commissural ganglion (sensu Cancer borealis)

The commissural ganglion in Cancer borealis is one of a pair of ganglia in the stomatogastric nervous system. It contains motor fibers that innervate the esophagus and houses projection neurons that send axons to the stomatogastric ganglion. It is also associated with an esophageal rhythm and contains the pyloric suppressor neuron, which can influence both pyloric and gastric motor patterns.

In Cancer borealis, the paired commissural ganglia are located on either side of the esophagus, near the junction of the esophagus and the stomatogastric nerve. They are part of the stomatogastric nervous system, positioned anterior to the stomatogastric ganglion and serving as major modulatory centers for it.

The commissural ganglia are involved in modulating the gastric mill and pyloric rhythms generated in the stomatogastric ganglion. Neurons within the commissural ganglia project to the stomatogastric ganglion via the stomatogastric nerve and release neuromodulators and transmitters that shape circuit output. They also contain an oscillatory esophageal rhythm circuit and neurons that innervate esophageal muscles.

In experimental research, pharmacological application of amines, peptides, or toxins may be associated with altered activity of commissural ganglion neurons, changing the modulatory input to the stomatogastric ganglion. Temperature changes, injury, or removal of neuromodulatory input may also be involved in altering commissural ganglion function and the motor patterns they influence.

The commissural ganglia of Cancer borealis are studied using electrophysiological techniques including intracellular and extracellular recordings, photoinactivation of identified neurons, and application of pharmacological agents. Anatomical techniques such as dye fills, immunohistochemistry for neurotransmitter markers, and confocal microscopy are used to map the structure and connectivity of commissural neurons.