Scn1a Conditional Knockout mouse models

Interneuron excitability in mouse depends on Scn1a, ortholog of human SCN1A, encoding the Nav1.1 pore-forming alpha subunit assembled from four homologous domains, each contributing six transmembrane segments with an S4 voltage sensor and a re-entrant P loop, plus the DIII to DIV linker carrying the IFM fast inactivation particle. Nav1.1 is enriched in the axon initial segment of parvalbumin and somatostatin interneurons, so haploinsufficiency preferentially silences inhibition and produces the disinhibition seen in Dravet syndrome, while milder missense alleles cause GEFS+ and specific gain of function variants cause familial hemiplegic migraine 3. Allele class maps precisely onto question: heterozygous conditional null models Dravet dosage, patient knockins such as R1648H or A1783V test channel biophysics, and humanized alleles enable antisense or gene therapy testing. Homozygous nulls die by roughly postnatal day 15 and seizure severity is strongly background dependent, so fix strain and choose interneuron-restricted Cre carefully.

Conditional deletion of Scn1a limits the genetic change to the lineage you choose. That helps in oncology, immunology, and metabolic work where systemic loss would muddy the read. After you confirm Cre specificity, crossing to Scn1a floxed stock yields usable cohorts.