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¿Es la neurosecreción hiperosmótica de las terminaciones nerviosas motoras un proceso dependiente del calcio?
Y Shimoni1, E Alnaes, R Rahamimoff
1Department of Physiology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Nature
|May 12, 1977
Resumen
La elevada osmolaridad del fluido extracelular aumenta significativamente la liberación de neurotransmisores de las terminaciones nerviosas. Esta neurosecreción hiperosmótica depende de la concentración de calcio intracelular, lo que tiene un impacto en la señalización nerviosa.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Biología celular Biología celular.
- Fisiología Fisiología Fisiología.
Sus antecedentes:
- La liberación espontánea de neurotransmisores está modulada por la presión osmótica del fluido extracelular.
- Las condiciones hiperosmóticas (aumento de la osmolaridad del 20-30%) mejoran la liberación de neurotransmisores de las terminaciones nerviosas motoras.
- El mecanismo de la neurosecreción hiperosmótica y su dependencia del calcio no se comprenden completamente.
Objetivo del estudio:
- Para investigar el papel de la concentración de calcio intracelular ([Ca]in) en la neurosecreción hiperosmótica.
- Para probar la hipótesis de que el aumento de [Ca]in causa la neurosecreción hiperosmótica.
- Para evaluar indirectamente [Ca]in en la sinapsis neuromuscular de la rana.
Principales métodos:
- Utilizó una técnica indirecta para estimar la concentración de calcio intracelular ([Ca]in) en la sinapsis neuromuscular de la rana.
- Se asume el potencial de la placa de extremo en miniatura (m.e.p.p.) la frecuencia refleja [Ca] en.
- Se examinó el efecto de la conductancia alterada del calcio (g ((Ca)) y los gradientes electroquímicos en la neurosecreción hiperosmótica.
Principales resultados:
- Se encontró que la neurosecreción hiperosmótica es dependiente de la concentración de calcio intracelular ([Ca]in).
- El estudio proporciona evidencia que vincula el aumento de [Ca]in con una mayor liberación de neurotransmisores en condiciones hiperosmóticas.
- Las mediciones indirectas sugieren una correlación entre m.e.p.p. frecuencia y [Ca]in.
Conclusiones:
- La neurosecreción hiperosmótica es dependiente de la concentración de calcio intracelular ([Ca]in).
- Los hallazgos apoyan la hipótesis de que la [Ca]in elevada media los efectos del estrés hiperosmótico en la liberación de neurotransmisores.
- Esta investigación contribuye a comprender la regulación de la transmisión sináptica.
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