stomatogastric nervous system

The stomatogastric nervous system (STNS) is the part of the peripheral nervous system in arthropods, such as crabs, lobsters, and insects, that controls the stomach and associated digestive structures. In decapod crustaceans, it consists of the stomatogastric ganglion, paired commissural ganglia, esophageal ganglion, and the connecting nerves, collectively coordinating the motor activity of the foregut.

The stomatogastric nervous system is located along the esophagus and dorsal surface of the foregut in arthropods. In crustaceans such as crabs and lobsters, it is situated in the cephalothorax, running from the paired commissural ganglia near the esophagus to the stomatogastric ganglion on the dorsal stomach wall.

The stomatogastric nervous system is involved in generating and coordinating the rhythmic motor patterns that control the movements of the esophagus, gastric mill, and pyloric stomach. It contains central pattern generators that produce stereotyped motor rhythms for food transport and grinding, modulated by neuromodulatory input from commissural neurons and descending projections.

In research contexts, manipulations such as stomatogastric nerve transection, pharmacological application of neuromodulators, or temperature changes may be associated with significant alterations in STNS motor output. As a well-characterized invertebrate nervous system, it is used as a model to study general principles of neural circuit modulation, plasticity, and rhythm generation.

The stomatogastric nervous system is examined using electrophysiological techniques applied to dissected or semi-intact preparations. Multiple extracellular and intracellular recordings can be made simultaneously from different nerves and neurons. Pharmacological bath application, immunohistochemistry, in situ hybridization, and imaging techniques are used to characterize its structure, neurochemistry, and functional organization.