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Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo
Published on: March 31, 2016
La demanda metabólica relativa de la inhibición y la excitación
D Waldvogel1, P van Gelderen, W Muellbacher
1Human Motor Control Section, NINDS, NIH, Bethesda, Maryland 20892, USA.
Nature
|September 13, 2000
Resumen
La inhibición cerebral es menos metabólicamente exigente que la excitación. Este estudio utilizó imágenes de resonancia magnética funcional para demostrar que la inhibición de la corteza motora no cambia la señal dependiente del nivel de oxígeno en la sangre, lo que sugiere impulsos de excitación.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- La neuroenergética es la neuroenergética.
- Neurociencia cognitiva y neurociencia cognitiva.
Sus antecedentes:
- La inhibición es un proceso sináptico metabólicamente activo, evidenciado por (14C) 2-deoxyglucose y estudios de espectroscopia de resonancia magnética.
- Las sinapsis inhibidoras son menos y están mejor posicionadas que las excitatorias, lo que sugiere un potencial para una mayor eficiencia metabólica.
Objetivo del estudio:
- Para probar la hipótesis de que la inhibición neural consume menos energía que la excitación neural.
- Para investigar las demandas metabólicas de la inhibición en la corteza motora humana utilizando neuroimagen funcional.
Principales métodos:
- Imágenes de resonancia magnética funcional (IRMf) relacionadas con eventos en voluntarios humanos.
- Inhibición de la corteza motora inducida durante la condición no-go de una tarea go/no-go.
- Estimulación magnética transcraneal (EMT) para confirmar la inhibición cortical.
Principales resultados:
- La inhibición de la corteza motora no produjo un cambio medible en la señal dependiente del nivel de oxígeno en la sangre (BOLD).
- Esto contrasta con los cambios esperados en la señal BOLD asociados con la excitación neural.
- Los hallazgos indican que la inhibición es metabólicamente menos exigente que la excitación.
Conclusiones:
- La inhibición neural requiere menos energía metabólica en comparación con la excitación neural.
- La "activación" observada en los estudios de imágenes funcionales probablemente refleja procesos excitatorios en lugar de inhibidores.
- Esta investigación aclara los distintos perfiles metabólicos de excitación e inhibición en el cerebro.
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