| 1995 |
Scn8a encodes a voltage-gated sodium channel alpha subunit (Nav1.6) expressed in brain and spinal cord but not skeletal muscle or heart; an intragenic deletion at the transgene insertion site results in loss of expression, causing motor endplate disease (med) phenotype including progressive paralysis, muscle atrophy, Purkinje cell degeneration, and juvenile lethality in mice. |
Positional cloning, transgene-induced deletion, expression analysis (tissue Northern blot) |
Nature genetics |
High |
7670495
|
| 2000 |
Nav1.6 (NaCh6) protein localizes to nodes of Ranvier in peripheral nerve and spinal cord, axon initial segments, dendrites of pyramidal cells, and motor neuron axons; it is the first sodium channel isoform localized to both nodes of Ranvier and dendrites. |
Immunohistochemistry with isoform-specific antibodies in rat nervous system sections |
The Journal of comparative neurology |
High |
10745220
|
| 2003 |
Recombinant Nav1.6 channels exhibit approximately 5-fold faster recovery from inactivation (repriming) and faster development of closed-state inactivation compared to Nav1.7, providing a molecular basis for high-frequency firing in large myelinated DRG neurons. |
Whole-cell patch clamp of recombinant Nav1.6 and Nav1.7 expressed in mouse DRG neurons |
The Journal of physiology |
High |
12843211
|
| 2003 |
Calmodulin (CaM) binds to the C-terminal domain of Nav1.6 in a calcium-independent manner; disrupting this interaction reduced Nav1.6 current amplitude by 62%, and CaM also modulates Nav1.6 inactivation kinetics in a calcium-dependent manner. |
GST-fusion protein pulldown, co-expression with CaM in transfected cells, whole-cell patch clamp, C-terminal mutagenesis |
The Journal of neuroscience |
High |
12967988
|
| 2003 |
In EAE (experimental autoimmune encephalomyelitis), Nav1.6 co-localizes with the Na+/Ca2+ exchanger (NCX) along demyelinated axons; 73.5% of injured (beta-APP positive) axons co-express Nav1.6 and NCX, suggesting that Nav1.6-mediated sodium influx drives reverse NCX operation and calcium-mediated axonal degeneration. |
Triple-label fluorescent immunohistochemistry in mouse EAE spinal cord |
Brain : a journal of neurology |
Medium |
14662515
|
| 2004 |
Nav1.6 channels exhibit use-dependent potentiation (increased current) during rapid repetitive depolarizations, in contrast to Nav1.2 which shows use-dependent decrease; this results from faster channel activation and resistance to slow inactivation in Nav1.6. |
Whole-cell patch clamp of Nav1.6 and Nav1.2 co-expressed with beta1 in Xenopus oocytes; fast inactivation-removed mutant channels used to dissect mechanism |
Biophysical journal |
High |
15465873
|
| 2005 |
p38 MAP kinase (p38alpha) phosphorylates Nav1.6 specifically at serine 553 within cytoplasmic loop L1 (joining domains 1 and 2); activation of p38 in neuronal cells significantly reduces Nav1.6 peak current amplitude without affecting gating; S553A substitution prevents this p38-mediated reduction. |
In vitro kinase assay with GST-fusion fragments of Nav1.6, site-directed mutagenesis (S553A), whole-cell patch clamp in p38-activated ND7/23 cells transfected with Nav1.6 |
The Journal of neuroscience |
High |
16014723
|
| 2006 |
Nav1.6 is required for repetitive high-frequency firing in retinal ganglion cells (RGCs); in Nav1.6-null (med) mice, maximal sustained and instantaneous firing rates are reduced by postnatal day 18. Compensatory upregulation of Nav1.2 and Nav1.1 at axon initial segments and nodes occurs in a cell-type-specific manner. |
Whole-cell patch clamp recordings from RGCs during postnatal development in med vs. wild-type mice; immunofluorescence for sodium channel isoforms at AIS and nodes |
The Journal of neuroscience |
High |
16822974
|
| 2007 |
