Figure 4.

Single bitter-tasting compounds picrotin and PROP activate spermatids. (A and C) Shown are traces from three representative cells in response to a series of picrotin (A) or PROP (C) concentrations. No responses were detected to 0.01, 0.1 and 1 μM of either compound. Thus, the shorter intervals were given between these stimuli than between higher concentrations. (B and D) Dose–response curves were plotted with the data from 20 to 44 responsive cells to picrotin (B) and PROP (D), with calculated EC₅₀ values of 20 ± 10 and 24 ± 12 µM, respectively.