title: 24-hour rhythmicity of NADPH-diaphorase activity in the neuropil of rat visual cortex.
abstract: In the present study we examined the daytime-dependent alterations of nitric oxide synthase in the visual cortex of the rat. For this purpose, the activity of the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d), an enzyme equivalent to nitric oxide synthase, was measured histochemically in rat visual cortex at 0600, 1200, 1800, and 2400 h using a photometric scanning method. Our results show day-time-dependent changes of the NADPH-d activity in the neuropil of the visual cortex. This was highest at 0600 h and decreased between 1200 h and 1800 h (unimodal profile of circadian activity). The number of NADPH-d-positive neuronal somata was not found to vary at the different time points.
authors.affiliation: Paul-Flechsig-Institute of Brain Research, Leipzig University, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Hilbig
authors.forename: K
authors.initials: K
authors.lastname: Punkt
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D008297:Male; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D009474:Neurons / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D014793:Visual Cortex / Q000502:physiology*
chemical_list: D009252:NADPH Dehydrogenase