2006 Annual Report 4d.Progress report. This report serves to document research conducted under a Trust Fund Cooperative Agreement between ARS and the California Strawberry Commission. Previously, we have shown that whole, crude berry extracts are able to reverse several parameters of brain aging, as well as age-related motor and cognitive deficits when fed to rats from 19-21 months of age. These effects may be the result of direct effects on brain signaling or indirect effects through antioxidant and anti-inflammatory properties of the polyphenols. The study conducted this year examined two different berryfruit diets (blueberry, BB and strawberry, SB) to determine whether the effects observed are indeed the result of differential effects of the polyphenols on the brain. Old (19 mo) F344 rats were fed a control, 2% BB, or 2% SB diet for 8 weeks prior to motor and cognitive testing. Results showed that SB-fed rats had improved performance compared to the BB-fed rats on the large plank. BB rats were better than SB rats on rod walking, while both diets improved motor function on the rotarod compared to control. Both berryfruit diets enhanced working memory in the Morris water maze. We are currently assessing regional localization of the BB and SB polyphenols and their putative differential effects on signaling parameters in these rats, with a view toward determining selective bioavailability and mechanism(s) of action. Additional details of this research can be found in the report for the parent project 1950-51000-063-00D Nutritional Modulation of Brain Aging and Cognitive Decline.