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An Isolated Retinal Preparation to Record Light Response from Genetically Labeled Retinal Ganglion Cells
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Células ganglionares retinianas que contienen melanopsina: arquitectura, proyecciones y fotosensibilidad intrínseca
1Howard Hughes Medical Institute and Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA.
Science (New York, N.Y.)
|February 9, 2002
Resumen
La melanopsina, un pigmento visual en las células ganglionares de la retina (RGC), impulsa el fotoentrenamiento circadiano. Este descubrimiento aclara cómo las señales de luz establecen el reloj biológico de los mamíferos a través de funciones visuales que no forman imágenes.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Cronobiología cronobiología.
- Biología Molecular Biología Molecular
Sus antecedentes:
- El núcleo supraquiasmático (SCN) actúa como el marcapasos circadiano de los mamíferos.
- Las señales de luz de los ojos fotoentrainan el SCN a través del tracto retinohipotálamico.
- Las células de bastón y cono no son esenciales para este proceso de arrastre de luz.
Objetivo del estudio:
- Investigar el papel de la melanopsina en el fotoentrenamiento del SCN.
- Para identificar los fotorreceptores específicos responsables de las funciones visuales que no forman imágenes.
- Para determinar si la melanopsina sirve como pigmento visual en estas células ganglionares retinianas especializadas (CGR).
Principales métodos:
- La clonación de melanopsina de rata y la generación de anticuerpos específicos.
- Análisis inmunohistoquímico para detectar la localización de melanopsina en RGCs de rata.
- Utilizando ratones transgénicos tau-lacZ para rastrear las proyecciones de RGC a la SCN.
Principales resultados:
- La melanopsina se detectó en los cuerpos celulares, dendritas y axones proximales de un subconjunto de RGCs de rata.
- Los axones de los RGC positivos para la beta-galactosidasa (que indican la expresión génica de la melanopsina) se proyectan hacia el SCN y otros núcleos cerebrales relevantes.
- Las RGCs de ratas intrínsecamente fotosensibles a la luz se expresan de manera consistente en melanopsina.
Conclusiones:
- La melanopsina está fuertemente indicada como el pigmento visual en las RGCs fototransductoras.
- Estos RGCs que contienen melanopsina son cruciales para establecer el reloj circadiano.
- La melanopsina facilita las funciones visuales que no forman imágenes, incluido el fotoentrenamiento circadiano y el reflejo de luz pupillar.
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