Classes Of Neural Cells Research Articles

Cell type-specific transcriptome profiling in mammalian brains.

A mammalian brain contains numerous types of cells. Advances in neuroscience in the past decade allow us to identify and isolate neural cells of interest from mammalian brains. Recent developments in high-throughput technologies, such as microarrays and next-generation sequencing (NGS), provide detailed information on gene expression in pooled cells on a genomic scale. As a result, many novel genes have been found critical in cell type-specific transcriptional regulation. These differentially expressed genes can be used as molecular signatures, unique to a particular class of neural cells. Use of this gene expression-based approach can further differentiate neural cell types into subtypes, potentially linking some of them with neurological diseases. In this article, experimental techniques used to purify neural cells are described, followed by a review on recent microarray- or NGS-based transcriptomic studies of common neural cell types. The future prospects of cell type-specific research are also discussed.

Fortuitous benefits of activity-based rehabilitation in stem cell-based therapy for spinal cord repair: enhancing graft survival.

Traumatic injuries to spinal cord elicit diverse signaling pathways leading to unselective and complex pathological outcomes: death of multiple classes of neural cells, formation of cystic cavities and glial scars, disruption of axonal connections, and demyelination of spared axons, all of which can contribute more or less to debilitating functional impairments found in patients with spinal cord injury. The multitude of pathobiological processes involved in spinal cord trauma may make it highly challenging to develop a clinically meaningful therapeutic approach targeting only a specific molecule or signaling pathway. A hopeful alternative might be a cell therapy, especially a transplantation approach using neural stem cells (NSC) with a clear potential to differentiate into various neural cell types. Provision of NSCs with capacity to differentiate into mature neural cells can ideally replace lost segmental neurons and dying oligodendrocytes around surviving axons. Furthermore, NSCs secrete various growth factors that provide protective or pro-regenerative effects. It has been also demonstrated that NSCs can exert powerful modulatory effects on immune cells ameliorating secondary degenerative processes.

P2X Receptors and Their Roles in Astroglia in the Central and Peripheral Nervous System

Astrocytes are a class of neural cells that control homeostasis at all levels of the central and peripheral nervous system. There is a bidirectional neuron–glia interaction via a number of extracellular signaling molecules, glutamate and ATP being the most widespread. ATP activates ionotropic P2X and metabotropic P2Y receptors, which operate in both neurons and astrocytes. Morphological, biochemical, and functional evidence indicates the expression of astroglial P2X1/5 heteromeric and P2X7 homomeric receptors, which mediate physiological and pathophysiological responses. Activation of P2X1/5 receptors triggers rapid increase of intracellular Na+ that initiates immediate cellular reactions, such as the depression of the glutamate transporter to keep high glutamate concentrations in the synaptic cleft, the activation of the local lactate shuttle to supply energy substrate to pre- and postsynaptic neuronal structures, and the reversal of the Na+/Ca2+ exchange resulting in additional Ca2+ entry. The consequences of P2X7 receptor activation are mostly but not exclusively mediated by the entry of Ca2+ and result in reorganization of the cytoskeleton, inflammation, apoptosis/necrosis, and proliferation, usually at a prolonged time scale. Thus, astroglia detect by P2X1/5 and P2X7 receptors both physiological concentrations of ATP secreted from presynaptic nerve terminals and also much higher concentrations of ATP attained under pathological conditions.

Bipotential glial precursor cells of the optic nerve express the NG2 proteoglycan

We have studied the expression of the NG2 chondroitin sulfate proteoglycan on bipotential glial precursor cells in cultures of postnatal rat optic nerve. Purified populations of these precursor cells were prepared by panning dissociated optic nerve cells on dishes coated with monoclonal A2B5 antibody. Using immunofluorescence double staining, we found that NG2 was present on almost 95% of the purified A2B5+ precursor cells. The NG2 core protein from optic nerve cells was identified by immune precipitation and PAGE and was found to be identical to the 300,000 Da NG2 core protein from a clonal rat cell line B49. Over a culture period of 5 d in medium containing 10% fetal calf serum, more than 80% of the NG2+ precursor cells acquired the glial fibrillary acidic protein (GFAP), an astrocyte-specific marker. Under these conditions, fewer than 10% of the NG2+ cells expressed galactocerebroside (GC), an oligodendrocyte-specific marker. These GFAP+GC- type II astrocytes continued to express the NG2 antigen for up to 10 d in culture. During a 5 d culture period in hormonally supplemented, serum-free medium, fewer than 15% of the NG2+ cells expressed GFAP, while up to 40% expressed GC. The NG2 antigen continued to be expressed for only a short period of time by these GFAP-GC+ oligodendrocytes, so that mature oligodendrocytes in the cultures became NG2-. These results support our previous suggestion that the NG2 antigen is found on a class of neural cells that can differentiate along more than one pathway.