title: Two realms of dark adaptation.
abstract: The recovery of rod responsiveness after saturating flashes is greatly retarded above a certain critical level of rhodopsin bleaching (approximately 0.1%). A mathematical description of the process of turn-off of the phototransduction cascade allows attributing different phases of the recovery to specific products of rhodopsin photolysis. The fast phase is determined by quenching of metarhodopsin II and activated transducin. The slow phase is controlled by decay of partially inactivated (phosphorylated and arrestin-bound) metarhodopsins, and by regeneration of rhodopsin. The transition between the two regimes of adaptation is rather abrupt, occurring within a few-fold range of stimulus intensity. This marks the border between reversal of light adaptation and dark adaptation, as it is commonly defined.
authors.affiliation: Institute for Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez Prospect, 194223 St. Petersburg, Russia.
authors.forename: M L
authors.initials: ML
authors.lastname: Firsov
authors.forename: A V
authors.initials: AV
authors.lastname: Kolesnikov
authors.forename: E Yu
authors.initials: EY
authors.lastname: Golobokova
authors.forename: V I
authors.initials: VI
authors.lastname: Govardovskii
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000818:Animals; D006152:Cyclic GMP / Q000502:physiology; D003623:Dark Adaptation / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011895:Rana ridibunda; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D012243:Rhodopsin / Q000031:analogs & derivatives* / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology
chemical_list: C013110:metarhodopsins; D012243:Rhodopsin; D006152:Cyclic GMP