Fig. 6. FLRFamide immunoreactivity in the anterior cardiac plexus (ACP) is derived from four axons which project to the structure through the superior oesophageal (son), stomatogastric (stn) and anterior cardiac (acn) nerves. (A) Montage of seven confocal micrographs showing the projection pathway of the axons that give rise to the ACPs. In this preparation, the axons (denoted by the arrows) travel through much of the nervous system as tightly associated fascicles. These fascicles can be followed unambiguously from the sons, through the stn and acns to the ACPs. In this image, the beginning and end of the right ACP are defined by asterisks. The left ACP is not shown. In this montage, the individual micrographs are brightest pixel projections of 30–55 optical sections taken at 2.0 µm intervals. (B) Confocal micrograph showing four FLRFamide labeled axons projecting into the acn. In this preparation, the four FLRFamide immunopostive axons that arborize into the ACPs are clearly visible entering the left acn. Each of these axons (arbitrarily designated 1–4) is indicated with an arrow. The branch point of axon 4 is marked with an asterisk and the left and right projecting branches labeled 4L and 4R, respectively. This image is a brightest pixel projection of 22 optical sections taken at 2.0 µm intervals. Scale bars, 200 µm (A); 100 µm (B). on, oesophageal nerve; STG, stomatogastric ganglion.