FIGURE 2.

Effect of external K⁺ on the intrinsic dynamics of bipolar cells. Static voltage- current relation (I-V curves) and impulse responses of a bipolar cell recorded in solution B (0.75 mM [K⁺]_o, ▴) and solution C (12 mM [K⁺]_o, ▵). Representative impulse responses for the two ionic conditions are estimated and plotted in the (I,V) plane as described in Methods. Asterisks mark those obtained at 0.75 mM [K⁺]_o. Note that at 12 mM [K⁺]_o, a 15-fold increase from 0.75 mM, I-V curves show inward rectification near and below resting potential and impulse responses are greatly speeded up in that voltage range.