IMMUNOCYTOCHEMICAL DISTRIBUTION OF LOCUSTAMYOINHIBITING PEPTIDE (LOM-MIP) IN THE NERVOUS-SYSTEM OF LOCUSTA-MIGRATORIA

Locustamyoinhibiting peptide (Lom-MIP) is one of the 4 identified myoi nhibiting neuropeptides, isolated from brain-corpora cardiaca-corpora allata-suboesophageal ganglion complexes of the locust, Locusta migrat oria. An antiserum was raised against Lom-MIP for use in immunohistoch emistry. Locustamyoinhibiting peptide-like immunoreactivity (Lom-MIP-L I) was visualized in the nervous system and peripheral organs of Locus ta migratoria by means of the peroxidase-antiperoxidase method. A tota l of 12 specific immunoreactive neurons was found in the brain. Proces ses of these neurons innervate the protocerebral bridge the central bo dy complex and distinct neuropil areas in the proto- and tritocerebrum but not in the deuterocerebrum nor in the optic lobes. The glandular cells of the corpora cardiaca, known to produce adipokinetic hormones, are contacted by Lom-MIP-LI fibers. The corpora allata were innervate d by the nervus corporis allati I containing immunoreactive fibers. Lo m-MIP-LI cell bodies were also found in the subesophageal ganglion, th e metathoracic ganglion and the abdominal ganglia I-IV. In peripheral muscles, Lom-MIP-LI fibers innervate the heart, the oviduct, and the h indgut. In the salivary glands, Lom-MIP-LI was detected in the intrace llular ductule of the parietal cells. Possible functions of Lom-MIP ar e discussed.