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La despolarización sin calcio puede liberar ácido gamma-aminobutírico de una neurona de la retina
1Department of Pharmacological and Physiological Sciences, University of Chicago, IL 60637.
Science (New York, N.Y.)
|October 16, 1987
Resumen
La liberación de neurotransmisores de las neuronas de la retina puede ocurrir sin la afluencia de calcio. Este estudio muestra que los cambios de voltaje por sí solos pueden desencadenar la liberación de ácido gamma-aminobutírico, lo que sugiere una nueva vía de señalización.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Biología celular Biología celular.
- Neurofisiología de la neurofisiología.
Sus antecedentes:
- La liberación de neurotransmisores es típicamente dependiente del calcio.
- Algunas neuronas de la retina pueden utilizar mecanismos de liberación independientes del calcio.
- El papel de las reservas intracelulares de calcio y la liberación por voltaje no está claro.
Objetivo del estudio:
- Investigar si los cambios de voltaje, independientemente de la afluencia de calcio, pueden regular la liberación de neurotransmisores en las neuronas de la retina.
- Explorar mecanismos alternativos para la transmisión sináptica en la retina.
Principales métodos:
- Aislamiento y co-cultivo de neuronas de la retina de peces solitarios (células horizontales y bipolares).
- Grabaciones electrofisiológicas para estudiar la comunicación entre células.
- Manipulando el amortiguamiento del calcio intracelular y bloqueando la entrada de calcio.
Principales resultados:
- La despolarización de las células horizontales indujo la liberación de ácido gamma-aminobutírico.
- La liberación se produjo incluso cuando se bloqueó la afluencia de calcio y se amortiguó el calcio interno.
- La tasa de liberación y la cantidad observadas apoyaron un papel en la transmisión sináptica.
Conclusiones:
- Las neuronas de la retina pueden liberar neurotransmisores, como el ácido gamma-aminobutírico, a través de un mecanismo independiente del calcio.
- Los cambios de voltaje pueden regular directamente la liberación del transmisor, ofreciendo una nueva vía de señalización.
- Este hallazgo desafía el requisito universal de la afluencia de calcio para la neurotransmisión en la retina.
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