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Participación de los mecanismos pre y postsinápticos en la potenciación postetánica en las sinapsis de Aplysia
J X Bao1, E R Kandel, R D Hawkins
1Center for Neurobiology and Behavior, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
Science (New York, N.Y.)
|February 14, 1997
Resumen
La potenciación posttetánica (PTP), una forma de plasticidad sináptica, es típicamente vista como presináptica. Este estudio revela que la PTP también involucra mecanismos postsinápticos, lo que desafía la teoría presináptica de larga data.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Biología celular Biología celular.
- La plasticidad sináptica.
Sus antecedentes:
- La potenciación posttetánica (PTP) es una forma bien establecida de plasticidad sináptica a corto plazo.
- La PTP tradicionalmente se atribuye únicamente a los mecanismos presinápticos que influyen en la liberación de los neurotransmisores.
Objetivo del estudio:
- Para investigar los mecanismos precisos que subyacen a la PTP en las sinapsis de las neuronas motor-sensoriales de Aplysia.
- Para determinar si la PTP involucra únicamente componentes presinápticos o si los factores postsinápticos contribuyen.
Principales métodos:
- Los experimentos utilizaron las sinapsis de las neuronas motoras sensoriales de Aplysia en cultivos celulares.
- Se realizaron inyecciones presinápticas y postsinápticas de quelantes de calcio.
- Se indujo la hiperpolarización postsináptica para evaluar su efecto en la PTP.
Principales resultados:
- La quelación presináptica de calcio redujo la PTP y aumentó la frecuencia del potencial postsináptico excitador espontáneo, pero no la amplitud.
- La inyección postsináptica de un quelante rápido de calcio también redujo la PTP.
- La hiperpolarización postsináptica también disminuyó la PTP, lo que indica una participación postsináptica.
Conclusiones:
- La PTP en estas sinapsis no está mediada exclusivamente por mecanismos presinápticos.
- Un mecanismo de inducción postsináptica contribuye significativamente a la PTP.
- Estos hallazgos requieren una comprensión revisada de la plasticidad sináptica a corto plazo.
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