of haptic stimuli with varying complexity. Previous studies have shown that noninformative vision of steady surroundings improves haptic spatial perception. However, due to the serial nature of haptic processing and limited capacity of working memory resources, we hypothesized that noninformative vision of limb movements may impair haptic perception. The study sample consisted of ninety-eight healthy adults who were randomized into two groups, matched for sex and age. Participants were required to explore two-dimensional haptic stimuli with varying complexity and to recognize them visually. The difference between the two experimental groups was a screen that would prevent the participants from viewing their hands during exploration in the nonobservation condition (NonOb). The other half of participants were able to see their hands in the manual movement observation condition (MovOb) thanks to the special design of the stimuli. As hypothesized, the persons in the MovOb condition made significantly more errors. The difference in error frequency between participants of the MovOb and NonOb condition was greater for complex stimuli than for simple ones. These results suggest that incoming visual information about own manual exploration movements increases competitive pressure for limited working memory resources, and therefore, more recognition errors are made. Covering the hands during exploration may constitute a helpful simplification of the task’s demands by supporting the maintenance of information in working memory. Additionally, the relation of haptic complexity and stimulus characteristics was analyzed.     

Surface expression and function of Cav3.2 T-type calcium channels are controlled by asparagine-linked glycosylation

Low-voltage-activated T-type calcium channels play important roles in neuronal physiology where they control cellular excitability and synaptic transmission. Alteration in T-type channel expression has been linked to various pathophysiological conditions such as pain arising from diabetic neuropathy. In the present study, we looked at the role of asparagine (N)-linked glycosylation on human Ca_v3.2 T-type channel expression and function. Manipulation of N-glycans on cells expressing a recombinant Ca_v3.2 channel revealed that N-linked glycosylation is critical for proper functional expression of the channel. Using site-directed mutagenesis to disrupt the canonical N-linked glycosylation sites of Ca_v3.2 channel, we show that glycosylation at asparagine N192 is critical for channel expression at the surface, whereas glycosylation at asparagine N1466 controls channel activity. Moreover, we demonstrate that N-linked glycosylation of Ca_v3.2 not only controls surface expression and activity of the channel but also underlies glucose-dependent potentiation of T-type Ca²⁺ current. Our data suggest that N-linked glycosylation of T-type channels may play an important role in aberrant upregulation of T-type channel activity in response to glucose elevations.     

Inhibition of BMP activity protects epithelial barrier function in lung injury

Epithelial injury is a central finding in pulmonary disease and is accompanied by disruption of epithelial barrier function, leading to pulmonary oedema and inflammation. Injured epithelial cells lose their properties and gain mesenchymal characteristics, a phenotypic switch that contributes to lung remodelling after injury. Here we studied bone morphogenetic protein (BMP) signalling and, in particular, the role of BMP2 and the BMP modulator BMPER in injured lung epithelium. Increased BMP activity, reflected by up‐regulation of the Smad1/5–Id1 axis, is detected after injury of lung epithelium in vitro and in vivo. Two members of the BMP family, BMP2 and BMPER, have opposing effects. BMP2 is up‐regulated after epithelial injury and causes epithelial dysfunction and hyperpermeability, mediated by the Smad1/5–Id1‐dependent down‐regulation of E‐cadherin. In contrast, BMPER expression is decreased following injury, which in turn impairs epithelial integrity, characterized by reduction of E‐cadherin and epithelial leakage in vitro and in vivo. High levels of BMPER antagonized BMP2‐Smad5–Id1 signalling and prevented BMP2‐mediated decrease of E‐cadherin and hyperpermeability, suggesting that BMPER restores epithelial homeostasis. Supporting this notion, pharmacological inhibition of BMP signalling by LDN193189 prevented reduction of E‐cadherin and disruption of epithelial barrier function. Inhibition of excessive BMP activation could be a new approach to restore epithelial integrity and prevent disruption of epithelial barrier function after lung injury. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Postmortem age estimation via DNA methylation analysis in buccal swabs from corpses in different stages of decomposition—a “proof of principle” study

International Journal of Legal Medicine - Age estimation based on the analysis of DNA methylation patterns has become a focus of forensic research within the past few years. However, there is...     

Metabolomics in postmortem cerebrospinal fluid diagnostics: a state-of-the-art method to interpret central nervous system–related pathological processes

International Journal of Legal Medicine - In the last few years, quantitative analysis of metabolites in body fluids using LC/MS has become an established method in laboratory medicine and...