FIG. 3.

Changes in membrane potential and calcium fluorescence in B21 during motor programs. A: experiment conducted in the isolated nervous system in which a cycle of a motor program was induced by stimulating the command-like neuron CBI-2. Note that centrally induced depolarizations were observed in both the soma and lateral process of B21. B: experiment conducted in the isolated nervous system in which a cycle of a motor program was induced by stimulating a gut afferent, the esophageal nerve (EN). Note that B21 was centrally depolarized. C: 2 cycles of an EN-evoked motor program in an experiment in which we monitored both the somatic membrane potential of B21 and the change in calcium fluorescence in the lateral process. Note the phasic increases in the 2 signals.