To investigate the role of certain neurohormones in agonistic behaviour, fights were staged between pairs of size-matched male shore crabs Carcinus maenas, and blood samples were taken immediately after the contests had been resolved. Samples were also taken from these crabs at rest (before and after fighting) and after walking on a treadmill. A control group of crabs also had samples taken on ...

The lateral giant (LG)-mediated escape behavior of the crayfish habituates readily on repetitive sensory stimulation. Recent studies suggested that the biogenic amines serotonin and octopamine modulate the time course of recovery and/or re-depression of the LG response after habituation. However, little is known of how serotonin and octopamine effect LG habituation and what second-messenger cas...

Octopamine, the invertebrate counterpart of adrenaline and noradrenaline, plays a key role in regulation of many physiological and behavioral processes in insects. It modulates these functions through binding to specific octopamine receptors, which are typical rhodopsin-like G-protein coupled receptors. A cDNA encoding a seven-transmembrane receptor was cloned from the nerve cord of the rice st...

The biogenic amine octopamine plays a critical role in the regulation of many physiological processes in insects. Octopamine transmits its action through a set of specific G-protein coupled receptors (GPCRs), namely octopamine receptors. Here, we report on a β-adrenergic-like octopamine receptor gene (BdOctβR1) from the oriental fruit fly, Bactrocera dorsalis (Hendel), a destructive agricultura...

Sleep is a fundamental process, but its regulation and function are still not well understood. The Drosophila model for sleep provides a powerful system to address the genetic and molecular mechanisms underlying sleep and wakefulness. Here we show that a Drosophila biogenic amine, octopamine, is a potent wake-promoting signal. Mutations in the octopamine biosynthesis pathway produced a phenotyp...

BACKGROUND In mammals and humans, noradrenaline is a key modulator of aggression. Octopamine, a closely related biogenic amine, has been proposed to have a similar function in arthropods. However, the effect of octopamine on aggressive behavior is little understood. RESULTS An automated video analysis of aggression in male Drosophila has been developed, rendering aggression accessible to high...

Octopamine is likely to be an important neuroactive molecule in invertebrates. Here we report the molecular cloning of the Drosophila melanogaster gene, which encodes tyramine p-hydroxylase (TBH), the enzyme that catalyzes the last step in octopamine biosynthesis. The deduced amino acid sequence of the encoded protein exhibits 39% identity to the evolutionarily related mammalian dopamine P-hydr...

1. The actions of the phenyliminoimidazolidine derivatives, NC7 and NC5 on octopamine receptors in the extensor-tibiae neuromuscular preparation of the locust are described. 2. The derivatives activate both OCTOPAMINE, and OCTOPAMINE2 receptors in this preparation. They are not selective agonists of OCTOPAMINE2 receptors that activate adenylate cyclase. 3. The relative potencies of NC5 and NC7 ...

The biogenic amine, octopamine, has been proposed as the transmitter in the firefly light organ (Evans, 1980; Robertson, 1981). Whereas initial studies implicated adrenaline (Smalley, 1965; Carlson, 1968a), octopamine was found to be more potent in inducing luminescence than any amine other than synephrine (Carlson, 19686). Octopamine, but not synephrine, was found in adult lantern segments (Ro...