Amount and distribution of lipofuscin in nerve and satellite cells from spinal ganglia of young adult and aged rabbits.
The quantitative aspects of the age-related accumulation of lipofuscin were studied in the rabbit spinal ganglia by stereological methods using the electron microscope. Both neurons and their associated satellite cells were examined. In neurons, the shape and structure of lipofuscin bodies differed in young adults (12-months-old) compared to aged rabbits (79-months-old), whereas substantial changes were not observed in satellite cells. Both in nerve and satellite cells, lipofuscin bodies were scattered singly in young adults, but were often clustered in old animals. Lipofuscin occupied an average of 0.36% of neuronal perikaryal volume in the young adults and 2.55% in the aged rabbits; these percentages are much lower than those observed in the same neurons of other species. In the satellite cells, the corresponding values were 0.29% and 2.02%. In the young adults, the mean size of lipofuscin bodies was significantly greater in neurons than in satellite cells; the size of these bodies increased with age by about 2.7 times in neurons and by about 1.7 times in satellite cells. Consequently, in the old rabbits the mean size of lipofuscin bodies was about 2.2 times greater in neurons than in satellite cells. It has been suggested that lipofuscin bodies are transferred from the neuronal perikaryon to the surrounding satellite cells and then removed via the capillaries. However, the present findings suggest that lipofuscin located in satellite cells represents pigment formed by these cells rather than being transferred from neuronal perikaryon. It would appear that the age-related accumulation of lipofuscin in the rabbit spinal ganglia has little effect on neuronal metabolism.
Ledda
M
M
Institute of Histology, Embryology and Neurocytology, University of Milan, Italy.
Barni
L
L
Altieri
L
L
Pannese
E
E
D000375:Aging; D000818:Animals; D005727:Ganglia, Spinal / Q000737:chemistry*; D006801:Humans; D008062:Lipofuscin / Q000032:analysis*; D008297:Male; D008854:Microscopy, Electron; D009474:Neurons / Q000737:chemistry*; D011817:Rabbits; D013045:Species Specificity
D008062:Lipofuscin