(A) Simultaneous intracellular recording of the LP neuron and extracellular recording of the lateral ventricular nerve (lvn), containing the axons of the LP, PD and PY neurons (arrows). Period (P) and the burst onset time (Δt) of the LP neuron are defined in reference to the pacemaker group (PD) burst. (B) Blocking the AB and PY synaptic inputs (10 µM picrotoxin) to the LP neuron disrupts its bursting oscillations. (C) The LP neuron, in picrotoxin, was driven with a noise current input (Inoise) for 60 min. In response, the LP neuron produced an irregular pattern of bursting. Specific inter-burst intervals (IBIs) were tagged and used for burst-triggered averaging. (D) Example of burst-trigger-averaged input current (IBTA, green). Individual traces are shown in gray. (E) For each IBI (300, 500, 700, 900 ms), IBTA was calculated and normalized to the (negative) peak value of IBTA for IBI = 300 ms. Different traces in each panel show the IBTA of different preparations. (F) The mean (across preparations) of the normalized IBTAs shown in panel E. (G) Traces in panel F normalized by IBI. (H–K) Four parameters define the shape of the IBTA: peak amplitude Iamp (H), peak phase Δpeak (I), slopeup (J) and slopedown (K) across preparations. IBI had a significant effect on amplitude Iamp (p<0.001), peak phase Δpeak (p<0.001), slopeup (p<0.001) and slopedown (p=0.002).