Voltage-gated sodium channels (NaV) are essential for the generation of action potentials and for cell excitability. NaV channels are activated in response to depolarization and selectively allow flow of Na+ ions. To date, nine NaV α subunits have been cloned and named Nav1.1-Nav1.. The Nav channels are classified into two groups according to their sensitivity to Tetrodotoxin (TTX): TTX-sensitive (NaV1.1, NaV1.2, NaV1.3, NaV1.4, NaV1.6 and NaV1.7 and TTX-resistant (NaV1.5, NaV1.8 and NaV1.9) . Mammalian Na+ channels are heterotrimers, composed of a central, pore-forming α subunit and two auxiliary β subunits. The expression of the α subunit isoform is developmentally regulated and tissue specific. Na+ channels in the adult central nervous system and heart contain β1 through β4 subunits, whereas Na+ channels in adult skeletal muscle have only the β1 subunit.nNavβ4 has been associated with Long QT syndrome8 and with Huntington's disease, showing a distinct down regulation of NaVβ4 in the presymptomatic stage of HD mice, whereas other voltage-gated ion channel subunits were later decreased