title: Changes of cytochrome oxidase activity in rat suprachiasmatic nucleus.
abstract: This paper evaluates the changes of cytochrome oxidase (CO) activity that take place in the suprachiasmatic nucleus (SCN) during the light-dark cycle. CO is a mitochondrial energy-generating enzyme used as a marker of neural oxidative metabolism. We measured CO activity using quantitative histochemistry calibrated with brain tissue standards and a computerized analysis image system. The results indicate that the CO enzyme activity changes on the basis of a circadian pattern, with the higher levels during the light phase (P < 0.0001). These changes are detected over a period of hours, in accordance with other studies on the possible short-term regulation of CO activity in the nervous system. It is, therefore, possible to apply this methodology to the study of the SCN and other brain areas which show functional rhythmicity.
authors.affiliation: Psychobiology Laboratory, Psychology Faculty, University of Oviedo, Spain.
authors.forename: L
authors.initials: L
authors.lastname: López
authors.forename: L
authors.initials: L
authors.lastname: Lorente
authors.forename: J
authors.initials: J
authors.lastname: Arias
authors.forename: H
authors.initials: H
authors.lastname: González-Pardo
authors.forename: J
authors.initials: J
authors.lastname: Cimadevilla
authors.forename: J L
authors.initials: JL
authors.lastname: Arias
mesh_terms: D000818:Animals; D003576:Electron Transport Complex IV / Q000378:metabolism*; D006651:Histocytochemistry / Q000379:methods; D008027:Light; D008297:Male; D017440:Photoperiod; D051381:Rats; D013194:Staining and Labeling; D013493:Suprachiasmatic Nucleus / Q000201:enzymology* / Q000528:radiation effects
chemical_list: D003576:Electron Transport Complex IV