Figure 1.

K⁺ currents in human spermatozoa. (A) Raw experimental traces showing the membrane currents evoked by a series of depolarizing voltage ramps (top left) that were imposed at 1 Hz. To analyse the results of such experiments, the currents evoked by successive depolarizations were pooled in order to obtain an average response for each spermatozoon (bottom right). (B) I_m–V_m relationships quantified under standard conditions (n = 12) and using Cs⁺-based pipette solution (n = 8). (C) Currents recorded from the same cells after 20–30 s exposure to K⁺-rich bath solution. (D) Values of resting V_m estimated by regression analysis (see Materials and Methods) of data recorded using the standard pipette filling solution and during to standard (5 mM K⁺) and K⁺-rich (130 mM K⁺) bath solutions. All data shown as mean ± s.e.m.