- Poster presentation
- Open Access
Axon initial segment potassium channel density in cortical neurons
- Wen Zhang1,
- Boqiang Fan1,
- Ping Zheng1 and
- Yuguo Yu1Email author
https://doi.org/10.1186/1471-2202-16-S1-P295
© Zhang et al. 2015
- Published: 18 December 2015
Keywords
- Cortical Neuron
- Intrinsic Factor
- Action Potential Duration
- GABAergic Interneuron
- Axon Initial Segment
There is a growing interest in estimating actual density ranges of Na+ channels in the very thin axon, especially in the action potential (AP) initiation zone, i.e., the axon initial segment (AIS, 20-50 microns away from the cell body). Both immunostaining studies and patch-clamp recordings indicated a relatively high density of Na+ channels in AIS of either pyramidal regular-spiking (RS) cells [1] or fast-spiking (FS) GABAergic interneurons [2, 3]. Here, we investigated potassium channel densities in AISs of both RS and FS cells in same recording conditions.
A. The bar graph shows peak K+ conductance density recorded in axon initial segment of cells (16 recording axons for RS pyramidal cell, 11 for FS interneuron) by outside-out axon patch recording technique. B. Summary of the results from partially blocking K+ channels. The AP dV/dt ratio is an exponentially decaying function of the spike duration.
In sum, the significant difference in potassium channel density in axonal initial segment where action potentials are initiated may play a critical role in controlling action potential properties of both RS- and FS-spiking cells in nervous system by the same general biophysical rule. These results may be important for constructing computational models of different types of cortical neurons.
Declarations
Acknowledgements
This project is funded by NNSF of China (31271170) and Eastern Scholar SHH1140004) at Shanghai Institutions of Higher Learning.
Authors’ Affiliations
References
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This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.