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Acciones mecánicas del agrandamiento de la columna dendrítica en la exocitosis presináptica
Hasan Ucar1,2, Satoshi Watanabe1,3, Jun Noguchi1,3
1Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
Nature
|November 25, 2021
Resumen
Las fuerzas mecánicas en los botones presinápticos mejoran la liberación de glutamato y el ensamblaje de la proteína SNARE. Este mecanismo mecanosensorial, que incluye la polimerización de actina, aumenta la transmisión sináptica durante más de 20 minutos.
Área de la Ciencia:
- La neurociencia
- Biología celular
- La biofísica
Sus antecedentes:
- La transmisión sináptica es crucial para la comunicación neuronal.
- El agrandamiento de la columna dendrítica durante el aprendizaje puede afectar mecánicamente la función presináptica.
- El papel de las fuerzas mecánicas en la transmisión sináptica no se entiende bien.
Objetivo del estudio:
- Para investigar los efectos mecánicos en los botones presinápticos.
- Identificar los mecanismos moleculares subyacentes de la mecanotransducción en la liberación sináptica.
- Para explorar cómo los cambios físicos en la sinapsis influyen en la liberación de neurotransmisores.
Principales métodos:
- Estimulación mecánica de los botones presinápticos mediante una pipeta de vidrio en cultivos en rodajas de rata.
- Medición de la liberación de glutamato y el ensamblaje de proteínas SNARE mediante transferencia de energía de resonancia Förster (FRET) y imágenes de fluorescencia durante toda la vida útil.
- Aplicación de soluciones hipertónicas de sacarosa para modular la actividad sináptica.
- Dos fotones de glutamato para inducir el agrandamiento de la columna.
Principales resultados:
- El empuje mecánico transitorio de los botones presinápticos aumentó la liberación de glutamato y el ensamblaje de la proteína SNARE.
- Estos efectos persistieron durante más de 20 minutos y fueron independientes del calcio citosólico.
- El ensamblaje de la proteína SNARE y la polimerización de la actina fueron críticos para la potenciación mecánica observada.
- El agrandamiento de la columna vertebral aumentó la liberación evocada y el FRET solo cuando ejerció presión física sobre los botones.
Conclusiones:
- Se identificó un nuevo mecanismo mecanosensorial y de transducción en los botones presinápticos.
- Las fuerzas mecánicas pueden aumentar significativamente la liberación de glutamato evocada y la formación de complejos SNARE.
- Este mecanismo proporciona información sobre cómo las señales físicas en la sinapsis regulan la comunicación neuronal y la plasticidad.
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