Optical recordings exhibited sufficient S/N to identify neuronal activity patterns.

<p>A. Original single-sweep optical recording of three different neurons (LP, PY, PD) after Di-4-ANEPPS application plus extracellular recording of the pyloric rhythm on the <i>dvn</i> (bottom trace). Analyzed areas are marked with circles in the high resolution photo (left). Areas included the cell membranes of the neurons analyzed. Scale bars mark the changes in fluorescence intensity. B. Cycle-triggered average (n = 16 cycles) of neurons shown in A. Averaging multiple cycles of optical imaging data improved S/N. C. The S/N was always higher for Di-4-ANEPPS, but independent of dye concentration. S/N was calculated using averaged data. D. Comparison of single-sweep LP optical recording in Di-4-ANEPPS (taken from inset in A.) and RH795 (different preparation).