Fig. 13.

Radula movements and intracellular recordings from left and right B51s during a carbachol-elicited motor program. In this experiment, depolarizing current is periodically injected into both B51s (e.g., left and right panels). The B51s are then returned to the resting membrane potential (e.g.,middle panel). Note that when the B51s are depolarized by current injection, CPG-elicited depolarizations are also larger in amplitude and longer in duration. Additionally, radula retractions become more vigorous. Changes in B51 activity and changes in radula movements occur in parallel. Thus, when B51 is no longer depolarized, radula retraction immediately becomes less vigorous. When B51 is depolarized, again radula movements immediately become enhanced.