Cell-type-dependent molecular composition of the axon initial segment

Andrea Lorincz, Z. Nusser

Research output: Contribution to journalArticle

200 Citations (Scopus)

Abstract

The exact site of initiation and shape of action potentials vary among different neuronal types. The reason for this variability is largely unknown, but the subunit composition, density and distribution of voltage-gated sodium (Nav) and potassium (Kv) channels within the axon initial segment (AIS) are likely to play a key role. Here, we asked how heterogeneous are the density and distribution of Nav and Kv channels within the AISs of a variety of excitatory and inhibitory neurons. Most of the studied cell types expressed a high density of Nav1.6, Kv1.1, and Kv1.2 subunits in their AIS, but the Nav1.1 subunit could only be detected in GABAergic interneurons. A proximo-distal gradient in the density of these subunits was observed within the AIS of certain nerve cells but not in others. For example, a gradual increase of the Nav1.6 subunit was observed in cortical layer 2/3 and hippocampal CA1 pyramidal cell (PC) AISs, whereas its density was rather uniform in layer 5 PC AISs. The Nav1.1 subunit was distributed evenly along the AIS of short-axon cells of the main olfactory bulb but was restricted to the proximal part of the AIS in cortical and cerebellar interneurons. Our results reveal a cell type-dependent expression of sodium and potassium channel subunits with varying densities along the proximo-distal axis of the AISs. This precise arrangement is likely to contribute to the diversity of firing properties observed among central neurons.

Original languageEnglish
Pages (from-to)14329-14340
Number of pages12
JournalJournal of Neuroscience
Volume28
Issue number53
DOIs
Publication statusPublished - Dec 31 2008

Fingerprint

Pyramidal Cells
Interneurons
Neurons
Voltage-Gated Potassium Channels
Sodium Channels
Olfactory Bulb
Potassium Channels
Action Potentials
Axons
Sodium
Axon Initial Segment

Keywords

  • Axon initial segment
  • Cerebellum
  • Cortex
  • Hippocampus
  • Immunohistochemistry
  • Olfactory bulb
  • Voltage-gated ion channels

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Cell-type-dependent molecular composition of the axon initial segment. / Lorincz, Andrea; Nusser, Z.

In: Journal of Neuroscience, Vol. 28, No. 53, 31.12.2008, p. 14329-14340.

Research output: Contribution to journalArticle

@article{aa286315100f4e8d8562ccd90477cdd0,
title = "Cell-type-dependent molecular composition of the axon initial segment",
abstract = "The exact site of initiation and shape of action potentials vary among different neuronal types. The reason for this variability is largely unknown, but the subunit composition, density and distribution of voltage-gated sodium (Nav) and potassium (Kv) channels within the axon initial segment (AIS) are likely to play a key role. Here, we asked how heterogeneous are the density and distribution of Nav and Kv channels within the AISs of a variety of excitatory and inhibitory neurons. Most of the studied cell types expressed a high density of Nav1.6, Kv1.1, and Kv1.2 subunits in their AIS, but the Nav1.1 subunit could only be detected in GABAergic interneurons. A proximo-distal gradient in the density of these subunits was observed within the AIS of certain nerve cells but not in others. For example, a gradual increase of the Nav1.6 subunit was observed in cortical layer 2/3 and hippocampal CA1 pyramidal cell (PC) AISs, whereas its density was rather uniform in layer 5 PC AISs. The Nav1.1 subunit was distributed evenly along the AIS of short-axon cells of the main olfactory bulb but was restricted to the proximal part of the AIS in cortical and cerebellar interneurons. Our results reveal a cell type-dependent expression of sodium and potassium channel subunits with varying densities along the proximo-distal axis of the AISs. This precise arrangement is likely to contribute to the diversity of firing properties observed among central neurons.",
keywords = "Axon initial segment, Cerebellum, Cortex, Hippocampus, Immunohistochemistry, Olfactory bulb, Voltage-gated ion channels",
author = "Andrea Lorincz and Z. Nusser",
year = "2008",
month = "12",
day = "31",
doi = "10.1523/JNEUROSCI.4833-08.2008",
language = "English",
volume = "28",
pages = "14329--14340",
journal = "Journal of Neuroscience",
issn = "0270-6474",
publisher = "Society for Neuroscience",
number = "53",

}

TY - JOUR

T1 - Cell-type-dependent molecular composition of the axon initial segment

AU - Lorincz, Andrea

AU - Nusser, Z.

