Protoplasmic Astrocytes Enhance the Ability of Neural Stem Cells to Differentiate into Neurons In Vitro

Protoplasmic astrocytes have been reported to exhibit neuroprotective effects on neurons, but there has been no direct evidence for a functional relationship between protoplasmic astrocytes and neural stem cells (NSCs). In this study, we examined neuronal differentiation of NSCs induced by protoplasmic astrocytes in a co-culture model. Protoplasmic astrocytes were isolated from new-born and NSCs from the E13-15 cortex of rats respectively. The differentiated cells labeled with neuron-specific marker β-tubulin III, were dramatically increased at 7 days in the co-culture condition. Blocking the effects of brain-derived neurotrophic factor (BDNF) with an anti-BDNF antibody reduced the number of neurons differentiated from NSCs when co-cultured with protoplasmic astrocytes. In fact, the content of BDNF in the supernatant obtained from protoplasmic astrocytes and NSCs co-culture media was significantly greater than that from control media conditions. These results indicate that protoplasmic astrocytes promote neuronal differentiation of NSCs, which is driven, at least in part, by BDNF

On the structure-properties relationship of the AMV anion exchange membrane

International audienceImportant parameters such as ion exchange capacity, conductivity, permselectivity, quantity of sorbed electrolyte and water uptake of the Selemion AMV anion exchange membrane conditioned in KCl and NaCl solutions were determined in order to assess the applicability of the two-phase model of structure microheterogeneity to this case. In general, a good consistency between the experimental results and the theoretical approach was obtained. Electrical conductivity measurements allowed evaluating the volume fractions of two distinct internal phases inside the membrane. Aside from the chronopotentiometric behaviour of the AMV membrane, SEM and XPS techniques contributed to provide a better description of the overall membrane homogeneity. Influence of co-ions in relation with water uptakes on the conductivity and permselectivity of the studied membrane has been shown. An existence of partition equilibrium between the electrolytes sorbed in the membrane and the external solution confirmed in this work should be introduced within the microheterogeneous mode