Action potential characteristics of single GFP+ and GFP cells.

Data are mean±SEM; n = number of cells, MDP = maximal diastolic potential, DDR50 = diastolic depolarization rate over the 50-ms time interval starting at MDP+1 mV, dV/dtmax = maximal upstroke velocity, APA = action potential amplitude, APD20, APD50, and APD90 = action potential duration at 20, 50, and 90% repolarization. *p<0.05.