Figure 9From: Distribution of serotonergic and dopaminergic nerve fibers in the salivary gland complex of the cockroach Periplaneta americanaDistribution of dopaminergic fibers on salivary ducts, the reservoir, and the reservoir muscle Summarized views of confocal image stacks through whole-mounts double-labeled with anti-dopamine (red) and BODIPY FL phallacidin (blue). The upper left inset presents a scheme of the various structures examined and outlines the areas shown in a-j. Asterisks in a,c,d,i indicate acinar tissue. a: Small salivary ducts (broad arrows) are mostly without dopaminergic fibers (long arrow). b: A small salivary duct without dopaminergic innervation at higher magnification. c: A dopaminergic fiber approaches a small salivary duct and terminates on the duct surface (arrowhead). d: A dopaminergic fiber (arrow) invades the epithelium of a small duct. A vertical section (inset) through the duct at the position indicated by the line in d demonstrates that the dopaminergic fiber (arrow) resides below the duct surface (broken line). e,f: Dopaminergic fibers (arrows) form a loose network on a large salivary duct and terminate on this structure (arrowheads). The inset in f shows a horizontal confocal section through the duct and visualizes a dopaminergic fiber within the duct epithelium, below the duct surface (broken line). g: The salivary nerve coming from the subesophageal ganglion and extending along the reservoir/salivary duct complex contains a single thick dopaminergic axon. h: On the reservoir duct, small dopaminergic varicose fibers reside superficially within the salivary nerve (arrows) or leave the nerve and extend over the duct surface. i: A loose network of dopaminergic fibers with fiber terminals (arrowheads) covers the reservoir. j: Dopaminergic fibers and terminals (arrowheads) within the reservoir muscle. White scale bars = 100 μm; yellow scale bars = 25 μmBack to article page