Mode of action of neuropeptides from the adipokinetic hormone family.

A large number of neuropeptides has been identified in the brain of insects. At least 35 neuropeptide precursor genes have been characterized in Drosophila melanogaster, some of which encode multiple peptides. Additional neuropeptides have been found in other insect species. With a few notable exceptions, most of the neuropeptides have been demonstrated in brain interneurons of various types. The products of each neuropeptide precursor seem to be co-expressed, and each precursor displays a unique neuronal distribution pattern. Commonly, each type of neuropeptide is localized to a relatively small number of neurons. We describe the distribution of neuropeptides in brain interneurons of a few well-studied insect species. Emphasis has been placed upon interneurons innervating specific brain areas, such as the optic lobes, accessory medulla, antennal lobes, central body, and mushroom bodies. The functional roles of some neuropeptides and their receptors have been investigated in D. melanogaster by molecular genetics techniques. In addition, behavioral and electrophysiological assays have addressed neuropeptide functions in the cockroach Leucophaea maderae. Thus, the involvement of brain neuropeptides in circadian clock function, olfactory processing, various aspects of feeding behavior, and learning and memory are highlighted in this review. Studies so far indicate that neuropeptides can play a multitude of functional roles in the brain and that even single neuropeptides are likely to be multifunctional.

Neuropeptides in interneurons of the insect brain.

http://directory.umm.ac.id/Data%20Elmu/jurnal/J-g/Journal%20of%20Insect%20Physiology/Vol46.Issue9.Sept2000/970.pdf

Sulfakinins reduce food intake in the desert locust, Schistocerca gregaria.

Newly discovered functions for some myotropic neuropeptides in locusts.

This review deals with those neuropeptidic hormones that are completely known in their primary structure together with the control processes that are linked directly or indirectly to development and reproduction. Actions are assessed for neuropeptides that regulate ecdysteroid and Juvenile Hormone production; oocyte growth or yolk deposition; and ecdysis and courtship behaviour. The combined data on the primary sequence, gene expression, biosynthesis, release, interaction with the receptor and mode of action provide an accurate account of the current knowledge on how these peptides function.

G. Gaede

Papers

The Explosion of Structural Information on Insect Neuropeptides