Fig. 1.

The capacitance jumps recorded in different extracellular Ca²⁺ concentrations. A, The Ca²⁺ current (top) and the capacitance jump (bottom) evoked by a 2 msec step from −80 to +10 mV in extracellular solutions containing 2 mm(solid trace) and 4 mm (dotted trace) Ca²⁺. Both the Ca²⁺ current and the capacitance jump were increased significantly in 4 mm Ca²⁺.B, The Ca²⁺ current (top) and the capacitance jump (bottom) evoked by a 10 msec step from −80 to +10 mV in extracellular solutions containing 2 mm (solid trace) and 4 mm (dotted trace) Ca²⁺. Only the Ca²⁺ current, but not the capacitance jump, was increased significantly in 4 mmCa²⁺. Data in A and Bwere obtained from the same calyx.