Fig. 1.

Morphology of the AP cell and the contralateral dorsal P cell. A, Light microscopic image of the AP cell (yellow/green, fluorescein-filled) and one of the two contralateral P cells, the dorsal P cell (orange/red, rhodamine-filled). Note the extensive overlap of the AP and P cell neurites contralateral to the AP cell soma. All four P cells have similar morphology and are mirror symmetric across the midline to the P cells on the opposite side. The dim somata result from autofluorescence and serve to show the outline of the ganglion. Anterior is up. Scale bar, 100 μm. B, Schematic of the P-to-AP cell circuit.