title: Cytochrome oxidase activity in hippocampal synaptic mitochondria during aging: a quantitative cytochemical investigation.
abstract: 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/microm(3) of tissue (Nv), the volume fraction occupied by mitochondria/microm(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.
authors.affiliation: Neurobiology of Aging Laboratory, INRCA Research Department, Via Birarelli 8, 60121 Ancona, Italy. c.bertoni@inrca.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Bertoni-Freddari
authors.forename: Patrizia
authors.initials: P
authors.lastname: Fattoretti
authors.forename: Belinda
authors.initials: B
authors.lastname: Giorgetti
authors.forename: Moreno
authors.initials: M
authors.lastname: Solazzi
authors.forename: Marta
authors.initials: M
authors.lastname: Balietti
authors.forename: Tiziana
authors.initials: T
authors.lastname: Casoli
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Di Stefano
mesh_terms: D000375:Aging; D000818:Animals; D002490:Central Nervous System / Q000473:pathology; D018891:Dentate Gyrus / Q000473:pathology; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D008928:Mitochondria / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000473:pathology; D010100:Oxygen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000378:metabolism*
chemical_list: D003576:Electron Transport Complex IV; D010100:Oxygen