Monoclonal antibody immunohistochemistry in the American cockroach identifies a novel neuropeptidergic system similar to,but distinct from this insect's (FM)RFamide-like system

A monoclonal antibody to peptidergic neurons in the neuroendocrine system of the Colorado potato beetle immunohistochemically labels neuropeptide-like substances throughout the cephalic neurosecretory system of the American cockroach, Periplaneta americana. The dictyopteran antigen shows a histological distribution similar to that of the neuropeptide-like material which we have described earlier using (FM)RFamide specific antibodies. It was conclusively demonstrated, particularly by means of a convenient double labelling procedure, that the (FM)RFamide- and the coleopteran neuropeptide-like antigens are not localized in the same neuronal structures, although both neurochemicals are in close vicinity to one another. The relative abundance of the immunoreactive products in neurons throughout the cockroach nervous system and retrocerebral complex, in addition to its apparently homologous distribution in species of different insect orders, suggests an important role of this material in insect neuro(endocrine)-physiology.