Figure 3 - Confocal photomicrograph of a vagal intramuscular arrays (IMA) nerve terminal in a tangential section of the lower esophageal sphincter of a rat.

There is one striated muscle fiber on the left side of the figure; however, all the other fibers are smooth muscles. Therefore, it indicates that this ending is located at the transition zone of striated and smooth muscle of the esophagus. It is to be noted that in rats, IMAs mostly innervate the smooth muscle portion and lower esophageal sphincter (LES) of the esophagus. IMAs are rarely seen in the striated part of the esophagus. Scale bar = 50 m. (Source: Courtsey of Winfried L. Neuhuber.).