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

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

Width of the QCD transition in a Polyakov-loop DSE model

We consider the pseudocritical temperatures for the chiral and deconfinement transitions within a Polyakov-loop Dyson-Schwinger equation approach which employs a nonlocal rank-2 separable model for the effective gluon propagator. These pseudocritical temperatures differ by a factor of two when the quark and gluon sectors are considered separately, but get synchronized and become coincident when their coupling is switched on. The coupling of the Polyakov-loop to the chiral quark dynamics narrows the temperature region of the QCD transition in which chiral symmetry and deconfinement is established. We investigate the effect of rescaling the parameter T_0 in the Polyakov-loop potential on the QCD transition for both the logarithmic and polynomial forms of the potential. While the critical temperatures vary in a similar way, the width of the transition is stronger affected for the logarithmic potential. For this potential the character of the transition changes from crossover to a first order one when T_0 < 210 MeV, but it remains crossover in the whole range of relevant T_0 values for the polynomial form.Comment: 10 pages, 6 figures, results for polynomial form of Polyakov-loop potential included, references added, final version to appear in Phys. Rev.

Probing the QCD Equation of State

We propose a novel quasiparticle interpretation of the equation of state of deconfined QCD at finite temperature. Using appropriate thermal masses, we introduce a phenomenological parametrisation of the onset of confinement in the vicinity of the phase transition. Lattice results of bulk thermodynamic quantities are well reproduced, the extension to small quark chemical potential is also successful. We then apply the model to dilepton production and charm suppression in ultrarelativistic heavy-ion collisions.Comment: 6 pages, 8 figures. Invited talk presented by R. A. Schneider at the XVI International Conference on Particles and Nuclei (PANIC02), Osaka, Japan, September 30 - October 4, 200