superior esophageal nerve (sensu Cancer borealis)

The superior esophageal nerve (SON) in Cancer borealis is one of the four nerves that together form the stomatogastric nerve (SGN). It is part of the stomatogastric nervous system and is involved in transmitting signals between the commissural ganglia and the stomatogastric ganglion, as well as contributing to the innervation of the upper foregut.

In Cancer borealis, the superior esophageal nerve runs along the upper portion of the esophagus. It is one of the nerves that converges to form the stomatogastric nerve as it courses toward the stomatogastric ganglion, which lies on the dorsal surface of the foregut.

The superior esophageal nerve is involved in conducting signals as part of the stomatogastric nervous system. It contributes to the communication pathway between the commissural ganglia and the stomatogastric ganglion, participating in the relay of modulatory and motor commands that regulate gastric and pyloric motor patterns.

In experimental neuroscience, transection of the superior esophageal nerve or the stomatogastric nerve as a whole is associated with isolation of the stomatogastric ganglion from descending modulatory input. This de-afferentation may be involved in the transition of central pattern generator circuits to stereotyped or simplified activity patterns, which is used experimentally to study circuit dynamics.

The superior esophageal nerve is examined using extracellular suction electrode recordings and intracellular recordings from stomatogastric nervous system preparations. Anatomical methods including axonal dye fills and immunohistochemistry allow characterization of which axons run within this nerve. Selective cutting of this nerve in experimental preparations allows researchers to study its modulatory contribution to stomatogastric circuits.