Video Experimental Relacionado
Updated: May 6, 2026
14:35
Single-cell Suction Recordings from Mouse Cone Photoreceptors
Published on: January 6, 2010
11.3K
La melanopsina y los sistemas fotorreceptivos de bastón y cono representan todas las principales funciones visuales
S Hattar1, R J Lucas, N Mrosovsky
1Howard Hughes Medical Institute and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Nature
|June 17, 2003
Resumen
La retina de los mamíferos utiliza tanto el sistema bastón-cónico como el de la melanopsina para la visión y la regulación circadiana. Estos sistemas trabajan juntos para controlar los reflejos de la pupila y el arrastre de la luz.
Área de la Ciencia:
- Oftalmología Oftalmología.
- La neurociencia es la neurociencia.
- Cronobiología cronobiología.
Sus antecedentes:
- Las retinas de los mamíferos poseen fotorreceptores bastón-cono y un sistema de expresión de melanopsina.
- El sistema de melanopsina media en las funciones visuales accesorias como el reflejo de luz pupillar y el foto-entrainamiento circadiano.
- La ablación de la melanopsina afecta parcialmente estas funciones, lo que sugiere que pueden estar involucrados otros sistemas fotorreceptivos.
Objetivo del estudio:
- Investigar las funciones de los sistemas bastón-cónico y melanopsina en las funciones visuales accesorias de los mamíferos.
- Para determinar si los sistemas fotorreceptivos adicionales contribuyen al reflejo de la luz pupillar y la regulación del ritmo circadiano.
Principales métodos:
- Medición del espectro de acción para el cambio de fase del ritmo circadiano en ratones con ablación de bastón y cono.
- Comparación de este espectro con el reflejo de luz pupillar y la fotosensibilidad a la melanopsina.
- Generación de ratones que carecen tanto de melanopsina como de fototransducción bastón-cono.
Principales resultados:
- El espectro de acción para el cambio de fase del ritmo circadiano en ratones con ablación de bastón y cono coincidía con el espectro reflejo de luz pupillar y la fotosensibilidad a la melanopsina.
- Los ratones que carecían de melanopsina y conos de varillas funcionales mostraron un deterioro completo del reflejo de la pupila, el arrastre del ciclo de luz / oscuridad y la respuesta de enmascaramiento de luz.
Conclusiones:
- Los sistemas fotorreceptivos del cono-varilla y la melanopsina son esenciales y colectivamente responsables de toda la entrada fotónica en las funciones visuales accesorias.
- Estos dos sistemas parecen ser los únicos que contribuyen al reflejo de la luz pupillar, al foto-entrenamiento circadiano y a las respuestas de enmascaramiento a la luz.
Videos de Conceptos Relacionados
01:32The Retina
56.7K
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.
56.7K
01:24Vision
48.6K
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.
48.6K
01:11Channel Rhodopsins
2.5K
Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins.
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
2.5K
01:20Anatomy of the Eyeball
8.6K
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...
8.6K
01:22Photoreceptors and Visual Pathways
8.5K
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,...
8.5K
01:26Visual System
2.3K
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...
2.3K