PMA enhances the amplitude of nRT T-current. A, representative traces of peak T-type current amplitudes (Vh −90 mV, Vt −50 mV) before (control, black trace) and during applications of 300 nM PMA (gray trace). PMA application increased T-current amplitude approximately 17%. B, representative traces of peak T-current amplitudes (Vh −90 mV, Vt −50 mV) before (control, black trace) and during applications of 300 nM 4αPMA (gray trace). Application of 4αPMA had very little effect on T-current amplitude.