Fig. 14.

C15 could not drive a CMP during the egestive-like BMP induced by esophageal nerve stimulation. In the quiescent state, injecting C15 with a 10 sec pulse of either 8 or 4 nA depolarizing current (filled bars) initiated a cycle of the CMP, shown by the barrage of IPSPs inC12 (arrowheads 1 and 2). A BMP was then driven by 2 Hz esophageal nerve stimulation (during open bar). C15 was excited during this program, at the same time as B8, and just before B4 (compare Fig. 11, and this synaptic drive is visible just before and after the current pulse). Depolarizing current (8 nA, previously suprathreshold for the CMP) injected into C15 at the phase in which it received synaptic excitation could not drive a CMP, shown by the lack of large IPSPs in C12 (arrowhead 3). Soon after the end of the BMP, C15 could again drive the CMP (4 nA,arrowhead 4).