Recent G.I. Publications
![Heinrich R., Ganter G.K. Nitric oxide/cyclic GMP signaling and insect behavior. (2007) In: Nitric Oxide Editors: Bruno Tota and Barry Trimmer; Adv Exp Biol 1:107-127.
Abstract: Behavioral control involves the perception of external information by sensory organs, its integration with proprioceptive information representing an individual’s internal state, selection of appropriate actions by central nervous circuits and their adaptive performance by effector systems. There is accumulating evidence from various species that the gaseous signaling molecule nitric oxide (NO) participates in the control of insect behavior on all these levels. In contrast to the spatially and temporally precise transmission at conventional chemical synapses, NO is formed on demand, freely diffuses through cellular membranes and may thus connect units of neurons without anatomically established synaptic interconnections into coordinated states of activity. As a laterally diffusing messenger, NO may influence populations of sensory afferences, interneurons and efferent cells contributing to all levels of processing between sensory activation and activation of neurosecretory and motor functions. After briefly summarizing some general aspects of NO signaling mechanisms and the distribution of its functional components in the insect nervous system, we will present a collection of studies demonstrating a direct contribution of NO to the processing of behaviorally relevant sensory information and the selection and coordinated performance of situation-specific behaviors.
Ganter G, Walton K, Merriman J, Salmon M, Brooks K, Maddula S, Kravitz E (2007) Increased male-male courtship in ecdysone receptor deficient adult flies. Behavior Genetics 37: 507-512.
Abstract: Male-male courtship is infrequent among mature adult Drosophila melanogaster. After pairs of mature adult males expressing a temperature-sensitive allele of the ecdysone receptor (EcR) gene were treated at a restrictive temperature, however, they engaged in elevated levels of male-male courtship. EcR-deficient males courted wildtype males and females, but were not courted by wildtype males. These results suggest that the ecdysone steroid hormone system may have a role in courtship initiation by adult male fruit flies.
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Wenzel B, Kunst M, Günther C, Ganter G, Lakes-Harlan R, Elsner N, Heinrich R (2005) Modulation of grasshopper acoustic communication behavior by the nitric oxide / cyclic GMP signaling pathway in central brain neuropils. Journal of Comparative Neurology 488: 129-139.
Abstract: Grasshopper sound production, in the context of mate finding, courtship, and rivalry, is controlled by the central body complex in the protocerebrum. Stimulation of muscarinic acetylcholine receptors in the central complex has been demonstrated to stimulate specific singing in various grasshoppers including the species Chorthippus biguttulus. Sound production elicited by stimulation of muscarinic acetylcholine receptors in the central complex is inhibited by co-applications of various drugs activating the nitric oxide/cyclic guanosine monophosphate (cGMP) signaling pathway. The nitric oxide-donor sodium nitroprusside caused a reversible suppression of muscarine-stimulated sound production that could be blocked by 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxaline-1-one (ODQ), which prevents the formation of cGMP by specifically inhibiting soluble guanylyl cyclase. Furthermore, injections of both the membrane-permeable cGMP analog 8-Br-cGMP and the specific inhibitor of the cGMP-degrading phosphodiesterase Zaprinast reversibly inhibited singing. To identify putative sources of nitric oxide, brains of Ch. biguttulus were subjected to both nitric oxide synthase immunocytochemistry and NADPH-diaphorase staining. Among other areas known to express nitric oxide synthase, both procedures consistently labeled peripheral layers in the upper division of the central body complex, suggesting that neurons supplying this neuropil contain nitric oxide synthase and may generate nitric oxide upon activation. Exposure of dissected brains to nitric oxide and 3-(5'hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1) induced cGMP-associated immunoreactivity in both the upper and lower division. Therefore, both the morphological and pharmacological data presented in this study strongly suggest a contribution of the nitric oxide/cGMP signaling pathway to the central control of grasshopper sound production. (c) 2005 Wiley-Liss, Inc.
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