PY - 2008/12/31

Y1 - 2008/12/31

N2 - The exact site of initiation and shape of action potentials vary among different neuronal types. The reason for this variability is largely unknown, but the subunit composition, density and distribution of voltage-gated sodium (Nav) and potassium (Kv) channels within the axon initial segment (AIS) are likely to play a key role. Here, we asked how heterogeneous are the density and distribution of Nav and Kv channels within the AISs of a variety of excitatory and inhibitory neurons. Most of the studied cell types expressed a high density of Nav1.6, Kv1.1, and Kv1.2 subunits in their AIS, but the Nav1.1 subunit could only be detected in GABAergic interneurons. A proximo-distal gradient in the density of these subunits was observed within the AIS of certain nerve cells but not in others. For example, a gradual increase of the Nav1.6 subunit was observed in cortical layer 2/3 and hippocampal CA1 pyramidal cell (PC) AISs, whereas its density was rather uniform in layer 5 PC AISs. The Nav1.1 subunit was distributed evenly along the AIS of short-axon cells of the main olfactory bulb but was restricted to the proximal part of the AIS in cortical and cerebellar interneurons. Our results reveal a cell type-dependent expression of sodium and potassium channel subunits with varying densities along the proximo-distal axis of the AISs. This precise arrangement is likely to contribute to the diversity of firing properties observed among central neurons.

AB - The exact site of initiation and shape of action potentials vary among different neuronal types. The reason for this variability is largely unknown, but the subunit composition, density and distribution of voltage-gated sodium (Nav) and potassium (Kv) channels within the axon initial segment (AIS) are likely to play a key role. Here, we asked how heterogeneous are the density and distribution of Nav and Kv channels within the AISs of a variety of excitatory and inhibitory neurons. Most of the studied cell types expressed a high density of Nav1.6, Kv1.1, and Kv1.2 subunits in their AIS, but the Nav1.1 subunit could only be detected in GABAergic interneurons. A proximo-distal gradient in the density of these subunits was observed within the AIS of certain nerve cells but not in others. For example, a gradual increase of the Nav1.6 subunit was observed in cortical layer 2/3 and hippocampal CA1 pyramidal cell (PC) AISs, whereas its density was rather uniform in layer 5 PC AISs. The Nav1.1 subunit was distributed evenly along the AIS of short-axon cells of the main olfactory bulb but was restricted to the proximal part of the AIS in cortical and cerebellar interneurons. Our results reveal a cell type-dependent expression of sodium and potassium channel subunits with varying densities along the proximo-distal axis of the AISs. This precise arrangement is likely to contribute to the diversity of firing properties observed among central neurons.

KW - Axon initial segment

KW - Cerebellum

KW - Cortex

KW - Hippocampus

KW - Immunohistochemistry

KW - Olfactory bulb

KW - Voltage-gated ion channels

UR - http://www.scopus.com/inward/record.url?scp=58149393984&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=58149393984&partnerID=8YFLogxK

U2 - 10.1523/JNEUROSCI.4833-08.2008

DO - 10.1523/JNEUROSCI.4833-08.2008

M3 - Article

C2 - 19118165

AN - SCOPUS:58149393984

VL - 28

SP - 14329

EP - 14340

JO - Journal of Neuroscience

JF - Journal of Neuroscience

SN - 0270-6474

IS - 53

ER -