Properties of outward currents in type II and type III neurons. Currents shown in records labeled 3 were obtained by subtraction of control outward currents in records labeled1 from currents recorded after exposure to X-cAMP, 1 mm TEA, or 100 μm 4-AP in records labeled2. A. Lack of effect of cAMP analog on outward currents in type II neurons. B, top record, Blockade by 1 mm TEA of outward currents in type II neurons. Bottom record, Lack of effect of 100 mm 4-AP on outward currents in type II neurons.C. Lack of effect of cAMP analogs on outward currents in type III neurons. D. Insensitivity of outward currents to TEA (1 mm, top record) and 100 4-AP (100 μm, bottom record) in type III neurons.