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Cytochrome Oxidase Activity in Hippocampal Synaptic Mitochondria during Aging: A Quantitative Cytochemical Investigation
Author(s) -
BERTONIFREDDARI CARLO,
FATTORETTI PATRIZIA,
GIORGETTI BELINDA,
SOLAZZI MORENO,
BALIETTI MARTA,
CASOLI TIZIANA,
STEFANO GIUSEPPINA
Publication year - 2004
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1297.007
Subject(s) - mitochondrion , cytochrome c oxidase , organelle , hippocampal formation , dentate gyrus , biology , ultrastructure , oxidative phosphorylation , endogeny , microbiology and biotechnology , chemistry , biochemistry , neuroscience , anatomy
A bstract : Synaptic mitochondria, cytochemically positive to cytochrome oxidase (COX) activity, were investigated by morphometric methods in the hippocampal dentate gyrus of adult and old rats. The number of mitochondria/μm 3 of tissue (Nv), the volume fraction occupied by mitochondria/μm 3 of tissue (Vv), the average mitochondrial volume (V), the longer mitochondrial diameter (F max ), and the ratio R:mitochondrial area/overall area of the cytochemical precipitate due to COX activity were measured on COX‐positive organelles. In old animals, Nv, Vv, V, and F max increased at a not significant extent; R was not significantly decreased. The complement (%) of longer organelles was higher in old animals. COX activity is currently considered an endogenous marker of neuronal oxidative metabolism; thus, although our findings refer to the discrete subpopulation of COX‐positive organelles located at synaptic terminals, they support that changes of mitochondrial ultrastructure and metabolic competence may contribute to the age‐related alterations of neuronal performances.