Nav1.6 channels underlie resurgent sodium current in globus pallidus (GPe) neurons; Nav1.6-null GPe neurons show significantly reduced resurgent current, impaired pacemaking and fast spiking, and inability to follow high-frequency stimulation. |
Whole-cell patch clamp in acutely isolated GPe neurons from Nav1.6-null mice; computational modeling |
The Journal of neuroscience |
High |
18057213
|
| 2008 |
Nav1.6 expression and persistent sodium current increase selectively in hippocampal CA3 neurons following kindling; heterozygous Nav1.6-deficient mice (Nav1.6+/-) resist initiation and development of kindling, identifying Nav1.6 as a participant in activity-dependent facilitation in hippocampal circuits. |
Immunocytochemistry, in situ hybridization, patch clamp recordings, kindling behavioral analysis in wild-type vs. Nav1.6+/- mice |
Epilepsia |
High |
18637833
|
| 2009 |
FGF14 N-terminal splice variants (FGF14-1a and FGF14-1b) differentially regulate Nav1.6 currents: FGF14-1b (but not FGF14-1a) attenuates Nav1.6 current density; an FGF14 mutant lacking the N-terminus increases Nav1.6 current density; the N-terminus is required for axon initial segment targeting of FGF14. |
Co-expression in neurons with patch clamp, immunofluorescence localization in neurons, deletion mutagenesis |
Molecular and cellular neurosciences |
High |
19465131
|
| 2009 |
Mechanical membrane trauma (bleb-inducing aspiration or uniaxial stretch) causes Nav1.6 channels to exhibit irreversible hyperpolarizing shifts in steady-state inactivation and activation, expanding window current; stretch of Nav1.6-expressing HEK cells causes tetrodotoxin-sensitive cytoplasmic Na+ increase, demonstrating Nav1.6 acts as a mechanosensitive sodium leak channel. |
Patch clamp of recombinant Nav1.6 in oocyte patches (cell-attached aspiration) and HEK cells (substrate stretch); Na+-dye fluorimetry |
American journal of physiology. Cell physiology |
High |
19657055
|
| 2010 |
Nav1.6 at axon initial segments contributes to persistent (but not transient or resurgent) sodium current in cerebellar granule cells; loss of Nav1.6 at AIS leads to faster action potential repolarization, larger post-spike hyperpolarization, and increased interspike-interval variability, demonstrating a role in temporal precision of repetitive firing. |
Whole-cell patch clamp of acute cerebellar slices and acutely dissociated granule cells from granule cell-specific Scn8a conditional KO mice; immunofluorescence for Nav subunits |
The Journal of physiology |
High |
20173079
|
| 2010 |
Beta1 (Scn1b) subunit is required for normal Nav1.6 localization at the axon initial segment during postnatal development; in Scn1b-null cerebellar granule neurons, Nav1.6 at AIS is reduced and Nav1.1 substitutes; beta1-mediated neurite outgrowth requires Nav1.6-mediated sodium current, and Nav1.6 resurgent current is reduced in Scn1b-null neurons. |
Immunofluorescence of AIS in Scn1b-null cerebellar neurons, whole-cell patch clamp recording of resurgent current, shRNA knockdown of Nav1.6 |
Proceedings of the National Academy of Sciences of the United States of America |
High |
20133873
|
| 2011 |
Rbfox proteins (Fox-1 and Fox-2) regulate alternative splicing of SCN8A by promoting inclusion of exon 18A over exon 18N; exon 18A selection is dependent on a Fox consensus binding site 28 bp downstream of exon 18A; exon 18A is required for production of functional full-length Nav1.6 protein. |
Scn8a minigene co-transfection with Fox-1 or Fox-2; mutagenesis of Fox binding site; RT-PCR of purified cell populations (neurons vs. glia) |
Molecular and cellular neurosciences |
High |
22044765
|
| 2012 |
The N-terminal domain of Nav1.6 (residues 1-153) interacts with the light chain of microtubule-associated protein Map1b; residues 77-80 (VAVP) contribute to this interaction; Map1b co-immunoprecipitates with endogenous Nav1.6 from mouse brain; co-expression of Map1b with Nav1.6 increases current density ~50%; mutation of the Map1b binding site prevents sodium current generation, establishing Map1b as a trafficking partner for Nav1.6. |
