English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
 
 
DownloadE-Mail
  Presynaptic Na+ Channels: Locus, Development, and Recovery from Inactivation at a High-Fidelity Synapse

Leão, R. M., Kushmerick, C., Pinaud, R., Renden, R., Li, G.-L., Taschenberger, H., et al. (2005). Presynaptic Na+ Channels: Locus, Development, and Recovery from Inactivation at a High-Fidelity Synapse. The Journal of Neuroscience, 25(14), 3724-3738. doi:10.1523/JNEUROSCI.3983-04.2005.

Item is

Basic

show hide
Genre: Journal Article
Other : Presynaptic Na+ Channels: Locus, Development, and Recovery from Inactivation at a High-Fidelity Synapse

Files

show Files
hide Files
:
3724.full.pdf (Publisher version), 2MB
 
File Permalink:
-
Name:
3724.full.pdf
Description:
-
OA-Status:
Visibility:
Restricted (Max Planck Institute for Multidisciplinary Sciences, MGMN; )
MIME-Type / Checksum:
application/pdf
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Leão, Ricardo M., Author
Kushmerick, Christopher, Author
Pinaud, Raphael, Author
Renden, Robert, Author
Li, Geng-Lin, Author
Taschenberger, Holger1, Author                 
Spirou, George, Author
Levinson, S. Rock, Author
von Gersdorff, Henrique, Author
Affiliations:
1External Organizations, ou_persistent22              

Content

show
hide
Free keywords: -
 Abstract: Na+ channel recovery from inactivation limits the maximal rate of neuronal firing. However, the properties of presynaptic Na+ channels are not well established because of the small size of most CNS boutons. Here we study the Na+ currents of the rat calyx of Held terminal and compare them with those of postsynaptic cells. We find that presynaptic Na+ currents recover from inactivation with a fast, single-exponential time constant (24°C, τ of 1.4-1.8 ms; 35°C, τ of 0.5 ms), and their inactivation rate accelerates twofold during development, which may contribute to the shortening of the action potential as the terminal matures. In contrast, recordings from postsynaptic cells in brainstem slices, and acutely dissociated, reveal that their Na+ currents recover from inactivation with a double-exponential time course (τfast of 1.2-1.6 ms; τslow of 80-125 ms; 24°C). Surprisingly, confocal immunofluorescence revealed that Na+ channels are mostly absent from the calyx terminal but are instead highly concentrated in an unusually long (≈20-40 μm) unmyelinated axonal heminode. Outside-out patch recordings confirmed this segregation. Expression of Nav1.6 α-subunit increased during development, whereas the Nav1.2α-subunit was not present. Serial EM reconstructions also revealed a long pre-calyx heminode, and biophysical modeling showed that exclusion of Na+ channels from the calyx terminal produces an action potential waveform with a shorter half-width. We propose that the high density and polarized locus of Na+ channels on a long heminode are critical design features that allow the mature calyx of Held terminal to fire reliably at frequencies near 1 kHz.

Details

show
hide
Language(s): eng - English
 Dates: 2005
 Publication Status: Issued
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: DOI: 10.1523/JNEUROSCI.3983-04.2005
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: The Journal of Neuroscience
  Other : The Journal of Neuroscience: the Official Journal of the Society for Neuroscience
  Abbreviation : J. Neurosci.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Washington, DC : Society of Neuroscience
Pages: - Volume / Issue: 25 (14) Sequence Number: - Start / End Page: 3724 - 3738 Identifier: ISSN: 0270-6474
CoNE: https://pure.mpg.de/cone/journals/resource/954925502187_1