Editorial: Neuroplasticity and Extracellular Proteolysis

Neuroplasticity refers to the ability of the Central Nervous System (CNS) to alter its structure and function in response to a variety of physiological and pathological processes such as development, cognition, injury or neurological diseases. Since more than four decades, studies on synaptic plasticity in the context of memory and learning attracted a remarkable interest. Soon after first seminal works on synaptic plasticity were published, research in this field was extended by studies on non-synaptic as wells as structural plasticity towards a goal to understand cellular and molecular determinants of cognition. Over the past two decades, yet two additional crucial players in neuroplastic phenomena started to be intensely investigated – glial cells and the extracellular matrix (ECM). Growing awareness that glial cells, especially astrocytes, are important regulators of synaptic functions gave rise to a novel concept of a tri-partite synapse. Also, over the last two decades, a growing body of evidence has accumulated that the extracellular matrix (ECM) in the brain is strongly involved in regulation of neurons, in particular, in synaptic plasticity. Thus, a concept of tetra-partite synapse was put forward by some neuroscientists. The cross-talk between neuron-glia-ECM system involves enzymatic degradation of proteins or peptides and amino acids occurring in each of these brain constituents by means of a variety of proteases. Importantly, it has been realized that proteases such as serine proteases and matrix metalloproteinases, not only accompany “robust” phenomena such as cell division, or development or neurodegnerative conditions but may play a very subtle signaling functions, particularly important in memory acquisition. Indeed, the repertoire of substrates for these enzymes covers a wide variety of proteins known to play important role in the neuroplastic phenomena (e.g. BDNF, TNF-a, ephrin systems, various cell adhesion molecules, etc.). In result, the role of metalloproteinases and such serine proteases as tissue plasminogen activator (tPA), neuropsin or neurotrypsin in synaptic plasticity as well as in learning and memory has been particularly well demonstrated. It needs to be emphasized, however, that in spite of a remarkable progress in this field, several basic questions regarding molecular and cellular mechanisms remain unanswered. Potential involvement of so many important players (various proteases and their substrates in neurons, glia and in ECM) points to an enormous potential for plasticity phenomena but makes also studies into underlying mechanisms particularly difficult. In the proposed Research Topic we provide both review of the current state of the art and present some original reports on specific aspects of the role of proteolysis in neuroplasticity phenomena. The present ebook starts with extensive reviews describing involvement of proteolysis not only in synaptic plasticity but also in regulating endogenous excitability and structural changes at the network, cellular and subcellular levels. Cross-talk between neuroplasticity and proteolysis is also emphasized in the context of development and in relation to various pathologies. Whereas in the first part of the present ebook, the major focus is on metalloproteinases, the successive articles address the role of neuropsin and thrombin. The Research Topic is concluded with a series of articles describing the components of extracellular matrix and adhesion proteins and their elaboration by mechanisms dependent directly or indirectly on proteolysis. We do hope that the present ebook will further stimulate the interest in the fascinating investigations into neuroplasticity-proteolysis cross-talk

New records of tardigrades from China, with zoogeographical remarks

Tardigrades are small (0.05-1.20 mm), hygrophilous micrometazoans. This paper reports on 18 species of tardigrades found in Sichuan, Yunnan, and Xizang Provinces in China, primarily in lichens and mosses. Eight species are new records for China: Echiniscus nepalensis Dastych, E. reticulatus Murray, E. spiniger Richters, Isohypsibius sattleri (Richters), Diphascon (D.) pingue (Marcus), Diphascon (A.) prorsirostre Thulin, Mesocrista spitsbergensis (Richters), and Platicrista angustata (Murray). Two species are new records for both Sichuan and Yunnan: Minibiotus intermedius (Plate) and Hypsibius pallidus Thulin; one species is new for Sichuan: Pseudechiniscus suillus (Ehrenberg); and three species are new for Yunnan: Cornechiniscus lobatus (Ramazzotti), Pseudechiniscus jiroveci Bartoš , and Doryphoribius flavus (Iharos). This and previous papers have reported on 86 species and subspecies of Tardigrada from China. This is only ca. 9% of the world limno-terrestrial and marine fauna of water bears. Among these 86 species only one is marine, three are found in freshwaters, and the others are terrestrial

Redescription of Doryphoribius vietnamensis (Iharos, 1969) (Tardigrada) comb. nov. on the basis of the holotype and additional material from China

Hypsibius vietnamensis IHAROS, 1969 was described from Huong tich, 60 km south-west of Hanoi in Vietnam. RAMAZZOTTI andMAUCCI (1983) transferred it to the genus Isohypsibius on the basis of drawings of claws. BEASLEY and CLEVELAND (1996) reported Isohypsibius vietnamensis (IHAROS, 1969) from Yunnan Province in China. We have re-examined specimens described by IHAROS (holotype) and those from China and determined that they should be transferred to the genus Doryphoribius due to their bucco-pharyngeal apparatus structure. Many years ago Hypsibius (Isohypsibius) flavus IHAROS 1966 was also transferred to the genus Doryphoribius SCHUSTER and TOFTNER (1982). It may suggest that some other species of genus Isohypsibius should also by transferred to genus Doryphoribius. Genus Doryphoribius differs from Isohypsibius by the presence of the ventral reinforcement bar on the buccal tube

Quasi-static probes of the QCD plasma

Screening correlators and masses were studied at finite temperature in QCD with two flavours of dynamical staggered quarks on a lattice. The spectrum of screening masses show a hierarchical approach to chiral symmetry restoration. Control of explicit chiral symmetry breaking through the quark mass was shown to be an important step to understanding this phenomenon. No sign of decays was found in the finite temperature scalar meson-like correlators in the confined phase

Influence of purge, time of waiting and TiCl4 dosing time in a low-pressure atomic layer deposition (ALD) reactor on properties of TiO2 layer

The aim of the study was to evaluate the influence of the ALD process parameters on mechanical properties and corrosion resistance of TiO2 layer. The TiO2 layer was deposited on stainless steel surfaces at constant temperature T = 200 °C and number of cycles nc = 500 (g ≈ 25 nm). The applied methodology consisted of potentiodynamic and impedance studies, as well as adhesion test. The obtained results were the basis for selection of surface treatment method for stainless steel implants for contact with blood. Appropriate parameters of surface treatment realized by means of the ALD method is of significant importance. It will contribute to the development of technological conditions of specified deposition parameters of TiO2 layers on steel implants

Influence of purge, time of waiting and TiCl4 dosing time in a low-pressure atomic layer deposition (ALD) reactor on properties of TiO2 layer

The aim of the study was to evaluate the influence of the ALD process parameters on mechanical properties and corrosion resistance of TiO2 layer. The TiO2 layer was deposited on stainless steel surfaces at constant temperature T = 200 °C and number of cycles nc = 500 (g ≈ 25 nm). The applied methodology consisted of potentiodynamic and impedance studies, as well as adhesion test. The obtained results were the basis for selection of surface treatment method for stainless steel implants for contact with blood. Appropriate parameters of surface treatment realized by means of the ALD method is of significant importance. It will contribute to the development of technological conditions of specified deposition parameters of TiO2 layers on steel implants

Magnetoelectricity at room temperature in Bi0.9-xTbxLa0.1FeO3 system

Magnetoelectric compounds with the general formula, Bi0.9-xRxLa0.1FeO3 (R =Gd, Tb, Dy, etc.), have been synthesized. These show the coexistence of ferroelectricity and magnetism, possess high dielectric constant and exhibit magnetoelectric coupling at room temperature. Such materials may be of great significance in basic as well as applied research.Comment: 11 pages of text and figure