TY - JOUR
T1 - Cytochrome oxidase activity in hippocampal synaptic mitochondria during aging
T2 - A quantitative cytochemical investigation
AU - Bertoni-Freddari, Carlo
AU - Fattoretti, Patrizia
AU - Giorgetti, Belinda
AU - Solazzi, Moreno
AU - Balietti, Marta
AU - Casoli, Tiziana
AU - Di Stefano, Giuseppina
PY - 2004
Y1 - 2004
N2 - 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/ μm3 of tissue (Nv), the volume fraction occupied by mitochondria/μm3 of tissue (Vv), the average mitochondrial volume (V), the longer mitochondrial diameter (Fmax), 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 Fmax 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.
AB - 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/ μm3 of tissue (Nv), the volume fraction occupied by mitochondria/μm3 of tissue (Vv), the average mitochondrial volume (V), the longer mitochondrial diameter (Fmax), 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 Fmax 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.
KW - Cytochrome oxidase activity
KW - Hippocampus
KW - Mitochondrial metabolic competence
KW - Morphometry
KW - Synaptic mitochondria
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U2 - 10.1196/annals.1297.007
DO - 10.1196/annals.1297.007
M3 - Article
C2 - 15246989
AN - SCOPUS:3242728502
VL - 1019
SP - 33
EP - 36
JO - Annals of the New York Academy of Sciences
JF - Annals of the New York Academy of Sciences
SN - 0077-8923
ER -