Morehead State University
Does Stress Worsen Alzheimer’s Symptoms?
Institution
Morehead State University
Faculty Advisor/ Mentor
Ilsun M. White
Abstract
Exposure to an extremely stressful situation impairs a range of behaviors, likely through multiple brain regions and the stress system, known as the hypothalamus-pituitary-adrenal (HPA) axis. Recent studies suggest that stressful events may worsen cognitive deficits in normal aging, dementia, and Alzheimer’s disease (ALZ). Our study examined the impact of stress on memory using an animal model. Male Wistar rats were used in this study in accordance with federal and institutional guidelines. In Experiment 1, rats were shaped to lever-press for food and divided into two groups: One group was placed in a restraint for 30 minutes (physiological stress); while another group was gently held (control). Rats were then trained on a simple learning task which required five lever-presses for each food pellet. Stress impaired acquisition of learning without affecting food consumption. In Experiment 2, rats were trained on the same task, then received scopolamine, a drug commonly used in animal models of ALZ. Scopolamine impaired memory and also affected food consumption. In Experiment 3, rats were trained on the same task, then received both scopolamine and stress hormone (pharmacological stress). Coadministration of scopolamine and stress hormone severely impaired memory. Our data suggest that stress impairs learning and memory of simple tasks and also predict that stress would worsen impaired memory seen in ALZ patients and that reducing exposure to stress would reduce this memory loss. Currently, we are examining sex differences in the effects of stress on memory. Zachary Abbott is an undergraduate research fellow. Supported by NIH grant: R15DA015351.
Does Stress Worsen Alzheimer’s Symptoms?
Exposure to an extremely stressful situation impairs a range of behaviors, likely through multiple brain regions and the stress system, known as the hypothalamus-pituitary-adrenal (HPA) axis. Recent studies suggest that stressful events may worsen cognitive deficits in normal aging, dementia, and Alzheimer’s disease (ALZ). Our study examined the impact of stress on memory using an animal model. Male Wistar rats were used in this study in accordance with federal and institutional guidelines. In Experiment 1, rats were shaped to lever-press for food and divided into two groups: One group was placed in a restraint for 30 minutes (physiological stress); while another group was gently held (control). Rats were then trained on a simple learning task which required five lever-presses for each food pellet. Stress impaired acquisition of learning without affecting food consumption. In Experiment 2, rats were trained on the same task, then received scopolamine, a drug commonly used in animal models of ALZ. Scopolamine impaired memory and also affected food consumption. In Experiment 3, rats were trained on the same task, then received both scopolamine and stress hormone (pharmacological stress). Coadministration of scopolamine and stress hormone severely impaired memory. Our data suggest that stress impairs learning and memory of simple tasks and also predict that stress would worsen impaired memory seen in ALZ patients and that reducing exposure to stress would reduce this memory loss. Currently, we are examining sex differences in the effects of stress on memory. Zachary Abbott is an undergraduate research fellow. Supported by NIH grant: R15DA015351.