Fig. 8.

Network neuron burst structure is regulated by feedback effects on MCN1 activity but not by MCN1 activity rate. Ai–Ci: in traces from an example experiment, rhythmic interruptions in the LG neuron bursts time-locked to the pyloric rhythm (PD: pdn) are evident during pyloric-timed MCN1 stimulation at 10 (Ai), 20 (Bi), and 30 (Ci) Hz. Aii–Cii: the LG burst structure was quantified by binning the timing of all LG action potentials during 10 gastric mill cycles in each condition relative to the pyloric cycle (normalized to 1.0; see methods). This analysis demonstrates that there is a smaller % of LG action potentials during and for a short period after the PD neuron burst at the 3 example MCN1 activity rates. D: the average % of LG action potentials occurring during the initial 35% of the pyloric cycle (Blitz and Nusbaum 2012; see methods) was greater during tonic stimulations than during pyloric-timed stimulations. However, there was no dependence of burst structure on MCN1 stimulation rate (n = 4–20). ***P < 0.001. ns, Nonsignificant.