2006 Annual Report 4d.Progress report. This report serves to document research conducted under a Cooperative Trust Agreement between ARS and the California Walnut Commission. The initial findings have been analyzed from our first study in which we assessed Morris water maze and motor performance in senescent rats maintained for 8 weeks on a control diet or one containing 2% blueberry extract (BB), 2% walnut powder, or 1% BB and 1% walnut powder. Results indicated that, overall, either BB or walnut supplementation produced increases in the mean difference between Trial 1 and Trial 2 performance in the Morris water maze, indicating a greater degree of memory for the platform location in the supplemented groups than in the control group. Initial analysis of the motor behavioral data indicated that there was some increase in performance in all of the supplemented groups in rotorod performance. However, we are still analyzing these and other results and will also be correlating these with our measurements of neuronal function. 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.