Morphological and electrophysiological properties of C-cells in bullfrog dorsal root ganglia.

Dissociated bullfrog dorsal root ganglion cells were voltage-clamped in the whole-cell configuration. Small spheroidal C-cells had a mean diameter of 14-30 microns and shared about 10% of the total population of the cells. The C-cells were characterized by a prominent calcium-activated potassium current underlying a hyperpolarization following the action potential. In contrast, a hyperpolarization-activated cationic inward rectifier was missing in all C-cells tested. These properties were completely different from those which have been observed for large spheroidal A-cells.