Figure 7.

The earlier phase peak and larger amplitude of the PD neuron PSP work to decrease the pyloric rhythm period. A, The schematic for the artificial dynamic-clamp synapse experiment. The LP neuron was hyperpolarized to remove the biological LP to PD synaptic current. The artificial synaptic current was calculated using a computer on the basis of preset parameters of the PD neuron membrane potential. The calculated current was injected into both PD neurons through intracellular electrodes. B, An example of the voltage traces of the PD neuron in control (Ctrl.; no injection) and in response to the artificial LP to PD synapse activated at different phases of the oscillation cycle. Vertical dotted lines indicate the beginning of the bursts of the control trace. C, The phase change in the PD neuron [(P_{during injection}–P_ctl)/P_ctl]is shown in response to the activation of the artificial synapse with different strengths and at different phases of the cycle. Increasing the artificial synaptic conductance injected at an early phase increased the extent of the phase change in the PD neuron. For clarity, only negative error bars are shown. D, An earlier peak of the artificial synaptic conductance (peak at 0, 100, and 200 msec in each cycle) also increased the extent of the phase change in the PD neuron. For clarity, only negative error bars are shown.