Fig. 1

Behavioral assessments. Rats treated with high-fat, high-protein, low-calorie, low-calorie high-protein diets for 10 weeks. Control adult and old rats treated with rodent standard pellet. After 10 weeks, behavioral tests were performed (n = 7). Anxiety-like behavior was assessed by elevated plus maze test (EPM) for 5 min. Percentage of open arm time (a) and percentage of open arm entires (b) in the EPM were shown. Center occupancy (d) and locomotion (c) were assessed by open field test for 5 min (n = 7). Percentage of recognition index (e) was measured by novel object recognition test (n = 7). A represented tracks showing 2 min path in the NOR (f). Data were presented as Mean ± S.E.M. ***P < 0.001 ver. Adult-C, ##P < 0.01, ###P < 0.001 ver. Old-C. $P < 0.05 ver. High-protein. Adult-C adult control rats, Old-C old control rats