Recommended Conferences

Genetic Engineering and Gene Therapy

Paris, France

Human Genetics and Genetic Disorders

Miami, USA

Tissue Engineering and Regenerative Medicine

Chicago, USA
Related Subjects
 

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

Author(s): Lorincz A, Nusser Z

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.

Similar Articles

Rat hippocampal neurons in dispersed cell culture

Author(s): Banker GA, Cowan WM

C1q induction and global complement pathway activation do not contribute to ALS toxicity in mutant SOD1 mice

Author(s): Lobsiger CS, Boillee S, Pozniak C, Khan AM, McAlonis-Downes M, et al.

A dramatic increase of C1q protein in the CNS during normal aging

Author(s): Stephan AH, Madison DV, Mateos JM, Fraser DA, Lovelett EA, et al.

When, where, and how much? Expression of the Kv3

Author(s): Gan L, Kaczmarek LK

Kv3

Author(s): Yasuda T, Cuny H, Adams DJ

A-type K+ channels encoded by Kv4

Author(s): Carrasquillo Y, Burkhalter A, Nerbonne JM

Functional specialization of the axon initial segment by isoform-specific sodium channel targeting

Author(s): Boiko T, van Wart A, Caldwell JH, Levinson SR, Trimmer JS, et al.

Role of axonal NaV1

Author(s): Royeck M, Horstmann MT, Remy S, Reitze M, Yaari Y, et al.

The role of the Rho GTPases in neuronal development

Author(s): GovekEE, Newey SE, van Aelst L

EphB-mediated degradation of the RhoA GEF Ephexin5 relieves a developmental brake on excitatory synapse formation

Author(s): Margolis SS, Salogiannis J, Lipton DM, Mandel-Brehm C, Wills ZP, et al.

Potential role of culture mediums for successful isolation and neuronal differentiation of amniotic fluid stem cells

Author(s): Orciani M, Emanuelli M, Martino C, Pugnaloni A, Tranquilli AL, et al.