Yeast two-hybrid screen, co-immunoprecipitation from mouse brain, alanine-scanning mutagenesis, whole-cell patch clamp in ND7/23 cells |
The Journal of biological chemistry |
High |
22474336
|
| 2013 |
In vivo knockdown of Nav1.6 in rat lumbar DRG via siRNA completely blocked development of mechanical pain behaviors and abnormal spontaneous bursting activity following local DRG inflammation; cells capable of repetitive firing had higher Nav1.6 expression, and spontaneously active bursting cells in inflamed DRG expressed high Nav1.6 immunoreactivity. |
In vivo siRNA knockdown, behavioral pain testing (paw withdrawal threshold), single-unit electrophysiology, qPCR and immunohistochemistry |
Pain |
High |
23622763
|
| 2014 |
The de novo SCN8A mutation p.Asn1768Asp (N1768D) results in increased persistent sodium current and neuronal hyperactivity; knock-in mice carrying this mutation exhibit seizures, SUDEP, and EEG-confirmed ictal discharges; severity scales with mutant protein dose (heterozygous < hemizygous < homozygous). |
Knock-in mouse model, video/EEG analysis, behavioral testing, transfected cell electrophysiology |
Human molecular genetics |
High |
25227913
|
| 2014 |
The de novo SCN8A mutation p.Thr767Ile causes enhanced channel activation with a 10 mV depolarizing shift in voltage dependence, increased ramp current, and increased spontaneous firing with paroxysmal depolarizing shift-like complexes in hippocampal neurons, establishing a gain-of-function mechanism for epilepsy. |
Site-directed mutagenesis, whole-cell patch clamp in transfected neuronal cells and hippocampal pyramidal neurons |
Neurobiology of disease |
High |
24874546
|
| 2015 |
Amyloid precursor protein (APP) co-localizes and interacts with Nav1.6 in mouse cortical neurons; APP knockdown decreases Nav1.6 currents and cell surface expression; APP increases Nav1.6 surface expression through a Go protein-dependent, JNK-mediated pathway; phosphorylation of APP at Thr668 by JNK enhances APP-Nav1.6 interaction and Nav1.6 surface expression. |
Co-immunoprecipitation, siRNA knockdown, dominant-active/negative Go mutants, JNK inhibitors, T668E/T668A mutagenesis, whole-cell patch clamp, surface biotinylation |
The Journal of biological chemistry |
High |
25767117
|
| 2015 |
The PI3K/Akt pathway, Wee1 kinase, and protein kinase C (PKC) regulate the FGF14:Nav1.6 protein-protein interaction complex; inhibition of GSK3 (a convergence point of these pathways) impairs excitability of hippocampal neurons. |
Split-luciferase complementation assay in live cells screening 12 kinase inhibitor pathways; dose-response validation; hippocampal neuron electrophysiology |
PloS one |
Medium |
25659151
|
| 2015 |
Nav1.6 is required for spike initiation at stretch-sensitive colorectal afferent endings; selective Nav1.6 antagonists (mu-conotoxin GIIIa and PIIIa) significantly reduced afferent responses to colorectal stretch, while Nav1.7 or Nav1.8 antagonists did not; computational modeling confirmed Nav1.6 is necessary for tonic spiking at sensory endings. |
In vitro colon-nerve preparation with selective toxin pharmacology, immunohistochemistry/Western blot, computational modeling |
Journal of neurophysiology |
High |
25652923
|
| 2016 |
Epilepsy-associated Nav1.6 mutations N1768D and L1331V dramatically increase resurgent sodium currents; cannabidiol preferentially inhibits resurgent and persistent sodium currents from wild-type and mutant Nav1.6 over peak transient currents; this inhibition reduces action potential firing in striatal neurons. |
Whole-cell patch clamp in HEK293T cells with Navβ4 peptide to induce resurgent current; Nav1.6 mutant channels; current clamp in striatal neurons |
Brain : a journal of neurology |
High |
27267376
|
| 2016 |
