High potassium exposure reveals the altered ability of astrocytes to regulate their volume in the aged hippocampus of GFAP/EGFP mice.

In this study, we focused on age-related changes in astrocyte functioning, predominantly on the ability of astrocytes to regulate their volume in response to a pathological stimulus, namely extracellular 50 mM K concentration. The aim of our project was to identify changes in the expression and function of transport proteins in the astrocytic membrane and properties of the extracellular space, triggered by aging. We used three-dimensional confocal morphometry, gene expression profiling, immunohistochemical analysis, and diffusion measurement in the hippocampal slices from 3-, 9-, 12-, and 18-month-old mice, in which astrocytes are visualized by enhanced green fluorescent protein under the control of the promoter for human glial fibrillary acidic protein.

Different twig litter (Salix caprea) diameter does affect microbial community activity and composition but not decay rate.

Small twigs represent a substantial input of organic carbon into forest soils, but potential influencing factors on their decomposition have rarely been investigated. Here, we studied potential effects of twig size on decomposition and associated composition and activity of microbial communities during decomposition. Because the surface area for microbial colonization and the volume of accessible substrate increases with decreasing twig size, we hypothesized that twig size affects both microbial community and decomposition rate.

Generation of reactive astrocytes from NG2 cells is regulated by sonic hedgehog.

NG2 cells, a fourth glial cell type in the adult mammalian central nervous system, produce oligodendrocytes in the healthy nervous tissue, and display wide differentiation potential under pathological conditions, where they could give rise to reactive astrocytes. The factors that control the differentiation of NG2 cells after focal cerebral ischemia (FCI) are largely unknown. Here, we used transgenic Cspg4-cre/Esr1/ROSA26Sortm14(CAG-tdTomato) mice, in which tamoxifen administration triggers the expression of red fluorescent protein (tomato) specifically in NG2 cells and cells derived therefrom.

Glial Cells - The Key Elements of Alzheimer´s Disease.

Alzheimer's disease (AD) is a complex neurodegenerative disorder with major clinical hallmarks of memory loss, dementia, and cognitive impairment. Besides the extensive neuron-oriented research, an increasing body of evidence suggests that glial cells, namely astrocytes, microglia, NG2 glia and oligodendrocytes, may play an important role in the pathogenesis of this disease. In the first part of this review, AD pathophysiology in humans is briefly described and compared with disease progression in routinely used animal models.

Intracellular Na(+) inhibits volume-regulated anion channel in rat cortical astrocytes.

Accumulating evidence indicates that increased intracellular Na(+) concentration ([Na(+) ]i ) in astroglial cells is associated with the development of brain edema under ischemic conditions, but the underlying mechanisms are still elusive. Here, we report that in primary cultured rat cortical astrocytes, elevations of [Na(+) ]i reflecting those achieved during ischemia cause a marked decrease in hypotonicity-evoked current mediated by volume-regulated anion channel (VRAC). Pharmacological manipulations revealed that VRAC inhibition was not due to the reverse mode of the plasma membrane sodium/calcium exchanger.