Biomaterial Database

Retinal noise, the performance of retinal ganglion cells, and visual sensitivity in the dark-adapted frog. 1987

A C Aho, and K Donner, and C Hydén, and T Reuter, and Orlov OYu

Department of Zoology, University of Helsinki, Finland.

By extracellular recording of action potentials from single ganglion cells in the dark-adapted eyecup of the frog, we show that four different characteristics of a cell, the frequency-of-response function, the variability in responses to low suprathreshold stimulation, the maintained discharge, and the susceptibility to desensitization by weak background lights, all seem to reflect the same intrinsic noise. In a small fraction of reliable cells this noise is close to that expected from dark isomerizationlike events in rods, but it differs by orders of magnitude between cells. We have also determined a threshold intensity for the phototactic jumping behavior of frogs in darkness. This intensity, while below the human threshold, is still above the threshold for an appreciable fraction of frog retinal ganglion cells, and the sensitivity of this visually guided behavior at 16 degrees C is not strictly limited by dark events in rods.

UI	MeSH Term	Description	Entries
D008029	Lighting	The illumination of an environment and the arrangement of lights to achieve an effect or optimal visibility. Its application is in domestic or in public settings and in medical and non-medical environments.	Illumination
D011896	Rana temporaria	A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.	European Common Frog,Frog, Common European,Common European Frog,Common Frog, European,European Frog, Common,Frog, European Common
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
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
D004056	Differential Threshold	The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold.	Difference Limen,Just-Noticeable Difference,Weber-Fechner Law,Difference Limens,Difference, Just-Noticeable,Differences, Just-Noticeable,Differential Thresholds,Just Noticeable Difference,Just-Noticeable Differences,Law, Weber-Fechner,Limen, Difference,Limens, Difference,Threshold, Differential,Thresholds, Differential,Weber Fechner Law
D004560	Electricity	The physical effects involving the presence of electric charges at rest and in motion.
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001522	Behavior, Animal	The observable response an animal makes to any situation.	Autotomy Animal,Animal Behavior,Animal Behaviors
D012165	Retinal Ganglion Cells	Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.	Cell, Retinal Ganglion,Cells, Retinal Ganglion,Ganglion Cell, Retinal,Ganglion Cells, Retinal,Retinal Ganglion Cell