Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Speech-Language Pathology, Department of Speech Pathology and Audiology. Title from pdf file main screen (viewed on July 25, 2010). Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Psychology Department, 2005. / Includes bibliographical references.

<p>Nerve injury induces up-regulation of the chaperone protein clusterin in affected neurons and adjacent astrocytes but the functional significance of this response is unclear. We find that motor neuron survival is significantly greater in clusterin(+/+) compared to (-/-) mice. These results suggest that endogenous expression of clusterin is neuroprotective after nerve injury. However, motor neuron survival in clusterin overexpressing mice was not different from that in wildtype mice. In contrast, treatment of neuronal cultures with clusterin-TAT recombinant protein is neuroprotective, including a positive effect on neuronal network complexity.</p><p>Since extracellular clusterin complexes are endocytosed after binding to various receptors, we examined the expression of known clusterin binding receptors in the spinal cord. We find that megalin is expressed in the nuclei of two cell populations in the mouse spinal cord: i) oligodendrocytes in late postnatal and adult spinal cord white matter, and ii) transiently (E11-15) in a population of immature astrocytes in the dorsal spinal cord. We find no correlation between clusterin and megalin in the intact or injured spinal cord. However, intranuclear localization of megalin, suggesting signalling properties, is supported by the co-localization with γ-secretase, the enzyme responsible for endodomain cleavage of megalin. Megalin deficient mice display a pronounced deformation of the dorsal part of spinal cord, an almost complete absence of oligodendroglial progenitor cells, and a marked reduction in the population of mature astrocytes at later prenatal developmental stages.</p><p>Taken together, our findings indicate that megalin is a novel signalling molecule for distinct populations of glial cells in the pre- and postnatal spinal cord. The functional role(s) of megalin is unknown. However, its expression patterns and cellular localization suggest that megalin regulates differentiation of oligodendrocytes and astrocytes in the prenatal spinal cord, as well as the function of myelinating oligodendrocytes in the postnatal spinal cord.</p>

Nerve injury induces up-regulation of the chaperone protein clusterin in affected neurons and adjacent astrocytes but the functional significance of this response is unclear. We find that motor neuron survival is significantly greater in clusterin(+/+) compared to (-/-) mice. These results suggest that endogenous expression of clusterin is neuroprotective after nerve injury. However, motor neuron survival in clusterin overexpressing mice was not different from that in wildtype mice. In contrast, treatment of neuronal cultures with clusterin-TAT recombinant protein is neuroprotective, including a positive effect on neuronal network complexity. Since extracellular clusterin complexes are endocytosed after binding to various receptors, we examined the expression of known clusterin binding receptors in the spinal cord. We find that megalin is expressed in the nuclei of two cell populations in the mouse spinal cord: i) oligodendrocytes in late postnatal and adult spinal cord white matter, and ii) transiently (E11-15) in a population of immature astrocytes in the dorsal spinal cord. We find no correlation between clusterin and megalin in the intact or injured spinal cord. However, intranuclear localization of megalin, suggesting signalling properties, is supported by the co-localization with γ-secretase, the enzyme responsible for endodomain cleavage of megalin. Megalin deficient mice display a pronounced deformation of the dorsal part of spinal cord, an almost complete absence of oligodendroglial progenitor cells, and a marked reduction in the population of mature astrocytes at later prenatal developmental stages. Taken together, our findings indicate that megalin is a novel signalling molecule for distinct populations of glial cells in the pre- and postnatal spinal cord. The functional role(s) of megalin is unknown. However, its expression patterns and cellular localization suggest that megalin regulates differentiation of oligodendrocytes and astrocytes in the prenatal spinal cord, as well as the function of myelinating oligodendrocytes in the postnatal spinal cord.

The distribution of urotensin-II-immunoreactivity (irU-II) was studied in the rat brainstem and spinal cord with the use of an antiserum against the human urotensin II (U-II) peptide. A population of ventral horn neurons in the spinal cord, hypoglossal nucleus, dorsal motor nucleus of the vagus, facial motor nucleus, nucleus ambiguus, abducens nucleus and trigeminal motor nucleus exhibited irU-II of varying intensities. The number of irU-II motor neurons was higher in the lumbar segments as compared to that of cervical, thoracic and sacral segments. Double-labeling the sections with U-II- and choline acetyltransferase (ChAT)-antisera revealed that nearly all irU-II ventral horn and brainstem neurons were ChAT-positive. The result provides the first immunohistochemical evidence of the presence of irU-II in cholinergic motoneurons of the rat spinal cord and brainstem.

No description available.

No description available.

No description available.

No description available.

This study explores the effects of surgical reconstruction and nerve repair on sensorimotor function and quality of life (QOL) for patients with base of tongue (BOT) cancer compared to healthy, age-matched adults. Sensations were tested on the anterior two-thirds of the oral tongue for two-point discrimination, light touch, taste, temperature, form and texture on 30 patients with BOT reconstruction with radial forearm free-flap and on 30 controls. Results indicated sensation for the unaffected tongue side and affected side with lingual nerve intact was comparable to controls, with poorer sensory outcomes for nerve repair. However, lingual nerves repaired with reanastomosis provided superior results to cable-grafting and severed nerves. Patients had decreased motor function only when the hypoglossal and lingual nerves were affected. Patients' QOL responses on the UW-QOL and EORTC QLQ-H&N35 revealed involvement of lingual and hypoglossal nerves resulted in poorer QOL outcomes. QOL interviews revealed additional problematic issues in this population not identified by standardized questionnaires. / Speech-Language Pathology