Browsing by Author "Morgan, Carlos"

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    Anatomy of corpus callosum in prenatally malnourished rats
    (SOC BIOLGIA CHILE, 2012) Olivares, Ricardo; Morgan, Carlos; Perez, Hernan; Hernandez, Alejandro; Aboitiz, Francisco; Soto Moyano, Ruben; Gil, Julio; Ortiz, Alexis; Flores, Osvaldo; Gimeno, Miguel; Laborda, Jesus
    The effect of prenatal malnutrition on the anatomy of the corpus callosum was assessed in adult rats (45-52 days old). In the prenatally malnourished animals we observed a significant reduction of the corpus callosum total area, partial areas, and perimeter, as compared with normal animals. In addition, the splenium of corpus callosum (posterior fifth) showed a significant decrease of fiber diameters in the myelinated fibers without changing density. There was also a significant decrease in diameter and a significant increase in density of unmyelinated fibers. Measurements of perimeter's fractal dimensions from sagittal sections of the brain and corpus callosum did not show significant differences between malnourished and control animals. These findings indicate that cortico-cortical connections are vulnerable to the prenatal malnutrition, and suggest this may affect interhemispheric conduction velocity, particular), in visual connections (splenium).
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    Overexpression of amyloid precursor protein increases copper content in HEK293 cells
    (2009) Suazo, Miriam; Hodar, Christián; Morgan, Carlos; Cerpa Nebott, Francisco Waldo; Cambiazo, Verónica; Inestrosa Cantín, Nibaldo; González, Mauricio
    Amyloid precursor protein (APP) is a transmembrane glycoprotein widely expressed in mammalian tissues and plays a central role in Alzheimer’s disease. However, its physiological function remains elusive. Cu2+ binding and reduction activities have been described in the extracellular APP135–156 region, which might be relevant for cellular copper uptake and homeostasis. Here, we assessed Cu2+ reduction and 64Cu uptake in two human HEK293 cell lines overexpressing APP. Our results indicate that Cu2+ reduction increased and cells accumulated larger levels of copper, maintaining cell viability at supra-physiological levels of Cu2+ ions. Moreover, wild-type cells exposed to both Cu2+ ions and APP135–155 synthetic peptides increased copper reduction and uptake. Complementation of function studies in human APP751 transformed Fre1 defective Saccharomyces cerevisiae cells rescued low Cu2+ reductase activity and increased 64Cu uptake. We conclude that Cu2+ reduction activity of APP facilitates copper uptake and may represent an early step in cellular copper homeostasis.