Anodic growth of nanoporous tin oxide layers in acidic electrolytes

The aim of this work was to synthesize SnO2 nanostructures with various morphologies by simple anodic oxidation (anodization) of metallic tin in acidic electrolytes. A series of Sn foil anodizations was performed in different electrolytes (oxalic acid, citric acid, tartaric acid) with various concentrations. It was confirmed that anodic oxidation of tin in the oxalic acid results in the formation of nanoporous oxide layers with completely open pores on the surface of the electrode. On the other hand, when citric acid or tartaric acid were used as an electrolyte, porous oxide with a compact layer on the surface was formed during electrolysis

Experience-Dependent Plasticity and Modulation of Growth Regulatory Molecules at Central Synapses

Structural remodeling or repair of neural circuits depends on the balance between intrinsic neuronal properties and regulatory cues present in the surrounding microenvironment. These processes are also influenced by experience, but it is still unclear how external stimuli modulate growth-regulatory mechanisms in the central nervous system. We asked whether environmental stimulation promotes neuronal plasticity by modifying the expression of growth-inhibitory molecules, specifically those of the extracellular matrix. We examined the effects of an enriched environment on neuritic remodeling and modulation of perineuronal nets in the deep cerebellar nuclei of adult mice. Perineuronal nets are meshworks of extracellular matrix that enwrap the neuronal perikaryon and restrict plasticity in the adult CNS. We found that exposure to an enriched environment induces significant morphological changes of Purkinje and precerebellar axon terminals in the cerebellar nuclei, accompanied by a conspicuous reduction of perineuronal nets. In the animals reared in an enriched environment, cerebellar nuclear neurons show decreased expression of mRNAs coding for key matrix components (as shown by real time PCR experiments), and enhanced activity of matrix degrading enzymes (matrix metalloproteinases 2 and 9), which was assessed by in situ zymography. Accordingly, we found that in mutant mice lacking a crucial perineuronal net component, cartilage link protein 1, perineuronal nets around cerebellar neurons are disrupted and plasticity of Purkinje cell terminal is enhanced. Moreover, all the effects of environmental stimulation are amplified if the afferent Purkinje axons are endowed with enhanced intrinsic growth capabilities, induced by overexpression of GAP-43. Our observations show that the maintenance and growth-inhibitory function of perineuronal nets are regulated by a dynamic interplay between pre- and postsynaptic neurons. External stimuli act on this interaction and shift the balance between synthesis and removal of matrix components in order to facilitate neuritic growth by locally dampening the activity of inhibitory cues

Blocking human fear memory with the matrix metalloproteinase inhibitor doxycycline

Learning to predict threat is a fundamental ability of many biological organisms, and a laboratory model for anxiety disorders. Interfering with such memories in humans would be of high clinical relevance. On the basis of studies in cell cultures and slice preparations, it is hypothesised that synaptic remodelling required for threat learning involves the extracellular enzyme matrix metalloproteinase (MMP) 9. However, in vivo evidence for this proposal is lacking. Here we investigate human Pavlovian fear conditioning under the blood-brain barrier crossing MMP inhibitor doxycyline in a pre-registered, randomised, double-blind, placebo-controlled trial. We find that recall of threat memory, measured with fear-potentiated startle 7 days after acquisition, is attenuated by ~60% in individuals who were under doxycycline during acquisition. This threat memory impairment is also reflected in increased behavioural surprise signals to the conditioned stimulus during subsequent re-learning, and already late during initial acquisition. Our findings support an emerging view that extracellular signalling pathways are crucially required for threat memory formation. Furthermore, they suggest novel pharmacological methods for primary prevention and treatment of posttraumatic stress disorder.Molecular Psychiatry advance online publication, 4 April 2017; doi:10.1038/mp.2017.65

Fine-structural distribution of MMP-2 and MMP-9 activities in the rat skeletal muscle upon training: a study by high-resolution in situ zymography

Matrix metalloproteinases (MMPs) are key regulators of extracellular matrix remodeling, but have also important intracellular targets. The purpose of this study was to examine the activity and subcellular localization of the gelatinases MMP-2 and MMP-9 in skeletal muscle of control and physically trained rats. In control hind limb muscle, the activity of the gelatinases was barely detectable. In contrast, after 5 days of intense exercise, in Soleus (Sol), but not Extensor digitorum longus (EDL) muscle, significant upregulation of gelatinolytic activity in myofibers was observed mainly in the nuclei, as assessed by high resolution in situ zymography. The nuclei of quiescent satellite cells did not contain the activity. Within the myonuclei, the gelatinolytic activity colocalized with an activated RNA Polymerase II. Also in Sol, but not in EDL, there were few foci of mononuclear cells with strongly positive cytoplasm, associated with apparent necrotic myofibers. These cells were identified as activated satellite cells/myoblasts. No extracellular gelatinase activity was observed. Gel zymography combined with subcellular fractionation revealed training-related upregulation of active MMP-2 in the nuclear fraction, and increase of active MMP-9 in the cytoplasmic fraction of Sol. Using RT-PCR, selective increase in MMP-9 mRNA was observed. We conclude that training activates nuclear MMP-2, and increases expression and activity of cytoplasmic MMP-9 in Sol, but not in EDL. Our results suggest that the gelatinases are involved in muscle adaptation to training, and that MMP-2 may play a novel role in myonuclear functions

The role of open-air inhalatoria in the air quality improvement in spa towns

Objectives: The present study was aimed at evaluating microbiological contamination of air in Ciechocinek and Ino­wro­cław – Polish lowland spa towns. Additionally, the impact of open-air inhalatoria on the quality of air was evaluated. Material and Methods: Air samples were collected seasonally in the urban areas, in the recreation areas and in the vicinity of inhalatoria in both towns using impaction. The numbers of mesophilic bacteria, staphylococci, hemolytic bacteria and actinomycetes were determined on media according to the Polish Standard PN-86/Z-04111/02. The number of moulds was determined on media according to the Polish Standard PN-86/Z-04111/03. Results: While the highest numbers of microorganisms were noted at the sites located in the urban areas, the lowest numbers were noted in the vicinity of the open-air inhalatoria. In all the investigated air samples the values of bioaerosol concentrations were below the recommended TLVs (≤ 5000 CFU×m–3 for both bacteria and fungi in outdoor environments). Location of the sampling site was invariably a decisive factor in determining the number of microorganisms in the air. Conclusions: The aerosol which is formed in the open-air inhalatoria has a positive influence on microbiological air quality. Owing to a unique microclimate and low air contamination, Ciechocinek and Inowrocław comply with all necessary requirements set for health resorts specializing in treating upper respiratory tract infections