Figure 6.

The interburst membrane potential is dependent on the strength of bursting activity. A, Across experiments, the interburst membrane potential (Vm) was dependent on burst frequency, spike frequency within the burst, and overall spike frequency (spikes/cycle). B, PD axon recording showing depolarization in response to blocking centrally generated activity. adj., Adjusted. C, Change in “resting” membrane potential across experiments. Individual experiments are shown in gray, and mean data points (±SEM) in black. The difference between means was significant (paired t test; p < 0.0001; n = 35). D, PD axon recording with centrally generated activity blocked, showing hyperpolarization in response to stimulation of the pdn mimicking pyloric bursting activity. E, Change in “resting” membrane potential across experiments. Individual experiments are shown in gray, and mean data points (±SEM) in black. The difference between means was significant (paired t test; p < 0.0001; n = 17). F, PD axon recordings showing the response to stimulating the pdn with 10 s trains at 5, 10, 20, and 40 Hz. G, Hyperpolarization in response to stimulation was dependent on frequency (repeated-measures ANOVA, p < 0.0001; Fisher's PLSD post hoc, p values between 0.004 and <0.0001). stim, Stimulation.