Figure 7. Neonatal Scn1b-null atrial myocytes have increased I_Na,L.

(A) Membrane capacitance (Cm) of P15–18 WT (black) or Scn1b-null (red) acutely isolated atrial myocytes. Plot shows combined Cm values obtained from the I_Na, I_Ca, and I_K recordings. (B) I-V relationships for I_Na,T are similar between genotypes. (C) Superimposed representative I_Na,L recordings from a WT and null atrial myocyte. (D) Current densities for WT and null atrial myocyte I_Na,L (pA/pF). (E) I_Na,L expressed as percentage of I_Na,T. Each dot represents the value from 1 cell. Data are presented as mean ± SEM. *P < 0.01 versus WT using Student’s t test.