Figure 7

Morphology and activity of motoneurons that drive the ovipositor pulsatile organs. (A) Recording from the efferent nerves (suction electrodes) to a opo8 (upper trace, n.8vC) and to the ipsilateral genital chamber muscle (lower trace, n.7vA, gc) before and after disconnection from cns by severing both connectives (seg cut, arrow) posterior to the subesophageal ganglion. The opo8 and gc rhythms persist almost undisturbed. (B) a. Branching of one motoneuron for genital chamber movement (7vA-1) in the terminal ganglion (tg, dorsal view) and b. its rhythmic activity along with the second motoneuron to M2 and, c. onset of a burst due to summation of postynaptic potentials elicited by premotor interneurons. (C) a. Branching types of two icM8 motoneurons in the terminal ganglion (tg, bilateral, dorsal view) which supply the opo8. b. Rhythmic activity of motoneuron 8v-1. Summation of excitatory postsynaptic potentials originating from premotor interneurons are the basis for bursting activity of the motoneuron. Lower trace shows synchronous activities of the ipsilateral genital chamber motoneurons. c. Expanded view of the onset of a burst.