Computer-assisted morphometry of synaptic plasticity during aging and dementia.
A computer assisted morphometric study has been carried out on synaptic membranes in the dentate gyrus supragranular layer and cerebellar glomerulus from adult, old and demented patients. Numerical (Nv) and surface (Sv) densities as well as average area (S) of the synaptic contact zones were calculated directly on electron microscopic negatives by means of an ASBA (Wild Leitz, AG) image analyzer properly programmed. The results showed a decrease of Nv in both the CNS areas investigated during aging and, to a higher extent, in senile dementia. S was found to be significantly increased in old and demented CNS as compared with adult values. In the old hippocampus Sv was decreased by 40% whereas no significant difference was present between old and adult cerebellum; in senile dementia this parameter underwent a significant decrease in both areas investigated. We interpret the present findings in terms of morphological remodelling capability of the synaptic junctional zones during aging and disease.
Bertoni-Freddari
C
C
Center for Surgical Research, Gerontological Research Department of the INRCA, Ancona, Italy.
Fattoretti
P
P
Meier-Ruge
W
W
Ulrich
J
J
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D002531:Cerebellum / Q000473:pathology; D003704:Dementia / Q000473:pathology*; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D009473:Neuronal Plasticity; D013570:Synaptic Membranes / Q000473:pathology*