Characterization of the cardiac ganglion in the crab Neohelice granulata and immunohistochemical evidence of GABA-like extrinsic regulation.

The aim of the present work is to provide an anatomical description of the cardiac system in the crab Neohelice granulata and evidence of the presence of GABA by means of immunohistochemistry. The ganglionic trunk was found lying on the inner surface of the heart's dorsal wall. After dissection, this structure appeared as a Y-shaped figure with its major axis perpendicular to the major axis of the heart.