title: Molecular identity of dendritic voltage-gated sodium channels.
abstract: Active invasion of the dendritic tree by action potentials (APs) generated in the axon is essential for associative synaptic plasticity and neuronal ensemble formation. In cortical pyramidal cells (PCs), this AP back-propagation is supported by dendritic voltage-gated Na+ (Nav) channels, whose molecular identity is unknown. Using a highly sensitive electron microscopic immunogold technique, we revealed the presence of the Nav1.6 subunit in hippocampal CA1 PC proximal and distal dendrites. Here, the subunit density is lower by a factor of 35 to 80 than that found in axon initial segments. A gradual decrease in Nav1.6 density along the proximodistal axis of the dendritic tree was also detected without any labeling in dendritic spines. Our results reveal the characteristic subcellular distribution of the Nav1.6 subunit, identifying this molecule as a key substrate enabling dendritic excitability.
authors.affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083 Budapest, Hungary. lorincz@koki.hu
authors.forename: Andrea
authors.initials: A
authors.lastname: Lorincz
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Nusser
mesh_terms: D000200:Action Potentials; D000818:Animals; D001369:Axons / Q000737:chemistry / Q000502:physiology; D056547:CA1 Region, Hippocampal / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D002462:Cell Membrane / Q000737:chemistry; D003712:Dendrites / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D049229:Dendritic Spines / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D005614:Freeze Fracturing; D007150:Immunohistochemistry; D015640:Ion Channel Gating; D008297:Male; D016253:Microscopy, Immunoelectron; D062550:NAV1.1 Voltage-Gated Sodium Channel; D062557:NAV1.6 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins / Q000032:analysis; D011901:Ranvier's Nodes / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D015222:Sodium Channels / Q000032:analysis*
chemical_list: D062550:NAV1.1 Voltage-Gated Sodium Channel; D062557:NAV1.6 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins; C568250:Scn1a protein, rat; C507811:Scn8a protein, rat; D015222:Sodium Channels
references.citation: J Physiol. 2002 Jun 15;541(Pt 3):665-72
references.pmid: 12068031
references.citation: J Neurosci. 1997 Sep 1;17(17):6512-21
references.pmid: 9254663
references.citation: EMBO J. 1989 Dec 1;8(12):3611-6
references.pmid: 2555170
references.citation: J Neurosci. 2008 Dec 31;28(53):14329-40
references.pmid: 19118165
references.citation: J Neurosci. 2006 Feb 15;26(7):2088-100
references.pmid: 16481442
references.citation: J Neurosci. 2008 Sep 10;28(37):9083-6
references.pmid: 18784286
references.citation: J Neurosci. 2007 Aug 22;27(34):8999-9008
references.pmid: 17715337
references.citation: Nat Neurosci. 2008 Feb;11(2):178-86
references.pmid: 18204443
references.citation: J Neurosci. 2003 Mar 15;23(6):2306-13
references.pmid: 12657689
references.citation: J Neurosci. 2005 Jan 26;25(4):799-807
references.pmid: 15673659
references.citation: J Neurophysiol. 1998 Jan;79(1):491-5
references.pmid: 9425219
references.citation: Nat Rev Neurosci. 2002 May;3(5):362-70
references.pmid: 11988775
references.citation: Nature. 2008 Mar 27;452(7186):436-41
references.pmid: 18368112
references.citation: Eur J Neurosci. 1998 Feb;10(2):478-87
references.pmid: 9749710
references.citation: J Comp Neurol. 2007 Jan 10;500(2):339-52
references.pmid: 17111377
references.citation: J Comp Neurol. 1999 Sep 20;412(2):342-52
references.pmid: 10441760
references.citation: Neuron. 1998 Sep;21(3):545-59
references.pmid: 9768841
references.citation: Annu Rev Physiol. 1998;60:327-46
references.pmid: 9558467
references.citation: Nat Neurosci. 2009 Aug;12(8):996-1002
references.pmid: 19633666
references.citation: Curr Opin Neurobiol. 2007 Jun;17(3):387-93
references.pmid: 17499496
references.citation: Science. 2009 Aug 7;325(5941):756-60
references.pmid: 19661433
references.citation: J Neurosci. 2007 May 30;27(22):5903-14
references.pmid: 17537961
references.citation: Neuron. 2006 Apr 20;50(2):291-307
references.pmid: 16630839
references.citation: Proc Natl Acad Sci U S A. 1998 Sep 29;95(20):11981-6
references.pmid: 9751776
references.citation: J Comp Neurol. 1998 Jan 12;390(2):194-210
references.pmid: 9453664
references.citation: J Cell Sci. 1995 Nov;108 ( Pt 11):3443-9
references.pmid: 8586656
references.citation: J Neurosci. 2005 Feb 16;25(7):1750-60
references.pmid: 15716411
references.citation: Trends Neurosci. 1997 Mar;20(3):125-31
references.pmid: 9061867
references.citation: Annu Rev Neurosci. 1996;19:165-86
references.pmid: 8833440
references.citation: Nat Neurosci. 2008 Nov;11(11):1253-5
references.pmid: 18836442
references.citation: Annu Rev Physiol. 2004;66:477-519
references.pmid: 14977411
references.citation: J Neurosci. 1998 May 15;18(10):3919-28
references.pmid: 9570819