Investigation Of Exercise Prescription On Diet-induced Changes In Memory, Cognition, And Hippocampal BDNF Levels

PURPOSE: It is well-understood that exercise and diet choice can improve several facets of an individual’s cognitive health, but little is known about the use of exercise prescription for long-term memory loss due to chronic consumption of a “western diet.” Thus, this project examined the prescription of interval-running exercise as a way to mitigate diet-induced long-term memory and cognitive decline. METHODS: Male and female C57BL/6 mice were fed either a high-fat diet (HFD; 60% kcal from fat) or a control diet (CD; 14% kcal from fat) from postnatal day (PND) 21. At PND 56, groups from each diet either remained sedentary or underwent eight weeks of an interval-running paradigm with ten cycles of 60 seconds of work and 30 seconds of rest five days per week. At PND 84, long-term memory was tested using several retention tests in a radial arm maze (RAM). An object placement test (OPT) was also used, where subjects were tasked to remember the locations of two objects. After 24 hours of retention, subjects were measured on their abilities to discriminate between novel and original object placements. After OPT was completed, brain samples were collected to test for brain-derived neurotrophic factor (BNDF; Mouse BDNF ELISA Kit). RESULTS: As a combined function of errors and time, there was no performance difference in RAM between exercised CD and HFD subjects (p = .583). Exercised HFD subjects performed significantly better than sedentary HFD subjects (p < .001). In OPT, exercised HFD (p < .001) and CD (p < .001) subjects investigated the novel object placement significantly more than the original placement, while sedentary HFD (p = .071) and CD (p < .236) subjects showed no difference. While BDNF data are not fully collected, behavioral data suggest a difference between exercised and sedentary subjects. CONCLUSIONS: Exercise effectively mitigated long-term memory and cognitive decline. The lack of difference within exercised subjects matters, as it demonstrates the ability of exercise to improve memory performance compared to sedentary subjects. Investigative differences of novel and original object placements in exercised subjects also demonstrates improved memory and cognitive abilities. Results can be used to formulate personalized treatment plans for individuals suffering memory decline due to chronic HFD consumption. Supported by: University of North Georgia Psychological Sciences PARKS Foundation and UNG CURCA Student-Faculty Collaborative Mini-Grant