The SCN8A gain-of-function mutation p.Met136Val increases peak current density (~1.5-fold) and resurgent current (~1.6-fold) without altering gating properties; it increases the fraction of high-firing neurons, lowers current threshold, and increases action potential frequency in trigeminal ganglion neurons. |
Whole-cell voltage clamp in transfected cells, current clamp in trigeminal ganglion neurons |
Molecular medicine (Cambridge, Mass.) |
High |
27496104
|
| 2016 |
CDYL (Chromodomain Y-like) epigenetic factor binds a regulatory element in the intron of SCN8A and recruits H3K27me3 activity to repress Nav1.6 transcription; CDYL knockdown in hippocampal neurons augments Nav1.6 currents and lowers seizure threshold; CDYL overexpression raises neuronal threshold and reduces epileptogenesis. |
Chromatin immunoprecipitation (ChIP), co-immunoprecipitation, siRNA knockdown, transgenic overexpression, patch clamp recordings, seizure susceptibility testing in mice |
Nature communications |
High |
28842554
|
| 2016 |
Nav1.6 somatic nanoclusters (~230 nm diameter) exist on the surface of hippocampal neuron soma that are stable for >30 minutes via an ankyrin-independent mechanism; non-clustered Nav1.6 channels show anomalous diffusion and can be transiently trapped in nanoclusters. |
Single-particle tracking, photoactivation localization microscopy (PALM), mean-square displacement analysis, Bayesian inference analysis |
Biophysical journal |
High |
27653482
|
| 2017 |
Loss of Scn8a in reticular thalamic (RT) neurons alters intrinsic RT cell excitability and causes failure in recurrent RT-RT synaptic inhibition, leading to enhanced thalamocortical network synchrony and absence epilepsy (spike-wave discharges); deletion of Scn8a in adult thalamus alone is sufficient to generate spike-wave discharges. |
Conditional KO (Cre-dependent deletion in RT cells), EEG recording, patch clamp in thalamic slices, adult-specific deletion |
Neuron |
High |
28238546
|
| 2017 |
Gain-of-function SCN8A mutation p.Asn1768Asp (N1768D) increases persistent sodium current density selectively in hippocampal CA1 pyramidal neurons (not bipolar neurons) and CA3 pyramidal and bipolar neurons; CA1 pyramidal neurons show early afterdepolarization-like action potential waveforms blocked by TTX, riluzole, and reverse Na/Ca exchange inhibitor SN-6, implicating elevated persistent INa and reverse NCX in hyperexcitability. |
Patch clamp of acutely dissociated neurons and brain slices from Scn8a N1768D knock-in mice; pharmacological dissection with TTX, riluzole, SN-6 |
Proceedings of the National Academy of Sciences of the United States of America |
High |
28193882
|
| 2019 |
Restricting expression of the gain-of-function SCN8A mutation p.Arg1872Trp to excitatory neurons (via Emx1-Cre) recapitulates seizures and juvenile lethality; expression in inhibitory neurons (Gad2-Cre or Dlx5/6-Cre) does not induce seizures, establishing excitatory neurons as the critical cell type for SCN8A encephalopathy pathogenesis. |
Conditional knock-in mouse model with neuron-type-specific Cre drivers (Emx1-Cre, Gad2-Cre, Dlx5/6-Cre); EEG monitoring; survival analysis |
Brain : a journal of neurology |
High |
30601941
|
| 2019 |
Multiple SCN8A epilepsy mutations (E1483K, R1872W) increase neuronal firing in primary neuronal cultures; loss-of-function mutations (R1620L) reduce neuronal firing; A1622D dramatically slows fast inactivation and induces depolarization block reducing neuronal firing despite epileptic presentation, confirming distinct genotype-phenotype correlations. |
Whole-cell patch clamp in neuroblastoma cells and primary cultured neurons; current clamp in neurons; computational modeling |
Brain : a journal of neurology |
High |
30615093
|
| 2019 |
