Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comment
. 2013 Mar 5;110(10):3715-6.
doi: 10.1073/pnas.1300520110. Epub 2013 Feb 25.

Reemerging role of cable properties in action potential initiation

Yunyong Ma  1 , John R Huguenard
Affiliations
Comment

Reemerging role of cable properties in action potential initiation

Yunyong Ma et al. Proc Natl Acad Sci U S A. .
No abstract available

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
A schematic cartoon depicting structural components associated the AIS. Darkness indicates intensity of Na+ fluorescence reflecting axoplasmic Na+ concentration ([Na+]). The AIS is functionally divided into three segments with distinct Na+ profiles (S1–S3) that have average lengths of 8, 14, and 21 µm, respectively. The proximal S1 segment connects to the soma with its large capacitance, but S3 is attached to the downstream myelinated axon that has very minor capacitive load. Compared with the S1 and S2 segments, the S3 region has the lowest density of Na+ influx but highest axoplasmic resistivity (thick resistor symbol) to the soma, and hence the lowest current load (small I). In contrast, the S2 segment with the highest Na influx has lower axoplasmic resistivity to the soma (thinner resistor symbol), and greater current sink (large I), that presumably prevent local depolarization and AP initiation. As illustrated, the spike initiation site in the AIS is located at the most distal 10-µm region, despite its lower Na current density, because it has highest internal resistance to the large somatic capacitive sink.
See this image and copyright information in PMC

Comment on

References

    1. Kole MH, Stuart GJ. Signal processing in the axon initial segment. Neuron. 2012;73(2):235–247. - PubMed
    1. Bender KJ, Trussell LO. The physiology of the axon initial segment. Annu Rev Neurosci. 2012;35:249–265. - PubMed
    1. Hodgkin AL, Rushton WA. The electrical constants of a crustacean nerve fibre. Proc R Soc Med. 1946;134(873):444–479. - PubMed
    1. Johnston D, Wu SM. Foundations of Cellular Neurophysiology. Cambridge MA: MIT Press; 1996.
    1. Moore JW, Stockbridge N, Westerfield M. On the site of impulse initiation in a neurone. J Physiol. 1983;336:301–311. - PMC - PubMed

LinkOut - more resources