Chronic Administration Of Docosahexaenoic Acid Improves The Performance Of Radial Arm Maze Task In Aged Rats

Abstract

1. In the present study, we investigated the effect of docosahexaenoic acid (DHA) on spatial memory related learning ability in aged (100 weeks) male Wistar rats. 2. Rats were fed a fish oil-deficient diet through three generations and were then randomly divided into two groups. Over 10 weeks, one group was per orally administered 300 mg/kg per day DHA dissolved in 5% gum Arabic solution and the other group was administered the vehicle alone. Five weeks after the start of the administration, rats were tested with the partially baited eight-arm radial maze to estimate two types of spatial memory related learning ability displayed by reference memory error and working memory error. 3. Chronic administration of DHA significantly decreased the number of reference memory errors and working memory errors. 4. The level of lipid peroxide (LPO) in the hippocampus tended to decrease with chronic DHA administration and demonstrated a positive correlation with the number of reference memory errors. 5. These results suggest that the accumulation of hippocampal LPO reduces spatial memory related learning ability in aged rats. Moreover, chronic administration of DHA was effective in decreasing the level of hippocampal LPO, then improving learning ability.

Royal jelly and its unique fatty acid, 10-hydroxy-trans-2-decenoic acid, promote neurogenesis by neural stem/progenitor cells in vitro

“…Cell protein (5 µg) was separated on a 10% gel of SDS-PAGE, and ERK1/2, its phosphorylated forms (A), and CREB and its phosphorylated forms (B) were detected by Western immunoblotting using the respective specific antibodies. DHA is essential for normal brain development (7), and its chronic oral administration enhances longterm memory in young and aged rats (5,6). A reduction in DHA concentration in brain impairs the spatial learning tasks regulated by olfactory bulb, where neurogenesis occurs in adulthood (8).…”

Assessment of nutritional interventions for modification of age-associated cognitive decline using a canine model of human aging

“…In Alzheimer's patients, cholestryl ester-DHA levels, a biomarker for DHA, is negatively correlated with the severity of dementia (Tully et al 2003). DHA also is thought to possess antioxidant properties (Gamoh et al 2001;Hashimoto et al 2002); thus supplementation should serve to replace oxidized DHA present in phospholipids. Furthermore, DHA readily toggles between several conformations, thereby allowing the membrane phospholipids to adapt to the changes in receptor or ion channel conformations (Huber et al 2002;Koenig et al 1997).…”

Chronic administration of DHA and UMP improves the impaired memory of environmentally impoverished rats

“…Consumption of DHA during development [15] or by aged rats [16] can improve learning and memory, and chronic administration of either the uridine source UMP, or especially, of DHA, can increase brain phosphatide levels [14].…”