Octopamine, a major aminergic neurotransmitter in invertebrates, exerts many of its actions through receptors which are associated with the activation of adenylate cyclase. The present study defines and characterizes a new class of potent octopamine agonists, the substituted phenyliminoimidazolidines (PIIs). Approximately 30 of these derivatives were examined for agonist and antagonist effects ...

Processing of olfactory information in the antennal lobes of insects and olfactory bulbs of vertebrates is modulated by centrifugal inputs that represent reinforcing events. Octopamine release by one such pathway in the honeybee antennal lobe modulates olfactory processing in relation to nectar (sucrose) reinforcement. To test more specifically what role octopamine plays in the antennal lobe, w...

G protein-coupled octopamine receptors of insects and other invertebrates represent counterparts of adrenoceptors in vertebrate animals. The alpha(2)-adrenoceptor agonist medetomidine, which is in clinical use as a veterinary sedative agent, was discovered to inhibit the settling process of barnacles, an important step in the ontogeny of this crustacean species. Settling of barnacles onto ship ...

Honey bees communicate the location and desirability of valuable forage sites to their nestmates through an elaborate, symbolic "dance language." The dance language is a uniquely complex communication system in invertebrates, and the neural mechanisms that generate dances are largely unknown. Here we show that treatments with controlled doses of the biogenic amine neuromodulator octopamine sele...

BACKGROUND Activity-dependent modulation of sensory systems has been documented in many organisms and is likely to be essential for appropriate processing of information during different behavioral states. However, the mechanisms underlying these phenomena remain poorly characterized. RESULTS We investigated the role of octopamine neurons in the flight-dependent modulation observed in visual ...

In insects, octopamine is present in neurohaemal regions of the thoracic sympathetic nervous system, but its cellular source is unknown. We describe a dorsal unpaired median neurone (DUM1b) in the locust metathoracic ganglion that forms a meshwork of varicose, presumably neurohaemal, endings on the surfaces of sympathetic nerves. Other targets include several ventral longitudinal muscles, the s...

An understanding of sleep requires the identification of distinct cellular circuits that mediate the action of specific sleep:wake-regulating molecules, but such analysis has been very limited. We identify here a circuit that underlies the wake-promoting effects of octopamine in Drosophila. Using MARCM, we identified the ASM cells in the medial protocerebrum as the wake-promoting octopaminergic...

The compounds 1-(2,6-diethylphenyl)imidazolidine-2-thione and 2-(2,6-diethylphenyl)imidazolidine showed the almost same activity as octopamine in stimulating adenylate cyclase of cockroach thoracic nervous system among 70 octopamine agonists, suggesting that only these compounds are full octopamine agonists and other compounds are partial octopamine agonists. The quantitative structure-activity...

Amine neurotransmitters, such as dopamine, serotonin, and noradrenaline, play important roles in the modulation of behaviors and metabolism of animals. InC. elegans, it has been shown that serotonin and octopamine, an invertebrate equivalent of noradrenaline, also regulate lifespan through a mechanism related to food deprivation-mediated lifespan extension. We have shown recently that dopamine ...

Efficient division of labor is one of the main reasons for the success of the social insects. In honey bees the division of labor is principally achieved by workers changing tasks as they age. Typically, young adult bees perform a series of tasks within the colony before ultimately making the transition to foraging outside the hive for resources. This lifelong behavioral development is a well-c...