( a) Schematic of the experimental paradigm for labeling Oct4 + pNSCs during embryogenesis (E16-18). Identification of pNSCs in the developing and adult forebrain. We show that Oct4+ pNSCs can give rise to dNSCs in the adult mouse periventricular region in naïve brains and in a loss of function model of dNSC repopulation. Retroviral lineage tracing and a triple transgenic mouse (Oct4CreER T2 ROSAyfp fl/fl GFAPtk) that permits pre-labeling of the very rare Oct4+ cells in vivo. Using labeling paradigms in the developing CNS, in combination with in vivo ablation paradigms in the adult, we demonstrate that pNSCs are the precursors to dNSCs in vivo. Herein we have used several transgenic mouse models that permit lineage tracking of pNSC progeny in embryonic, neonatal and adult mice. These findings support the hierarchical lineage relationship between pNSCs and dNSCs. ![]() 4 showed that in conditional Oct4 loss of function mice (Oct4fl/fl Sox1Cre), repopulation of the dNSC population following ablation does not occur. First, in vitro culture experiments demonstrate that adult-derived pNSC colonies can be induced to form dNSC neurospheres (in EGF + FGF + heparin, EFH) but not vice versa, and second, transplantation of pNSCs onto the rostral migratory stream (RMS) revealed pNSC derived neuroblasts on the RMS and neurons in the olfactory bulb. Previous work supports the hypothesis that pNSCs are lineally related to dNSCs 7. Definitive and primitive NSCs can be further differentiated based on the expression of cell surface markers c-kit and ErbB2 9. pNSCs generate clonally derived, multipotent colonies in the presence of leukemia inhibitory factor (LIF) 6, 7. In vitro, dNSCs proliferate in the presence of epidermal growth factor (EGF) and fibroblast growth factor (FGF) to form clonally derived colonies of cells termed neurospheres 8. Primitive NSCs are rare (more than 10 fold less frequent than dNSCs) and have a long cell cycle time of 3–5 months in the adult brain 4, 7. The pNSC does not express GFAP, but does express low levels of the pluripotency marker, Oct4 5, 6, 7. A second population of primitive NSCs (pNSCs), initially isolated during development as early as embryonic day (E) 5.5, persists into adulthood. Within the well-documented neurogenic niche of the adult forebrain germinal zone, glial fibrillary acidic protein (GFAP) expressing definitive NSCs (dNSC) infrequently divide with a cell cycle time of 2–4 weeks to produce more rapidly dividing progenitors that migrate along the rostral migratory stream towards the olfactory bulb and generate interneurons 1, 2, 3, 4. You can also have better information about the patient's optical system's alignment so that you can decide which IOL is best for the patient.The adult mammalian central nervous system contains two distinct populations of neural stem cells (NSCs). Additionally, general eye care specialists can use this information to select and recommend the best vision correction treatment. Surgeons benefit from this information when planning surgical procedures such as refractive lensectomies, AK's, Accommodative and Multifocal IOL's and for post-op evaluations. This 5-in-1 system provides auto-refraction, corneal topography, ray tracing aberrometry, pupillometry and auto-keratometry, saving time, space and money.īy integrating wavefront aberrometry with corneal topography, the iTrace provides a unique analysis that subtracts corneal from total aberrations in order to isolate the internal aberrations of the eye. ![]() ![]() The iTrace sequentially projects 256 near-infrared laser beams into the eye to measure forward aberrations, processing data point-by-point. The iTrace measures quality of vision and visual function using a fundamental thin beam principle of optical ray tracing, a first in eye care diagnostics. It offers easy to interpret reports, is simple to integrate, networkable and saves time, space and money. Visual analysis is not based only on sphere, and cylinder – iTrace offers an objective perspective of the complete visual pathway, analyzing aberrations from low to high order. The iTrace™ combines, auto refraction, corneal topography, auto-keratometry, wavefront aberrometry and pupillometry in one system.
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