Molecular identity of dendritic voltage-gated sodium channels.
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.
Lorincz
Andrea
A
Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083 Budapest, Hungary. lorincz@koki.hu
Nusser
Zoltan
Z
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*
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
J Physiol. 2002 Jun 15;541(Pt 3):665-72
12068031
J Neurosci. 1997 Sep 1;17(17):6512-21
9254663
EMBO J. 1989 Dec 1;8(12):3611-6
2555170
J Neurosci. 2008 Dec 31;28(53):14329-40
19118165
J Neurosci. 2006 Feb 15;26(7):2088-100
16481442
J Neurosci. 2008 Sep 10;28(37):9083-6
18784286
J Neurosci. 2007 Aug 22;27(34):8999-9008
17715337
Nat Neurosci. 2008 Feb;11(2):178-86
18204443
J Neurosci. 2003 Mar 15;23(6):2306-13
12657689
J Neurosci. 2005 Jan 26;25(4):799-807
15673659
J Neurophysiol. 1998 Jan;79(1):491-5
9425219
Nat Rev Neurosci. 2002 May;3(5):362-70
11988775
Nature. 2008 Mar 27;452(7186):436-41
18368112
Eur J Neurosci. 1998 Feb;10(2):478-87
9749710
J Comp Neurol. 2007 Jan 10;500(2):339-52
17111377
J Comp Neurol. 1999 Sep 20;412(2):342-52
10441760
Neuron. 1998 Sep;21(3):545-59
9768841
Annu Rev Physiol. 1998;60:327-46
9558467
Nat Neurosci. 2009 Aug;12(8):996-1002
19633666
Curr Opin Neurobiol. 2007 Jun;17(3):387-93
17499496
Science. 2009 Aug 7;325(5941):756-60
19661433
J Neurosci. 2007 May 30;27(22):5903-14
17537961
Neuron. 2006 Apr 20;50(2):291-307
16630839
Proc Natl Acad Sci U S A. 1998 Sep 29;95(20):11981-6
9751776
J Comp Neurol. 1998 Jan 12;390(2):194-210
9453664
J Cell Sci. 1995 Nov;108 ( Pt 11):3443-9
8586656
J Neurosci. 2005 Feb 16;25(7):1750-60
15716411
Trends Neurosci. 1997 Mar;20(3):125-31
9061867
Annu Rev Neurosci. 1996;19:165-86
8833440
Nat Neurosci. 2008 Nov;11(11):1253-5
18836442
Annu Rev Physiol. 2004;66:477-519
14977411
J Neurosci. 1998 May 15;18(10):3919-28
9570819