Influence of the shape of intracellular potentials on the morphology of single-fiber extracellular potentials in human muscle fibers

Attention of the investigators is usually pointed to the peak-to-peak characteristics of single-fiber action potentials (SFAPs) that are mainly determined by the depolarizing phase of the intracellular action potential (IAP). However, the final portion of the SFAP has often specific shape that has t...

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Detalles Bibliográficos
Autores: Rodríguez Falces, Javier, Navallas Irujo, Javier, Gila Useros, Luis, Malanda Trigueros, Armando, Dimitrova, Nonna Alexandrovna
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2012
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/55593
Acceso en línea:https://hdl.handle.net/2454/55593
Access Level:acceso abierto
Palabra clave:Intracellular action potential
IAP spike duration
SFAP third phase
SFAP morphology
Descripción
Sumario:Attention of the investigators is usually pointed to the peak-to-peak characteristics of single-fiber action potentials (SFAPs) that are mainly determined by the depolarizing phase of the intracellular action potential (IAP). However, the final portion of the SFAP has often specific shape that has to be related to peculiarities of the repolarization phase of IAP and the duration of its spike. A novel piecewise SFAP model is proposed to achieve greater insight into the nature of declining portion of the negative phase and of the third phase of SFAP. It was found that the SFAP third phase is essentially determined by the specific profile of the transition of the IAP falling phase toward the resting voltage, whereas the SFAP declining negative phase is more dependent upon the width of the corresponding IAP spike. We tentatively suggest that the duration of the spike of human IAPs should be over approximately 0.75 ms.