THE EFFECT OF CALORIC RESTRICTION ON LIPOFUSCIN ACCUMULATION IN MOUSE-BRAIN WITH AGE

Caloric restriction (CR), has been shown to extend average and maximum lifespan in rodents and other animals as well as to delay a wide vari ety of manifestations of aging. The purpose of this study was to furth er elucidate the relationship between lipofuscin (LF) accumulation and the aging process by examining the effect of lifelong CR on LF accumu lation in brain cells. Specifically, 1) we include age groups of CR (C RI congruent to 90 kcal/wk and CR2 congruent to 58 kcal/wk) and ad lib idum fed (AL; similar to 120 kcal/wk) mice including groups at maximum lifespan; 2) CR was the major dietary manipulation; 3) LF was identif ied using EM; 4) LF was quantified by areal measurement; and 5) the re sults were analyzed by inferential statistics. We have found that 1) L F increased with age and 2) that animals in the CR2 group had signific antly less overall LF in the perikarya of the granule cells of the den tate gyrus when compared to CR1 or AL animals at equivalent ages. In a ddition, CR2 mice at maximum lifespan (45 mo.) had slightly less LF th an did CR1 or AL mice at their maximum lifespans (36 mo.). Our results clearly demonstrate that CR (at 52%, but not 25% of AL diet) retards the overall accumulation of LF with time and, further, suggest that LF accumulation is not simply a linear function of age.