Browsing by Subject "nervous system"

Now showing 1 - 5 of 5
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    Ablation of Ezh2 in neural crest cells leads to aberrant enteric nervous system development in mice
    (Public Library of Science, 2018-08-31) Kim, Hana; Langohr, Ingeborg M.; Faisal, Mohammad; McNulty, Margaret; Thorn, Caitlin; Kim, Joomyeong; Anatomy and Cell Biology, School of Medicine
    In the current study, we examined the role of Ezh2 as an epigenetic modifier for the enteric neural crest cell development through H3K27me3. Ezh2 conditional null mice were viable up to birth, but died within the first hour of life. In addition to craniofacial defects, Ezh2 conditional null mice displayed reduced number of ganglion cells in the enteric nervous system. RT-PCR and ChIP assays indicated aberrant up-regulation of Zic1, Pax3, and Sox10 and loss of H3K27me3 marks in the promoter regions of these genes in the myenteric plexus. Overall, these results suggest that Ezh2 is an important epigenetic modifier for the enteric neural crest cell development through repression of Zic1, Pax3, and Sox10.
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    Adipose-derived stem cell conditioned medium for the treatment of amyotrophic lateral sclerosis: pre-clinical evidence and potential for clinical application
    (Medknow Publications, 2019-09) Walker, Chandler L.; Department of Biomedical and Applied Sciences, School of Dentistry
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    Blood Supply to the Human Spinal Cord. II. Imaging and Pathology
    (Wiley, 2015-01) Bosmia, Anand N.; Tubbs, R. Shane; Hogan, Elizabeth; Bohnstedt, Bradley N.; DeNardo, Andrew J.; Loukas, Marios; Cohen-Gadol, Aaron A.; Department of Neurological Surgery, IU School of Medicine
    The blood supply of the spinal cord is a complex system based on multilevel sources and anastomoses. Diseases often affect this vascular supply and imaging has been developed that better investigates these structures. The authors review the literature regarding pathology and imaging modalities for the blood supply of the spinal cord. Knowledge of the disease processes and imaging modalities used to investigate these arterial lesions of the spinal cord will assist the clinician when treating patients with spinal cord lesions.
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    Electrode - Fiber Distance and Active Unit Conduction Velocity Estimation
    (Office of the Vice Chancellor for Research, 2010-04-09) Qiao, Shaoyu; Yoshida, Ken
    Advanced neuroprosthetic electrodes are indwelling devices that are being developed to create a bidirectional interface to the nervous system. They are a key enabling technology under development to restore function to those suffering from neurological disorders or injury, and have the potential to restore function to paralyzed limbs, sight to the blind, or hearing to the deaf. Their ultimate performance is dictated by keeping the distance between the active sites on the implant structure and the target nerve cell minimized. Currently, there is no analytical way to evaluate the distance between the electrode and the active cell without histologically examining the implanted tissue post-mortem. We report here on the development of a method to estimate not only the distance, but also the conduction velocity of the action potential. A tissue filter relationship was derived through analysis of the reciprocity equations in the frequency domain and transformation of the spatial frequency to time frequency. The derived function relates how the SFAP is transformed as a function of distance and conduction velocity. A 3-D finite element (FE) volume conductor model of an electrode residing in a nerve fascicle was created to determine the potential distribution in the nerve fascicle, and derive the tissue filter function. Single fiber action currents were filtered using the tissue filter function to simulate the predicted action potential for different fiberelectrode distances and action potential conduction velocities. A power spectral density (PSD) analysis was then implemented for the simulated SFAPs, to quantify changes in the PSD of the recorded simulate SFAPs. The model shows that a smaller electrode-fiber distance results in the broader bandwidth signal. It further showed that the faster conducting fiber, the fewer weights the spatial filter function and the broader the bandwidth. These factors result in a quantitative change in the PSD of faster conducting fibers, resulting in a peak in modulation in the 2nd peak of the PSD (around 5-6 kHz) which is a function of velocity and distance. Through the use of multiple electrode sites, the conduction velocity can be predicted and differentiated from the effect of distance.
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    Standardizing methods and procedures for mouse retinal flat mounts and glial cell counts
    (Office of the Vice Chancellor for Research, 2015-04-17) Anderson III, Richard; Dharmarajan, Subramanian; Belecky-Adams, Teri L.
    Introduction: The mammalian retina contains neuronal cells as well as a number of non-neuronal glial cells. The different types of glial cells include Müller glia, retinal astrocytes, and microglia. Müller glial cells and astrocytes nourish neurons and microglia act as sentinels that respond to injury or disease within the nervous system. The long-term goal of our laboratory has been to study interactions between microglia, Muller glia and astrocytes in healthy and diseased tissue. The focus of the present study was to develop a technique that would allow the laboratory to study changes in cell number in retinal flat mounts and cultures. Methods: Immunohistochemistry (IHC) was performed to fluorescently label mature murine retinal tissue. Retinal flat-mounts were stained with SOX2, a nuclear marker for glial cells or IBA1 for microglial cells, and counter-stained with Hoechst solution to label all nuclei. Pure cultures of mouse microglial cells treated with liposomal clodronate (a drug which specifically targets and ablates microglia) and vehicle were counter stained with Hoechst solution. Cell counts were performed on the images of the fluorescently labeled samples using Image-J software. Results: Convolutions were used to filter images of immunolabeled cultures and retinal flat mounts to make the images clear enough to capture cell number. The cell count assistance protocol yielded acceptable cell count results of the stained cells and determined a detectable difference in the number of clodronate treated cells versus vehicle treated control cells. The images produced of the retinal flat-mounts were analyzed to determine the percentage of SOX2 positive Müller glia in the mature murine retinal tissue. Conclusion: A modified Image J program could be used to determine cellular number in cultures and retinal flat mounts. Mentor: Teri L Belecky-Adams, Department of Biology, Indiana University-Purdue University Indianapolis