Figure 1. Changes in fictive behavior 15 min after treatment with Veh, 40 μM (Low), or 250 μM (High) l-DOPA. Each preparation only received a single treatment, which remained in the bath for the duration of the recording. A, Histogram of all BMPs recorded in all 21 experiments during the pretreatment observation period and following treatment. Each bin is indicated by a percentage value, calculated by dividing the duration of large-unit activity in Rn that occurred during the retraction phase by the total duration of large-unit Rn activity during the BMP. This graph indicates that there are four distinct clusters of BMPs that we designate as rejection, intermediate, bites, and swallows. B, Nerve recordings for the vehicle, low, and high treatments showing a 40-s time segment. Protraction phase is marked by light gray and retraction is marked in dark gray. The BMP classification is indicated at the top and closure activity is marked by brown boxes. Black bars under the BMP designation represent large-unit Rn activity, which has been associated with closure of the radula (Morton and Chiel 1993a,b). C, Summary data for the total number of BMPs. For all box plots, the boundaries of each box are the first and third quartiles (Q1 and Q3) and the line within the box is the median. The upper and lower extremes are the minimum (or maximum) data value within (Q1 or Q3) ± 1.5 times the interquartile range. Data outside the extremes are marked as open circles. D1, Summary data of the preference for intermediate BMPs. A value of one indicates the group exclusively expresses intermediate BMPs. D2, Summary data of the preference toward bite BMPs. Sample size for C, D1, and D2 is seven experiments for each group. E, The occurrence of BMPs. Each box represents the duration of a single BMP. Each row is an individual experiment. F1, Duration of protraction for the different treatment groups. F2, Duration of retraction for the different treatment groups. Sample size for the groups in F is Veh = 24, Low = 54, High = 104 BMPs for seven ganglia in each group. The same dataset was examined for all subsequent figures. *p < 0.05, **p < 0.01, and ***p < 0.001.