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El glutamato activa localmente las salidas dendríticas de las interneuronas del tálamo
1Department of Neurobiology, State University of New York, Stony Brook 11794-5230, USA.
Nature
|August 11, 1998
Resumen
Las interneuronas tálamicas utilizan terminales dendríticos únicos para controlar el flujo de información a la corteza. La activación del receptor de glutamato metabotrópico en estas dendritas inhibe las neuronas transmisoras, lo que sugiere cálculos independientes.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- La neurociencia celular es la neurociencia celular.
- Los sistemas sensoriales son sistemas sensoriales.
Sus antecedentes:
- El relé de información desde el tálamo a la corteza está cerrado dinámicamente.
- Las interneuronas inhibidoras en el núcleo geniculado lateral (LGN) son cruciales para esta entrada.
- Las interneuronas tálamicas poseen estructuras dendríticas únicas con doble función pre y postsináptica.
Objetivo del estudio:
- Para investigar la función de las terminaciones dendríticas distales de las interneuronas LGN.
- Para determinar si los receptores metabotrópicos de glutamato (mGluR) en estas dendritas pueden modular la actividad neuronal.
- Para explorar las capacidades computacionales de las interneuronas del tálamo.
Principales métodos:
- Registros electrofisiológicos (somáticos) de las interneuronas LGN.
- Aplicación de los agonistas de mGluR.
- Análisis de los arreglos sinápticos triádicos que involucran a los terminales de la retina, las dendritas de las interneuronas y las dendritas de las neuronas transmisoras.
Principales resultados:
- Los agonistas de la mGluR activaban las terminales dendríticas de las interneuronas, inhibiendo las neuronas relevadoras postsinápticas.
- La activación se produjo en ausencia de potenciales de acción en las interneuronas.
- Las grabaciones somáticas no mostraron respuesta a los agonistas de mGluR, lo que indica un aislamiento eléctrico dendrítico.
Conclusiones:
- Los terminales dendríticos de las interneuronas del LGN pueden calcular y modular de forma independiente la transmisión sináptica.
- Las interneuronas tálamicas exhiben funciones computacionales distintas a través de salidas axonales versus dendríticas.
- Este estudio proporciona información sobre el funcionamiento de los circuitos triádicos en la LGN.
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