Axon termination conditions for electrical stimulation.
IEEE Trans Biomed Eng
; 40(7): 654-63, 1993 Jul.
Article
em En
| MEDLINE
| ID: mdl-8244426
ABSTRACT
The cable model for electrical stimulation near the terminal of a passive fiber is derived for excitation by an arbitrary, time-varying, applied extracellular field. Unless the termination impedance is comparable to that of mammalian node of Ranvier, the end-conditions require the longitudinal intracellular current at the fiber terminal to be negligibly small. This requirement substantially alters the membrane potential profile from that obtained with a fiber of infinite length. Stimulation near the end of a fiber may result in lower thresholds and may reverse the anodal/cathodal threshold ratio obtained with stimulation in the mid-portion of the fiber. Chronaxie for stimulation near the terminal may be much smaller than at a distance from the terminal and the strength-duration curve may be nonmonotonic. These differences may have significant implications for any application of electrical stimulation where fiber terminations may play a role in the excitatory process.
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Bases de dados:
MEDLINE
Assunto principal:
Terminações Pré-Sinápticas
Limite:
Humans
Idioma:
En
Revista:
IEEE Trans Biomed Eng
Ano de publicação:
1993
Tipo de documento:
Article