Immunocytochemical demonstration of a neuropeptide in Ascaris suum (Nematoda) using an antiserum to FMRFamide.

A FMRFamide-like peptide has been detected in the nematode Ascaris suum, using the peroxidase-anti-peroxidase (PAP) immunocytochemical technique. Positive reactions were obtained in both the central nervous system and the peripheral nervous system of the worm, the strongest reactions being in the anterior nerve ring, the cephalic papillary ganglia, the lateral ganglia and the dorso-rectal ganglion. Immunoreactivity was observed along the length of the main nerve cords of the worm and, to a lesser extent, in the pharyngeal nerve cords. The possible role of this neuropeptide in the physiology of the nematode is discussed.