Neurosphere

About: Neurosphere is a research topic. Over the lifetime, 5145 publications have been published within this topic receiving 321088 citations.

Specification of CNS glia from neural stem cells in the embryonic neuroepithelium.

Abstract: All the neurons and glial cells of the central nervous system are generated from the neuroepithelial cells in the walls of the embryonic neural tube, the ‘embryonic neural stem cells’. The stem cells seem to be equivalent to the so-called ‘radial glial cells’, which for many years had been regarded as a specialized type of glial cell. These radial cells generate different classes of neurons in a position-dependent manner. They then switch to producing glial cells (oligodendrocytes and astrocytes). It is not known what drives the neuron–glial switch, although downregulation of pro-neural basic helix–loop–helix transcription factors is one important step. This drives the stem cells from a neurogenic towards a gliogenic mode. The stem cells then choose between developing as oligodendrocytes or astrocytes, of which there might be intrinsically different subclasses. This review focuses on the different extracellular signals and intracellular responses that influence glial generation and the choice between oligodendrocyte and astrocyte fates.

N-CAM Binding Inhibits the Proliferation of Hippocampal Progenitor Cells and Promotes Their Differentiation to a Neuronal Phenotype

Abstract: Cell adhesion molecules (CAMs) play important roles during the development of the nervous system On the basis of our previous observations that binding of the neural CAM (N-CAM) inhibits astrocyte proliferation and alters gene expression, we hypothesized that N-CAM may influence the balance between the proliferation and the differentiation of neural progenitor cells Rat and mouse hippocampal progenitor cells were cultured and showed dependence on basic FGF for proliferation, immunoreactivity for nestin, the presence of limited numbers of differentiated cells, and the ability to generate glial cells and neurons under different culture conditions Addition of soluble N-CAM reduced cell proliferation in a dose-dependent manner with no evidence of apoptosis The inhibition of proliferation by N-CAM was accompanied by an induction of differentiation to the neuronal lineage, as indicated by a twofold increase in the percentage of microtubule-associated protein 2-positive cells even in the presence of mitogenic growth factors Experiments using hippocampal cells from N-CAM knock-out mice indicated that N-CAM on the cell surface is not required for these effects, suggesting the existence of heterophilic signaling These results support a role for N-CAM and N-CAM ligands in the inhibition of proliferation and the induction of neural differentiation of hippocampal neural progenitor cells