Figure 8.

Effects of peptides on ACh-induced muscle contraction. ACh (5 μM) was applied until the contraction reached its peak and then was washed out with saline. Contraction strength is normalized to the initial contraction prior to the application of peptide for each individual worm. Error bars show standard error. (a, b) Effects due to single exposure to peptides. 10 μM peptide was introduced at −10 min and washed out at time 0 (time when peptide present indicated by gray shading). Responses to 5 μM ACh were tested every 10 min after removal of peptide. (c, d) Effects during extended exposure to peptide. 10 μM peptide was initially introduced at time 0 (arrow), and 5 μM ACh was applied every 10 min; in each case, ACh was washed out with Ascaris saline containing 10 μM peptide.