Both forms widely expressed in the nervous system. Expressed in corpora cardiaca, corpora allata, hypocerebral ganglion, frontal ganglion, frontal connectives, recurrent nerve, esophageal nerves, protocerebrum, pars intercerebralis, antennal lobe, tritocerebrum, circumesophageal connectives, subesophageal ganglion, thoracic ganglia and abdominal ganglia. Not detected in abdominal perisympathetic organs (at protein level). Belongs to the NPY family.