Synonyms
Definition
Electrical impulses (action potentials (APs) or spikes) which encode and transmit information in the nervous system are initiated in the proximal anatomical region of the axon termed axon initial segment (AIS). The voltage threshold for spike initiation and the exact location and length of the spike trigger zone (TZ) within AIS, as well as the amplitude and waveform of the action potential in different neuronal classes, depend on the geometry and passive electrical properties of a neuron as well as on the type, spatial distribution, and density of a variety of voltage-sensitive ionic channels.
Detailed Description
There is little disagreement over attributing action potential initiation to a site in the axon initial segment (AIS) under most circumstances. The question of the exact location and length, however, of the spike trigger zone (TZ) in the axon, as defined in functional terms, is less clear. In most studies, the spike TZ was characterized by...
References
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Further Reading
Bender KJ, Trussell LO (2012) The physiology of the axon initial segment. Annu Rev Neurosci 35:249–265
Buffington SA, Rasband MN (2011) The axon initial segment in nervous system disease and injury. Eur J Neurosci 34:1609–1619
Debanne D, Campanac E, Bialowas A, Carlier E, Alcaraz G (2011) Axon physiology. Physiol Rev 91:555–602
Kole MH, Stuart GJ (2012) Signal processing in the axon initial segment. Neuron 73:235–247
Kuba H (2012) Structural tuning and plasticity of the axon initial segment in auditory neurons. J Physiol 590:5571–5579
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Zecevic, D., Popovic, M. (2014). Action Potential Initiation. In: Jaeger, D., Jung, R. (eds) Encyclopedia of Computational Neuroscience. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-7320-6_237-1
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DOI: https://doi.org/10.1007/978-1-4614-7320-6_237-1
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