TNF-α/STAT3 signaling upregulates Nav1.6 in DRG neurons: STAT3 binds the Scn8a promoter, interacts with p300, and promotes histone H4 hyperacetylation at the Scn8a promoter region, leading to increased Nav1.6 transcription following L5 ventral root transection; TNF-α inhibition reduces STAT3 recruitment and Nav1.6 upregulation. |
Chromatin immunoprecipitation (ChIP), co-immunoprecipitation (STAT3-p300), qPCR, Western blot, in vivo pharmacology |
Journal of neuroinflammation |
High |
30736806
|
| 2020 |
Scn8a antisense oligonucleotide (ASO) treatment reducing Scn8a transcript by 25-50% delays seizure onset and lethality in the Scn8a-R1872W mouse model in a dose-dependent manner; a single Scn8a ASO treatment also extends survival of Dravet syndrome (Scn1a+/-) mice from 3 weeks to >5 months. |
Intracerebroventricular ASO injection in conditional Scn8a-R1872W knock-in mice and Scn1a+/- mice; EEG recording; survival analysis; open field and wheel running assays |
Annals of neurology |
High |
31943325
|
| 2020 |
CaMKII phosphorylates Nav1.6 at Ser-561 and Ser-641/Thr-642 within the first intracellular loop; CaMKII inhibition reduces Nav1.6 transient and persistent currents by ~72% and causes a 5.8 mV depolarizing shift in activation; S561A and S641A/T642A substitutions recapitulate these effects, demonstrating CaMKII modulates Nav1.6 channel activity. |
CaMKII-specific inhibitor CN21, whole-cell voltage clamp in Purkinje neurons and ND7/23/HEK293 cells, immobilized peptide arrays, LC-MS/MS phosphoproteomics, site-directed mutagenesis, computational modeling |
The Journal of biological chemistry |
High |
32611770
|
| 2020 |
Nav1.6 undergoes S-palmitoylation in mouse brain at three sites (Cys1169, Cys1170, Cys1978); enhancing palmitoylation increases Nav1.6 current while blocking it reduces current and shifts steady-state inactivation; Cys1978 is exclusive to Nav1.6 among all Nav isoforms and its palmitoylation specifically regulates current amplitude; loss of S-palmitoylation at specific sites alters neuronal excitability in DRG neurons. |
Acyl-biotin exchange assay in mouse brain and HEK cells, whole-cell voltage clamp with palmitic acid and 2-bromopalmitate, site-directed mutagenesis, current clamp in DRG neurons |
The Journal of biological chemistry |
High |
32161114
|
| 2020 |
JAK2 phosphorylates FGF14 at Y158, a site that mediates both FGF14 homodimerization and FGF14:Nav1.6 complex formation; JAK2 inhibition increases FGF14 homodimerization while decreasing FGF14:Nav1.6 interaction; through Y158, JAK2 controls FGF14-dependent modulation of Nav1.6 channels; JAK2 inhibitor Fedratinib reduces hippocampal CA1 firing in a FGF14-dependent manner. |
High-throughput screening (split-luciferase), in vitro phosphorylation, mass spectrometry, FGF14Y158A mutagenesis, patch clamp electrophysiology in hippocampal neurons |
Biochimica et biophysica acta. Molecular cell research |
High |
32599005
|
| 2020 |
Patient iPSC-derived neurons from SCN8A-related epilepsy exhibit variant-specific alterations: mutations p.R1872L and p.V1592L show elevated persistent current, while p.N1759S shows increased resurgent current; all three patient neuron lines have shorter axon initial segment lengths and prolonged action potential repolarization compared to controls. |
Patient iPSC-derived excitatory neurons, whole-cell patch clamp, immunofluorescence for AIS length (ankyrin-G staining), MEA network activity |
Brain : a journal of neurology |
High |
32968789
|
| 2021 |
Selective expression of gain-of-function SCN8A mutation R1872W in somatostatin (SST) interneurons confers audiogenic seizure susceptibility; SST interneurons from mutant mice are hyperexcitable but hypersensitive to depolarization block; aberrantly large persistent sodium currents contribute directly to SST dysfunction; GqDREADD activation of WT SST interneurons also produces prolonged electrographic seizures. |
Cre-dependent conditional knock-in (SST-Cre), EEG, patch clamp electrophysiology, pharmacology, computational modeling, chemogenetics (GqDREADD) |
