Thesis (Ph.D.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 177-206.

Despite the overwhelming evidence for atrophy of the NGF-dependant Basal Forebrain Cholinergic neurons during aging, there is no persuasive evidence towards a decrease in NGF and/or NGF mRNA content in the brain of aged animals. Previous experiments from our laboratory have shown that NGF is released as a precursor protein and cleaved into the mature form in the extracellular space under the influence of a complex protease cascade. These recent findings have lead us to propose that any alterations in levels and/or activity of this maturation/degradation cascade might affect NGF's biological activity and perhaps lead to cognitive impairments in a subset of aged rats. To investigate this possibility, we measured protein and mRNA levels of the protease cascade players (NGF, pro-NGF, tPA, plasminogen, plasmin, MMP-9, neuroserpin). We found significantly decreased levels of both pro-NGF protein and NGF mRNA, but no difference in the remaining elements of the protease cascade, when comparing aged impaired (Al) to the aged unimpaired (AU) animals. Our second objective was to investigate whether animals trained in the Morris Water Maze would preserve their cognitive status in two additional behavioral paradigms, the Novel Object Location (NOL, spatial memory) and Novel Object Recognition (NOR, nonspatial memory) tasks. We found that both AU and AI animals in the MWM were impaired in the NOL when compared to the young controls, with the AI animals performing significantly worse than the AU in this particular task. In the NOR tasks, AI animals performed significantly worse compared to both young and AU animals. In conclusion, further experiments are required to better understand the implication of the complex protease cascade involved in NGF's maturation and degradation as well as its effect on memory of aged animals. In addition, because the segregation of animals (aged impaired/unimpaired) is a crucial step in aging research, we now have additional behavioral paradigms (NOL/NOR) that confirm the cognitive status of these animals.

Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 5 uppsatser.

Thesis (M.Sc.). / Written for the Dept. of Anatomy and Cell Biology. Title from title page of PDF (viewed 2008/05/14). Includes bibliographical references.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 110-138. Also available online.

As pesquisas em lesão medular tiveram um avanço significativo nas últimas duas décadas. Várias substâncias têm sido testadas, dentre elas, os fatores neurotróficos que são proteínas que auxiliam na maturação e desenvolvimento do sistema nervoso. O objetivo deste estudo foi conduzir testes que propiciem a análise dos efeitos da recuperação funcional locomotora e regeneração axonal em ratos submetidos a testes experimentais com a utilização da substância neurotropina-4. O estudo consistiu de 30 ratos adultos jovens, da raça Wistar, que foram submetidos à lesão medular ao nível de TX, provocado por um aparelho denominado NYU impactor. Os ratos foram divididos em dois grupos de 15 ratos cada, denominados de grupo controle e grupo tratamento, que receberam aplicação de água destilada e 1g de neurotropina-4, respectivamente. Estes foram avaliados funcionalmente pela escala BBB e submetidos à análise histológica. Concluiu-se que a neurotropina-4 promove a recuperação locomotora funcional e diminui os efeitos secundários da lesão medular, comparativamente ao grupo controle / Research into spinal cord injury has advanced significantly over the past two decades. Many substances have been tested, including the neurotrophics factors, which are proteins that aid in the maturation and development of the nervous system. The objective of this study was to conduct tests that provide the analysis of the effects of the locomotor functional recovery and axonal regeneration in rats subjected to experimental tests with the use of the substance neurotrophin-4. The study consisted of thirty young adult rats, Wistar race, which received TX level of spinal cord injury through a device called NYU impactor. The rats were divided into two groups of fifteen rats each, called the control group and treatment group, which received application of distilled water and 1 g Neurotrophin-4, respectively. They were evaluated functionally by the BBB scale and submitted to the histological analysis. It was concluded that the Nt-4 promotes the recuperation of the locomotor function and reduces the side effects of spinal cord injury, compared to the control group

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Diss. (sammanfattning) Linköping : Univ., 2001. / Härtill 4 uppsatser.