Catherine M Davidson

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Neuroblasts undergo asymmetric stem cell divisions to generate a series of ganglion mother cells (GMCs). During these divisions, the cell fate determinant Prospero is asymmetrically partitioned to the GMC by Miranda protein, which tethers it to the basal cortex of the dividing neuroblast. Interestingly, prospero mRNA is similarly segregated by the dsRNA(More)
BACKGROUND Drosophila axis formation requires a series of inductive interactions between the oocyte and the somatic follicle cells. Early in oogenesis, Gurken protein, a member of the transforming growth factor alpha family, is produced by the oocyte to induce the adiacent follicle cells to adopt a posterior cell fate. These cells subsequently send an(More)
The asymmetric segregation of cell-fate determinants and the generation of daughter cells of different sizes rely on the correct orientation and position of the mitotic spindle. In the Drosophila embryo, the determinant Prospero is localized basally and is segregated equally to daughters of similar cell size during epidermal cell division. In contrast,(More)
Ten-month-old rats were subjected to permanent bilateral occlusion of both common carotid arteries (2-VO) to chronically but moderately reduce brain blood flow. 2-VO impaired Morris water maze acquisition as soon as 7 days post-surgery. 2-VO also caused a later-appearing impairment on the radial arm maze which did not reach significance until 63 days(More)
Manganese chloride (Mn) was dissolved in the drinking water (0, 2, or 10 mg/ml) of dams and their litters from conception until postnatal day (PND) 30. Parturition was uneventful in the Mn-exposed rats and no physical abnormalities were observed. The rats exposed to 10 mg/ml Mn showed a 2.5-fold increase in cortical Mn levels. Their weight gain was(More)
Adult rats underwent permanent bilateral occlusion of the common carotid arteries (2VO) to determine the effect of chronic cerebral ischemia on vision and retina. They were monitored post-surgically for the presence of the pupillary reflex to light. Some rats were tested for 6 months post-surgically on a radial arm maze task and then tested in another(More)
The chondroitin ABC lyase digestion products of normal human femoral condyle articular cartilage and of purified aggrecan were analyzed for their mono- and nonsulfated disaccharide composition. Changes in the total tissue chemistry were most pronounced during the period from birth to 20 years of age, when the -[GlcAbeta,3GalNAc6]- disaccharide content(More)
Chronic reductions in cerebral blood flow associated with aging and progressive neurodegenerative disorders can precipitate cognitive failure. To assess whether chronic cerebrovascular insufficiency elicits neuronal apoptosis, apoptotic cell death in the hippocampus was quantitated in a rat model of permanent carotid occlusion. Bilateral carotid artery(More)
Corticosterone, a glucocorticoid secreted during stress responses, has a range of actions that help birds respond to stressors. Although effects of corticosterone treatment have been described in several avian species, the impacts of defined increases in plasma corticosterone on early development and on corticosterone stress responses are little known.(More)
In the present study, we sought to determine whether low-grade, chronic vascular insufficiency induced in a rodent model of chronic cerebrohypoperfusion is sufficient, in and of itself, to trigger cleavage of the amyloid precursor protein (APP) into beta A-sized fragments. We report that chronic two vessel occlusion (2VO) results in progressive accumulation(More)