Figure 1.

Increased persistent current in SCN8A-p.Asn1768Asp mutant channel. Wildtype and mutant cDNAs were transiently transfected into the neuronal cell line ND7/23. At 100 ms after induction of an action potential, cells expressing the mutant cDNA had 20% persistent current compared with 1% in the wildtype. Cells were held at −120 mV, and a family of step depolarizations (−80 to +60 mV in 5 mV increments) were applied every 5 s. Insets show persistent inward currents (normalized by maximal transient peak currents) from WT and p.Asn1768Asp channels at the end of a 100 ms step depolarization to −80 mV (black, control) and +20 mV (red). [reprinted from Veeramah et al. (2012), with permission].