Effects of axotomy on calcium influx in reticulospinal neurons of larval lamprey [abstract]

Abstract only availableThe lamprey is a prime example of the remarkable axonal regeneration that can occur in lower vertebrates. Previous studies showed that spinal cord transected lamprey recover normal locomotor behavior in about 8 weeks (McClellan, 1998). With increasing recovery time, increasing numbers of axons from injured reticulospinal (RS) neurons in the brain regenerate across the lesion site and for greater distances below the lesion. One factor that might affect axonal regeneration is the individual properties of the RS neurons. During electrical activity (action potentials) in these neurons, calcium influx occurs through voltage-gated and chemical-gated calcium channels. First, previous research demonstrated that in injured RS neurons from lamprey, action potentials are missing a component that is due to calcium influx and that is present in uninjured RS neurons (McClellan, 2003). Furthermore, it has been shown that when calcium channels and calcium influx are blocked in uninjured (normal) RS neurons, firing patterns are similar to these observed in injured RS neurons. Second, lamprey RS neurons in cell culture retract as a result of calcium influx (Ryan et al., 2004). Thus, preliminary results suggest that injured RS neurons may down regulate calcium channels to lower intracellular calcium and to allow axonal regeneration. The purpose of the project was to determine the factors that influence axonal regeneration and obtain evidence for the possible down regulation of calcium channels in injured RS neurons. A calcium indicator dye was loaded into RS neurons and the neurons were stimulated to produce electrical activity (action potentials) during which fluorescence images were captured. The calcium indicator dye allowed imaging of the levels of intracellular calcium and changes in fluorescence. However, a higher signal-to-noise ratio is needed before calcium levels can be compared in injured and uninjured larval lamprey RS neurons.Life Sciences Undergraduate Research Opportunity Progra

Electromagnetic stimulation of a composite scaffold for wound healing

Title from PDF of title page (University of Missouri--Columbia, viewed on May 24, 2013).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Sheila GrantIncludes bibliographical references.Vita.Ph. D. University of Missouri--Columbia 2012."May 2012"[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Decellularized tissues have been investigated as natural sources for tissue scaffolds as synthetic mimicry of the natural extracellular matrix is quite difficult. In addition, gold nanomaterials have been studied for their ability to provide nanostructural cues for cell growth as well as their ability to interact with free radicals. Meanwhile, electromagnetic fields (EMFs) have been explored as an adjunct therapy for chronic wounds due to clinical evidence of wound healing enhancement. This dissertation investigated the incorporation of all three in the design and evaluation of an electromagnetically-stimulated composite scaffold comprised of decellularized porcine diaphragm and gold nanomaterials. Composite scaffolds were synthesized and characterized through biocompatibility, cell proliferation, and reactive oxygen species assays. The scaffolds were then subjected to an EMF while in cell culture to determine the cellular effects of this treatment. The results indicated the successful design of a biocompatible composite scaffold capable of free radical level modulation and enhanced cell proliferation, especially when subjected to an EMF. It was also shown that the interaction of the EMF and gold nanomaterials transiently enhanced cell spreading. Future studies are needed to elucidate the specific mechanisms for these effects and to further develop the system as an advanced wound therapy.Includes bibliographical references

Quarantine Dance Corps

Inspired by Mitchell Roses\u27s Exquisite Corps, the Modern Dance III class came together virtually with a creative response to COVID-19, and turned disruption into an opportunity to connect our Ohio Northern University Theatre Arts students and faculty from a distance. The project’s intent was to keep us connected as a campus community