Parametric study of EEG sensitivity to phase noise during face processing

Background

The zitter (zi/zi) rat, a loss-of-function mutant of the glycosylated transmembrane protein attractin (atrn), exhibits widespread age-dependent spongiform degeneration, hypomyelination, and abnormal metabolism of reactive oxygen species (ROS) in the brain. To date, the mechanisms underlying these phenotypes have remained unclear.

Results

Here, we show differentiation defects in zi/zi oligodendrocytes, accompanied by aberrant extension of cell-processes and hypomyelination. Axonal bundles were relatively preserved during postnatal development. With increasing in age, the injured oligodendrocytes in zi/zi rats become pathological, as evidenced by the accumulation of iron in their cell bodies. Immunohistochemical analysis revealed that atrn expression was absent from an oligodendrocyte lineage, including A2B5-positive progenitors and CNPase-positive differentiated cells. The number and distribution of Olig2-positive oligodendrocyte progenitors was unchanged in the zi/zi brain. Furthermore, an in vitro differentiation assay of cultured oligodendrocyte progenitors prepared from zi/zi brains revealed their normal competence for proliferation and differentiation into mature oligodendrocytes. Interestingly, we demonstrated the accelerated recruitment of ED1-positive macrophages/microglia to the developing zi/zi brain parenchyma prior to the onset of hypomyelination. Semiquantitative RT-PCR analysis revealed a significant up-regulation of CD26 and IL1-β in the zi/zi brain during this early postnatal stage.

Conclusion

We demonstrated that the onset of the impairment of oligodendrocyte differentiation occurs in a non-cell autonomous manner in zi/zi rats. Hypomyelination of oligodendrocytes was not due to a failure of the intrinsic program of oligodendrocytes, but rather, was caused by extrinsic factors that interrupt oligodendrocyte development. It is likely that macrophage/microglial activation in the zi/zi CNS leads to disturbances in oligodendrocyte differentiation via deleterious extrinsic factors, such as the cytokine IL1-β or ROS. Atrn might be involved in the activation of brain macrophages/microglia by suppressing excessive migration of monocytes into the CNS, or by accelerating the transformation of brain monocytes into resting microglia. Understanding the pathogenesis of the zi/zi rat may provide novel insights into the developmental interaction betweens macrophages/microglia and cells of an oligodendrocyte lineage.     

Adaptive behaviour of the spinal cord in the transition from quiet stance to walking

Background

Parkinson??s disease is characterized by a continuous loss of neurons within the substantia nigra (SN) leading to a depletion of dopamine. Within the adult SN as a non-neurogenic region, cells with mainly oligodendrocytic precursor characteristics, expressing the neuro-glial antigen-2 (NG2) are continuously generated. Proliferation of these cells is altered in animal models of Parkinson??s disease (PD). Exercise and environmental enrichment re-increase proliferation of NG2⁺ cells in PD models, however, a possible mechanistic role of dopamine for this increase is not completely understood. NG2⁺ cells can differentiate into oligodendrocytes but also into microglia and neurons as observed in vitro suggesting a possible hint for endogenous regenerative capacity of the SN. We investigated the role of dopamine in NG2-generation and differentiation in the adult SN stimulated by physical activity and environmental enrichment.

Results

We used the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-model for dopamine depletion and analysed newborn cells in the SN at different maturation stages and time points depending on voluntary physical activity, enriched environment and levodopa-treatment. We describe an activity- induced increase of new NG2-positive cells and also mature oligodendrocytes in the SN of healthy mice. Running and enriched environment refused to stimulate NG2-generation and oligodendrogenesis in MPTP-mice, an effect which could be reversed by pharmacological levodopa-induced rescue.

Conclusion

We suggest dopamine being a key regulator for activity-induced generation of NG2-cells and oliogodendrocytes in the SN as a potentially relevant mechanism in endogenous nigral cellular plasticity.     

A novel and facile synthesis of N-cyclohexyl-benzofurans by one-pot three-component reaction

Abstract  

A simple and efficient synthesis of N-cyclohexyl-benzofuran derivatives was achieved via a one-pot three-component reaction of cyclohexylisocyanide, an aromatic aldehydes, and phenols in DMF for 10 h with good yields.     

Growth Cone Pathfinding: a competition between deterministic and stochastic events

Background  

Growth cone migratory patterns show evidence of both deterministic and stochastic search modes.     

Levamizole enhances immune responsiveness to intra-dermal and intra-muscular hepatitis B vaccination in chronic hemodialysis patients

Background  

Hemodialysis patient are at high risk for hepatitis B virus (HBV) infection.     

Probing local innate immune responses after mucosal immunisation

Background  

Intranasal immunisation is potentially a very effective route for inducing both mucosal and systemic immunity to an infectious agent.     

Breakup modes of a laminar hollow water jet

Graphical Abstract  

     

Flow visualization of supersonic transverse jet over Mach 2 freestream of a sharp cone

Graphical abstract  

     

Visualizations of the flow around a swimmer in turbulent regime

Graphical abstract  

     

A Canadian national survey of attitudes and knowledge regarding preventive vaccines

Background  

Vaccines have virtually eliminated many diseases, but public concerns about their safety could undermine future public health initiatives.     

Slowing of axonal regeneration is correlated with increased axonal viscosity during aging

Background  

As we age, the speed of axonal regeneration declines. At the biophysical level, why this occurs is not well understood.     

Effects of monoclonal anti-PcrV antibody on <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis>-induced acute lung injury in a rat model

Background  

The effects of the murine monoclonal anti-PcrV antibody Mab166 on acute lung injury induced by Pseudomonas aeruginosa were analyzed in a rat model.     

Long noncoding RNAs in neuronal-glial fate specification and oligodendrocyte lineage maturation

Background  

Long non-protein-coding RNAs (ncRNAs) are emerging as important regulators of cellular differentiation and are widely expressed in the brain.     

Coherent structures of the turbulent round jet in different focal lengths

Graphical abstract  

     

Evidence for non-independent gating of P2X<Subscript>2</Subscript> receptors expressed in <Emphasis Type="Italic">Xenopus</Emphasis>oocytes

Background  

P2X₂ receptor is an ATP-activated ion channel which is widely expressed in the nervous system, and mediates synaptic transmission.     

Temperature distribution on an isoflux surface cooled by an impinging liquid jet with a 40° Wall Jet Swirl Generator

Graphical Abstract  

     

Two-layer exchange flows over a dune: effect of large-scale bottom roughness

Graphical Abstract  

     

Entry of inclined hydrophobic and hydrophilic circular cylinders into water

Graphical Abstract  

     

Numerical visualization of counter rotating vortex ring formation ahead of shock tube generated vortex ring

Graphical Abstract