FIGURE 4.

The effect of lidocaine on Lumbriculus variegatus behavior. L. variegatus were exposed to lidocaine (0–1 mM) and tested for the ability of tactile stimulation to elicit (A) body reversal or (B) helical swimming. Lidocaine was then removed and the ability of L. variegatus to perform (C) body reversal or (D) helical swimming was tested after 10 min and 24 h. Data are expressed as a ratio of the movement score after exposure relative to the movement score at baseline. (E) The effect of lidocaine on free locomotion was measured before lidocaine exposure (Baseline), after 10 min exposure to 0–1 mM lidocaine (Lidocaine Treatment), 10 min after lidocaine removal (Rescue 10 min), and 24 h after lidocaine removal (Rescue 24 h). Quantification of the area covered by L. variegatus following (F) lidocaine treatment and (G) removal of lidocaine for 10 min and 24 h are expressed as a percentage of the area covered at baseline. Error bars represent the standard error of the mean, n = 8 for each concentration. Veh: Artificial pondwater. *p < .05, **p < .01, ***p < .001, ****p < .0001