Overview: Progress in Insect Neurophysiology

Abstract

In recent years, neurohormonal mechanisms governing insect development, metabolism and behavior have been brought into sharper focus by key conceptual and technological advances. These include the introduction of antibodies, development of more sensitive and specific bioassays and improved liquid chromatography and peptide sequencing technologies. If a dominant theme existed at ICINN ’86, it was a continued focus on the structure elucidation of endogenous hormones and transmitters. Two strategies underlie the sequencing of novel peptides. One begins with the knowledge that a process such as eclosion, primary urine secretion or ecdysone release is controlled by a “factor” or hormone. The hormone is isolated using its action on the physiological target as a biological assay. Structure determination follows prior knowledge of the neuropeptide’s physiological action. The second, more general strategy is to choose a convenient bioassay such as hindgut contraction or heartbeat and to purify excitatory or inhibitory substances from tissue extracts. This strategy was taken for proctolin, Periplanetin CC1/CC2 and for the leucokinins reported at this conference (see below), all of which have myotropic actions on muscle.