(a) Selected VSD traces during fictive local bending. From the dorsal surface: dorsal and ventral inhibitory and excitatory motor neurons DI-1, VI-2, DE-3, and VE-4; from the ventral surface: the Retzius cells, ‘Anterior Pagoda’ cells (‘AP’; well-known postsynaptic partners of the P cells with unknown function). Below the traces, a simultaneously recorded intracellular trace of the PVL cell is displayed with injected current trains (in both columns). Scale bars: 0.2% relative fluorescence change, 100 mV membrane potential change, 2 nA injected current. (b) Magnitude and phase of the coherence of activity in individual neurons with the local bend rhythm in DE-3R. (c) Coherence maps of the VSD signals of all cells on the dorsal (left) and ventral (right) surfaces of the ganglion. Colors of cell bodies indicate coherence relative to DE-3R. A yellow needle on PVL indicates a sharp electrode for electrical stimulation. Note that PVL was only weakly stained by the VSD because it was left partially covered with sheath tissue to preserve its health.