The stomatogastric ganglion (STG) is a small ganglion in decapod crustaceans that contains the cell bodies and synapses of neurons involved in the control of the foregut. In particular, the neurons of the pyloric central pattern generator (CPG) and the gastric mill CPG.
See the Crab Stomatogastric Nervous System for more information about the organization of nerves and musculature.
There are between 24 and 30 neuronal cell bodies in the STG. The number differs slightly between species and there is some individual variability among members of the same species.
The cell bodies form a rind around the central neuropil area. The neuropil is where the synaptic interactions occur.
All neurons in the STG send axons either to muscles or to anterior ganglia.
For more information see the Scholarpedia entry on the stomatogastric ganglion.