MIDLIFE ONSET OF DIETARY RESTRICTION EXTENDS LIFE AND PROLONGS COGNITIVE-FUNCTIONING

Fourteen-month-old C57BL/6 (NIA) mice were placed on a nutritionally c omplete diet providing 139.4 kcal/week. Over a 2-month period the food ration of experimental mice (AE) was reduced to 85 kcal/week, where i t remained for the duration of the study. An aged control group (AC) c ontinued with the higher calorie diet. At age 22 months, AC mice and h alf of the AE mice (AE22) were given a battery of behavioral tests. Th e remaining AE mice (AE25) were given the test battery at age 25 month s. Also, a middle-aged control group (MC) was tested at age 13 months. Mid-life onset caloric restriction (CR) increased longevity and prese rved strength, coordination, and spontaneous alternation behavior, and altered responses to enclosed alleys. A spatial discrimination in the Morris water maze and a spatial delayed matching-to-sample water-esca pe task were insensitive to age and diet. The aged mice were adversely affected by testing.