---
_id: '3485'
abstract:
- lang: eng
text: 1. GABAergic interneurones differ from glutamatergic principal neurones in
their ability to discharge high-frequency trains of action potentials without
adaptation. To examine whether Na+ channel gating contributed to these differences,
Na+ currents were recorded in nucleated patches from interneurones (dentate gyrus
basket cells, BCs) and principal neurones (CA1 pyramidal cells, PCs) of rat hippocampal
slices. 2. The voltage dependence of Na+ channel activation in BCs and PCs was
similar. The slope factors of the activation curves, fitted with Boltzmann functions
raised to the third power, were 11.5 and 11.8 mV, and the mid-point potentials
were -25.1 and -23.9 mV, respectively. 3. Whereas the time course of Na+ channel
activation (-30 to +40 mV) was similar, the deactivation kinetics (-100 to -40
mV) were faster in BCs than in PCs (tail current decay time constants, 0.13 and
0.20 ms, respectively, at -40 mV). 4. Na+ channels in BCs and PCs differed in
the voltage dependence of inactivation. The slope factors of the steady-state
inactivation curves fitted with Boltzmann functions were 6.7 and 10.7 mV, and
the mid-point potentials were -58.3 and -62.9 mV, respectively. 5. The onset of
Na+ channel inactivation at -55 mV was slower in BC's than in PCs; the inactivation
time constants were 18.6 and 9.3 ms, respectively. At more positive potentials
the differences in inactivation onset were smaller. 6. The time course of recovery
of Na+ channels from inactivation induced by a 30 ms pulse was fast and mono-exponential
(τ = 2.0 ms at -120 mV) in BCs, whereas it was slower and biexponential in PCs
(τ1 = 2.0 ms and τ2 = 133 ms; amplitude contribution of the slow component, 15%).
7. We conclude that Na+ channels of BCs and PCs differ in gating properties that
contribute to the characteristic action potential patterns of the two types of
neurones.
acknowledgement: We thank Drs J. Bischofberger and J. R. P. Geiger for critically
reading the manuscript, Mrs B. Plessow-Freudenberg and K. Zipfel for technical assistance,
and Mrs B. Hillers for typing. This work was supported by the German Israeli Foundation
grant I 0352–073.01/94 to P. J.
article_processing_charge: No
article_type: original
author:
- first_name: Marco
full_name: Martina, Marco
last_name: Martina
- first_name: Peter M
full_name: Jonas, Peter M
id: 353C1B58-F248-11E8-B48F-1D18A9856A87
last_name: Jonas
orcid: 0000-0001-5001-4804
citation:
ama: Martina M, Jonas PM. Functional differences in Na+ channel gating between fast-spiking
interneurones and principal neurones in rat hippocampus. Journal of Physiology.
1997;505(3):593-603. doi:10.1111/j.1469-7793.1997.593ba.x
apa: Martina, M., & Jonas, P. M. (1997). Functional differences in Na+ channel
gating between fast-spiking interneurones and principal neurones in rat hippocampus.
Journal of Physiology. Wiley-Blackwell. https://doi.org/10.1111/j.1469-7793.1997.593ba.x
chicago: Martina, Marco, and Peter M Jonas. “Functional Differences in Na+ Channel
Gating between Fast-Spiking Interneurones and Principal Neurones in Rat Hippocampus.”
Journal of Physiology. Wiley-Blackwell, 1997. https://doi.org/10.1111/j.1469-7793.1997.593ba.x.
ieee: M. Martina and P. M. Jonas, “Functional differences in Na+ channel gating
between fast-spiking interneurones and principal neurones in rat hippocampus,”
Journal of Physiology, vol. 505, no. 3. Wiley-Blackwell, pp. 593–603, 1997.
ista: Martina M, Jonas PM. 1997. Functional differences in Na+ channel gating between
fast-spiking interneurones and principal neurones in rat hippocampus. Journal
of Physiology. 505(3), 593–603.
mla: Martina, Marco, and Peter M. Jonas. “Functional Differences in Na+ Channel
Gating between Fast-Spiking Interneurones and Principal Neurones in Rat Hippocampus.”
Journal of Physiology, vol. 505, no. 3, Wiley-Blackwell, 1997, pp. 593–603,
doi:10.1111/j.1469-7793.1997.593ba.x.
short: M. Martina, P.M. Jonas, Journal of Physiology 505 (1997) 593–603.
date_created: 2018-12-11T12:03:34Z
date_published: 1997-12-15T00:00:00Z
date_updated: 2022-08-22T08:25:26Z
day: '15'
doi: 10.1111/j.1469-7793.1997.593ba.x
extern: '1'
external_id:
pmid:
- '9457638'
intvolume: ' 505'
issue: '3'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1160038/
month: '12'
oa: 1
oa_version: Published Version
page: 593 - 603
pmid: 1
publication: Journal of Physiology
publication_identifier:
issn:
- 0022-3751
publication_status: published
publisher: Wiley-Blackwell
publist_id: '2902'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Functional differences in Na+ channel gating between fast-spiking interneurones
and principal neurones in rat hippocampus
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 505
year: '1997'
...