The effect of age and caloric restriction on the ultrastructure and pattern of lipofuscin accumulation in granule cells of the dentate gyrus of the hippocampus of C3B10RF1 female mice, a morphometric analysis

grantor: University of TorontoMagnitude, rate and distribution pattern of lipofuscin accumulation, within populations of neurons, were assessed under three conditions of life long caloric restriction at three adult ages, in C3810RF1 mice. Perikaryal lipofuscin was quantified by morphometric techniques applied to electron micrographs of granule cells of the dentate gyrus. Results were analysed by descriptive and inferential statistics. Full caloric restriction decreased the magnitude and rate of total perikaryal lipofuscin accumulation in populations of cells, and attenuated a number of the age related changes in the intercellular distribution pattern of lipofuscin including the mean, variance and skewness. It is proposed that lipofuscin is a marker for the primary process of senescence, hypothesised to be the increasing intrusion of entropic events in metabolically vulnerable cells. Increased variability of metabolic function among cells with age, as measured by increasing intercellular variability of lipofuscin, may represent a definitive mechanism underlying the decreased functional reserve seen in tissue with age.M.Sc