Search results for "Neuroepithelial cell"
showing 10 items of 37 documents
The adult spinal cord harbors a population of GFAP-positive progenitors with limited self-renewal potential
2013
Adult neural stem cells (aNSCs) of the forebrain are GFAP-expressing cells that are intercalated within ependymal cells of the subventricular zone (SVZ). Cells showing NSCs characteristics in vitro can also be isolated from the periaqueductal region in the adult spinal cord (SC), but contradicting results exist concerning their glial versus ependymal identity. We used an inducible transgenic mouse line (hGFAP-CreERT2) to conditionally label GFAP-expressing cells in the adult SVZ and SC periaqueduct, and directly and systematically compared their self-renewal and multipotential properties in vitro. We demonstrate that a population of GFAP+ cells that share the morphology and the antigenic pr…
Localization of the two constitutively expressed nitric oxide synthase isoforms (nNOS and eNOS) in the same cell types in the saccule maculae of the …
2003
There is growing evidence for a nitric oxide/cyclic GMP pathway of signal transduction in the vestibular system. Recently, two isoforms of nitric oxide (NO) synthase (nNOS and eNOS) and NO itself have been identified at the light microscopic level in the vestibulocochlear system of mice using specific antibodies and a new fluorescence indicator. In order to acquire more information about signal transduction and tissue modulation in this neuroepithelium at the cellular and subcellular levels, ultrathin sections of London Resin White-embedded saccule maculae of the frog Rana pipiens were incubated with various concentrations of commercially available antibodies to nNOS and eNOS. The immunorea…
Organisation and maturation of the human thalamus as revealed by CD15
2001
The distribution of the CD15 antigen (CD15, 3-fucosyl-N-acetyl-lactosamine, Lewis x) has been studied immunohistochemically in the fetal human thalamus. Its changing patterns could be related to three successive, but overlapping, periods primarily due to its association with radial glial cells, neuropil, and neural cell bodies, respectively. From 9 weeks of gestation (wg), a subset of CD15-positive radial glial cells distinguished the neuroepithelium of the ventral thalamus, a characteristic also seen in the developing mouse. Distal processes of the radial glial cells converged at the root of the forebrain choroid tenia, which was also CD15 positive. From 13 wg until approximately 20 wg, CD…
Subtypes of glial cells in the Drosophila embryonic ventral nerve cord as related to lineage and gene expression
2008
In the Drosophila embryonic CNS several subtypes of glial cells develop, which arrange themselves at characteristic positions and presumably fulfil specific functions. The mechanisms leading to the specification and differentiation of glial subtypes are largely unknown. By DiI labelling in glia-specific Gal4 lines we have clarified the lineages of the lateral glia in the embryonic ventral nerve cord and linked each glial cell to a specific stem cell. For the lineage of the longitudinal glioblast we show that it consists of 9 cells, which acquire at least four different identities. A large collection of molecular markers (many of them representing transcription factors and potential Gcm targ…
Neuronal Cell Nuclear Factor. A Nuclear Receptor Possibly Involved in the Control of Neurogenesis and Neuronal Differentiation
1997
We have cloned from a cDNA library of neuronal derivatives of retinoic-acid-induced embryonic carcinoma cells a nuclear receptor that may be involved in the control of late neurogenesis and early neuronal differentiation. The receptor which is practically identical in sequence with germ cell nuclear factor, has been designated neuronal cell nuclear factor (NCNF). NCNF is exclusively expressed in the neuronal derivatives of PCC7-Mz1 cells, with the expression beginning within hours of exposure to retinoic acid. In the developing mouse brain, NCNF is expressed in the marginal zones of the neuroepithelium which are known to contain young postmitotic neurons. NCNF binds to the DRO sequence ther…
Astrocytes give rise to new neurons in the adult mammalian hippocampus
2001
Neurogenesis in the dentate gyrus of the hippocampus persists throughout life in many vertebrates, including humans. The progenitors of these new neurons reside in the subgranular layer (SGL) of the dentate gyrus. Although stem cells that can self-renew and generate new neurons and glia have been cultured from the adult mammalian hippocampus, the in vivo primary precursors for the formation of new neurons have not been identified. Here we show that SGL cells, which express glial fibrillary acidic protein and have the characteristics of astrocytes, divide and generate new neurons under normal conditions or after the chemical removal of actively dividing cells. We also describe a population o…
Subventricular zone neural progenitors protect striatal neurons from glutamatergic excitotoxicity.
2012
The functional significance of adult neural stem and progenitor cells in hippocampal-dependent learning and memory has been well documented. Although adult neural stem and progenitor cells in the subventricular zone are known to migrate to, maintain and reorganize the olfactory bulb, it is less clear whether they are functionally required for other processes. Using a conditional transgenic mouse model, selective ablation of adult neural stem and progenitor cells in the subventricular zone induced a dramatic increase in morbidity and mortality of central nervous system disorders characterized by excitotoxicity-induced cell death accompanied by reactive inflammation, such as 4-aminopyridine-i…
Vascular‐derived TGF‐β increases in the stem cell niche and perturbs neurogenesis during aging and following irradiation in the adult mouse brain
2012
Neurogenesis decreases during aging and following cranial radiotherapy, causing a progressive cognitive decline that is currently untreatable. However, functional neural stem cells remained present in the subventricular zone of high dose-irradiated and aged mouse brains. We therefore investigated whether alterations in the neurogenic niches are perhaps responsible for the neurogenesis decline. This hypothesis was supported by the absence of proliferation of neural stem cells that were engrafted into the vascular niches of irradiated host brains. Moreover, we observed a marked increase in TGF-β1 production by endothelial cells in the stem cell niche in both middle-aged and irradiated mice. I…
The LIM Homeodomain Factor Lhx2 Is Required for Hypothalamic Tanycyte Specification and Differentiation
2014
Hypothalamic tanycytes, a radial glial-like ependymal cell population that expresses numerous genes selectively enriched in embryonic hypothalamic progenitors and adult neural stem cells, have recently been observed to serve as a source of adult-born neurons in the mammalian brain. The genetic mechanisms that regulate the specification and maintenance of tanycyte identity are unknown, but are critical for understanding how these cells can act as adult neural progenitor cells. We observe that LIM (Lin-11, Isl-1, Mec-3)-homeodomain geneLhx2is selectively expressed in hypothalamic progenitor cells and tanycytes. To test the function ofLhx2in tanycyte development, we used an intersectional gene…
Subventricular Zone Astrocytes Are Neural Stem Cells in the Adult Mammalian Brain
1999
AbstractNeural stem cells reside in the subventricular zone (SVZ) of the adult mammalian brain. This germinal region, which continually generates new neurons destined for the olfactory bulb, is composed of four cell types: migrating neuroblasts, immature precursors, astrocytes, and ependymal cells. Here we show that SVZ astrocytes, and not ependymal cells, remain labeled with proliferation markers after long survivals in adult mice. After elimination of immature precursors and neuroblasts by an antimitotic treatment, SVZ astrocytes divide to generate immature precursors and neuroblasts. Furthermore, in untreated mice, SVZ astrocytes specifically infected with a retrovirus give rise to new n…