The Journal of neuroscience |
High |
34544834
|
| 2022 |
Reducing Nav1.6 expression in hippocampus (via shRNA AAV) rescues cognitive impairments and attenuates synaptic deficits in APP/PS1 Alzheimer's model mice; Nav1.6 knockdown reduces Aβ levels by suppressing BACE1 transcription through a mechanism involving reduced intracellular calcium overload (via suppressed reverse NCX), increased inactive NFAT1, and thereby decreased BACE1 transcription. |
AAV-shRNA hippocampal injection, behavioral tests (Morris water maze), amyloid plaque quantification, ELISA, Western blot, calcium imaging |
Aging cell |
Medium |
35353937
|
| 2023 |
The MAPK-ERK-CREB signaling pathway upregulates Nav1.6 (Scn8a) transcription in DRG during oxaliplatin-induced neuropathic pain; activated p-CREB directly binds the Scn8a promoter region as demonstrated by ChIP; inhibition of CREB reduces Nav1.6 mRNA and protein and alleviates pain. |
Western blot, RT-qPCR, ChIP, immunofluorescence, in vivo kinase inhibitor pharmacology in rats |
Toxicology letters |
Medium |
37453670
|
| 2024 |
Selective expression of gain-of-function SCN8A variant R1872W in parvalbumin (PV) interneurons is sufficient to cause spontaneous seizures and seizure-induced death; PV interneurons from mutant mice show increased persistent sodium current, susceptibility to depolarization block, and reduced inhibitory synaptic transmission onto pyramidal cells. |
PV-Cre conditional knock-in, EEG, patch clamp electrophysiology (persistent current, evoked firing, IPSCs in pyramidal cells) |
JCI insight |
High |
39435659
|
| 2024 |
SCN8A alternative splicing isoforms (neonatally expressed NaV1.6N vs. adult NaV1.6A) show small but significant differences in voltage dependence; many disease-associated variants exhibit isoform-dependent functional effects; TTX-resistant versions of both isoforms show significant functional differences from WT channels, highlighting the importance of molecular context in variant characterization. |
Automated patch clamp in ND7/LoNav cells (engineered low-endogenous-Nav cell line), comparison of 15 variants in two splice isoforms with and without TTX-resistance mutations |
JCI insight |
High |
38771640
|
| 2011 |
Beta-subunit regulation of Nav1.6 is weak compared to Nav1.8; the beta4-subunit induces a hyperpolarizing shift in Nav1.6 activation (-7.6 mV) but does not alter inactivation or current density; the intracellular C-terminal domain of the beta1-subunit is essential for strong regulation of Nav1.8 but not Nav1.6. |
Co-expression of Nav1.6 with beta1-beta4 subunits in Xenopus oocytes, whole-cell patch clamp, beta-subunit chimera analysis |
Journal of neurophysiology |
Medium |
21562192
|
| 2016 |
FHF2 isoforms differentially regulate Nav1.6-mediated resurgent currents in DRG neurons: FHF2A enhances long-term inactivation and negatively regulates fast resurgent current; FHF2B lacks this long-term inactivation enhancement and positively regulates resurgent current; FHF2A and FHF2B expression are differentially regulated in a radicular pain model. |
Patch clamp electrophysiology in DRG neurons and cell lines; FHF2A/Navβ4 chimeric constructs; FHF2 isoform-specific siRNA knockdown |
Pflugers Archiv : European journal of physiology |
Medium |
27999940
|
| 2019 |
Nav1.6 deletion from retinal ganglion cells (via AAV-Cre in Scn8a-floxed mice) during EAE reduces pro-inflammatory cytokines (IL-6, IFN-γ) and reactive gliosis marker (GFAP) expression, reduces macrophage infiltration in targeted optic nerves, and improves axonal health, demonstrating Nav1.6 promotes neuroinflammation and axonal degeneration following demyelination. |
AAV-Cre conditional deletion in floxed Scn8a mice during EAE, gene expression analysis, immunohistochemistry, contralateral eye controls |
Journal of neuroinflammation |
Medium |
31722722
|