Biomaterial Database

[Additions to the theory of the dual nature of photoreception]. 1990

A S Novokhatskiĭ

On the grounds of clinico-physiologic investigations the author revises the existing dual theory of photoreception. The paper describes complex clinical investigations of visual functions in patients with alimentary and essential hemeralopias and shows that rods and cones do not function in conditions of scotopic illumination without the presence of rhodopsin. On the grounds of investigations of the phenomenon of inversion and depression in the short-wave part of the visible spectrum in normal persons after dark adaptation in conditions of scotopic illumination, the author comes to a conclusion that there is a so-called "rhodopsin filter" just the presence of which in the process of dark adaptation creates conditions for appearance of this phenomenon. The author believes that there exist two kinds of photoreception: a direct disc two-component and a mediated rhodopsin one-component, as well as the third, transitory, that corresponds to those conditions of illumination in which the Purkinje's phenomenon appears.

UI	MeSH Term	Description	Entries
D010786	Photoreceptor Cells	Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.	Ciliary Photoreceptor Cells,Ciliary Photoreceptors,Rhabdomeric Photoreceptor Cells,Rhabdomeric Photoreceptors,Cell, Ciliary Photoreceptor,Cell, Photoreceptor,Cell, Rhabdomeric Photoreceptor,Cells, Ciliary Photoreceptor,Cells, Photoreceptor,Cells, Rhabdomeric Photoreceptor,Ciliary Photoreceptor,Ciliary Photoreceptor Cell,Photoreceptor Cell,Photoreceptor Cell, Ciliary,Photoreceptor Cell, Rhabdomeric,Photoreceptor Cells, Ciliary,Photoreceptor Cells, Rhabdomeric,Photoreceptor, Ciliary,Photoreceptor, Rhabdomeric,Photoreceptors, Ciliary,Photoreceptors, Rhabdomeric,Rhabdomeric Photoreceptor,Rhabdomeric Photoreceptor Cell
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D003118	Color Perception	Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.	Color Perceptions,Perception, Color,Perceptions, Color
D003623	Dark Adaptation	Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.	Scotopic Adaptation,Adaptation, Dark,Adaptation, Scotopic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012243	Rhodopsin	A purplish-red, light-sensitive pigment found in RETINAL ROD CELLS of most vertebrates. It is a complex consisting of a molecule of ROD OPSIN and a molecule of 11-cis retinal (RETINALDEHYDE). Rhodopsin exhibits peak absorption wavelength at about 500 nm.	Visual Purple
D014794	Visual Fields	The total area or space visible in a person's peripheral vision with the eye looking straightforward.	Field, Visual,Fields, Visual,Visual Field