Properties of voltage-dependent barium currents in neurons of pelvic parasympathetic ganglia of rabbit.

Properties of voltage-dependent barium current (IBa) were examined in parasympathetic neurons of the rabbit urinary bladder, in vitro. Transient low-threshold IBa was evoked by voltage jump from a holding potential (Vh) of -100 to -50 mV. Additional transient high-threshold IBa appeared at potentials more positive than -30 mV. Long-lasting high-threshold IBa was evoked at 0 to -20 mV. High-threshold currents were blocked by omega-conotoxin but not by dihydropyridines.