Related Experiment Video
Updated: Jul 27, 2026
13:02
An Isolated Retinal Preparation to Record Light Response from Genetically Labeled Retinal Ganglion Cells
Published on: January 26, 2011
Ganglion cell pathways for rod vision
1Department of Psychology, University of Rochester, NY 14627.
Vision Research
|February 1, 1994
Summary
Rod vision acuity shows minimal change with eccentricity. Beyond 15 degrees, P-cell sampling predicts acuity, but it drops closer to the fovea, not reaching M-cell limits even at 5 degrees.
Area of Science:
- Visual neuroscience
- Retinal physiology
Background:
- Rod vision is crucial for low-light conditions.
- Understanding retinal ganglion cell function is key to visual processing.
Purpose of the Study:
- To investigate how rod vision acuity changes with eccentricity.
- To compare measured acuity with the sampling limits of retinal ganglion cell mosaics.
Main Methods:
- Measurements of rod vision acuity using two distinct techniques.
- Analysis of ganglion cell (P-class and M-class) sampling properties.
Main Results:
- Rod vision acuity varies slightly with eccentricity.
- Acuity beyond 15 degrees eccentricity is predicted by P-cell sampling.
- Closer to the fovea, acuity falls below P-cell limits but remains above M-cell limits.
Conclusions:
- P-cell sampling properties primarily influence rod vision acuity at larger eccentricities.
- Rod vision at 5 degrees eccentricity can be supported by a small fraction of P-cells, suggesting significant neural convergence.
Related Concept Videos
01:32The Retina
The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.
01:24Vision
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
01:20Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
01:22Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
01:26Visual System
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Once through the pupil, the light passes through the lens, a...
01:24Color Vision
Color perception begins in the retina, the light-sensitive layer at the back of the eye. Two main theories explain how colors are seen: the trichromatic theory and the opponent-process theory. The trichromatic theory, proposed by Thomas Young in 1802 and extended by Hermann von Helmholtz in 1852, suggests that color vision is based on three types of cone receptors in the retina. These cones are sensitive to different but overlapping ranges of wavelengths corresponding to red, blue, and green.