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The identification of faks in the chick embryonic brain neuroepithelium and their response to pressure

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Description: The embryonic brain is a hollow organ initially composed of more cavity than tissue, with brain expansion occurring coincident with the occlusion of the spinal neurocoel. The brain becomes a closed compartment that accumulates cerebrospinal fluid (CSF) in the cavity primarily via an osmotic gradient and the ventricles expand as a result of hydrostatic pressure. The neuroepithelium grows by cell proliferation stimulated by tension across the cells created by intraluminal pressure (ILP). Such a response suggests the presence of tension receptors on the neuroepithelium that relay signals to the nucleus and thus stimulate mitosis. Focal adhesion kinases (FAKs) are non-receptor protein tyrosine kinases implicated in tissue formation and cell migration. FAK has been found to be localized at the interface between the integrin receptor for ECM binding and the actin cytoskeleton for force generation, which makes it a prime candidate for the regulation of mechanical force into an intracellular chemical signaling pathway. FAKs have been found in epithelial cells of the lungs, fibroblast cells, cardiac cells, and smooth muscle cells to name only a few. The common factor in each of these cells is the presence of stretch related events that all require mechanoreceptors such as FAKs. Preliminary results in this study using immunostaining support the idea that FAKs are found on the neuroepithelium of the stage 20 chick embryonic brain. Further investigations are needed, including an assessment of other members of the mechanosensory complex. In addition, a demonstration of the up-regulation of FAKs in response to an increase in pressure is required to indicate FAKs as the interface between external pressure and connection to the nucleus. This finding may give us a partial answer as to how ILP regulates cell proliferation in the neuroepithelium.
Language: English
Format: Degree Work